DAC MK2 Output to Subwoofer

Newbie here but went all in with the concept/approach of PS Audio. I just bought a full stack, Powerplant 12, MK2 DAC, M700s, AirLens. I have XLR from DAC to amps and am trying to add a new SVS Micro 3000 subwoofer via the DAC’s Left and Right RCA outs to the unbalanced L/R inputs to the sub. I even sprang for AudioQuest Mackenzie Analog Interconnects… but when I enable the RCA output, and the music is playing, I get a very loud hum/buzz coming out of the main speakers (!) and no audible sound from the sub. If I turn off the sub while the music is playing, the hum/buzz goes away. I tested with a different system (my home theater) and the sub works fine. SVS Support posits a “back-feed issue between the two sets of outputs” from the PSA DAC. Sadly, PS Audio Support has not responded. Any idea of what, if anything, I am doing wrong? I appreciate any feedback. Thanks!

-Mark

Mark, wekcome to t he forums, and sounds like youll have a great new system once you figure out this issue. I can’t give any advice on your technical issue, however, if you’ve only contacted support via email, I’d highly recommend calling them instead.

Sounds like a ground loop. Is the sub on the same circuit as the dac? If no can you test by putting in an extension cord from sub to dac ac circuit?

Thank you both for the quick replies! I have only done email and Messaged via the web page. Not much of a phone guy but will try to break from work to call during their limited Help Desk hours.

Was on the same circuit (home run) as the DAC but I thought the PowerPlant was supposed to take care of all that. Anyway, tried multiple outlets in the home with a solid extension cord and got the same damn noise. If I remove the XLR, no problem, sub emits. Gotta be an issue with the DAC. :frowning:

Tested multiple sources into the DAC, tested different RCA cables, no difference. Same damn noise.

Does your sub have a high level input? In this case you could connect your sub to the speaker output of your amp, which is what many vendors recommend, anyway.

You can get a “speaker level to line level” transformer from Jensen. Then you can connect the speaker output from the M700 to the transformer and the transformer RCA outputs to the SVS sub. I had my system configured like that and it works perfectly.
i will find the model number and report back.
I dont think you should have a load on both XLR ans RCA outputs from the DAC at the same time.
By the way I have a couple of the SVS micro’s and they are great little subs.

Here’s the place I bought mine. They have gone up in price quite a bit in the last couple of years.

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Hi Mark. Sorry about the lack of support. That shouldn’t be happening.

Is the hum/buzz 120Hz? Kind of like angry insects?

What concerns me is your comment there’s nothing coming out of the sub. Can you disconnect the XLR feeding the amps and just have the RCA from the DAC feed the sub? You need to get that to work first. Let me know if I can help.

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If I understand correctly, the OP wanted to try exactly what I did. XLR out to mains, and also use RCA out to subs. In my case it worked but there was a big sonic penalty, since the dacs output wasn’t designed for that. An XLR Y splitter would work for that, or as other suggested, see if it’s possible to drive sub via speaker level, or get a preamp with dual outputs.

First find out if the sub is really working as Paul suggested. Should have something even if ground loop. Second if you want low level to go to sub w/o a pre, you really should do speaker level connections. Get that Jenson box mentioned above send the sub back and get a REL that is designed ground up for music using speaker level connections. Another option is JL Audio CR-1 but its probably cheaper to buy a REL.

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Im quite happy with my rythmik f15.

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I too have a Rythmik. G25HP. But it does not have high level. May have same buzz. needs to figure out where buzz is coming. I think OP’s setup is not supported by PSAudio. Paul suggests his type of setup via a Preamp.

Though running XLR and RCA parallel out of the MKII CAN work, we generally don’t recommend it. This can cause some funky impedance mismatch trouble. The output stage in the DAC is really only designed to output to one device (2 if running monos). Easiest solution would be to get an analog preamp. Even if it’s passive. The output stage will be much more accommodating for XLR to amps and RCA to a sub. The overall sound quality will also take a big jump up using a preamp.

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I do know @vkennedy61 is about to list is beautiful Silver BHK Pre for a very good price. if you want that look him up.

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I will be posting it either this weekend or early next week depending on jetlag.

Thanks @brian.fitterman

Sadly, no. Line level only.

Hi Baldy,

Rad! That could be just the thing. I was worried about going from the amps directly to the sub. What would best practice? I can go single banana plug to RCA from Left output of amp A and single banana plug to RCA from Right output of amp B going to the Jensens. Or should I go L AND R banana plug (Y adapter) to single RCA from amp A and the same from amp B?

I’m also curious, what if I went banana plug from the amps straight to the sub? Would it blow up in my face? :slight_smile:

Thanks a lot for your input!

-Mark

Hi Paul!

Thanks for replying, I’m a big fan, and you have definitively helped create a great community here. I’m a little overwhelmed but grateful.

I don’t have technical ears so couldn’t say what frequency, and I don’t yet have an analyzer, but angry insects is a great analogy.

I mispoke when I said nothing was coming out of the sub, I just couldn’t hear it over the buzz. But I can confirm that there is sound coming out of the sub. With amps all the way off and also when on standby, music plays thru the sub with no noise. Amps on, and the angry insects attack. Removing the XLRs, the sub emotes with no buzz, so we are on the right track.

And I don’t mean to beat up on Tech Support, I work in I.T. so I understand the challenges. I was just anxious because everything was going so well. No biggie. Thanks for your help!

-Mark

Hi James,

So looking at the BHK Sig Pre for example, I would go DAC XLR to Pre and then Pre XLR to Amps plus RCA to the sub. To me it looks like the same thing where there is only one pair of XLR outputs and one pair of RCA outs, just like the DAC. I’m guessing different internals. I was hoping to use the built-in pre in the MK2 but that appears not to be the best way to go… decisions decisions lol

Thanks!

-Mark

The Jensen SC-2NR has screw terminals on the input side and RCA’s on the output side. You can use plain speaker wire to go to the input side of the transformer. There is nothing to be gained by using anything special. Belden Canare 4S11 (Star Quad cable, 14 AWG) s a good choice for the input and Blue Jeans LC-1 Sub RCA is a good choice for the output side of the transformer.

I have wired them from the amp speaker output terminals using bare wire or spades and also with wires coming from the speaker input terminals.
The nice feature of the Jensen is that it is also a ground isolator so should kill any ground loops in your wiring.

Nice system you have put together!

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