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rolling output tubes

I have a pair of Melody M880 monoblocks in my 2nd system. They use KT88s and have a bias adjustment pot for each KT88. Can I use EL34s or other output tubes instead?

Do output tubes and transformers have to be "matched"? A dealer once told me that transformers designed for KT88s will not achieve EL34's potential. But I thought he tried to sell me another amp. LOL...

This is for my 2nd system and is in a smaller room 12X11. The speakers are 90dB. I want something a bit euphonic from this system but not too much. What other output tubes should I try?

The suggested bias for KT88s is 50mA. But I found it sounded the best between 40-45mA, depending on the tubes used. So if I move to other tubes, what bias level should I start with?

Thanks a lot.
vett93
vett93 OP
205 posts
 
I have rolled the input and driver tubes already. The stock tubes are probably Shuguang KT88s. I am using cryo'ed Gold Lion KT88s and they do sound better than the stock tubes.

I found that it sounds more SS like if I increase the biases. Is this common? With higher biases, they sound more aggressive, extended, etc....

The manufacturer is not responsive. I had asked a few questions through their importer, but got no answer.
tpsonic
1,092 posts
 
Tried the other directio,lowering.Shuguang makes several kt-88s,thus my sugestion for 88-98s.
nsgarch's avatar
nsgarch
2,524 posts
 
I thought your question was about the possibility of substituting EL-34's for the KT-88's.
vett93 OP
205 posts
 
Yes, my question is about substituting EL34s for KT88s. Thanks.
cyclonicman
693 posts
 
Vett, the web-site below may be helpful. Also 6 Moons audio reviewer of Melody 880 states that the KT88 M880 is on equal turf for harmonic richness with EL34 amps.

http://sixmoons.com/audioreviews/melody4/m880.html

http://www.mclink.it/com/audiomatica/tubes/el34.htm
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