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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
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
rodman99999
6,171 posts
 
Vett93: YES- Sometimes a manual will include a range, rather than one specific setting for your bias adjustment(ie: Cary SLM-100= 150 to 175 mA). The upper limits of that range will yield a more dynamic presentation, and sometimes sibilance or glare can result also(more Solid State-ish). Of course- the other direction takes one into the "more relaxed presentation" zone. Hopefully: Somewhere in the middle- one will find transparency, with the right tubes/equipment.
mrtennis
3,295 posts
 
the problem isn't the tubes it's the amplifier. melody products are very unromantic. they are typical of the modern tube design, not the classic or vintage tube design. i doubt you will be able to extract much warmth from that amp.
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