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Can OTL's drive ribbons well?

Seeking comment on ability of OTL's to drive mids/highs ribbons, specifically on Genesis II.5/300/350.Prefer to consider without zero autoformers as they have a reputation of bleaching sound(?).Can they do it without losing their special sonic ability of speed and organic liquidity? I guess I am really asking this question of the more affordable OTL's, ie.Transcendant, Atmasphere MA1 etc. If OTL's cant do it, which tubes can provide fast organic liquidity with dynamics at around $4000 and hopefully much less(new or used)-- again specifically driving ribbon mids and highs?

Finally does anyone use Cello duet 350 to drive ribbons?If so how do vocals sound?
Thanks and appreciate your comments
aer

Showing 3 responses by rushton

rushton's avatar
rushton
2,445 posts
 
OTL compatibility will depend on the minimum impedance and how steep the curve is. For the Atma-Sphere MA-1s, call Ralph Karsten at Atma-Sphere for advice. He can probably tell you if he's got any customers running this combination and how well it works.
http://www.atma-sphere.com/contact/index.html
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rushton's avatar
rushton
2,445 posts
 
Gregadd, I'll beg to differ with you on one point you make: "Tubes are too slow to get the speed out of ribbons." One of the reasons OTL tube amplifiers are so good with electrostatics is precisely their speed. OTL tube amplifiers have incredible speed throughout their frequency range, coupled with high resolution and transparency; the impedance of the speaker is the only issue in how good a match there will be (and with an OTL like the Atma-Sphere MA-2 impedance is not much of an issue unless it's dropping sharply below 3.5 ohms or so). Whether a ribbon will be a good match for an OTL will be a function of impedance matching, not speed. Since many electrostatics have rising impedance curves, and since OTLs are happier with high impedance loads than are solid state amps, it makes for a good combination. I just don't know about ribbons.

As to solid state versus tube OTL speed, I'd match the speed of an Atma-Sphere MA-1 or MA-2 to that of the best solid state amps any day, the solid state amps certainly don't surpass the Atma-Sphere as to "slew rate" or "rise time" (rated at 600 volts/microsecond, matching the Spectral solid state amps which exceed almost all others).

As to traditional transformer-based tube amps, I'll agree with you based on my listening, but I personally prefer any number of them to ss for other important characteristics.
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rushton's avatar
rushton
2,445 posts
 
Hmmm..., LPs do have signal response above 20KHz...

In fact, this is one of the challenges for well designed analog front-ends: the cutting lathe can place a very high frequency sounds, including harmonic distortion, into the record grooves that then have to be dealt with effectively, for good and ill.

For some spectral analysis graphs, see:
http://users.bigpond.net.au/christie/comparo/part4.html
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