The ORST is a very early Orange/MATAMP head predating the typical OR120 or OR80 Orange amps.
A number of years back, Neil had made a few clones of this amp and had one last set of parts available. You can perform a google search to see various posts on some of the appropriate forums for the particulars.
This core of this kit revolves around the Partridge transformers. I believe these were sourced out of a 1960s/70s Carlsbro 100/7 PA.
As such, the amp can be built as either 50W (two EL34s) or 100W (four EL34s).
There is a chance the other components came from the same Carlsbro head: original Rendar input and send/receive jacks, impedance and voltage selector sockets/plugs, Radio Spares toggle switch, Bulgin mains socket, etc.
In addition to the aforementioned parts, the following is also included:
- Reproduction Orange/MATAMP ORST chassis including chrome handles and inner shield/cover for input/depth/drive section
- Beautiful Orange/MATAMP reproduction Traffolyte front panel
- 4x Orange/MATAMP Bulgin skirted knobs, 2x small for bass and treble controls
- 2x NOS Belling-Lee fuse holders
- 2x NOS McMurdo preamp valve sockets with shields
- 2x NOS Radio Spares tag boards (very difficult to obtain nowadays - this is NOT the one currently available for JMI Vox builds)
- choke (unknown UK manufacture)
- 6-way double-pole rotary for input cap selection (Depth)
- 4-pole 3-way rotary for Drive/Studio/Stage
- potentiometers: Radio Spares 2x 1M linear (Bass and Treble), 1x 1M log (Volume) and one Plessy 1x 50k linear (Boost)
- most of the Iskras/Pihers are NOS
- 4x NOS octal sockets
- various brass British Association screws, washers and nuts
In addition, I have also done some reverse engineering of the circuit/layout based on pictures of original ORST amps. The files of which will be included with the amp.
Neil also laid out pen markings on masking tape to represent the various screw hole locations on the chassis.
There's also a set of water-slide decals for some of the chassis markings included.
I'm probably missing one or two items, so please reference/study the pictures, all that is included is shown in the pictures.
A couple of IMPORTANT things to note:
1. this "kit" does not contain every single part needed for this build. For example, you will have to source most of the electrolytic capacitors, indicator, wire, etc. Likely other bits and bobs. However, it DOES contain all of the DIFFICULT to SOURCE/COSTLY parts (e.g., Partridge transformers, Traffolyte front panel, Radio Spares tag boards, various British hardware, etc.)
2: this is NOT a build for a beginner, it will require someone who has successfully built tube/valve amplifiers before. In my opinion, this "kit" would really cater well to someone who has built Marshall amplifiers who want something a bit different/outside the norm.
Asking $850 (shipping included - note that the Partridge transformers alone weigh 18 lbs the pair!) to the lower 48 U.S. only. Contact me if you are outside the U.S. and interested.
References available.
