Does anyone else own a Henry's Radio Amplifier (1967)

[RetroRichard]

I have owned, repaired and used (since 1967) a HENRY'S RADIO set up comprising:
Stereo Pre-Amplifier Model SP6-2A (incl. front panel, knobs etc)
Stereo Main Amplifier Model MPA 12+12 (2x 12W)
Power Supply Model MU 24/40

Does anyone else own such a HiFi module set? I have the circuit diagram for the SP6-2A and am trying to get a copy of the MPA 12+12 amplifier.
The set is still in use to play outputs from 2 FM tuners and a Collaro record deck.
Any info would be welcome

[Radio Wrangler]

For a moment I wondered if you meant a Henry Radio amplifier. This similar sounding firm was in Los Angeles and produced kilowatt power shortwave amplifiers for radio amateurs. The engineering was rather good, the things were large, heavy and largely unaffordable on this side of the Atlantic.

What a difference a plural makes!

David

[G6Tanuki]

Yes, I was sort-of hoping it would be a Henry Radio amplifier - if it was, then the owner would have a really valuable treasure on his/her hands !

[ajgriff]

Originally Posted by Radio Wrangler

What a difference a plural makes!

Possessive rather than plural ie, belonging to Henry rather than multiple Henrys. Sorry, couldn't resist.

Alan

[AC/HL]

Both the thread title and the context are crystal clear

[jamesperrett]

I don't have a circuit diagram but I have a copy of the Henry's 10th edition catalogue which features the MPA12/3 and MPA12/15 together with the MU24/40 power supply. There's a connection diagram and instructions in there which I can scan if that would be of any help.

[RetroRichard]

Yes my set is from Henry's Radio in Edgware Road London, not the US manufacturer. I just wondered if anyone else has one. Apparently not it seems.

Thanks for the offer James, I have the relevant description brochure catalogue so have the connection instructions. I have the Pre-amp circuit diagram but not the one for the main Amplifier.
Cheers
Richard

[john5187]

Hi, you are not alone. I have an MU24/40 that powers an MPA 12+12 and an SP6-2 Preamp, with a Garrard deck. It is still in its 1965 Record Housing Radiogram Cabinet. Until today has not been switched on since 1973, and it still works on one channel if in stereo mode but switches to both channels if in mono. The amp is working fine, i think the fault might be in one side of the preamp. I am going to investigate tomorrow, anybody got any other clues?

[RetroRichard]

Hello John5187,

So that makes 2 of us! An exclusive club apparently.

Mine is in a cabinet built by my father with the Pre-Amp fed by a Collaro 4T200 record deck, a Dynatron FM2.LV valve tuner and a Bi-Pak stereo tuner (transistor and IC). The Dynatron is original and I added the Stereo tuner in the 80s. I have repaired the Dynatron tuner and it works well, the Collaro unit and Stereo tuner also work well.

Good luck with the pre-amp repair. Note that the Pre-Amp circuit diagram and pcb are positive earth from the power supply. I assume you have a circuit diagram for the SP6A pre-amp, if not let me know and I can give you hints from my one.

The output wires from the pre-amp to the main amp are easy to swap over to test which channel of the pre-amp has failed.

Over the last few years, I have changed all of the electrolytic capacitors on the pre-amp for modern versions, replaced the transistors with low-noise devices and mended a few dry joints or broken tracks. I suspect your unit's fault is probably one of those or a combination. It helps if you have an audio signal generator and can trace the signal with a twin-beam 'scope.

Good luck

[FIXITNOW]

i have a couple off amp pcb's marked as Henelec (5 to 8W) each never got round to building them. I think they are a Henry's item