carlsbro stingray / super schematic

Cant find the schematic so decided to carry on don't want to change anything that doesn't need changing or cost will be more than the amps are worth
I have tested the main caps in power supply and although still in spec one is leaking so both will be changed
looking at the output boards i have tested the caps and they seem ok see test results in pics
the small caps on left side of board are input caps and tested ok the one on the right tested ok
which ones would you change ?
20200113_123612 by glenn jarrett, on Flickr
20200120_103740 by glenn jarrett, on Flickr
 
If a 47uF cap tests as 82uF suggests its leaky. Increase in capacitance is a sign an electrolytic is degrading and leaking, as the oxide layer is dissolving and thinning. Testing in-circuit isn't ideal, and you can't measure leakage directly. Leaking caps can lead to other components failing so its wise to unsolder one end of each cap and test for leakage, or just replace.



How old is this? More that 20 years, replacing electrolytics is likely to be needed anyway.


Any datecodes?
 
Most of this vintage used a common amplifier, similar to the H&H range but without the 741 op amp.
 

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DannySteel

Member
2020-11-22 11:50 am
Hi all,newbie here.

Ive just bought a 1978 Carlsbro Stingray combo similiar to the one detailed in this thread and have deduced the heat sink may have been removed.The back panel looks identical to the last pic in Page 1 of this thread...multiple holes on the backboard where,I assume,the original would have been.
My queston is this: is it safe for me to use this amp at low volume e.g. not above 9 o’clock on the Master Volume or should i get a heat sink added? If so do I just mount a new heat sink onto the back panel using TO3’s and a fin shaped heat sink or is it more complicated than that? I have no experience in this area so apologies if my questions are amateur.

Many thanks in advance for any help and advice offered.