Bush SRG100 amplifier issues (I'm a newbie!)

[PeterThePainter]

Hello all. My first post here.

I have been lucky (you may disagree!) enough to buy a very nice condition SRG100 radiogram. I have the original sales document showing it to be bought in 1964, together with the instruction booklets etc that it came with. It's had one owner prior to me.

I bought it "working" - which it does to a degree, the radio works, the Garrard deck works, the cabinet is in pristine condition. The issue I have is volume, or lack of, which affects both deck and radio, so I assume an amplifier issue.

I have found the documentation on removing the amp from the cabinet, and presume I'll need to do that. That's fine I can do that. This is my first foray into a "restoration" project so I am looking for ideas on what I'll need to do to fix the issue. Any likely causes? I am competent in soldering and replacing components doesn't fill me with dread. I presume the capacitors will mostly be up for replacement, but is there anything else specific that I need to look for connected to the issue I'm having with volume. TYIA!

[Station X]

Hello and welcome to the forums. You'll find useful information here:-

https://www.vintage-radio.com/repair...ion/index.html

I expect the problem is the cartridge. Search the forums for "Buzz Test"

[PeterThePainter]

Thanks! Would that not be confined to deck volume? I have the same issue with radio volume. I did read the buzz test article the other night, and will do that anyway thanks.

[Nuvistor]

It’s possible you have faults in both the radio section and the cartridge so a buzz test will test the amplifier section.
If that test fails then voltage reading taken on the amplifier will hopefully point in the right direction.
Apologies if it’s not needed but high voltages are present in the radio gram so take suitable care when working on the item.

[Edward Huggins]

Welcome to the Forum! This is an interesting Radiogram in that it is a of a Hybrid design. This is because the Mono tuner section is very early transistor and the Stereo audio sections are valved. This introduces some additional complexity over, say, an all-valve or an all-transistorised unit. This is because they have two seperate internal power supply requirements. Also the valved output stages are in push-pull. Also I do hope that the centre stacking spindle is still in-situ on the Garrard autochanger. Not the easiest of "starter" projects, but there will be much help to you from the Members here. What test and measuring equipment do you have?

[John10b]

This should provide you with very decent sound quality, once you have it working correctly.
I would suggest you download the service information, see up top, only £1.99 well worth it.
John

[Herald1360]

Loads of AF11x transistors there to add to the fun

Search up top on "tin whiskers" for the gory details!

[PeterThePainter]

Well, that all sounds fun, and positive too! All parts are present and correct, it really is in fantastic condition and very much unmolested. I'll have a look at all suggestions, and thanks to all for replying. Glad to hear it should provide good sound!

My testing equipment is limited to a multi-meter I'm afraid.

[John10b]

In most cases a multimeter is all you need. Once you have obtained the circuit diagram check your power supply voltages, then check the audio amp voltages etc, remember you are dealing with mains voltages so take care.
John