Replacing KT88s with KT90s - a good idea?

[horace]

Hi

The four KT88s in my Chinese valve amp are cheap as chips 'no brands'. ThoughtI might try some replacements. Seems the Electro Harmonix tubes are well regarded and reasonably priced.

Should I try replacing my KT88s with EH KT90s? They are apparently a drop in replacement for KT88s.I read somewhere that KT90sare more powerful - does this equate to more wpc, or is it not as straightforward as that?

Grateful for your opinions.

As a tube-rolling newcomer, how much of an improvement/change should I expect from new/different output tubes and would a greater improvement come from new signal valves?

It's all Greek to me....

Cheers

Martin

[i_should_coco]

horace wrote:

Hi

The four KT88s in my Chinese valve amp are cheap as chips 'no brands'. ThoughtI might try some replacements. Seems the Electro Harmonix tubes are well regarded and reasonably priced.

Should I try replacing my KT88s with EH KT90s? They are apparently a drop in replacement for KT88s.I read somewhere that KT90sare more powerful - does this equate to more wpc, or is it not as straightforward as that?

Grateful for your opinions.

As a tube-rolling newcomer, how much of an improvement/change should I expect from new/different output tubes and would a greater improvement come from new signal valves?

It's all Greek to me....

Cheers

Martin

If they're a drop-in replacement, give it a whirl. I expect the power difference to be marginal - certainly not enough to be significant.

As to whether it's an improvement, well, that has to be suck it and see...

[Tel]

Blimey, and I thought KT88 were 'grunty'

In my limited experience Martin, changing the signal valves will have more of an effect.

[jonjin]

I don't think it is a drop-in replacement as such... it depends on the circuitry. Do check the manual or give the manufacturers an e-mail. I remember when I had the Art Audio Concerto Mk 1 (KT88) they couldn't use KT90s but the Mk 11 could. And yup you'll get more watts... but that might not equate to better sound

JJ

Edit - you could swap it for 6550s definitely though... gives a more linear balance across the frequencies... again different opinions on the different brands of 6550 but I was going to try the Winged C Svets... they do now also have the Gold Lion KT88 reissues but these are quite £££...

[musicbox]

Only use the KT90s if you are sure the amp can take them.

BTW my Graaf can take KT90s but I found them a bit bright compared to slightly more mellow KT88s whic I prefer.