Don,
The SP10 sounding "too solid state"? I only remember the Stereophile debates about the SP9 and SP14 about this aspect. I have owned the SP10 mk2 and it did not sound like any of the other SS preamplfiers of that time - the Mark Levinson ML7, the Rowland Coherence or the Grodinsky. It had the characteristic "liquid" sound of tubes and even some fatness in the bass, although better control that the conrad johnson preamplfiers of that period. All IMHO.
Although I have no opinion on this matter some designers refer that systems using balanced cables are much less sensitive for cable quality, even for short distances.
My bad, I was thinking of the SP11, I think, but could have been the SP9. Honestly, it has been a long time and I am not likely keeping the models straight.
I do not have any problem with SS power supplies sound-wise as they are not in the direct signal path. That said, HV transistors tend to be unreliable, at least as implemented in many tube audio designs, so a tube-based supply (including rectifier) would probably cause less light-dimming at turn-on and not take out as many SS components every year or two.
Was it the SP6 that used opto-isolators at the outputs?
JFET's are tube-like but cheating, at least a little... MOSFETs are generally poor choices in the audio signal path due to noise.
MOSFETs as buffers and DC-restore, after the gain stage? There the noise is reduced by the gain of the input stage... I am not sure how adding them in place of coupling caps can reduce the noise floor, however; I suspect other reasons, though those may include reduced effective noise with a lower-impedance output stage provided by the MOSFETs. MOSFET noise is process-dependent, size-dependent, etc. but hard to get around. JFETs do not have the same noise characteristics. Chopper-stabilized op-amps suppress the noise but have other issues. I am not an expert in their (MOSFET) design, at least not at audio frequencies, just know in the past I've avoided them in low-noise stages if possible or worked around them. My (wideband RF/mW/mmW) designs have mostly had BJT or JFET inputs.
None of which has anything to do with the RCA vs. XLR debate, sorry...
I can not believe it.
I spoke also to Spectral and they told me that their equipement is mainly engineered for the use of RCA.
But i tryed an XLR between a DMC30SS and DMA260 (advice from dealer).
This was a big improvement in sound not subtle (faster more live).
Sorry Kee!
Steve Williams Site Founder | Site Owner | Administrator | Ron Resnick Site Co-Owner | Administrator | Julian (The Fixer) Website Build | Marketing Managersing |