11 Apr Breaking News: The Vega works! (Updated)
Another little update, just remind us of all of the importance of the Schaffer Vega:
In 1977 Angus was first introduced to the brand new technology of the wireless guitar system. The New York Palladium 1977 concert would be the very first time Angus would use the brand new wireless guitar transmitter. Before this, Angus was limited to the length of the guitar wire, so stage crew used to guide the guitar cable behind him during his audience walk about routine.
The very first system was a Schaffer-Vega diversity system, which was a bulky system, the transmitter was usually duct taped to Angus’ guitar to avoid any movement or disconnection from the guitar jack, at one point it possibly even being implanted into the cavity of his Gibson SG to help with stability of the unit during Angus’ wild stage antics. Angus would continue to use these systems for at least a decade or more. More recently, Angus (and Malcolm) have been using the Lectrosonics wireless guitar systems on stage.
Bon Scott told in an interview about his first encounter at the New York Palladium dressing room “I walked into the dressing room and there was Angus at one end playing his guitar and the amps at the other. No cords were connecting ’em! It was amazing to see. And Angus had this ‘Cheshire Cat’ grin all over his face and evil thoughts seemed to be going through his brain as to what havoc he could wreak with this evil little invention”….
Angus eagerly stated in an interview in 1977, “When we get back to Europe the first stop is gonna be London… No one will know what’s hit ’em!”
This is from – again – the official site. Every time I re-read these, some new info pops up into my mind.
Such as, for example: “at one point it possibly even being implanted into the cavity of his Gibson SG to help with stability of the unit during Angus’ wild stage antics.” As we were discussing on the comments.
And also, the fact that Angus used it for 10 or more years, thus making it 1977-1987 maybe longer? It would include the albums “Fly on The Wall” and “Blow Up Your Video”. Interesting. I was only able to recognize its influence until Flick of the Switch.
Tuesday the 12th of April, late afternoon, I will finally be able to start my own testing of all these theories. I think these are far more than theories already… 😉
SUPERB update: Reading the article, this is what Ken Schaffer personally stated regarding the compander/boost part. I think this says it all.
To your eyes now:
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Update: trying to kill time when I am off here, I decided I would do another search (google) for “Schaffer Vega” (with quotes).
Well, surprise surprise: found!
This is probably the BEST set of images and info I could ever find. LOTS of precious info for us. Please read and discuss if you would.
Images follow of the PDF found here:
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Update: Brother Jake (Jacob, “Headwhop26”) has made, published and sent me this; now, I woke up and seen it, after laughing and grinning for circa 15 minutes, I had to post it immediately. This will be the image to the new category “Laboratory” where we – the community – will post tricks, discoveries, attempts etc including this Vega thing. Jacob, you are inspiring brother! Thank you!!!!
Yes, you read that right. I’m in India right now, but just a lengthy phone call with Guido – the tech guy “father” of the Secret-1 – and he was thrilled and excited to let me know that… The Cetec-Vegas that I gave him to fix and make work… Work, and as intended!
I just heard some on the phone and was blown away. Naturally it’ll be my pleasure to test them upon my return on the 12th of April and I’m already counting the days.
More good news though: it works as I had hypothesized. There is a boost right away on the transmitter followed by a compander (compressor) and the signal gets sent (boost first, compressor second). On the receiver, there is an expander – WITH THE OPTION OF BEING SWITCHED OFF, LEAVING THE COMPRESSED SIGNAL ON and YES, COMPRESSION AMOUNT CAN BE REGULATED, TOO! – THEN comes another boost but this last boost uses a power transformer to be activated! This last stage only can add a boost up to +20db (can be set to -20, 0, +20db). This last stage also “cleans” the white noise.
All these additional regulations are performed from Inside. It was NOT so on the original Schaffer Vega for guitar, UNTIL a cheaper version came out more affordable one or two years later! Circuitry is the same.
As you can already see, there is a rather complex signal path in the transmitter-receiver.
The additional surprise is that… I may have a prototype for us to try made by Guido when I’m back, to test along with my original units.
I don’t want to be here; I want o be in my lab right now, where I belong.
You may think “Fil, don’t you think it is a bit bold to go just out and say that “the circuitry is the same”?
It is, sorry. However, I have this to show you:
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Read the description that comes with it, the almost unreadable (but after all, readable) underneath:
It says that “the only difference between the B&T – maybe, same unit as this Cetec Vega DIversity – and the more expensive Schaffer Vega is that it requires a few minutes of your time to do a soundcheck”.
Well, I think that these few minutes of our time are due to the controls – not accesible on the outside, but on the inside – that regulate boost and compression (the two boosts and the compander-expander). While the boost on the transmitter is accessible from the outside as well, the compander-expander controls may have been present on the original Schaffer Vega. The ONLY existing picture I have ever seen of the original Schaffer Vega is this one:
All of the above turned out untrue: the only difference between the B&T and the original SVDVS (Schaffer Vega Diversity System) was that the B&T was not a “Diversity” system, i.e., it did NOT have dual antennas on the receiver, just one. So there was “just” one receiver inside the receiving unit, bringing the cost a lot down. This is the only difference!
Additionally, I was able to find a way better picture of an original SVDVS and posted it up at the top of the article 🙂
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See if you can make out any detail. I need eye glasses lol
This is instead the front panel of “our” Cetec Vega current Diversity system, reposted for you to make out possible differences (number of knobs, etc.):
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Please note that all of the three units I bought, are “microphone” wireless units. This meaning, that they can not be used with guitar until they are modified. What I know of the modification for now – talking about it quickly over the phone with Guido – is that he “added” a converter on the transmitter, that is, a “Plug” that plugs into the microphone input that has little pins that allows for 1/4 input guitar jack.
Additionally, he may have brought the signal from “mic type” to “guitar input” type. Not sure of differences in resistance and things like that. He however did the modification, and they are playing successfully the guitar in their laboratory with it.
The addition of the converter/plug for guitar on the outside of the unit (i.e., the converter “protruding” out of the transmitter, to let you slide in the 1/4 jack) was necessary, as I had also opened the transmitter for curiosity and had verified that there is NO room to fit internally a 1/4 input jack; it would hit the internal components of the transmitter.
bananePosted at 07:03h, 21 April
Good morning from Vienna 🙂 Kon, thanks for sharing all the interesting technical information, very interesting to read.
kzissPosted at 23:15h, 20 April
Hi Fil and 06AngusSG
>Thanks for this great post. Do you have any audio clips?
No I do not have any audio clips at the moment and I do not have a digital video camera but it is possible to record a signal into my computer through the default Windows recorder so therefore after I work out a way to properly record an audio sample of the attenuated signal coming from the output of my overdriven Marshall JTM-45 into my Marshall quad box or through my own speaker/ cabinet simulator circuit design that I am exprerimenting with then I will be able to send the resulting signal directly into the computer and thus record a sample.
>So, from what I’m understanding from this is:
>One would need to insert a 50k ohm resistor into the >“ground” side of the guitar signal?
Yes the 50K resistor should be connected between the guitar audio signal at the guitar output phono jack and the ground.
>1) if done in the guitar, you could have pedals & such >between the guitar & the amp?
Yes this is why it is best to insert the 50K resistor in the guitar itself and use a switch to switch this 50K resistor in or out of circuit so that you can then have any pedals & such between the guitar and the amp and still get the effect of the 50K grounding resistor on the guitar output signal itself.
If you have a speciallized modified or customized wiring guitar circuit that is wired to produce a balanced output signal instead of the normal single unbalanced signal, then you must not connect the 50K resistor between one of the balanced audio signals and the ground, but instead you will need to wire up the 50K resistor between the two balanced audio signals themselves.
>2) if done on the amp you would have to only a cable >between the two?
Yes the 50K grounding resistor must directly load down the signal directly coming from the output of the guitar itself so therefore if you only use a cable between the guitar and the amplifier then the 50K grounding resistor will affect the guitar sound but if you use effects & such between the guitar and the amplifier then the 50K grounding resistor wired up in the amplifier will have no effect on the guitar signal itself but it might affect the effects unit if the effects unit is the type that is sensitive to the input impedance of any subsequent stage that it is connected to.
For example a Jen or a Vox VA47 or a Jim Dunlop Cry Baby wha wha pedal circuit requires that any subsequent effects unit or preamp or amplifier connected after the wha wha pedal have a very high input impedance ( ideally around 1 Mega ohms or higher ) in order to work properly.
This is the reason why a stock Jen / Vox VA47 / Jim Dunlop Cry Baby wha wha pedal does not work properly with a significantly reduced wha wha effect if a Dallas Arbiter Fuzz Face or a Jim Dunlop Fuzz Face or any other accurate Fuzz Face copy is connected directly after the Cry Baby wha wha pedal because the Fuzz Face circuit has an approximately 10K input impedance and this very low input impedance of the Fuzz Face drastically loads down the output signal coming from the Cry Baby wha wha pedal.
As I understand it Jimi Hendrix has his Cry Baby wha wha pedal connected before the Fuzz Face but he still seemed to get the proper full range wha wha effect so therefore I assume that Jimi”s tech Roger Mayer might possibly have wired up a high impedance output bufffer inside Jimi’s wha wha pedal so that the wha wha circuit is isolated and thus no longer loaded down by any subsequent effects unit or preamp or amplifier which has a low input impedance.
I have overcome this problem with my own Jen Cry Baby wha wha by wiring up a simple FET output buffer which has a 1 Mega ohms input impedance inside the wha wha pedal so that the output signal from the wha wha circuit is never loaded down by a Fuzz Face pedal or any other low impedance effect unit or preamp etc that is connected after the wha wha pedal.
I have also removed the stock SPDT switch in my Jen Cry Baby wha wha pedal and replaced it with a double pole /double throw (DPDT) switch so that the guitar signal is fully bypassed (“true bypass”) and thus no longer loaded down by the approximately 47K input impedance of the wha wha circuit when the wha wha pedal is switched off .
>So, if my assumtion is correct, to try this out; one could simply modify a guitar cable by opening up the end and inserting a 50k resistor into the ground side connection of the tip?
Yes this is a very simple way to insert the 50K resistor without having to open up and rewire the guitar. Idealy it would be best if a little switch could be wired on to the guitar cable so that you can switch the 50K grounding resistor in or out of circuit.
Alternatively you could wire up a short cable with a male phono socket on one end and a female phono socket on the other end and wire up the 50K grounding resistor inside thisso that you can then be able to connect thisshort cable between your guitar and your guitar cable without having to rewire the guitar cable itself.
All the best.
06AngusSGPosted at 01:10h, 21 April
Thanx so much for the detailed reply!!! 🙂 Time to go buy a couple of resistors and hack some cables to try your technique!!!!
Your wealth of info could surely be useful here.
For your consideration; check out the “User Performance” video section here. Myself along with a lot of the other performers here use Audacity for recording. It’s a FREE program and works, seemingly, well.
Off to the electronic store!!!! Thanks again!!!! 😛
kzissPosted at 03:08h, 21 April
My friend is more knowlegeable about computers and recording with the computer so I will ask him if he knows how to best use the Audacity program .
As well as buying a 50K resistor , you might also want to experiment with a 10K ohms resistor in order to make your guitar pickups be loaded down even more and respond similar to how they would if you had a Fuzz Face pedal connected after the guitar thus helping you to get some of the Jimi Hendrix Gibson SG sound or the dark sounding Gibson SG through the Fuzz Face played through the 100 watt Marshall as heard on the 1967 album by Blue Cheer called “Vincebus Eruptom ” .
The 10K resistor will give you the dark mellow sound when the guitar volume control is set at full volume and then the sound will clean up and be thinner when you turn down the guitar volume control.
The 50K or the 10K grounding resistor can also be very helpful for creating a smoother creamy or more ” bluesy” distortion sound if the guitar pickups ( especially single coil pickups ) or the treble response before the distortion stage in an amplifier or an overdrive pedal result in an unpleasant or discordant harshness to the treble frequencies of the guitar.
If you want you can wire up a 3 – position SPDT “centre off” switch so that you can switch between the 50K or the 10K resistors or no resistor at all at the “centre off ” setting.
An alternative to using a fixed resistor value is to wire up a 1 mega ohms potentiometer ( linear or logarithmic taper depending on your preference) followed by a 10K resistor wired in series with one end of the 1 mega ohms potentiometer so that the guitar sound does not fully go to ground and die off when you turn down the 1 mega ohms potentiometer, and this variable grounding resistance or pickup dampening control can help you to mellow down the sound of excessively bright sounding pickups without fully rolling off the highs in the way that the normal guitar tone control does.
This might also help pickups with ceramic magnets or alnico 8 or alnico 5 magnets sound closer to the mellower sound of pickups with alnico 2 magnets or vintage pickups with aged alnico magnets.
The 1 mega ohms potentiometer followed by the 10K resistor in series wired between the guitar signal and the ground could be wired up in the guitar itself or in a small box mounted on a short lead that will be connected between the guitar and the main guitar lead.
All the best.
06AngusSGPosted at 04:17h, 21 April
So, the best I could find close was a 47k. I wired it into a 8″ cable with a male at one end, female at the other. (The resistor was in the male end.) However I ended up with a mixed result.
When used in conjunction with my Comp. & Boost I DO believe the sound/tone IS there. The problem I’m ending up with is it is very “hissy,” even squeals a bit. (with pedals or straight into the amp). While playing it is mostly un-noticeable but as soon as I go quiet it’s as loud as can be.
First attempt I wired the resistor to fit inside the cable end cover. I thought, maybe there was some unwanted touching going on so the second try I left the end cover off and used a big loop on the resistor and could see for sure that nothing was touching where it shouldn’t. But ended up with the same problem as before. Also, the noise (hum, hiss, squeal) would change depending on my position to the amp. The only thing that would seem to tame the problem was to touch the end cover at the female end of the short cable. It would just about silence it????
Would love to have your input. I really think this WILL work out for a big sound benefit if I can get rid of the “noises.”
Do you think building the “box” version would be a better alternative? I really don’t want to modify the guitar wiring or the amp. I like the versatility of just disconnecting.
EDIT: Also wondering if the resistor watt value matters. I bought 1/4watt resistors. Should they be bigger?
And here is a pic of attempt #2 for clarity of what I got going. 🙂
kzissPosted at 06:29h, 21 April
The 47K resistor value is perfectly OK because it is very close to 50K and the wattage rating of the resistor does not matter because the guitar pickups put out very weak signals in the millivolts range.
I suspect that there might possibly be something wrong with the ground shielding of the cable or at least the ground shielding on one end of the cable , especially considering that the noise goes away when you touch the end cover at the female end of the short cable.
If you have a multimeter , set it to the lowest ohms range and then connect the two probes to the ground sleeves at the ends of the cable and if the shielding is OK then there should be a zero resistance reading. Hold the probes firmly on the ground sleeves of both ends of the cable and then move or bend or gently stretch the cable and see if this causes the resistance reading to increase or to go open circuit. There should always be a zero resistance reading (short circuit) when you play around with the cable.
I have had problems with short cables as well as long cables developing intermittent grounding problems.
Judging by the photo the resistor leads are short so therefore there should not really be a pronounced noise problem coming ffrom the approximately one inch long resistor wire that is connected to the signal lug of the cable plug but just to be on the safe side it is a good idea to cut the excess length of the resistor wire and only leave a short length so that this can be soldered on to the end of the terminal lug of the signal tip of the plug and then you can insert a short piece of heatshrink tube to cover the exposed solder terminal lug and the resistor body , and to then solder the other wire of the resistor to the grounded terminal lug in the plug.
If you do not have heatshrink tube you can then try using sticky tape or electrical tape to cover the signal treminal lug and the resistor body so that the signal lug or the signal end of the resistor does not accidentally come into contact with the grounding terminal lug or with the metal cover of the plug.
For my experiment to see what happens when the guitar signal is loaded down I used a resistance substitution wheel which has two approximately 15 inch long unshielded wired with alligator clips at both ends and I set the resistance wheel to the 47K position and this is working OK with only a slight amount of hiss noise generated by the 15 inch long unshielded wire and this slight hiss goes away when I place the resistance substitution wheel and the two 15 inch long wires in the space between the chassis wall and the printed circuit board behind the input jack of my opened up and laid upspide down Marshall JTM-45 amplifier.
I have set the switch to cascade the Normal channel into the High treble channel thus producing the heavier gain and distortion levels and even so the hiss from the unshielded wire of the resistance substitution wheel is not a problem so therefore your 47K grounding resistor which has much shorter wires should not be causing hiss problems if every thing else is OK.
If the cable is in proper condition without any grounding problems then it does not matter if the resistor is connected to the male plug or to the female plug however it is best to connect this short cable with the 47K resistor in it to the end of the guitar cable that goes to the amplifier because the low impedance created by the 47K grounding resistor will then help to suppress hum that gets picked up by the long guitar cable .
Another thing to note is to make sure that there is a proper firm connection beteween the grounded sleeve of the female socket of the short cable and the grounded sleeve of the male plug of the guitar cable when the guitar cable male plug is inserted into the female socket of the short cable.
Some cheaper quality plugs and sockets can cause intermittent grounding problems the clip lugs inside the female sockets do not make a very firm connection with the sleeve of the male plug that is inserted in the female socket and because of this you might have to wiggle the plugs to establish the full ground connection and even then the ground connection can still become intermittent when the cable is moved.
If there are some intermittent grounding problems caused by the female socket of the short cable then you might be able to minimise this by wrapping a layer of sticky tape over the joined male plug of the guitar cable andthe female plug of the short cable so that these will not come apart of move around .
All the best.
kzissPosted at 06:41h, 21 April
I just looked at your photo again but this time it was fully enlarged and I noticed that the 47K resistor is not actually connected to signal wire of the male plug.
The wire coming from the gold band end of the resistor is connected to the grounding lug of the plug but the wire coming from the yellow band end of the resistor is also connected to the ground on the other side so therefore it will have no effect on the guitar signal.
The wire coming from the yellow band end of the resistor should have been connected to the short upside down L- shaped terminal lug on the middle and on which the end of the white coloured signal wire is soldered to.
Doing this will cause the 47K resistor to work properly and hopefully this will also solve the noise problem.
All the best.
06AngusSGPosted at 08:15h, 21 April
Thanks for noticing my naive mistake. (and pardon for all the questions 🙂 ) I’ve not done electronics since high school. Just getting back into it lately. The mechanics like soldering & placement come easy. It’s all of the working theory I have forgotten.
I was under the assumption that the resistor should remain only in the ground side of the circuit. 😉
So now I have it done as per your instructions and I’m wishing that it wasn’t 11pm here. The “noise” is GONE and it sounds AMAZING!!!! 8) I can only play with my MV mod way down so I’m not even getting the full effect of this little gem but I will for sure be doing some sound clip comparisons to post here tomorrow. 😛
Thanks again Kon for the wonderful info and help.
Fil, I think you’re going to be surprised as to what a single resistor can do!!!!
bananePosted at 08:17h, 21 April
Great Jon, looking forward to hear this! 🙂
SoloDallasPosted at 08:21h, 21 April
I know! That’s why in fact solos (on 10) are darker and then, sound brightens while rolling off. That’s surely a good part of it (the SECRET-1 also has this). This we know. But there’s that “bass” boost that has to be re-created. Plus the compressor. THIS is why this morning (it’s mornin’ here) I’m going to Guido. Going to write an article on the Vega and Guido’s work AFTER I come back today. PS Jon, I’ll be in The US of A the whole month of June! Whole family will be there. We’ll be on a similar time-frame 🙂
bananePosted at 08:28h, 21 April
Good to know, will try this out too, wasting some time until the Vega arrives 🙂
Btw, Fil, did the shirts arrive yet?
SoloDallasPosted at 08:30h, 21 April
Nein Sir, no shirts yet 🙂
BTW Franz, I’m going to Guido now, Questions for him?
bananePosted at 08:36h, 21 April
Damn post, I payed for express and priority delievery, they told me it should arrive around tuesday…next time I’ll fly to rome to bring them personally 😀
Yeah, I have some questions:
1) how do I connect the guitar to the transmitter unit? detailed photos of where I have to connect the guitar jack would be nice.
2) That Vega I ordered seems to be battery driven, probably with a 9V battery. Could I just connect a high quality stabilized 9V power supply to the battery plug? How much Ampere the the power supply has to deliever?
3) And any other things I have to consider when using it?
*Edit*: And of course many thanks to Guido for his great work and for answering my questions 🙂
SoloDallasPosted at 08:48h, 21 April
It’s not YOUR side of the post bro, it’s mine! (Italian, sigh). We both know that.
Anyway: you see I didn’t shoot videos… waiting for them to be there. Will shoot the Back in Black solo tut as soon as I have one of the two shirts on 🙂 Now, fair questions. I think that on the internals Vega pictures you can already see where Guido soldered the jack cable, but I’ll take another picture today and will try and describe how he soldered. I suppose it’s easy. Mike here also did it, and he doubled checked with Guido personally yesterday via email. Franz, you will have Guido’s own email (as a Vega owner 😛 ) if you want, so you can ask all you want. Yes, your units run also on 9v batteries (the receivers). However, I do suppose that the “right” sound will come off of the power supply. So your question is very important. However, I know Guido already has answered that to me. The reason I know this is, that the “replica” will ALSO sport a power supply made for it since Guido knows that the power supply is an important part of the right boost (it’s really a matter of voltage he told me, he mentioned +12/-12v to me, I don’t have an idea of what that means yet).
bananePosted at 08:58h, 21 April
Yeah, what’s annoying me is that you and all the people here are waiting for the video now 🙂 But well, we can’t do anything here but praying for an early delievery 🙂
Yes, having Guido’s mail address would be great in case I have any problems. And of course I won’t spam him with questions 🙂
Yeah, thought that the power supply is important here, but I don’t have any clue about electronic things, so I don’t know what power supply to buy. Will test it with battery and power supply then and compare the results.
Thanks again to Guido 🙂
06AngusSGPosted at 08:31h, 21 April
I tried it along with my comp/boost & without really quick. I didn’t have the neighbor knock but the wife came out with that “look” 😡
Without the comp/boost it does make a small difference but with the pedals it’s night and day. I actually think with all three parts the xtra bass is there. I can’t quite tell now. I can’t wait till morning!! 😛
PS: Where in the U.S. you going to be? If your close enough it would be great to actually meet.
SoloDallasPosted at 08:34h, 21 April
San Diego. I can almost give you an address, we’ve almost booked a big house on the beach. We’re in talks with an agency. Would LOVE to meet. I’ll be there for a whole month. So, we can skype easily, etc.
06AngusSGPosted at 08:42h, 21 April
O.k. Cool. We’ll be on the exact same time frame. Still a little far to just make a day visit (that’s around 1,100mi. from here) but yes, Skype would work really well. Hit me up when you get here. 🙂
I’m already feeling sorry for the jet lag you’re gonna get 😉
SoloDallasPosted at 08:51h, 21 April
Jon, jet lag is my friend already. With all the travelling I did in my last 15 years of life, we made friends lol I can’t wait to be back in the US. I love the US 🙂 I think I’ll bring over one SG 😛
bananePosted at 09:00h, 21 April
And don’t forget to make a shopping tour through that stores with used electronic parts, maybe you’ll find some Vegas 😀
headwhop26Posted at 17:26h, 21 April
Hmmm, San Diego is at least on the same side of the planet as I am… maybe I need to plan a road trip for the month of June… 😉
rjofigPosted at 14:28h, 21 April
Boo, should have come to Florida instead, Fil 🙂 I’ll probably be in San Jose for work for a couple days in June, but it’s still kind of far. Cheers,
AntPosted at 18:23h, 21 April
it would be so epic if we could all meet up 🙂
06AngusSGPosted at 02:27h, 22 April
So….posted a small sound comparison over in the “SD Filespace” Didn’t end up with a lot of time today and something is hay wire either with my mic or interface???? 🙁
Anyway the recording is dirty but the difference still can be heard. 1st part is with the Resistor 2nd is w/o.
kzissPosted at 06:53h, 21 April
>Do you think building the “box” version would be a better >alternative? I really don’t want to modify the guitar wiring >or the amp. I like the versatility of just disconnecting.
The short cable with the 47K resistor should work OK.
The box version is for if you prefer to use a potentiometer to vary the actual grounding resistance value to personal taste instead of being limited to a single fixed resistor value.
However since you are specifically seeking to recreate the effect of the Shaeffer Vega wireless system on Angus Young’s guitar tone then the cable with the 47K grounding resistor and this signal then going into your compression / boost unit should help you to achieve this.
All the best.
SGACEPosted at 09:02h, 21 April
Thanks for the useful information, I am really glad that there are other people than me to know and give that proper attention to groups like Blue Cheer…
Is it possible to send a photo to show us how to connect the resistor to the terminal of the cable?
06AngusSGPosted at 17:18h, 21 April
Here you go George:
Pay no attention to the crappy soldering. I was in a hurry and this was the 3rd attempt on the same jack. (due to MY lack of understanding 😉 )
To majorly simplify Kon’s great knowledge & info; it’s a matter of bridging the resistor between the two sides of the signal (+/-). 🙂
Working on sound clips in a bit. Will have them here today 8)
SGACEPosted at 17:30h, 21 April
excellent, nice photos man, thanks..
hotguitPosted at 18:50h, 21 April
i’m new here but i’m very interested in angus’ tone
So this 47K res. can help to tame highs a bit?
i play a SG61 CS in a 1975 marshall 1959 100W (no pedals at all) but i’m not very happy about the tone; too much top ends (both bass and highs) and the gain is not enough. (there is something wrong in the tone but i can not understand what it is)
Is this mod (the 47K res) of help?
bananePosted at 19:00h, 21 April
Hi and welcome 🙂 Had the same problem with my SG standard. Changed the pickup to an AY signature, problems with too much treble/bass gone now. What pickups do you have?
hotguitPosted at 19:04h, 21 April
stock C.S. Gibson SG61 pick ups: 57 classic
bananePosted at 20:59h, 21 April
Hm, can’t say anything about the 57 classic pickups, don’t know them 🙂 maybe some other guys here can help out?
kzissPosted at 19:53h, 23 April
Wiring up a 47K resistor between the guitar output signal and the ground will roll off some of the excessive brightness of your SG so you might prefer this mellower sound even though it is without the additional gain boost and the cpompression created by the Shaeffer Vega Diversity wireless system.
Another advantage to thr 47K grounding resistor wired to the output of your guitar or to your guitar cable is that it reduces some of the background hum because the resulting much lower impedance of the guitar signal.
I used to have Gibson 1957 Classics on my Gibson Les Paul guitar but I eventually removed them because after doing an A/B listening test with a few other pickups.
For the A/B test I wired up a length of shielded cable to a phono jack with a 500K grounding resistor and another 500K grounding resistor in series with a 0.022 uf capacitor soldered to it in order to recreate the same loading effect as the normal 500 K volume control and the 500K tone control and the 0.022 uf treble cut capacitor in the Les Paul guitar so that the pickups that I am testing will be properly loaded down as the pickups in the Les Paul are thus ensuring an accurate A/B listening test.
I did the A/B listening test by attaching the other pickups on top of the guitar strings above the existing 57 Classic pickups , and with the pickups facing the direction whereby the magnets were in phase with the magnets in the 57 Classics so that there would not be the cancelling out of frequencies caused by the opposing magnetism of the pickups facing each other.
The pickups that I tried out in the A/B test included a 1960’s Gibson T-top pickup with the patent numbber stamped underneath it and also a few other pickups including a Seymour Duncan 59 Neck, a Seymour Duncan Alnico Pro 2 Neck, Belman PAF copy pickups ( Belman were an Australian guitar and pickup manufacturer but they no longer exist) and a Dimarzio PAF copy.
The Gibson 57 classics did not sound as good as these other pickups. The 57 Classic pickups seemed to have a somewhat grainy and sterile sounding midrange compared to these other pickups which had a smoother and sweeter sounding midrange so I ended up replacing the 57 Classics with the Belman pickups.
Ideally I would have liked to wire up the 1960’s Gibson T-top pickup in my Les Paul but I want to keep this as a reference pickup so that I can compare it with other pickups, and the Belman and the Seymour Duncan pickups sounded close to the Gibson T- top pickup.
All the best.
kzissPosted at 10:16h, 20 April
Thank you for posting up the specs information for the Shaeffer Vega Diversity wireless unit.
One very important factor that affects the tonality of the guitar is the fact that the input impedance of the Shaeefer Vega diversity unit is 50K ohms which is much lower than the 1 Mega ohms that is needed in order to allow the full frequency response of the guitar pickups to pass through.
The very low 50K ohms input impedance causes the guitar pickups to be noticeably loaded down and this causes the treble response ogf the pickups to become mellower thus resulting in a smoother creamier sounding overdrive sound through the Marshall amplifier or any other amplifier or overdrive unit used after the Shaeffer wireless unit.
The effect of the 50K input impedance on the guitar pickups is approximately similar to the treble roll off that happens when a Jen Cry baby or a Vox VA47 Cry Baby or another similar copy wha wha pedal with the stock single pole/ double throw (SPDT) switch is used whilst the wha wha effect is switched off because even though the wha wha is switched off , the SPDT switch causes the guitar signal to always be connected to the input of the wha wha circuit which loads down the guitar pickups. When I measured the input impedance of my Jen Cry Baby wha, the reading was approximately 47 K ohms .
The 50K impedance of the Shaeffer wireless unit and the 47K input impedance of the Cry Baby wha wha pedals also affects the response of the guitar volume control whereby when the volume control is at the full volume (10) setting the guitar sounds mellower and when you turn down the volume control the sound quickly cleans up and the bottom end is reduced to some extent compared to how it sounds at the full volume setting.
I have never come across a Shaeffer wireless unit but I believe that it’s very low 50K input impedance is the reason why some people say that Angus Young’s SG sounded like the tone control was rolled down to some extent.
The effect of the very low input impedance on the guitar pickup frequency response is even more pronounced with the Dallas Arbiter Fuzz Face or the Jim Dunlop Fuzz Face because when I measured the input impedance of the Dallas Arbiter Fuzz face, the reading was approximately 10K ohms and this drastically rolls off the high freqiuency response when the guitar volume control is set to the full volume setting and then when you turn down the volume control the guitar sound cleans up and the sound ois thinner and brighter. Jimi Hendrix often used this characteristic effect of the Fuzz Face by turning down the guitar volume ontrol to get the bright clean sound and then turning the volume control up to get the characteristic sounding dark fat overdriven sound of the Fuzz face.
I have just experimented with temporarily connecting a 50K resistor with alligator clips between the ground and the input jack of my 1996 JTM-45 Reissue amplifier which I have heavily modified with switches to produce the various tonal variations of the JTM-45 / JTM50 / JTM100 / 1959 etc amplifiers and I have also added a switch that switches between the normal parallel operation of the Normal channel and the high Treble channel or the cascaded operation whereby the Normal Channel feeds into the High Treble channel thus producing much more gain and overdrive.
Because the Shaeffer wireless unit boosts the guitar signal , I have approximated this gain boost by setting the switch to cascade the Normal and the High treble channel to produce a similar level of distortion heard on ‘Back in black’ and when I connected the 50K resistor grounding resistor to the input jack of my JTM-45 , my 1992 Gibson SG amplifier took on the fatter, creamier sounding sounding characteristic with the mellower treble closer to that heard on ‘Back in black’.
I am also going to wire up more switching modifications to my JTM-45 to be able to get the 2204/ /2203 tonality which has that nice distinctive crunchy metallic “crangg” which sounds great for rhythm guitar.
For all those who like to experiment and for those who want to be able to simulate the tonal characteristic of the Shaeffer wireless unit on the AC/DC guitar tone but who cannot afford to buy an old Shaeffer wireless sysytem or who cannot find this unit , then I recommend that you try out loading down the input of your amplifier or the output jack of your guuitar with a 50K resistor wired between the ground and the signal.
Of course this 50K grounding resistor will not recreate the compression effect of the shaeffer wireless systen , but it will load down the guitar pickups similar to that of the 50K input impedance of the Shaeffer wireless unit.
If you have a decent sounding overdrive unit or a high gain amplifier or a Marshall Modern Vintage (MV) or a Marshall 2204/ 2203 or a Non Master Volume Marshall amplifier modified to get more gain by cascading the Normal and the High Treble channels then this will provide more than enough gain levels to produce the AC/DC level of Marshall amplifier distortion as that created by the boosted and compressed guitar signal coming from the Shaeffer wireless unit and the 50K grounding resistor will help to produce the fatter , creamier guitar sound as well as the advantage of less background hum because 50K is much lower than the 1 mega ohms input impedance of the Marshall amplifiers and many other amplifiers and other guitar effects units.
If you weant you can replace one of the stock volume or tone control potentiometers of your guitar with a potentiometer that has a push / pull switch so that you can switch the 50K grounding resistor in or out of circuit from the output jack of your guitar or you could replace one oof the potentiometers on your Marshall or any other amplifier with a new potentiometer of the same K ohms value which has a push / pull switch with the 50K resistor wired to the swuiitch so that you can then switch this in or out of circuit on your amplifier.
Please note that if you decide to connect the 50K grounding resistor to the input of the amplifier then this will only affect the guitar sound if the lead coming from the guitar is directly connected to the input of the amplifier but if you use any effects unit or any other preamp between your guitar and the amplifier then the 50K resistor mounted in the amplifier will not affect the guitar pickup s sop therefore it is best to wire up this switchable modification directly in the guitar itself.
This simple modification with the 50K resistor will help you to come closer to nailing the ‘Back in black’ etc AC/DC sound.
All the best.
SoloDallasPosted at 11:49h, 20 April
Thanks for this great post. Do you have any audio clips? Eager to hear you. Thanks again and welcome here, Fil 🙂
06AngusSGPosted at 17:55h, 20 April
So, from what I’m understanding from this is:
One would need to insert a 50k ohm resistor into the “ground” side of the guitar signal?
1) if done in the guitar, you could have pedals & such between the guitar & the amp?
2) if done on the amp you would have to only a cable between the two?
So, if my assumtion is correct, to try this out; one could simply modify a guitar cable by opening up the end and inserting a 50k resistor into the ground side connection of the tip?
ar2619RobPosted at 12:30h, 13 April
So, what d’ya know Fil?
SoloDallasPosted at 13:23h, 13 April
New POST Sir. Just out!!!! It IS as expected!
AngusrocksPosted at 12:17h, 13 April
We all know that Angus is using Wizard amps, too.
To me it was interesting to see in this video that this Wizard amp already has the boost function.
andreiPosted at 23:05h, 11 April
I’m saving money already for this…
KevPosted at 17:05h, 11 April
I can’t wait to hear new results from your quest!!! 🙂
LolloRnRPosted at 19:00h, 11 April
Me too! I’m also looking forward to hearing some cable-wireless comparisons and above all to hearing how does the “vega boost” sound compared to other clean boost units (like the great secret-1).
solocaliPosted at 16:37h, 10 April
Fil what albums do you think angus used the 2204 on, high voltage-highway to hell?
jonassweden1Posted at 00:51h, 09 April
Yeah, and I saw them live at Stockholm Olympic Stadium 3rd of June last year; a really great performance, they where amazingly tight moving into their 60s…!! Cheers / Jonas
mrkrausmanPosted at 17:38h, 08 April
Mike’s Vega up and sizzling! The 1st impression is that the Vega is a boost monster and difficult to tame. It took me a couple of sessions to get to the point where it wasn’t overdriving my preamp (fuzzy distortion).
So what I did was go back to plugging in my SG and got the amp sounding good. Metro/Mike/Bray 1987. preamp 8, master 6-7. Bass 2, presence 2-3 (just a little NFB to stabilize the amp) mid and treble at 5.
Back to wireless. Shaffer article is spot on and I refer to that above. The transmitter (TX) does determine the amount of compression and can be monitored visually on the Reciever (RX). I ended up around 8. I ran the RX at 0 (at +20 was too much boost. At -20 I got a clean sound and less boost.) There is also an audio adj pot, accessed with a screwdriver that will adjust the overall gain.
The fun will be in the fine tuning of the gear. I believe tweaking my 1987 peamp to be more ‘Vega-friendly’ could be in the future. I may end up reducing some gain to clean up some bass but we will see. Fil I hope this gives you a starting point to help you when you fire yours up.
The Sound. The sustain was so long it was difficult to get used to but that sensitivity is adjustable on the TX. Right now it sounds more like LTBR than BnB but I’m still learning. 🙂
mrkrausmanPosted at 17:53h, 08 April
PS, I would strongly recommend a good attenuator so you really drive those EL 34’s without blowing your ears out lol.
MikePosted at 18:19h, 08 April
Fil I can’t wait to here the Vega on some of your circuits particularly the 2203 and 1959.
SoloDallasPosted at 04:46h, 09 April
Sweet lord Mike, so exciting to read. For me, only three days and I’ll too Vega around. Now Even before trying, my idead has been that:
– connected to amp via rear panel = LTBR (and maybe a few live early shows)
– connect to amp VIA MONITOR OUTPUT ON FRONT PANEL = Back in Black
Have you tried the monitor output?
MikePosted at 07:12h, 09 April
‘Taming the Vega’. No I havnt tried the front as yet but thanks for the heads up I will for sure. There is no doubt that you are onto something here. I havn’t had much time to experiment but exciting times ahead and it’s all your fault Fil 🙂 Thanks for the inspiration! I played around with intros to Overdose and Riff Raff and I got chills.
SoloDallasPosted at 09:02h, 09 April
Mike, thank you, it gives me happiness 🙂 It’s not me suggesting it’s the monitor output, it’s Angus himself: ”
” find all about it here!
Mike: PLEASE TRY it. I can’t wait, but I have to.
So, I’ll say this again, even before tying this myself, but I have been having this in my mind for months now:
The Let There Be Rock sound was obtained with the rear output boost; ALL of the other sounds after that, mostly if not exclusively, were obtained – in my really humble opinion – with the FRONT boost.
Once I am back in the lab, I will test it thoroughly and write about it PLUS full length video describing my theories and trying to reproduce faithfully all those tones.
I think HighWay to Hell was played rhythm section with just the amp (mostly); lead was played instead with the front boost. This is in fact detailed in “AC/DC in the Studio”, where the sound engineer in fact remembers this and states it.
Edit: it may also be – since Angus talks about a “switch” in reality, not a “knob” – that by adjusting that +20db boost in the rear, one gets to desired result and not by the front output; this is really right now what I think about now and you are the ONLY one who can test this in advance. Pretty exciting if you ask me.
MikePosted at 19:30h, 09 April
Fill I plugged into the front monitor jack. I can tell you that this jack’s gain is independent from the ‘boost switch’ and ‘audio adj’ on the back. It’s gain is only controlled by the mon. pot next to the jack.
I am hesitant to give much description of the sound to you because I know our gear is not the same and also I would like you to form your own opinion without preconception. I will tell you that there is sustain and mid boost and I think you will be pleased.
There are a couple of things I gleaned from the Angus interview you posted regarding their Marshall amps.
1. Angus speaking about the Marshall factory: “We go down there and try them out and fool around with amps and tell them what we want and they doctor them up.”
I take that to mean obviously that those amps were not stock but were variations
of the original circuit.
2. “At the moment( in 1983), they’re all back to the old style of Marshalls, they’re very clean. They don’t have these master or preamp settings.”
We know from videos and live shows that in the late 70’s Angus used 2203’s and 2204’s or master volume amps. This quote from 1983 gives me the impression that they went back to plexis 1959’s and 1987’s. We also know that the guitar sound changed during this period. Sorry if you’ve already mentioned and know all this but the Marshall preamp setup is also a big part of ‘the tone’ as you well know and worth mentioning before you Vega. Also it seems to me the Vega emphasizes the characteristics or flaws maybe in the preamp setup.
SoloDallasPosted at 04:40h, 10 April
I re-read this 4 times. This is the level of interest I have in it. Total. Thanks Mike… counting the days was never this fun!
MikePosted at 05:14h, 10 April
Well some groundwork has been layed now we anxiously await your Vega analysis. I look forward to more revelations.
SoloDallasPosted at 05:46h, 10 April
And they will come. I just need to lay may hands on them
MikePosted at 20:44h, 10 April
I had another try at the Vega both back and front. I am liking the front monitor right now and here’s why. I was having trouble with too much distortion so i backed off the gain on amp and guitar and TX pot (vega)-not satisfied. So today I first turned up the TX all the way as Shaffer says. I then backed of Mon. pot to around 9 o’clock and amp vol I to 7 and hello!! It cleaned things up and some Angus came out playing some ‘For those about…’. The Mon pot is key because it controls the amount of overdrive and with the TX dimed you get the full Vega ‘compansion’.
This is pretty loud even on my Dr Z Airbrake(bedroom level maxed).
1987 preamp 8 /master (vol I. 7 Bray vintage hot off)/ pres 0/bass 3/middle 6/ treble 6
SoloDallasPosted at 04:45h, 10 April
PS was re-reading also everything, and when Angus mentions the “monitor switch” it MUST be the front output, Mike. The rear output has no mention of “monitor”. There’s only “audio” in text there. So the choice of word “monitor” speaks at lengths imho; what differs is Angus’ take on “switch”, but this is a minor – and maybe also typical – thing of Angus, where he almost never gets it right when it’s about gear lol.
SoloDallasPosted at 08:21h, 10 April
was re-reading the last part of this comment of yours. Yes, I had read that. It seems that by that time – 1983 at least – Angus specifically went back to 1959s and 1987s. In fact, the rehearsals for Flick of the Switch videos do show Angus with super lead type amps only, no MVs. Malcolm still has MVs there (Malcolm was still pretty “dirty” here). This – reading it in another perspective – might indicate that Angus did really indulge into MVs earlier, which would – could – provide a little more evidence that he indeed used extensively MVs in the previous years. We can see that in some live videos; however, by boosting his amps via the SVDS, it is harder to tell if he was really playing mostly MVs or NMVs. I think I will have to train my ear with the SVDS, and now it seems I will finally be able to, having 3 working units. I am reading all of this again and again, as it’s the only thing I can do today in this hot day again. I can’t wait to be back.
mrkrausmanPosted at 17:44h, 06 April
I know this has been talked about before regarding Angus’ wireless but I’ve been thinking since I’ve had my Vega on the bench. One thing we have commented from videos is that there doesn’t seem to a chord coming out of his SG to a transmitter. I believe that the Vega was mounted in the guitar cavity. If you take out the circuit board it will fit inside and the input can be wired direct. There is a volume control which could have replaced one of the guitar pots or it could have been mounted elsewhere on the SG. I believe all of his SG’s where modded with transmitters. Just some thoughts.
mrkrausmanPosted at 17:48h, 06 April
I’m not sure the flexible antenna would work inside though. It could have been attached along the guitar body. :-/
SoloDallasPosted at 18:02h, 06 April
My take is that the antenna was made longer and taken out of the control cavity via a hole, then, it would run across the back part of Angus guitar strap. I actually have seen pictures of Angus with the antenna running that way
mrkrausmanPosted at 18:15h, 06 April
I’m going to wire my transmitter to guitar today. Not sure of exact pinout to guitar plug but I’ll figure it out. I will comment later.
SoloDallasPosted at 18:19h, 06 April
PLEASE keep me updated. You much likely will have your hands and ears on it before I will (next tuesday). SO curious to know.
jubalubaPosted at 00:29h, 10 April
In this video it looks like a flexible antenna like thing is sticking out near the mount for the strap. Possibly out of the vibrato system or from the cavity. But it might be my eyes that are playing me a trick.
jubalubaPosted at 00:37h, 10 April
Never mind. Turns out it is just the strap.
jubalubaPosted at 00:38h, 10 April
How embarassing… he he
MikePosted at 05:31h, 10 April
No problem. I am excited that you are interested enough to look.
SoloDallasPosted at 05:45h, 10 April
And you are right. Juba, why be embarassed? Do you have a rough idea of how many times I made such mitakes? It’s all in the sake of discovery, and it’s all good. Plus, solodallas.net is not devoted to perfection. It’s devoted to emotional (and rational) findings and experiences. It’s all good 🙂
jubalubaPosted at 14:31h, 10 April
No big deal. It happens all the time (and thank you for being patient with us rookies). And this is one of the reasons that I think solodallas.net is such a great community. You can actually share your thoughts without being flamed. This is a fantastic place.
By the way, about 6:50 in this video, we can clearly se a white square on the back side of Angus’ guitar. Does anybody have an idea of what that might be?
MikePosted at 16:44h, 10 April
It looks like the size and shape of a vega transmitter . Could they have made a pocket for it? Whatever it is, it looks flush to the guitar surface or not sticking up.
MikePosted at 17:21h, 10 April
Here is a screenshot of that frame: https://i563.photobucket.com/albums/ss72/mrkrausman/angus_guitar.jpg
It would make sense to mount it for easy access because the batteries have to be changed often. Also if a transmitter or reciever had a problem it could easily be changed. I hope Fil chimes in on this.
MikePosted at 17:41h, 10 April
I checked the picture and compared the location on my SG and that is directly opposite the bridge. It could also be hardware common to SG’s of that period. (Fil would know) I doubt if they routed out the guitar there but I really don’t know. Interesting though because it’s white and the right size and I’m not ready to debunk as yet. 😛
frankjossPosted at 18:21h, 10 April
Sorry to nose in on the exchange but does this vid add anything to the grindstone ?
(Glasgow 78), there seems to be a strange setup on the back of the strap . I have almost no tech knowledge but if it helps
jubalubaPosted at 19:34h, 10 April
And the jack cable that is just hanging, not connected to anything.
OldSchoolRocker666Posted at 19:39h, 10 April
Does the room where the neck pickups on SG guitars is located offer any space that can be used to put small wireless parts into it? Considering that Angus supposly never used his neck pickups alot he could of taken the pickup away, and perhaps use the room left for something, maybe? No idea just came to my mind. 🙂
SoloDallasPosted at 17:51h, 06 April
Mike (finally I get your name: PS: Aries is a KICKASS sign!) BINGO! There is PROOF of what you say, and I had dared suggest this months ago, in some comment answering one question. There is a live video – ’78 I think – of Angus with the jack cable coming out from a different place, and another video where there is no jack at all, still you can hear he is playing, no playback. In the early times, it is a SURE thing that the SV was in fact in his SG control cavity. Good thinking! 🙂
mrkrausmanPosted at 06:27h, 07 April
I just remembered I saw ACDC in concert in 78 at Toledo Ohio speedway and he was less than 100 feet from me on stage. If I only knew then what I know now :/. We never knew we were witnessing history. I was very young but i still get chills remembering the performance.
headwhop26Posted at 06:33h, 07 April
🙂 A guy I work with saw them in 1979 in Texas(?), and he said it was one of the most rocking shows of his life. He’s a cool dude
mrkrausmanPosted at 06:44h, 07 April
You know it might have been in 79 not real sure there I know it was with Bon RIP and Sammy Hagar opened the show. It might have been the Highway to Hell tour…it was a long time ago .
mrkrausmanPosted at 06:55h, 07 April
I saw many great bands of that era: Aerosmith Van Halen Scorps, Journey Nugent Def Leppard. They could never touch the ‘bad boys of rock n roll’ some called them.