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McIntosh C11 preamp with Cornwallswith wooden mid and upgraded crossover


audioaddict

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I live near Peter Bliss and had him do a pair of Cornwalls in a similar way to the ones he has written about here. I already have KHorns(stock from 1984) in another room. I initially thought the redone Cornwalls were nice but a bit forward in the mids and top for my taste. I have been using a pair of Mac Mc75 amps from the 60's for the main power. I bought a nice but not perfect C11 that was on this forum to complete the combo. It came with reissue Tung Sol 12ax7s. I initially thought there might be something wrong with the preamp; there was very little bass and almost no midbass. I am in the audio business so great gear presents itself all the time and much to my wife's dissappointment I am loath to let a bargain pass. So about a week ago a guy who used to work with me and now works for Transparent Audio brought in an old HK A500 integrated and matching tuner which I bought for $275.

It had all original tubes including 4 Telefunkens in the preamp section.

I plugged it in place of the Mac gear and was blown away. It killed the Mac stuff by a wide margin. Being a Mac guy from way back I knew something was amiss. So I hunted through a bunch of old gear in my garage and came up with 2 more old Telefunken tubes so I could replace the full set of the new TungSols to see what happened. Now all the Telefunken tubes tested between 25 and 30 on my B&K tester where 22 is the minimum for still being good, so their best days are behind them. The Tung Sols all tested over 100 so they were new. I had also tried some NOS GE tubes; better but still not great, which is why I thought there was something wrong with the preamp. I was truly not prepared for whatI heard. All of a sudden the old C11 sounded like a world class preamp. The balance was amazing. There was now a full lush sound that I had been totally missing. The detail was equal to the new Tung Sols but the edge was gone the sound was smooth and natural. The sense of depth was at least twice what I was hearing before.

Now the Mac system was light years ahead of the HK ,as it should have been, and all was right in the universe. I loaned 4 of the tubes to a friend to try in his newer Mac preamp. He had the exact same experience with his speakers which are not Klipsch but cost over $20,000 a pair. I just bought a bunch of used Telefunkens on ebay and I am going to throw some into my demo Mac C500 preamp at work as soon as they arrive. I guess the point of this is that these tubes sounded better after most af their life had been used up and the noise floor was close enough to the other new tubes that if you can find some cheap give them a try. They may just transform your system without breaking the bank. I didn't write this till I had bought enough used ones to last a good while.

I tried the C11 on my Khorns and my Thiel speakers with similar results. The Thiels were horrible with the new tubes and displayed everything Thiel haters complain about and when the Telefunkens went in the Thiels became the speakers that Thiel lovers covet, detailed, spacious, textured with a tonal correctness and orchestral layering that few speakers can display at any price. The tubes may be the cheapest upgrade you will ever make that can transform any system. My friend asked me why no one has ever been able to duplicate this sound and I remembered that about 15 years ago the old National tubes were very close but did not have life expectancy of the Telefunkens mine were done in about 3 years. The Telefunkens I am using are all at least 45 years old and still sound fantastic and are still quiet enough to use in the phono stage with a moving magnet with a 2.5 millivolt output. I don't write much in forums even though I belong to several because as a jaded old audiofool and being in the business I never want to be promoting anything I sell but his experience was so profound I needed to share it and this is not something I can sell. This is what makes audio fun, a true find that doesn't need a mortgage and seems to be universally matched. If you have a 12ax7 preamp just go find some Telefunkens. I hope you have the same experience.

Also never post after taking pain medicine. You are right this is long.

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Dennie,

Are you by chance a member of BARF (Bay Area Riders Forum) ?

Thanx, Russ

No, actually I am not. But a good friend of mine is. I've been to the forum a couple of times, but it has been a while.

Why, are they using my "Bunny with a Pancake on its head"???? [:o] [;)]

Dennie

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