Getchell Amplifier in Indy (no affiliation) has two 2300s (with manuals and docs) and a pair of 250Tis for sale, if you get over there I'll bet Bobby will fire it up for you. When I stopped in last week he was running a C27 as the preamp.
MC275 MK-VI vs vintage MC275 ?
- Thread starter ofery
- Start date
How do you come to that conclusion?
I'v been running the factory tubes for 4 years without a problem, nor have felt any need to change them.
We keep bringing up things that your mismatching, power amp, preamp, speakers. You say your not going to change your preamp to match the power amp, and I assume you'll be keeping the speakers. So I'm beginning to wonder why you started the thread, because we're not matching your thinking, and your thinking brought you here.
I see a miss match with the preamp and power amp
I feel your not doing justest to the speakers with a low watt power amp.
If you don't want to get rid of the preamp and speakers, your best option is a different power amp.
If the problem is due to faulty tubes, I would first be looking at the small signal tubes rather than the outputs.
In any case, the amplifier should be checked out before making any assumptions.
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My thought on this:
I have fallen into the "tube rolling" on a couple of my amps, and although I wasn't a believer, I am now. Some of the old / NOS tubes really are built better and amplify the sounds more accurately IME. Even comparing new tubes to old tubes on my tester shows a significant difference.
On my vintage amp, definately a difference where it seems that the modern tubes I've tried mask some of the detail, of course I haven't tried all new and old tubes, just the typical favorites. Still collecting NOS tubes (obsessively).
On my more modern tube amp, it doesn't seem to matter as much. My theory on this is that the modern amps are designed and tested with modern tubes, and produce their music with the modern tube design and quality. I would expect that this is the case with new McIntosh as well as many other new tube amplifiers, just a walk around AXPONA tells me that there is no shortage of good new tube amps with good new tubes. It's possible that vintage amps are more sensitive to the quality of tubes or to the quality available at the time.
If the OP wants to try new Gold Lion tubes to see if he's happy, or go find tubes decades older than the amplifier I'm interested in the results. Like others I don't think that the MC275 really has enough headroom to run the 250Tis well, but maybe the OP likes lower SPL listening, maybe a smallish room, maybe not a dynamic music listener, and maybe JBLnut is a very good voice on how well this will work as he has BTDT and felt that it works.
Seems like trying a different preamp is a good idea, even if it's modern SS stuff, borrow one or see if a local audio retailer will let you trial something, ... even if you want to keep your current preamp it would be nice to see if that is the weak link. Interconnect cables also, if they're suspect then maybe try something different to see how it works.
Bill Ferris
Lunatic Member
10 years on my four Mac 275 VI`s 4-2-7, and they sound excellent(confirmed last night, via the Super Tramp live in Paris 1979 concert`s excellently recorded DVD), so much so, that I`ve never felt any reason/motivation to even consider changing the original factory tubes over those years.
Of course, mine are driven with a very high quality 24/96 digital crossover(loud speaker management) device via balanced connections, so impedance compatibility, and their sonic effect`s type issues, appear to not be a problem, at least in my case.
While we all know that the pure vintage vacuum and "magic smoke" interact within these units to create the special sound, it should also manifest itself in frequency output aberrations.
It would be interesting to compare the frequency distribution of these two amps interacting with the interconnects and C11 preamp. If the differences are as great as ofrey is saying it should be approaching 3 dB somewhere in the two units response.
It would be interesting to compare the frequency distribution of these two amps interacting with the interconnects and C11 preamp. If the differences are as great as ofrey is saying it should be approaching 3 dB somewhere in the two units response.
chuckworkb
Super Member
I had a V, and went V1, and the difference in bass response for me was completely reverse of your experience. I have Telefunken 12AX7 and Amperex !2AT7 tubes, along with a set of Penta Labs KT88's in there and it sounds night and day better than the V. Everyone hears things differently.
onemug
Super Member
Same result as you. The bass was much better than expected when I got the VI.
UncleBingo
Super Member
I may be reading this differentIy than some other posters here,but here's my take on it: Mismatch to speakers or no, the probIem stated was a difference in "QuaIity" (hazy sound) vs an even Iess powerfuI amp (MC240) that did NOT sound hazy (seems Iike that sort of removes/negates the power paradigm, for the time-being)
Re-tubing seems Iike a very inexpensive way to determine if the nature of the ampIifier improves to the owners Iiking (compared to going back down the ampIifier or speaker rabbit-hoIe)
I can say that I was Iess than impressed by the 275 I heard with stock tubes that had reportedIy very few hours on it-but there are admittedIy a number of variabIes in pIay in the Iistening situation in that case
I won't mention the particuIar brand of tubes as I don't want to paint them with a broad brush, but I've had reaIIy good experience with some of that brand's offerings and some wtf moments with some of their other offereings