The current delivery of the ACA is the limiting factor here and also what distortion level you set a limit as being acceptable. The level will be a little more into 6 ohm but not by much. The actual impedance (not just a nominal 6 ohm figure) is very important.
I had some fun today🙁 trying out the balanced mono mode. I have two Dacs with Balanced outs. I chose one of them and wired iup both amps and was somewhat disappointed in that the output level was really low. I use Spotify to stream and even at max volume it was pretty poor.
In SE mode I use an active pre and assume that I would need an active balanced pre to inprove matters?
In SE mode I use an active pre and assume that I would need an active balanced pre to inprove matters?
can you confirm that you wired them properly?
pin 1 to ACA GND
pin 2 to ACA R channel RCA hot
pin 3 to ACA L channel RCA hot
R channel Hot out to one spk lead
L channel Hot out to second spk lead
pin 1 to ACA GND
pin 2 to ACA R channel RCA hot
pin 3 to ACA L channel RCA hot
R channel Hot out to one spk lead
L channel Hot out to second spk lead
Ahh,...... I had been out today looking after a grandchild and thought I would wind down by listening to some music.....but I got carried away and thought I would try the XLR balanced out mode. 😡 I wired the speaker leads all wrong! The XLR wiring is fine. Thanks Zen Mod......tomorrow is another day.
Me again. I tried both amps XLR balanced with the correct speaker wiring and still think that one stereo amp sounds superior. I tried making a pseudo balanced input to both ACAs so that I could use my non-blanced pre but the reccommended wiring (joining pins 1&3 of the XLR) made the amps unhappy with a buzz.
Should I not join XLR pins 1&3?
Should I not join XLR pins 1&3?
if zou want to drive it balanced/bridged via balanced signal, it must be proper balanced signal , cable and input to amp
no joining of pins, that's practically converting to SE signal, so there is no bridging
no joining of pins, that's practically converting to SE signal, so there is no bridging
Whether I use a true balanced connection, invert one channel with the resistor mod, or use pseudo balanced I am not getting more than about one third of the stereo volume. All internal wiring is as in the build guides.
Just throwing this out there but, what position is the switch in for true balanced operation and how many volts does your true balanced device output?
The Dac outputs 4v from the balanced outs. I have looked at the build guide again and see that there are options for a front switch, rear switch and no switch.
I have no switch. The XLR is connected to Pin 1 - Buss, Pin 2 - R RCA, Pin 3 L RCA. If the switch is meant to toggle between Stereo and Balanced mono does this lift one of the connections to enable mono? I can't find anything that says this.
I have no switch. The XLR is connected to Pin 1 - Buss, Pin 2 - R RCA, Pin 3 L RCA. If the switch is meant to toggle between Stereo and Balanced mono does this lift one of the connections to enable mono? I can't find anything that says this.
Keep in mind that tha ACA is an inverting amp - the positiv channel has the negative output so connect here the negative pole of the speaker, the positiv pole goes to the other channel where the negative input is.
I just "finished" my ACA and the left or A channel is barely audible. I triple checked all connections and the parts on the board but no luck. All of the voltages that it says to check in the troubleshooting measure as they are supposed to. I resoldered the input and the output for that channel on the back panel, still no improvement. Does anyone have any ideas on what to try next?
That's fine
See the wiring guide in the build guide for documentation of all configurations. The "Side A" RCA input is pulled out of the circuit when the switch is toggled to the position for Mono RCA Bridged. Not relevant to your particular situations, but that's the only case I remember of the connection being 'lifted', if that's what you're asking.
Symptom (If I read correctly) - You aren't getting the perceived volume level you expect with a differential signal at the XLR input and the speaker hooked to both channels bridged.
It sounds like you have both the RCA inputs and the XLR input wired, correct? You mention the DAC(s), but are you using an analog pre-amp in the circuit, and/or are you using digital volume control for the DAC?
I'd recommend doing a quick gain check on each channel using the RCA inputs. If they don't measure the same, then there's at least part of your problem. If they measure the same, then move on.
Then, I would measure the gain in the balanced configuration.
Note - I'd use a handheld battery powered DMM. No need for anything fancy. Just a nice ballpark will be good.
Thanks for your reply. I will carry out all the checks recommended but for clarity the analog pre is not used when using the balanced XLR input only the mono RCA bridged.