2. amps-preamps
  3. 155837-115562

I like my Peachtree Nova300 more than my new (to me) Pass XA30.5 HELP!

I recently acquired a Pass XA30.5.  I have a LTA MZ2 on order to match with it, but in the meantime, I hooked it up to the preamp section of my Peachtree Nova300 using SE inputs/outputs.  I have Tekton Electron SE speakers and a Cambridge Audio CXC transport.  I found the sound of the Pass to be wooly, rolled off on the highs and not as clear or articulate as the Peachtree as an integrated.  There was a richness and liquidity to the sound but I lost detail and fidelity.  Am I doing something wrong?  Is the preamp section in the Peachtree not a good match with the Pass amp?  Is using the SE outputs severely compromising the SQ? I've read so many great things about the Pass XA30.5 and though it sounded good, I was kind of disappointed.  There was a trade-off with the Peachtree that I don't think I'm willing to make.  Anyone have any pointers or thoughts?

thanks!
adam8179

Showing 2 responses by almarg

almarg's avatar
almarg
9,670 posts
 
Hmm. In the measurements section of Stereophile’s review of the Nova300 John Atkinson states as follows:

... all measurements of the nova300 were taken using Audio Precision’s auxiliary AUX-0025 passive low-pass filter, which eliminates noise above 200kHz that might otherwise overload the SYS2722’s input circuitry. Without the filter, there was almost 1V of ultrasonic noise present at the Peachtree’s output, with a center frequency of 472kHz.

And I would expect that 1 volt of ultrasonic noise to be considerably greater when the Nova300’s preamp section is being used in conjunction with the Pass amp, since a speaker load is not connected to the Nova in that situation.

In other words what you’ve got in that setup is a **very** powerful RFI generator located somewhere in the vicinity of the Pass amp. I’m thinking that a significant contributor to the problem may be the result of that RFI finding its way into the Pass amp, either by coupling into the power wiring or the interconnect cables or the speaker cables, or perhaps directly through the air.

Good luck. Regards,
-- Al

almarg's avatar
almarg
9,670 posts
 
The 100 ohm output impedance of the Peachtree's preamp section, which Stereophile measured as being "constant across the audio band," is fine for driving the XA30.5.

Are jumpers connected between pins 1 and 3 of the XA30.5's XLR input connectors?  If not that would most likely be the cause of at least part of the problem, and perhaps all of it.

Good luck.  Regards,
-- Al

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