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KT88 or 6550 ?

N

Nounours1820

New Member
Hi friends,

In order to have some fun during this winter, I plan to build two monoblocks amplifiers. The monoblocks that I plan to build:

http://triodeelectronics.com/trmk3tuampki.html

accept both the KT88 tubes or the 6550 tubes.

So I have 2 simple questions:

a-/.from a qualitative viewpoint, what is the best : the KT-88 or the 6550 ? or to avoid a shortcoming, what are the sonic differences between these tubes ?

b-/ I also to plan a pair of smaller monoblocs (for a second and smaller system):
http://www.oddwattaudio.com/ow77-88.html

and I can chose between the KT88 or the KT88BG (BG stands for BlueGlass).
Do you know the differences, and "what is the best" is this question is not stupid...

Thank you very much for your help,
 
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I ran both 6550 and KT88 tubes in a Jolida SJ502A integrated. I found the 6550 better balanced overall. The KT88's seemed to emphasize the bass and upper mids in an unnatural way. Just my two cents.
 
Thanks analogguyinadig ...

The choice will be difficult, because on some other forums I have read the the 6550 is limited at the both end of the spectrum (bass and highs) , but is very musical...

Choice is not easy...
 
There are some Chinese made KT88-98 tubes that get some great reviews. Also, I previously stated that the KT88's emphasized the bass and upper mids, I meant bass and lower mids, sorry. BTW, I think the 88-98 tubes are manufactured by Shuguang (Not certain of the spelling.) Whichever way you go, it looks like a most enjoyable project.
 
If your running UL (ultralinear) KT88s are needed. 6550 need a regulated screen supply around 300 vdc. I believe Dyna Mk3s came with KT88s in the 60s...
 
Nounours1820 said:
Hi friends,

In order to have some fun during this winter, I plan to build two monoblocks amplifiers. The monoblocks that I plan to build:

http://triodeelectronics.com/trmk3tuampki.html

accept both the KT88 tubes or the 6550 tubes.

So I have 2 simple questions:

a-/.from a qualitative viewpoint, what is the best : the KT-88 or the 6550 ? or to avoid a shortcoming, what are the sonic differences between these tubes ?

b-/ I also to plan a pair of smaller monoblocs (for a second and smaller system):
http://www.oddwattaudio.com/ow77-88.html

and I can chose between the KT88 or the KT88BG (BG stands for BlueGlass).
Do you know the differences, and "what is the best" is this question is not stupid...

Thank you very much for your help,
Click to expand...
6550 and KT88 are in most respects intervhangable.
KT88 allows > 500V on the screens, thus allowing UL above 60w.

"Blue" is bluecolored glass.
 
Nounours1820 said:
Thanks analogguyinadig ...

The choice will be difficult, because on some other forums I have read the the 6550 is limited at the both end of the spectrum (bass and highs) , but is very musical...

Choice is not easy...
Click to expand...

I wonder at what frequencies? If you think about how low most speakers will go, then think about how old you are, and 40 to 15k might be the full spectrum anyway. I know when I had my hearing tested a couple years back (I'm 52) it was fine out to 16k but fell off after that. A super tweeter is wasted on me.
 
jaymanaa said:
I wonder at what frequencies? If you think about how low most speakers will go, then think about how old you are, and 40 to 15k might be the full spectrum anyway. I know when I had my hearing tested a couple years back (I'm 52) it was fine out to 16k but fell off after that. A super tweeter is wasted on me.
Click to expand...


Yoda-Jay Kenobi,

The gain must have been cranked up so much to be able to perceive a 16K audio tone,
and let's also say to be able to hear It within a mix of typical music itself is phenomenal.
I find It very hard hard for myself to hear above 13.8K (recent test). Goobers tend to figure
out freq. capabilities (performance) standards via circuit and other critical component test
measurements as opposed to performing an outright spot-on natural & comprehensive
acoustic test, using microphone / computer apps for analysis & evaluation within ones
personal listening space, and then compare it to what one could actually hear & delineate.

No need at this time to go through the non-rudimentary details at this time which
can be explained in detail online.

One would be able to render a fairly accurate profile of ones system trough this acoustical
derivation method (simply?), a bit of know-how & Knack by the use of a mic and freely
downloadable software.

So! essentially; from audio source to speaker within It's listening environment can be sized up
by an acoustic computer analysis method, which although may not be as precise as provincial
techniques, still paints an fairly honest portrayal of your gears specs within It's domain.
 
Thanks Guys, it seems almost impossible to decide before having lesoned to both the KT88 and the 6550... Fortunately they are interchangeable, so I will have to try one and the other...
 
I have a pair of Mk3s running vintage GE 6550s. I really like em. I suggest trying KT88s. That way I'll know if I should too. :thmbsp:
 
A good example of one will always be better than a bad example of another, depends on maker and such.
 
In those amps the KT-88 or bigger is the best choice for new production as the high B+ of the Dynaco Mark III's is a too much for 6550. If you can afford it I would if I were you go straight for the new KT-150 tube which looks like a good improvement over the KT-120. I say this as new production are not nearly as rugged as NOS (New Old Stock) which have gotten rare and thus go for big $

The sonics should be really nice and that tube should last a long time in that environment compared to the smaller tubes. You might have to add an additional transformer for the KT-150 bigger filaments. Triode should be able to advise you, as the stock transformers may be fine with the 20% bigger requirement.
 
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