SoloDallas® SD50X Guitar Amp Head


Regular price $3,200.00 Sale

SD50X - Hand built in Belgium by Dries Pottevijn

This item is Made to Order. After your purchase, we will be in contact with the production time and your shipment window.

For more information regarding lead time and options, please send an email before ordering to


SoloDallas is on a mission is to uncover the lost treasures from rock history and bring them to fellow toneseekers.

SoloDallas is on a mission is to uncover the lost treasures from rock history and bring them to fellow toneseekers.

This amplifier is no exception. Our resident aficionado, Fil Olivieri discovered something about the amps Angus toured and recorded his band's biggest albums with that few guitarists know. Even many of the guitar magazine writers got it wrong! Contrary to popular belief Angus wasn't using common amps by that lovely British company he helped introduce to a new generation. Photographic evidence and Fil's personal conversations with this legend's guitar tech and engineer have confirmed his amplifiers during that time were actually a rare 50w transitional model built during a short period from late 1967 to 1969. Collectors refer to this model as the "Blackflag" due to the black screen printed logo next to the input. This amp was basically a modified version of their original 45w model. Most notably, KT66 power tubes were swapped with more reliable EL34 tubes, power transformer was upgraded to accommodate new power tubes and the GZ34 tube rectifier was exchanged for a solid state rectifier. These upgrades gave this classic a little more low-mid grind, faster attack and increased the output by about 5w. Exactly what Angus needed to express his signature style!

Amazingly few if any amp builders have had any interest in reproducing this amp of legendary proportions ...  Until now!

Ladies and gentlemen we proudly introduce the SoloDallas SD-50X.

We have carefully studied a prime example of this circuit inside and out to offer a perfectly voiced specimen made to exacting standards by our European engineers.  A peek under the hood reveals a combination of impeccable hand-wiring and through hole construction. Every part and component is sourced from the most reputable suppliers and the quality and attention to detail can be seen and heard throughout. If you would like to join a growing list of artists that are rediscovering this rare tone-filled treasure then look no further! 

Please contact us prior to completing checkout for shipping quote. Since this is a heavy item, shipping will be quoted separately.

Only built to order ! A lead time of 8 weeks is standard.


  • 50 watts
  • 1967 JTM50 "Blackflag" legendary circuit with Solodallas' mods
  • EL34 power tubes (2) and 12AX7 preamp tubes (3)
  • Solid-state rectifier
  • Master Volume upon request (+ $50)
  • 4-8-16 ohms speaker impedance selector
  • Voltage requirement (120, 240, ..) can be specified when ordering
  • Solid pine head cabinet