Just got a Vox Supreme from the original owner

[Mick Bailey]

I had a call a week ago from a long-standing customer who was moving house. He said "You know that Vox Supreme - do you want it?". I immediately said yes and it's now mine; 1970, one owner from new (he picked it up directly from the factory) and with all the original tags with serial numbers matched to the amp. There can't be many surviving with that provenance. I had it in for a very minor issue about 15 years ago and was struck by how good an amp it was. It now switches on but hums, so some work to do as it wasn't used at all in those intervening 15 years.

It came with the knurled knobs and fittings to attach to the tilt-back cabinet, but sadly the original handle and fittings have been lost (the handle broke decades ago). Oddly, the cabinet is drilled for both the traditional strap handle as well as a later strap handle. I understand that some transition amps had both sets of drillings/markings, but need to establish if this is one.

Hopefully the reverb still works, as this is one area that's tricky to restore, being based on gramophone cartridges as transducers. I'm hoping that there isn't too much wrong with it as I recall it being quite difficult to work on with the fragile wiring and PCB.

[R.G.]

Congratulations, Mick! Great amp there. I've worked on a Defiant and a Conqueror, as well as doing a preamp-replacement PCB for the series, so I may have answers to a few questions if you get stuck.

Best advice if you want to actually use the amp to make sound - replace every electrolytic cap in it, then see if it works. 15 years without bias voltage is pretty damaging to electros. The reverb uses a step-UP transformer to drive the piezoelectric phono cartridge with a high voltage, which I found odd. Last time I looked, replacement phono cartridges are still available, but don't go there unless you're forced to.

These things are not nearly as hard to work on as the Thomas Organ Vox amps from the USA. Oddly, though, certain parts of the circuitry are near-relicas. This had to have been an echo of the time that UK Vox was cooperating with Thomas Organ in the US.

[Mick Bailey]

The last time I heard it the reverb worked but was weak and I expect by now it may not work at all. Its had a 3 pin IEC socket fitted but the original Bulgin plug and socket are with the amp. Also it has the foot switch. I'll take some pictures.

I'm hoping there's nothing too badly wrong with it - I haven't yet tried it myself and was going off what the original owner told me. I want to give it a good look over and assess the electronics before powering it again.

[R.G.]

Good luck with it!!!

[J M Fahey]

Sadly those DIY reverb tanks were weak even when new.so donīt expect much even if properly restored.

Being out of production for decades guess NOS cartridge prices will be all over the place.

[R.G.]

They run about US$40 to $50 fromaudio replacement places not trying to make a killing. The sky is the limit if they think you're working on a guitar amp.

I once converted a Defiant (Supreme's little brother) to a regular spring style tank insert. Worked.

[J M Fahey]

They run about US$40 to $50 fromaudio replacement places not trying to make a killing. The sky is the limit if they think you're working on a guitar amp.

I once converted a Defiant (Supreme's little brother) to a regular spring style tank insert. Worked.

Thatīs the way to go.
You need to buffer drive circuit because any coil driven tank will be MUCH lower than any crystal/Piezo one; recovery side will work reasonably well.

Or plain ditch the Reverb section and use signal out/in to drive and recover from any modern board, even a digital Belton "tank"

[R.G.]

I left the transformer in for the built in driver's load, and shunt-fed that to the reverb tank coil through a capacitor. Worked.

I agree with the Beltone tank. I did a PCB aimed at holding a BTDR module and having the opamps and power supply conditioning to bolt inside a gutted reverb shell, so you could replace any shell/tank guts with the module. Worked, and is adaptable for the common input and output impedances for tanks. Several people have used these in reverb replacements for home-grown Supreme/Conqueror/Defiant or UL700-series clones, and think well of it.

[Mick Bailey]

I had a Bird Golden Eagle combo in for restoration a few years ago and it used a similar arrangement to the Vox. I gave up trying to get hold of transducers and converted it to a Fender-type arrangement. Although this worked much better than the original setup, it still bothered me that I never got the original tray working, though it would have been more than the owner wanted to pay to find those 1958 cartridges.

I'd be happy to fit a Belton unit and leave the amp in a state where some future owner could refit the original tray if they really wanted to. I've only ever heard this type of tray at the end of its life and don't know what it would have sounded like when the amp was brand-new. Without a compelling reason to chase down the original cartridges I'd opt for something more effective and reliable.

[R.G.]

PM me Mick