Schiit setup troubleshooting


I have 2 Aegir amps set up in monoblock configuration. The Schiit Freya S serves as my pre-amp. My source is a Lumin U1 Mini, connected via optical to a Chord Qutest DAC. The Qutest is connected to the Freya via single-ended connections, and the Freya is connected to the 2 Aegir amps via XLR. So, single-ended input into the Freya, then balanced output to the Aegir amps - this setup is not producing any audio. I have confirmed that there is a signal traveling to the Freya from the DAC. As recommended by Schiit, I am using the NEXUS modes on the Freya pre-amp (i.e. active modes, which should convert the single-ended signal to balanced), to no avail. Any thoughts on what might be causing this?
vingard
First, just to make sure something simple isn't being overlooked, I assume you are connecting each speaker to the two positive output terminals of the corresponding amp, given that you are using the amps in mono mode. And I assume you have seen in the manual for the Freya S that it has a 60 second delay following turn-on.

Second, by any chance are the speakers AC powered (for example do they include a powered woofer), or do you have powered subwoofers connected to the amps? If so, the negative input of the powered speaker or sub may be grounding or excessively loading the signal on the positive output terminal of the amp to which it is connected, causing the amp to shut down.

Regards,
-- Al
 
@almarg The speakers are connected correctly. I was not aware of the start-up delay on the Freya S, but it has been running continuously since I powered it on last night. I do have a powered sub connected to the speaker terminals on the amps (correctly, as far as I am aware), but I have turned the sub off as I attempt to troubleshoot this issue.  The speakers are passive - Buchardt S400.
I would definitely try disconnecting the sub altogether.

If I understand correctly you are connecting the two amps to a single powered sub (i.e., both amps are connected to the same sub, with the sub providing speaker-level inputs for two channels). If so, it is likely that there is a ground path within the sub that is connecting one of the two positive output terminals of each amp (the output terminal of the amp that I presume is connected to a negative input terminal of the sub) to the corresponding positive output terminal of the other amp. Which could very likely account for the problem. And that path would exist even when the sub is turned off.

Regards,
-- Al

I'll give that a try when I get home this evening. Is there any possibility that using a single-ended input into the Freya (in this case the DAC), then outputting via balanced XLR to the amps could be the cause of the issue?
Is there any possibility that using a single-ended input into the Freya (in this case the DAC), then outputting via balanced XLR to the amps could be the cause of the issue?
After looking at the manual for the Freya S I don't see any concerns with that, given that you are using a Nexus mode.

Regards,
-- Al



@atmasphere 

I don't think the Freya S has tubes. I believe the Freya+ is the tubed model.
Then that qualified as a dumb question :)
How do you know the Freya is running? If it accepts single-ended inputs, then its easy to tell- you can simply connect an RCA cable to the input and touch the pin of the RCA at the other end. You should hear a buzz in the speaker if the volume is up a bit. 
You can perform this same test on the amplifiers. So if it won't pass the signal through the Freya, try that test on the amps. If that's a no-go, make sure your speakers are connected properly, if that's OK then this points at the amps...
Is the freya the new link in your system?

Have chosen the correct rca in using the top left remote button?
Are the connections in the rear correct? Ie xlr out, not in.

Mute isn't accidentally on

Just brainstorming:-)
I checked my speaker<->amp connections last night and it turns out that they are connected correctly. I removed the Chord Qutest from my system and inserted a Schiit Yggdrasil in its place, connected to the Freya S via balanced XLR. Now the system works perfectly (fully balanced throughout). Perhaps the Qutest is the issue - I will need to test that separately this weekend.
I check my speaker<->amp connections last night and it turns out that they are connected correctly.

Is the sub still connected?  And can you indicate the specific make and model of the sub, and describe exactly how it is connected to the amps?

In any event, glad you have made some progress.

Regards,
-- Al


I actually disconnected the sub completely and this did not solve the problem - it is a REL T5i.  
What had you been connecting the black (ground) wire in the Speakon cable to?

The manual for your sub does not provide a specific recommendation for connecting a single sub to monoblock amps having balanced/differential outputs, stating that they "strongly advocate" using two subs with monoblocks (whether balanced or not). However based on their recommendations for other applications of your sub, and on recommendations I’ve seen in other REL manuals, when you reconnect the sub you should first try leaving the black wire unconnected. And if a hum results you should connect it to a ground point on the preamp. Such as the ground shell of an unused RCA connector (using an RCA plug with the center pin unconnected), or perhaps to a chassis screw.

In any event, the black wire should absolutely not be connected to a red output terminal of either amp, and probably not to a black output terminal either.

Regards,
-- Al