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To identify a passive component

H

hugh811

Active Member
Hi everyone,

I am working on an diy tube amplifier of a friend of mine. Just for hobby. It is a SE amp with 45s as power tubes. There is no schematics available from the previous owner, according to my friend.

There is a passive component, it looks like a capacitor. On my capacitance meter, it reads 178uf.

image.jpg image.jpg

Nothing else. By Internet, it seems that S+M means Siemens? I am not sure about it. Then the number 10.95, what does it mean?

I need your advice to shed light on these stuffs.

The amplifier also has two big multi-section can capacitors, then once again, no indication. Its “father“ maybe wants not to leave any traces behind.

Thank you for your comments.
Best regards,
Hugh
 
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Usually I just replace simple components, with the same parts or something similar of the same value. First thing is to look at the schematic, it is important to understand and avoid mistake. Now there is no schematic, no value printings on the component.

In this case, there is an unknown factor: what is the original value of the capacitor ? Maybe after 20 years since the amplifier was made, the capacitor value has shifted a lot. That is why I want to seek your comments to see if there is any clue to get the answer.

180uf capacitor and not the first filter capacitors, nor in a voltage divider or multiplier circuit ? I have never seen this kind of value in a vintage tube amp, and it is not the value that we have often seen. Now, i have to look at it again to see what it is for.

Fortunately that it is not in a hurry since my friend has a number of different amplifiers at his disposal. I will take my time.

Thank you once again for your comment.
 
Do you have any idea where it is used in the circuit? Might need to sketch out a portion of the schematic. 180 uF is a standard value.
 
The builder has put everything in a very small chassis. Of the size of a small size men shoes box.

Including: 1 rectifier tube, two 6SL7s, two 45s, Two power transformers (a separate filament transformer for 45s), two OPTs, two big multi-section can capacitors, bias adjustment, hum pots, two single volume control pots...

To have access to the components under the chassis, removing the back cover is helpless, i need to disconnect first the OPT connection to the speaker terminal trips. It is the only way to see what are inside the amp.

So I just put this project on shelve for a while :), until i feel that I have enough patience again and more skills to do it.
 
Fair guess its a cap, just because tube amps rarely have anything else that looks like that. SET amps don't tend to have very many parts either so figuring out what it does shouldn't be too hard. The real question is what voltage it needs to be. If its on the HV side its probably 300v+. If its a cathode cap, then its probably not more than 100v. Based on the value I'll guess its a cathode cap but thats purely a guess.
 
Post some pics of the amp, top and bottom. I know nothing about tube amps, but these guys helped me find out what one of my tubers came from. There are some good savvy techs here.

GeeDeeEmm
 
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