Hacker Gondalier GP42 - servicing amp

[Martin63]

Hi - new member, first post.
I have purchased a Hacker GP42 to restore, this being only the second record player I have restored. Would consider myself competent with a soldering iron and meter, but a novice at valve technology (and most other electronic circuitry).
Have serviced the deck and have run the amp using a digital radio as input - it sounds really good with no distortion.
Where I need some help is in establishing whether I should be replacing any components whilst I have the unit apart. I have used https://www.vintage-radio.net/forum/...d.php?t=111739 as a tutorial and have checked all the resistors and the three key voltages.
1) 7 of the resistors are more than 20% out of tolerance (R1, R4, R7, R8, R9, R11, R12). Should I replace these, and what difference should I expect in performance if I do so (or will the amp likely fail in the near future if I don't?)
2) measured voltage across C8 at 235.5v, C11 £279.1v and C12 £263.8v on DMM. Presumably these are all close enough to spec?
3) DO I need to replace any of the capacitors or can I safely leave alone?

Many thanks

[Edward Huggins]

If it "sounds really good with no distortion" then why faff about with it? You may have read much about the "need" to change capacitors. Yes, there are key mains and coupling caps that may need attention in due course, but for now leave well alone!

[John10b]

The tutorial you refer to is very informative, and as stated the capacitors are considered very reliable. You say there is no distortion and it sounds ok, also your voltage readings, using your DMM are close enough, the original voltage reading were taken using AVO meter. So I would agree with Edward.
John

[Nickthedentist]

Could we have a clearer picture, please, Martin?

The coupling capacitors we're especially interested in are just blurry red blobs in your original image

If it were mine, I would replace these two capacitors as a matter of course, and then leave well alone as Edward suggests.

[PJL]

How far you want to go with restoration depends on how often you plan to use it. If you will be using it regularly I would replace the out of tolerance resistors and capacitors.

[Michael Maurice]

All the GP42's I've seen have had Mullard mustard coupling capacitors which should be fine. I replace the two 220K resistors on the top tag strip together with the 220R, 2.2K on the bottom tag strip and the 4 47uF electrolytic capacitors.

[Martin63]

Nick - do these pics of the caps help?

[Nickthedentist]

That's much better!

Michael, what do you think? Are those the Mullards you were referring to? They certainly look like their C296 "mustards", albeit bright red.

[Herald1360]

The one with visible text has LEMCO on it so not Mullard Mustards.

If they're plastic film types they should be OK.

Not sure those resistors look original? Has anyone been at it already?

[Station X]

Originally Posted by Herald1360

Not sure those resistors look original? Has anyone been at it already?

That's what I thought, five band resistors. The soldering on the Lemco capacitors looks original though.

[Martin63]

I replaced the resistors last week! Am inclined to leave the rest alone as it’s working well.
Thanks all for your help.