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My first Tube Amplifier

I have a 40 years of audio history starting with Garrard Turntable, Fisher Intergrated(SS), ADS bookself speaker on 1978.

But I started using tube amplifier on 1999.

Since then I had been using only tube amplifier in my main system.

My last SS main amplifier was Krell KSA 150 to drive Apogee Duetta Signature speakers.


http://www.jadis-electronics.com/photos/ja500/45/3/ja500.jpg

My first tube amplifier was Jadis 500 which comprised of 4 pieces weighing 120 lb each.

B&W 801 driven by Jadis 500 gave most deep and powerful bass at my home.

But it generated too much heat so it was hard to use during summer.

It was memorable experience to use it for 4 years.

I may not go back to such monster tube amplifier again.



How about you?

What is your first tube amplifier?



I bet two cents on no one had used larger one as the first tube amplifier than mine.


shkong78

Showing 7 responses by bdp24

bdp24's avatar
bdp24
10,096 posts
 
@unreceivedogma, if the Altecs are, as I suspect, a nominally 16 ohm load, that would be a good reason.
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bdp24
10,096 posts
 

@roberjerman, Music Reference's Roger Modjeski has thoroughly investigated the Futterman, and thinks highly of it. He has confirmed the amp's low output impedance, and other superior operating characteristics. The only negative I have heard about the design is in regard to reliability, due to what I don't know.

Harvey Rosensberg (and his engineer George Kaye) made some changes to the amp when he started building them under his New York Audio Labs company name, having bought the rights to the design from Mr. Futterman shortly before the latter's passing. They too are known to be failure prone. Ralph Karsten's Atma-Sphere OTL's, on the other hand, are known to be very reliable, though they suffer from somewhat high output impedance (relative to the Futterman).

@shkong78, yes, OTL's are known for their transparency, but many planar loudspeakers have a nominal impedance lower than OTL's like to see. Magneplanars, for instance, have an impedance of 4 ohms and lower, a tough load for an OTL. Atma-Sphere's Ralph Karsten recommends using an Anti-Cable Autoformer with his amps when partnered with low-impedance speakers such as Maggies. Most contemporary ESL's also are low-impedance designs, at least at certain frequencies.

bdp24's avatar
bdp24
10,096 posts
 
@unreceivedogma---OTL’s (primarily and most-famously the Futtermans) came to be considered a good choice for use with the original Quad, primarily because an OTL likes to operate into a high impedance load, and the Quad was/is nominally 16 ohms. The problem was, and remains, that most ESL’s have a wildly-varying impedance curve (the Quad from under a single ohm to maybe 50), and a curve like that creates large variations in loudspeaker frequency response unless the amp has a low output impedance. The Futterman was good in that regard; not all OTL’s are.
bdp24's avatar
bdp24
10,096 posts
 
I neglected to mention.....Brooks’ tech Tom Carione was in the shop on Wednesdays and Saturdays (and remains so, the shop now run by Brooks’ widow Sheila), and Saturday was my regular visiting day. I can’t tell you how many times I would enter the shop and see Tom at his work bench, a Jadis amp sitting upside down on it, taken apart for repair. Not once did I see a Music Reference amp like that! I also never saw a MR amp on the used product shelves, but lots (and lots) of ARC’s. Tom showed me the scorches around the output tube sockets on the circuit board in all of them. Make of that what you will.
bdp24's avatar
bdp24
10,096 posts
 
@ramtubes, Yep Roger, it was those expensive Jadis that my $20,000 price point was referring to. Brooks had them and the almost equally expensive VTL’s in his main room, driving (usually) Wilson speakers. The Jadis are beautiful to look at, have great fit & finish, and those massive transformers! But what is their price buying you, in terms of sound? Why is it a seriously flawed design (your example above) can find favor with some audiophiles? Are they listening with their eyes ;-) ? Or are such matters not what actually determines the sound (or lack thereof) of an amp? If an amp can have such an obvious shortcoming in it’s design, what does that say about the talent of it’s designer? And what other design flaws lie hidden within it’s beautiful exterior? John Atkinson’s reports often reveal them, but audiophiles don’t "believe" in bench test results, thanks to the writings of Harry Pearson and other purely-subjective reviewers. Harry also introduced the disgusting-to-me term of "High End" into perfectionist audio (J. Gordon Holt’s preferred term), leading to the belief that price equals performance. ’Taint necessarily so.
bdp24's avatar
bdp24
10,096 posts
 

Brooks Berdan very much liked the Music Reference amps (and he was extremely hard to please), recommending and selling them to his customers. But some of his customers wanted to spend more money (bragging rights? bling?), and Brooks didn't mind taking his 40 points out of a $10,000-$20,000 sale instead of a $2,000-$4,000 one.

If more consumers carefully read John Atkinson's test bench reports they would have a much better idea what's going on under the hood of the amps that get reviewed. Amplifier sound quality is determined by many things, but just as a Pop song's ultimate quality is limited by it's chord structure and melody, an amp can not outperform the limitations imposed upon it by it's basic design. Changing the fuse in an amplifier, even if you perceive it to make a difference, is not going to improve the amp's linearity, increase it's power output, or decrease it's instability when driven into clipping. And spending more money on an amp does not necessarily buy one any of those. But you knew that ;-) .

bdp24's avatar
bdp24
10,096 posts
 

I like Wolf's post so much I'll follow his lead. A blackface 1967 Fender Showman amp (four 6L6 power tubes) with a 15" JBL D140 driver for my '68 Fender Precision bass, and a blackface '66 Deluxe Reverb for guitar.

For hi-fi, a Fisher X-100A, bought used in 1968 to drive a pair of AR 4X loudspeakers (wish I'd known about the Dynaco A-25!). Next was the combination of D-51 and D-75 amps from Audio Research, new in '72, used to bi-amp Magneplanar Tympani T-I's.

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