Hi,
A relative who passed away left these in his loft. Apart from knowing this is audio equipment, I have absolutely no idea what I'm looking at. Can anyone give me any pointers at what these might be please?
Thank you
I guess you're not into electronics?
In order, left to right, A stereo power amplifier, A power supply unit for the amplifier, A Stereo pre-amplifier.
All three units connect together to form the complete amplifier system, so there should also be several interconnecting cables with plugs to match the sockets on the various units.
Be aware though, vintage electronic equipment uses high voltages which can be lethal if you're not familiar with type of equipment you're dealing with.
They look like quite a nice system.
@katie-bush Thank you for the reply and insight.
I have the cables too but I don't dare plug in and switch on incase I start an indoor fireworks display.
I'm definitely into audio equipment but more on the DJ end of things. Some electronics too but not so much on the soldering iron end of things.
I wonder if this was a kit or store bought. I couldn't see any branding so I couldn't identify where it could have originated.
That's good news on the cables!
I'll stick my neck out and say it looks like it was kit built. The chassis pressings look almost DIY, suggesting home build, or low number kits.
Definitely worth getting going, and by the look of it, it's been well stored. The biggest issue will be old capacitors, which tend to fail 'leaky' (electrical leakage that is), but that depends on age, and on the construction types of the capacitors. Wax coated (waxy) capacitors are about the worst, and the Hunts branded 'Mouldseal' that crack their outer shells. Electrolytic capacitors, the big aluminium, cylindrical ones, can also fail leaky, but can most often be reformed by careful application of the mains via a variac, or at least a 'series lamp limiter'.
As I say, it looks like a nice amplifier set up.
This looks like a kit built system. Possibly a Mullard 10 - 10. Top performer in its day.
If you are worried about smoke / fireworks, google "dim bulb tester".
It looks well made, I'm tipping it will work as is. Just a matter of hooking it up.
You might want to look under the chassis and see if there are any wax paper capacitors, they should be replaced if found. They can destroy your sound and output valves in time.
It has a pair of EL84s in each channel so it should be good for about 10 watts RMS per channel. The output transformers look pretty decent too.
Enjoy the nice warm valve sound / even harmonic distortion!
I'll have to get some to give it a once over with a voltage meter and to check the components.
It is lovely just to look any truly well kept.
It came with a Garrad turntable, spare headshell plus replacement stylus still in the platic in the box.
Worth noting the output is 'Push-Pull' and as such says "quality sound". It would have been modestly priced kit in its time (not cheap) and nicely presented on top. Take a look underneath, grab a few pictures and see how well put together it is where it matters most.
@katie-bush I'll be sure to have a proper analytical look. I'd love to hear how those valves sound when they warm up
Valves, being somewhat imperfect devices, add their own colouration to the sound. If you like it, that's good. Modern solid state amplifiers have vanishingly low levels of THD and phenomenal damping factors, so much so that they disappear from the equation when assessing a sound system.
To couple to speakers, valves need transformers. These are also imperfect devices and, due to phase reversal effects, limit the amount of negative feedback that can be used. This in turn limits the speaker damping factors and THD figures that can be achieved.
A valve amplifier driving a sealed bass enclosure is not such a good idea because it can't drive the non-linear load presented by the variable air pressure in the box so accurately. The bass will sound muddy. A bit like a modern amp on long cables. Vented enclosures are generally better.
Due to output stage bias pump-up effects, an RC coupled valve amplifier will get quite dirty when driven into overload. This is one of the reasons guitarists like them.
Remember "That's not an amplifier, it's a musical instrument!"
It does look like a kit or home built but extremely well done by someone who had good skills.
Photos of under the chassis would be nice, see what components were used.
In the 1960’s that would have been a home hi-if that would have been the envy of many, with the Garrard turntable etc a really fine system.
Frank
Looks beautifully made.
Don't attempt to power it up without speakers connected. Valve amplifiers can really object to this sort of abuse!
It’s as well built under the chassis as above, very skilled who made it. The output transformers were one of the best available. There is a date code on one of the power supply capacitors of 1967, looks like it could be Feb but cannot see it properly.
There are lots of components capacitors/ resistors that are of that era, unfortunately many of those capacitors will require changing and possibly many resistors. As noted by Marion the Hunts brown mould seals will be faulty and I think there is a Wima type as well.
The power amplifier uses the Red Hunts capacitors, I have no experience of those but they will require testing, if faulty could cause major damage and write off the unit.
Its more than 50 years old but looks like new.
Frank
It’s as well built under the chassis as above, very skilled who made it.
Agreed and note the use of the Tektronix style ceramic/silver cup tag strips. Not the usual paxolin and steel eyelets. As already said, someone spent time and thought on this.
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Local knowledge will be needed here but in Oz paper caps were gone by 1967. Philips mustards, Ducon blues and UCC whites (the DiPols anyway) were all polyester and you just never change them.
Did Hunts make epoxy dipped paper caps? If so, they'll all need to go.
I have heard that nobody likes Hunts!
There are quite a few carbon comp resistors in there. If you start hearing hisses and crackles, consider replacing them all with modern metal film parts.
I don’t think it matters who make them, paper dielectric capacitors have a much shorter life than the polyester types. The Mullard Mustard range, even the later 1970’s Wima polyester capacitors were excellent and rarely failed, but still worth testing with their being many years old.
Frank
Has anyone ever found a bad Philips mustard cap? I haven't, in more years of TV service than I care to remember...
An exception must be made for a part that's failed due to the catastrophic failure of something else. Same goes for other polyesters.
Has anyone ever found a bad Philips mustard cap? I haven't, in more years of TV service than I care to remember...
An exception must be made for a part that's failed due to the catastrophic failure of something else. Same goes for other polyesters.
No, never found a bad mustard, at least not one that has failed in use. I found one in my spares draws that contain literally hundreds of them with a lead broken off but that hardly counts....!
Whoever built that was either a professional or had extremely good constructional skills. Absolute candidate for a good and respectful restoration. The wiring to the mains transformer has been laced. I don't think there are many people who can do this now. There are quite a number of resin dipped Hunts capacitors in the pre-amplifier/control unit that will be a leaky as a sieve by now but it looks like he's used much better quality capacitors in the main amplifier although they will still need testing.
I think it would be a very good sounding amplifier when restored. Coupled up to a pair of bass reflex speakers I think it would give a very good account of itself.
What Garrard turntable did it come with?
