2. amps-preamps
  3. 1251337559

Has anyone bi-amped with a Cary SLP-05?

I have this rather weird problem I am hoping the collective wisdom of Audiogon will be able to help me sort out.

The SLP-05 preamp has a pair of RCA outputs, and a pair of XLR outputs. I recently tried bi-amping using both outputs, and the result is the SS power amp always fails to work, no matter what output it is connected to. Here are the configurations which I tried:

SLP05-> (RCA)-> Cary CAD2000-> speaker
(Full range). Result: success

SLP05-> (XLR)-> Cary CAD200-> speaker
(Full range). Result: success

SLP05-> (XLR)-> Cary CAD211AE-> mid/tweet
SLP05-> (RCA)-> Cary CAD200-> woofer
(Bi-amped). Result: CAD211AE works, CAD200 produces no sound from the woofer.

SLP05-> (RCA)-> Cary CAD211AE-> mid/tweet
SLP05-> (XLR)-> Cary CAD200-> woofer
(Bi-amped). Result: CAD211AE works, CAD200 produces no sound from woofer.

SLP05-> (XLR)-> Cary CAD200-> mid/tweet
SLP05-> (RCA)-> Cary CAD211AE-> woofer
(Bi-amped with valve amp on bottom). Result: Now here is the interesting thing. Put the SS amp on the mid/tweet and the valve amp on the woofer, and it works! I am succesfully bi-amping!

Now obviously this is not what I want, because I would rather have the SS amp on the woofer. I checked and rechecked the connections and there was no problem. I swapped RCA and XLR cables to my spares and there was no problem. I swapped speaker cables and there was no problem.

I even borrowed another two SS power amps and the result was the same - each time, the SS power amp refused to power the woofer in bi-amp configuration.

I am wondering whether there is something about the higher input impedance of the valve amp that makes the SLP-05 preferentially drive it.

This problem has me beat. I can't figure it out. Can anyone help?
amfibius

Showing 2 responses by silverlight99

silverlight99
3 posts
 
Hey guys, I'm wanting to do the very same thing as I have 2 sets of monoblocks I'd like to use with my Cary SLP-05. Two CAD-211 FE's which I'd like to use for the mid/hi and Spectron Musician III Mk II fully balanced mono's. The Spectrons have no problem running down through 1 ohm, but the conceptual issue I have before even getting this set up (waiting for a rack for the Cary amp's so they're somewhat protected from the kids running around) is that the impedence matching (input impedance) is so different for both amps and that fully bridged the Spectrons will need to be attenuated (add to that, and this I would think would be relevant for everyone doing this, isn't XLR running about 6db louder than unbalanced RCA connections?). So my LF would be far too loud relative to the mids/highs unless I introduce a passive, fixed attenuator (say in a XLR tube at the amp input) spec'd to the right level so as to minimize quality degradation. Anyway, this is my chief concern, level matching.
silverlight99
3 posts
 
Almarg - thx very much for the response, most helpful. slow delay as I didn't get a notifier for a response (don't know if that's a possibility on this forum). so I'm now getting closer to giving this a run. The speakers I'm using are the new eFicion F300's. they're an excellent speaker, with two separate units - bass and then mid/high. I'll check with the manufacturer if they're both rated at 8 ohms and how consistent. I will let you know what success I have! I'm guessing as a check if I set up the system without the attenuator on the bass from the Spectron's I can measure the actual voltage arriving at the speakers as a confirmation, but not sure.
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