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

Coot, is that Placette VCU a Placette Audio passive linestage preamp? If so, you might have an impedance mismatch with the D-Sonic M2 which I believe have an input impedance of only 10Kohm. Actually there some confusion, is the D-Sonic M2 input impedance 10Kohm or 60Kohm? At 10Kohm it will give trouble (roll off highs) to resistor type passive preamp and some tube preamps. If the input impedance 60Kohm, there should be no problem.

I'd check the input impedance spec of the newer D-Sonic amps.

The older ones were stock Icepower, 10K ohm input impedance, not a great match for most higher output impedance pre-amps, like most tube pre-amps. DOn't know about Placette specifically.

Newer D-Sonics use Pascal Class D modules I believe and I recall reading these have 40K or so input impedance, which is much better for use with high output impedance pre-amps.

I would confirm the D-Sonic output impedance specs though in that I am not 100% certain about specs of the newer D-Sonics.

ALso if anyone is interacting with D-Sonic to buy, if you can ask them to confirm what Class D modules their newer amps use, I would really like to know for sure. Pascal Class D modules have been inferred elsewhere where I have read but not confirmed. I'm not sure the specs I see published on D-sonic site match Pascal or not. THat does not mean that those modules are not used and tweaked in some ways by D-Sonic, though I recall in the past D-Sonic seemed to merely put stock Icepower modules in a box with no apparent electronic mods. Not sure what D-Sonics expertise is to be able to do electronic tweaks as opposed to merely packaging amp modules from other sources.

At D-Sonic website under the Product tab, the input impedance for the 600W and 1500W output M2 series are listed as 60Kohm. But I e-mailed Mr. Deacon last month asking him what is the input impedance of the M2-1200S and M2-3000S stereo amp. He replied 10Kohm. So I'm not sure, but 10Kohm should be fine for all solid state active preamps and most tube preamps.

TObe,

10K ohm input impedance may be fine for many tube pre-amps, but I would just note that there are some Class D amps designed to work well with any pre-amp, inlcuding tube, like Wyred4Sound and Bel Canto, that introduce 60Kohm or higher input impedance for that purpose for best results in all cases. 10K may sound fine but could be more hit or miss for best results in terms of dynamics and low distortion IMHO. The reason is that most impedance ratings including those for pre-amp outputs are nominal for all frequencies but actual impedance varies significantly by frequency, so my opinion is that a high amp input impedance is a good insurance policy in order to be safe.