HELP with new Crack build - Squeal [resolved]

[Blkout]

Hello bottleheads, first post here and new Crack owner but I have a small issue and I need some assistance.

I finished building my Crack a few days ago but I notice that I have a distant background squealing. At 1/4 volume its almost inaudible depending on which headphones I use but I can hear it more clearly with my HD 800's than my HD 650's. At 1/2 volume its certainly audible and at 3/4 volume or above, its just annoying.

I would like to add that I don't believe the squealing is present when music is playing though, only when there's no signal. I will double check to make sure but I believe even during quiet passages of music there's no sign of the squeal. I don't believe its my RCA cables because I have another solid state amp that I've used with these same cables and there's no noise with that amp.

So far I have checked all of my solder joints, to me they look fine but I suppose someone else might see things differently, if it helps, I can try to upload a picture later today to see if anything looks out of the ordinary. I have also tried moving/wiggling all of my wires to see if anything changed and it didn't.

Any ideas? Anyone else seen this issue?

[Paul Birkeland]

Unplug the interconnects going to the Crack, then listen again.  That will remove both your source and your cables from the list of things that could be causing the squeal.

If you are using your computer as your audio source, you may be hearing noise generated by the computer.

Otherwise, I would suspect a flaky solder joint.  Does the squeal happen in both channels?

[Blkout]

Thanks. I will try that today. I am using my PC as a signal source but I can rule that out and connect the crack to my home theater receiver and see if that makes any difference.

The squeal is in both channels and it sounds like its varying in pitch slightly at a very high rate almost like a switching noise.

[Paul Birkeland]

The sound you are describing sounds just like a noisy computer.

-PB

[Blkout]

That's certainly a possibility, but since I can't hear the noise with my solid state headphone amp even though the source is the same, do I not hear the noise with that amp because the SS amp has better filtering?

If it should turn out be my PC as the source of the noise, is there anything that can be done to cure this with the Crack amp?

[Blkout]

The sound you are describing sounds just like a noisy computer.

-PB

Kudos to you sir, there's no noise when the RCA's aren't plugged in therefore, it must be my PC generating the noise. I assume my SS amp must be filtering this noise out where the Crack isn't.

Is there a PC solution to this?

[Paul Birkeland]

Kudos to you sir, there's no noise when the RCA's aren't plugged in therefore, it must be my PC generating the noise. I assume my SS amp must be filtering this noise out where the Crack isn't.

Is there a PC solution to this?

A laptop running on its battery may not exhibit this noise.

The solid state amplifier may have much lower input impedance or some other loading that is filtering some of the noise (and probably some of your music to).

An external DAC fed by an optical cable will get rid of noise like this.  A FiiO D03K will do the job for under $40.

-PB

[Blkout]

Thank you again sir. The FiiO is certainly cheap enough. Any reason to consider a Schiit Modi 2 or ODAC over the FiiO? Just considering my options.

[Paul Birkeland]

It all comes down to what you want to spend. To perform the experiment of getting rid of the noise, I would spend the least amount of money possible.

-PB

[Blkout]

It all comes down to what you want to spend. To perform the experiment of getting rid of the noise, I would spend the least amount of money possible.

-PB

Valid point.

[Blkout]

I just wanted to give an update...

I purchased a Schiit Modi 2 Uber DAC and received it a few days ago. The crack amp is now dead silent. I'm using an optical cable out of my Creative ZxR sound card to the Modi 2 and then into the Crack and it sounds pretty stunning. Very pleased with this setup and my Crack is dead silent even at full volume, not a hint of hiss or noise, however the Crack is so powerful that I rarely need to turn the volume knob more than 1/4 turn. My HD 800's sound wonderful on this setup. I got a Mullard CV4003 coming tomorrow to play around with.

I'm just happy there's nothing wrong with my crack amp or my assembly. Thank goodness as I wasn't looking forward to troubleshooting it.

I like it so much I went ahead and ordered a Speedball upgrade based on so many positive reviews about the upgrade.