2. amps-preamps
  3. 1243215247

Audio Research amps - balanced & non

Ideas/suggestions anyone?
I have an original ARC SP-10 pre-amp (perfect, re-tubing once in a blue moon but totally reliable after ~25 yrs so reluctant to replace) but I would like to replace my original D-115 amp with VTM 200's (i.e. balanced) or get a VT-130SE (also balanced) to bi-amp alongside the D-115 to drive the bass end, assuming that's even possible.

Question - can balanced power amps work with a 'pre-balanced' pre-amp like the SP-10, or even work in a bi-amp arrangement as the only balanced component? I suspect not but would like some user comments.
Thanks!!
westchr

Showing 6 responses by martykl

martykl
3,578 posts
 
The VT-130SE does not have a phase splitter and requires a true balanced input to operate correctly. If the SP-10 is not a balanced design you can't run it directly into a VT-130 SE.

Good Luck

Marty
martykl
3,578 posts
 
Sorry, I didn't see the bi-amp part of your post. Some active x-overs will output a true balanced signal even if the input is single ended. The NHT x-2 is an example. If you bi-amp as follows: Source -> ARC sp-10 -> NHT x-2 -> ARC vt-130 se/main speaker (via NHT balanced main out) + subwoofer (via NHT subwoofer out), you should be okay.

Marty
martykl
3,578 posts
 
Dgarretson,

With a single ended input through an XLR adaptor the VT -130 SE will produce less than half the power output that it will produce with a true balanced input signal and that only with THD nearly an order of magnitude higher. I'm unsure of the precise reason for this result, but that was the position of the tech dept. at ARC when I posed this question to them some years back. I feel okay about describing such operation as "incorrect" rather than "sub-optimal", but I'm you're certainly entitled to feel differently about that.

Marty

Marty
martykl
3,578 posts
 
Guys,

Just quoting ARC as best as I recall. They may have used imprecise language for my benefit, but the conversation definitely was in terms of power output and THD (or possibly just "distortion"). I'm pretty sure that the "less than half" and "order of magnitude" are verbatim from ARC.

Marty
martykl
3,578 posts
 
Eldartford,

To be fair to Jafox, I don't think he was dissing the quality of the devices (including the one I suggested) being recommended for use between the pre and power amps when he used the term "junk". Rather, it seems to me that he was advocating the "simplest signal path" philosophy shared by many hobbyists on this site. Whether you agree or disagree with that position, I'd cut him some slack as I think he meant no disrespect.

Marty
martykl
3,578 posts
 
Never mind my previous post - Jafox has responded in his own fashion.

Marty
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