mc275 is auto bias, correct? if so, then you don’t NEED matched tubes, though it may still be better to have them
another piece of advice... don’t chase old stock power tubes in the 6550 kt88 type, new tubes are excellent old tubes won’t outperform them, old stocks are giant waste of money from a sound quality perspective |
another piece of advice... don’t chase old stock power tubes
I tend to agree, unless they are 1950s NOS GEC KT66's. |
Thanks for the reply. Yes, it is auto bias.
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Is that an early MC275, or the later model? I notice a much greater difference in valves in the early model.
The preference to KT88 is because GREAT 6550s can break the bank.. 500-1000. a pair More than NOS KT88 GL
6550 GE TungSol, Old stock. That is a different sound than a KT88s
I like both, I have both Solvex and Golden Lyon (not my favorite). Good valves.
I have a few sets of 6550 GEs. I also found a Tube Tec valve that was pretty darn good.
I like the KT88, bottom to top, if the valve is going to be doing bass duty, too.
If it’s in a mid/highs, I use a 6550 GE. It’s just tough to beat that sound. It’s a little slim in the BASS department, but VERY smooth mids, and wonderful highs.
If you’re a vintage Klipsch, horn kind of guy.. They just do a great job with Macs, MC60s, and older 275s, sporting that valve, and Tellies/RCA for the signal valves.
Just so you know PSVANE makes a heck of a valve, over the last few years..Power and signal.. ShuGuang 6550s, are great valves also and without breaking the bank..
Very important to get matched valves with the old Macs, Yes it matters. Mac is different, not like anyone else... A Mac will show you every flaw in your system. Mismatch valves cause an early breakup, on the top especially. MATCH the valves...
Enjoy the sound..
Regards
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Any idea how good or bad is the stock tube compared to the, say, Genalex Fold Lion reissue? |
It is a MC275 MK IV.
@oldhvymec when you say matched, do you mean two matched pairs or a matched quad? I read somewhere that since it is a push pull and auto bias, two matched pairs, one for each channel may be fine.
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I have a mkIV as well and found greater upgrade to sound by rolling in NOS for the small signal tubes.
I did also replace power tubes with GL kt88s which made what I felt was a smaller improvement compared to the small signal tubes. |
A pair of pairs? LOL sounds funny. ME I'm picky.. I'd have to look at the way they auto bias. It's been a while. If I remember, there was a reason I used quads in a 275, I think it was early break up. It's been 30 years ago.
I would still pick up quads for that 275. Match the signal valves too, pairs per rail. It uses like 12az7 right? match them in pairs and look at their position. preamp, signal, la-te-da. Put them in, that way.. L vs R (one pair)
I remember. To match the valves in my 60s if I wanted to use them and not have an issue, between the two. AND they will. I match left to right. I had a few problems with that. VERY sensitive, Klipsch La Scala, or Jensens speakers per say, show EVERY flaw, from higher floor noise, L/R, distortion, all kinds of crap, behind mismatched valves. Gotta be picky with the old stuff and the new for the BEST SQ.
Regards |
Genalex Gold Lion reissue
Yes the GL are very popular,, i tried them, returned them, Prefered the Svet's I just posted a series of answers on this very topic last night. 6550=kt88 My prefered is the Svet 6550. NOS- New Production, exact same tube. KT88=6550 NOS 6550=New 6550 https://forum.audiogon.com/discussions/6550-vs-kt88-vs-kt90 |
I just posted a series of answers on this very topic last night.
6550=kt88
<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>.
One was designed in the US one was designed in the EU.
They physically look different, as does the KT 90 you reference also.
They are not the same, nor do they sound the same. ALL 3 differ in design, and vary from manufacture to boot.
6550 does not = KT88 and certainly not a KT90 valve, different all together again.
I read your findings, I had to wash my face with cool water and take a TUMS! Pure bla bla bla...
Please! You started a tube flipping business right... and paid 1500.00 for a pair of valves.
TUBE FLIPPING. I admire you're stones... Mercy
VA, It's stands for Valves Anonymous. Might help. GA, Gamblers Any, AA, NA...
Regards |
SED
all Svet issues, SED, Winged C, NOS, New Prod, are all =. Just go with new production.
Especially if you need close matching. |
KT90 is quite dif,, has some points over the 6550/88, but for open-ness soundstage, go 6550/88. Here you go makea compare, 'all 88/6550 ever made, the specs are so close = makes no difference, like twin brothers. Not 1 audiophile in the world could detect a blind test A/B twix 6550 vs KT88. Impossible, as they voice near identical. Sure there may bea mini-scule dif twix every lab's 6550/KY88, even there it will be tiny. So to sum up 6550 vs KT88, mini-scule dif Brand X vs Brand Y KT88 miniscule dif. Thats said, I am in agreement with another audiophiles opinions of the GL's, He did not like their voice, and neither did I./ These Svet voice beautiful and are made like tanks = Gold Winner in my book
https://frank.pocnet.net/sheets/049/6/6550.pdf
https://frank.pocnet.net/sheets/164/k/KT88spec.pdf
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painful ignorance on display in this thread, coupled with bravado and confidence
oldhyvme - don't waste your breath
ugh |
The McIntosh branded tubes in the MC275 IV, are JJ tubes with McIntosh name on them. They are nothing special. Most of the Mac owners get the Gold Lion KT88 as replacements. There seems to be a consensus that the GL tubes are the best sounding in the Mac. |
oldhyvmec - don’t waste your breath!
<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>
Well OP is getting 2 cents worth. I was glad to help, If I did, or not, I’m not sure. Golden Lyons? WOW. I picked up two matched sets of KT77 (sixtets), I had a set of NOS Volvo, Red Rubies, and EH fat bottle and Slim Jims EVERYONE outperformed the Golden Lyons. I had failure to top it off, with the GL.
Golden Lyon are within 10%, the Red Rubies and both EH types were within 5%.. The GLs were 30-100% more expensive... ????
Solvex are great for the ol 275s, Better than JJs sonicly.
You know I noticed the post number 1000.
Quit the little chatterbox aren't I...
Now I need a raise, this job has some serious wage issues. :-)
Regards |
