• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Coupling cap replacement

Can any one tell me what quality of cap this is. Would a upgrade be audible. coupling cap i think 20211224_141113_HDR.jpg
 
It's a generic film cap. It depends on the application (circuit position) whether or not a different one will be audible. The 940 and 942 series from Cornell-Dublier have some audio cred are available from Mouser. For not silly money and if you only need 2 the standard Mundorf Supremes in this value might be OK.

Search: Humble Homemade Cap Test

S.
 
Hello! I just installed a pair of Mundorf MCap EVO Al.Oil caps as couplers in an Adcom GFA-535.
1644377414575.jpeg

I can hear a small improvement, but only when switching between the modified '535 and another one on which I haven't yet replaced the coupling caps. I don't trust my perception when I know which amp has the Mundorf caps, so I did a single-blind test with my wife. Among other qualities, she has a background in amateur choir music and a very good ear, but like most people does not care much about sound quality and is brutally honest. I faced away from her for the test.
I asked her two questions, "is there a difference between 'upper' and 'lower' amp?" and "do you like the sound of one more than the other?"
Listening to Rachmaninov Vespers, Robert Shaw Festival Singers, tracks 1 & 2 on Telarc, she heard a definite difference and preferred the Mundorf amp.
Listening to Loreena McKennitt, "The Gates of Istanbul," a noisy tune with lots of metal percussion she again heard a difference but liked the stock capacitor amp better.
I'm happy there is any difference at all. I was fully prepared to consider the extra 10 dollars the same as setting a 10-dollar bill on fire and offering it to the gods of audio. It's not all synesthesia.

Paul
 
Hello! I just installed a pair of Mundorf MCap EVO Al.Oil caps as couplers in an Adcom GFA-535.
View attachment 1023488

I'm happy there is any difference at all. I was fully prepared to consider the extra 10 dollars the same as setting a 10-dollar bill on fire and offering it to the gods of audio. It's not all synesthesia.

Paul
I like these caps too and honestly, spending $20 extra on an amp build over using generic caps is not something I will lose sleep over. I have zero interest in trying $600 coupling caps but I do like the way these alu/oil EVO caps sound over other coupling caps I have tried and knowing I like these, that's what I use in stuff that I build now. They do sound better to me after a few hours of use.