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Tube rolling with Quicksilver Mono 60s -- from KT77 to KT88? KT 120? etc.

Happy Turkey Day!  I have Quicksilver 60 Monos and I'm using Gold Lion KT77s. They sound great. The amp came with JJ KT88s and they were a bit bright/harsh. The GL 77s are better.

For variety's sake, I'm thinking of having another set to just try for variation. The monos can use KT77, KT90, KT88, KT120 or KT150 outputs.

I have heard the Gold Lion KT88s are great tubes, but I'd also be open to others (not more 77s, though).

Does anyone one have a sense of the kinds of sound changes might be brought by either KT90 or better KT88 or KT120 or KT150s?

If it matters, I'm using a QS Line stage and stand mount speakers, 8 ohm 87 db.

One thing I'm looking for (possibly) is a somewhat tighter bass, but I'd be open to hearing what other sonic changes might result from other tubes.

Thanks.

128x128hilde45
donvito
400 posts
 
No they are not! An equivalent tube to the 7581 is a KT66 or a 6LG type of tube!
pindac's avatar
pindac
2,864 posts
 
To adlib on the advice given,
The Person offering advice, is a very experienced owner of Tubes with access to Tubes from a Two Generation Collection.
This person has always been supportive to make Matched Tubes available for loan, and offered much valuable guidance.
The Person has been instrumental in helping others create a understanding of how Tube Rolling can influence their systems.

The advice made available to myself relating to my Monoblocks was to undertake the investigation to learn what was the best Input Valve configuration to get the best from the resident Output Valves.
This is what I did and it has proved so far to be a very economical approach, if the Pre Amp Purchase and Build is deducted from the £700

I felt more compelled to further investigate the Pre side of the System as a result of the impressive improvement to the Sound Quality being experienced 
hilde45's avatar
hilde45 OP
4,974 posts
 
I see. I listed the tubes my amp can handle, that's why I'm asking. 
oldhvymec
5,101 posts
 
6L6 are all over the place for sale. Brand new and matched, about 115 for a matched set of 8. DON'T buy them.

IF they are Solvex, (the older solvex) it is night and day in sonics, and how long they will last, they are outstanding.

The old GE and RCA, metal cover 7581 valve.. serious valve there, super high plate voltage. REAL high, and will stand up..

The 115 sets of 8..LOL Just a bad place to even start.. :-(

WHY? Out of over 150 valves I bought in 3 lots, none of them were at 50% of the TRUE industrial 7581. Closer to 15-30% NEW.. OK, NEW..

Just under a year ago I listened to an MC240 every day for just under 3 years. I used industrial, RCA 6L6 mil/spec metal tube.. They still have 50% wear left on them.. I took the amp down for it's first EVER major service.

This is so fun, chompin' on my turkey sandwich. :-)

Regards

noromance's avatar
noromance
9,769 posts
 
Donvito is correct. I got carried away on tubes and forgot the QSilvers. While you can generally go up from 6L6 to KT88 in an amp designed for the smaller tube, you can't always go down from a big tube to a smaller tube in an amp designed to work with a bigger tube. This is because the plate voltage among other specs won't tolerate lower powered tubes. The TS 7851A maxes at 500v anode while a KT77 can stand 800v. I suspect the QS may have 600v on hand and that rules out the smaller 6L6 class tubes.
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