Ohm Walsh Micro Talls: who's actually heard 'em?

is it the absolute value of the preamp output impedance, or the ratio or magnitude of amp input impedance to pre-amp output impedance in the end that matters?
Mapman (System | Reviews | Threads | Answers)

The manufacturer's stated specs are a starting point, but impedance output and input varies across the frequency spectrum, and sometimes greatly beyond the nominal spec. This is why reading the Stereophile test measurements can be valuable. Atkinson addresses the impedance measurements across the frequency spectrum, and bases his matching recommendations on what he discovers.

Hi Rebbe and to all in the best thread at the 'Gon.

RE JUICY:
This was posted on their site today:

"Time to turn out the lights...

It has been a great 5 years, but it is time for me to retire. I will no longer be building any new production batches of the BlueBerry, Peach, Tercel or pCAT. I WILL however, be completely supporting all customers (in and out of warranty) with their repair, upgrade and modification needs.

The web site will be here for ahwile (as reference), but I am removing the PayPal purchase buttons.

If you have any questions about your product, just send me an e-mail."

Dante7, that's months old news.

Nevertheless, if a used Juicy Peach I or II comes up, it's a good candidate for Rebbi, IMO, provided he doesn't require a phono stage.

Rebbe,

After some investigation, the ARC sp16 I use is also a candidate for you at least technically, though the cost may be a tad higher.

Here are the specs:

260 ohms Single Ended main;

20K ohms minimum (amplifier input) load and 1000 pF maximum capacitance

So ARC recommends a ratio actually of about 77:1 for this pre-amp, which is well beyond the 10:1 minimum that many indicate in general.

With your Bel Canto's input impedance of 10000 ohms (half the ARC recommended value) the ratios with ARC sp16 would still be over 38:1, still almost 4 times the consensus minimum, so I think the Bel CAnto will work fine with any of the tube pre-amps identified above (Manley, ARC, Juicy) with the similar low output impedance specs.

I disagree that a 10:1 ratio is a consensus minimum. IMO, people who state that ratio are either repeating what they've read in a thread somewhere, or they have limited experience hearing what different impedance ratios produce, or they simply don't know what they're supposed to hear. Consensus by repetition is an uninformed consensus.

The Bel Canto amps may work well with an SP16, but I'd still look for a lower output impedance to get the optimal performance from the amps. However, if you can find a good price on a used SP16, then it's certainly worth a try.

FWIW, a Burson buffer will correct impedance mismatches. Reviews state there is no sonic degradation when putting a Burson in the signal chain. I've not tried one.