Coincident Linestage vs CJ CT5 or Allnic L-3000

02-12-13: Abruce
The Coincident is not balanced, this comes from a reliable source but I wonder how you can really tell

From the CSLS description at the Coincident website:

The circuitry of the Statement is fully balanced from input to output. The sonic performance is optimized for balanced and single ended operation. The choice of balanced or single ended will be determined by the ancillary components used with the Statement. If the amplifier or source component is designed to be optimized for balanced operation, for example, then using the Statement in balanced mode will yield the best sonic results. Single ended mode is recommended when used with components designed for single ended operation.

Looking at the rest of the description that is provided for the CSLS, the one thing that raises some doubt in my mind about its internal signal path being fully balanced (when the XLR connectors are used and the rear panel switches are set to balanced mode) is that there is apparently only one single-section triode tube per channel. Perhaps I'm missing something, but I'm not sure how a balanced active gain stage can be implemented with a single triode.

Although Atmasphere has described in past threads an approach involving applying one of the two signals in a balanced signal pair to the grid of a tube, and injecting the other signal into the cathode circuit, thereby driving the grid and cathode in opposition. That approach would allow a single triode to accept a balanced input signal pair, with the output transformer converting the signal that is output from the plate to balanced. Whether or not that kind of approach would constitute a "fully balanced" signal path is debatable, IMO.

In any event, regardless of its topology it is by essentially all accounts an exceptional performer. Obrennan & Brownsfan, congratulations and enjoy!

Regards,
-- Al

02-13-13: Philipwu
my guess is ... when a transformer is used to split signal that enters from RCA connector into positive & negative phase for further "procresing" then the amp is fully balance.

I don't think we can say, based on the description at the Coincident site, whether or not the RCA inputs are converted into a balanced pair of signals. In fact, their statement that I quoted in my previous post could be taken to mean that the circuits are configured very differently depending on whether the rear panel switches are set to balanced or unbalanced.

... if a balance connector is added for convenience and subsequently, signal enter through this balance connection then get converted by transformer into SE circuit,i would guess it would not be full balance circuit, right?

Yes, but again there is no specific indication that that is how the circuit is designed.

The only meaningful clues, as I see it, are that the design is transformer coupled at both its inputs and its outputs, and that the only active device in between is a single-section triode. Which per my previous post probably means, at least arguably, that it is not "fully balanced" in the usual sense of that term. Although if the topology is such that a balanced signal pair is input to the tube via the grid and cathode circuits, as I described earlier, and the single-ended output from the plate is converted to balanced via the output transformer, the design could perhaps be considered as falling within a loose definition of "fully balanced."

Regards,
-- Al

06-12-14: Charles1dad
I called Grant Fidelity today and left a message, no reply yet. I'll send an email ....

Charles, there is a very understandable, and very sad, reason for the lack of response. See their website.

Best,
-- Al

Marco, congratulations on the CSLS!

I don't know if it inverts polarity in the signal path between its RCA inputs and its XLR output (the website says "in phase" but conceivably that could just apply to the path between XLR input and XLR output).

In any event, though, even if it is inverting polarity I don't see why interchanging + and - at one end of the speaker cables wouldn't correct for that (assuming it matters at all, which would be recording dependent).

Also, btw, a polarity reversal would be 180 degrees, not 90.

Enjoy! Regards,
-- Al