A little crack static...

[meeklo062704]

I just picked up a Crack from a local buy through head-fi today. As much as I wanted to build it myself, I really didn't want to wait for the shipping queue to complete, so my impatient inner child made me buy the used one. It sounds amazing, but I am getting a sound that sounds like a cross between soft static and interference. I was getting a steady click in the static, but changing wall plugs fixed that. Right now I am running rca out from my asus essence stx with flac files through jriver, and it's all powering a set of Sennheiser hd650's. The rca cables I'm using are pretty cheap, just what I had lying around. I dropped all volume through windows, and disconnected the rca cables from the Crack one at a time, and the interference went out each channel when it was unplugged.

So my question is, will a better power cable and rca cables possibly help me out with this one? There's no speedball in it yet, I want to get used to the sound before I upgrade so I can enjoy the change more.

[Paul Birkeland]

I dropped all volume through windows, and disconnected the rca cables from the Crack one at a time, and the interference went out each channel when it was unplugged.

It's either your cables, or your source.  Substituting either will be pretty easy to determine which is the culprit.

[meeklo062704]

My next steps are a speedball, and then a usb dac. I'm planning on diy'ing some interconnects and a power cable, I'll just have to do some browsing to find some decent components to do it. I've read several different things saying that mac os handles audio better than windows, so I'll try some experiments with a hackintosh in the near future as well.

[John EH]

My next steps are a speedball, and then a usb dac. I'm planning on diy'ing some interconnects and a power cable, I'll just have to do some browsing to find some decent components to do it. I've read several different things saying that mac os handles audio better than windows, so I'll try some experiments with a hackintosh in the near future as well.

I'd just go the USB DAC route.  Not sure how serious you are about DAC's but right now I'm listening to my newly built crack through a computer (Raspberry Pi) and HiFiMeDIY Sabre USB DAC ($40).  Amazing sound.  I also have the HD 650's.

You pipe digital through a DAC to Crack through HD650's and you're going to love it.

John

[meeklo062704]

I found an adapter, so I ran from the headphone out jack on the essence stx to rca on the Crack. Dead silent on interference, just music. So if there is interference on the rca jack and none on the headphone out, will better rca cables help out in this one? I tried moving it away from the computer and turning off my cell phone and neither of those did anything.

[meeklo062704]

Finally confirmed that it's a ground loop issue. Tried a cheater plug on it last night, and immediate dead silence except for music. How safe is it to run the cheater plug until I can get an external dac?

[Doc B.]

We cannot recommend the use of a cheater plug simply because of liability issues, as you are defeating the safety ground we have put into the design. I am not saying that it doesn't solve your issue, just that we cannot condone it.

[meeklo062704]

We cannot recommend the use of a cheater plug simply because of liability issues, as you are defeating the safety ground we have put into the design. I am not saying that it doesn't solve your issue, just that we cannot condone it.

I absolutely concur with that. I really don't want to use it. A decent isolator that won't degrade the signal should be at least $100, so I'd rather dump that money into a dac. Its just going to be a month or 2 to make a decision on one, and get the money set aside. Any advice on a diy fix? Btw doc, kudos on the fantastic amp. Any plans for a bottlehead dac to go with the bottlehead crack?

[adamct]

There is a Bottlehead DAC in the works, but it is a ways away from being available for purchase.

If you want a cheap and capable DAC and only need USB inputs, then get an ODAC or a Schiit Modi.

Best regards,
Adam

[meeklo062704]

There is a Bottlehead DAC in the works, but it is a ways away from being available for purchase.

If you want a cheap and capable DAC and only need USB inputs, then get an ODAC or a Schiit Modi.

Best regards,
Adam

I'll be waiting impatiently for that one. I was looking at the modi, but I couldn't help wondering if the bifrost would bea worthwhile jump. I know some dacs and amps play better together than others. Just checking because there's a bifrost with usb on head-fi for $325.

[adamct]

My personal opinion is that DACs don't make that much of a difference once you get over the $100 mark, provided you control for the strength of their output signal, so I'm probably not the right person to ask. I have several DACs ranging in cost from $100 to $1,000, and I doubt I could tell the difference between them in a blind test.

[meeklo062704]

I keep going back and forth between liking one of the schiits and reading nothing but good about an hrt music streamer ii, or even an odac. Can't lie about it, the schiit dacs are pretty. Also, I've read opinions on both sides, for pc to dac, usb or optical? I've read more positive about usb than optical.

[Grainger49]

There is probably a component that needs better grounding.  However, if you have a solidly grounded component, and all the signal commons are tied to the chassis of the equipment, then the interconnect common grounds every component in the system.  API Power Wedges used this principle and they were UL approved.  I have owned two.

[Doc B.]

You could try plugging the amp back in with the cheater removed and try connecting a wire from the Crack chassis to the source component chassis. It's a fairly slim chance that it will help, but it's also easy to try.