It appears, as is typically the case, that the XLR/RCA switch on the Audio Horizons 3-series DACs selects between the XLR and RCA digital INPUT connectors, and has nothing to do with which analog output connector is being used. The XLR and RCA analog output connectors are presumably driven simultaneously, as Brf indicated.
So the reason that you hear nothing when "XLR" is selected is that nothing is connected to the XLR digital input connector. The MBL preamp has nothing to do with the issue.
The bottom line: Hey, no problem!
Regards,
-- Al |
Just to be sure that something simple is not being overlooked, are you certain that the switch on the DAC is selecting which analog output connector it provides a signal to, as opposed to which digital input connector it is accepting a signal from?
Regards,
-- Al |
What is the model number of the Audio Horizons DAC?
And am I correct in understanding that the switch you have been referring to as the "switch on DAC" and as the "DAC switch" is located on the DAC, not on the preamp? Or are you referring to a switch on the preamp, which acts on the input of the preamp that is connected to the DAC?
Regards,
-- Al |
Dac is connected with digital cable to cdp Is the digital cable RCA or XLR? And, repeating my earlier question, what is the model number of the DAC? Regards, -- Al |
Does the digital cable, that is connected between the DAC and the CDP, have RCA connectors or does it have XLR connectors?
Regards,
-- Al |
If you are saying that with the Sugden preamp everything worked well when the digital input to the DAC was provided on its RCA input connector, while the input select switch on the DAC was set to select its XLR input connector, that makes little sense.
If that is really what was happening, the only explanations I can think of are that either the input select function of the DAC is malfunctioning, or its design is such that there is some amount of "crosstalk" (unwanted coupling) between its two digital inputs. In either case the condition would presumably be very marginal, such that small differences in grounding conditions that may occur depending on which preamp is connected would mean the difference between the DAC working and not working.
That all seems very farfetched, but those are the only explanations that occur to me if the facts you have reported are accurate.
In any event, if you are inputting to the RCA digital input on the DAC, its XLR/RCA input select switch should be set to RCA.
Regards,
-- Al |
03-25-13: Pavpet
No I'm saying with the sugden preamp hooked in xlr , dac in xlr everything workks fine , so I know the dac is fine ,if I switch preamps use the mbl on xlr ,I have no audio I realize that is what you are saying. You are saying that when you apply a digital input signal to the RCA digital input of the DAC, and set the DAC so that its unconnected XLR digital input is selected, you get audio when the Sugden preamp is connected to the DAC's analog output via XLR, but not when the MBL preamp is connected to the DAC's analog output via XLR. My comments in response to that are in my preceding post. Regards, -- Al |
Thanks, Dave. An inconsistency or reversal of pins 2 and 3 in the connections between the DAC and the preamp would only result in an inversion of absolute phase, though, which would at most have subtle sonic consequences on some recordings, and no consequences on many others. It would not cause the audio to be absent.
It is conceivable to me, though, that differences between the two preamps in how the grounding of pin 1 is handled could contribute to the (quoting from one of my earlier posts) "small differences in grounding conditions that may occur depending on which preamp is connected" that I speculated might "mean the difference between the DAC working and not working" when its input select switch is wrongly set to the XLR position.
That speculation is also, of course, a long shot, but regardless of what is going on it would seem clear that the switch on the DAC should not be set to select an input other than the one that is connected, whether it happens to work that way or not.
Best regards,
-- Al |
The performance of a digital cable, balanced or unbalanced, will often be significantly dependent on the relation between its length and various unspecified variables, including the risetimes and falltimes of the digital output signal of the CDP or transport, among others. More often than not, it would be desirable to avoid intermediate lengths such as 1 meter, and choose a length of about 1.5 meters (approximately 5 feet) or slightly longer, or, if practicable, a very short length (e.g., 8 or 10 inches or less). See this paper. Good luck! -- Al |
