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Old 5th November 2002, 03:41 AM   #11
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Default tantalum caps

Hmmmmmmmm....tantalum caps, yummy.
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Old 5th November 2002, 03:45 AM   #12
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Default sounds like tubes

Hmmmmmmmmm.......
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Old 5th November 2002, 03:47 AM   #13
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Default Yummy

Thanks for clarifying that...
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Old 5th November 2002, 04:00 AM   #14
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Default Thanks for clarifying that...

I did no such thing..... some people like tantalums for audio and some do not. I am not going to decide for anyone. I have heard passionate proponents and equally biased opponents. The same goes with silver Mica caps.

I feel strongly both ways,
Fred

P.S. Sorry.... its those damned elections. Like the Devo song says:
Freedom from Choice.
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Old 5th November 2002, 04:26 AM   #15
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Default Re: sounds like tubes

Quote:
Originally posted by Fred Dieckmann
Hmmmmmmmmm.......
yah. incidentally, that tube preamp shown, the RS-1, is an excellent preamp apparently, one of the better ones my editor has heard - and he's heard a LOT.

i'll open up the one i have soon to see what it's like inside. i see one mention of tantalum caps on that web page, but with the headphone amp, not this preamp. i can't see where he's using them though.
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Old 5th November 2002, 05:20 AM   #16
dorkus is offline dorkus  United States
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Default hmm...

i just did a quick comparison test between this new preamp and my current homebrew one, a simple 2 JFET Boberly buffer (a la Harry Haller) with shunt attenuator - not the nicest implementation (lots of cheapo parts, was a weekend project) but still a faily good-sounding unit. the weirdest thing... i was comparing the 2nd mov't of Rimsky-Korsakov Scherezade (CSO/Reiner Living Stereo CD), and when i switched from the Ray Samuels to my own homebrew, it sounded like the oboe solo was being played faster. huh??? i kid you not, my girlfriend who was casually listening (she's an oboist, played the solo herself in university orchestra) swore i sped up the CD or something. going back to the Ray Samuels, it seemed to get the free pacing of the solo better, with more dynamic nuance and phrasing inflections... kinda like good tube gear eh? on the other hand the tonal balance is not as tubey as i initially suspected - it's actually pretty neutral and close to my JFET buffer, but a little more bloom in the lower midrange and bass and *maybe* slightly more pronounced upper midrange... again, sort of like tubes. interesting...
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Old 5th November 2002, 07:39 AM   #17
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sorry to make such a fuss over an otherwise mundane piece, but i had heard the AD797 tends to sound cold and "bipolary" - am i wrong? i'm curious how the designer was able to voice the circuit like this, as it doesn't sound like any opamp circuit i've heard before

After reading this entire thread, I have to ask -- what exactly is "cold and bipolary"? If the goal of an ideal amplifier is to produce a sonically accurate copy of the source material, then it's hard to beat something like an AD797.

not totally accurate probably, but interesting and highly reminiscent of tubes

If you believe the spec sheets, the THD vs. frequency is at .0001% upto about 50KHz, where it climbs to a whopping .00013% -- even at 100KHz (which is getting close to the bandwidth of a lot of practical audio amps), it's only .0003%

I would hope that this sounds nothing like a tube amplifier, as it'd be missing all of the distortion (relatively speaking) that tubes typically introduce.

Assuming that the designer took some reasonable measure of care in the design and layout (and discounting all other components in the system), the audio should sound about as close to the original recording as you're reasonably going to get right now.

FWIW, Madrigal uses the AD797 in the Mark Levinson 38 series preamps (and possibly others).
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Old 5th November 2002, 09:02 AM   #18
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Default the audio should sound about as close to the original recording as you're reasonably

Boy that's a relief.............

First the power supply design by numbers and now this......

Thiis my lucky day. Now I can take up bird watching since all the frontiers in audio design have been conquered.

Free at last,
Fred
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Old 5th November 2002, 09:36 AM   #19
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"For low-production stuff, normal retail should be about 5x bill-of-materials to stay in business."

Try 10x if you want to be sucessful.

If you are buying parts and building stuff in quantities that small that you are only charging 5X, you won't be able to compete for very long.

Some of us have already tried that.

Jocko
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Old 5th November 2002, 12:13 PM   #20
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Are you sure about use of the AD797 in ML hardware? I thought they were using Burr Brown/TI devices. Just curious ....
mlloyd1
Quote:
Originally posted by schmad
FWIW, Madrigal uses the AD797 in the Mark Levinson 38 series preamps (and possibly others).
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