Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: Loquah on November 18, 2012, 02:40:06 PM

Title: Is it my Crack or my DAC?
Post by: Loquah on November 18, 2012, 02:40:06 PM
After working really hard to remove inducted noise from the input stage on my crack, I've now got noise coming from my DAC!!

Before I get stroppy with the people that sold me the DAC (I've had multiple problems with this particular model), I thought I should check if there's anything I can try to solve the following symptoms...

The Crack sounds almost silent when there is no source plugged in. With RCAs connected to the Crack, but disconnected from the source, there is minimal (if any) increase in induced noise. When I connect the RCAs to the DAC outputs, the noise level immediately jumps into easily audible range if Crack volume is 40-50%.

I've tried different RCAs (all good quality - Tara Labs, Stinger, Neotech) with no change.

The DAC in question is an Audio-gd NFB-5.2. Should I be cranky about this noise in the circuit or am I missing something?
Title: Re: Is it my Crack or my DAC?
Post by: grufti on November 18, 2012, 04:08:58 PM
You have eliminated the RCA interconnects. You have eliminated your Crack headphone amp as the source of the noise.

What's left as the origin of the noise is the [weird] Audio-gd NFB-5.2 DAC. I wouldn't be cranky about it. I would just get it fixed or better yet get my money back.

Anybody wondering about the [weird] comment might just want to take a look at the images on the www.audio_gd.com website.
Title: Re: Is it my Crack or my DAC?
Post by: Jim R. on November 18, 2012, 04:11:58 PM
Do you have the ACSS selected for the output, or the standard output signal?

-- Jim

Grufti -- whatever happened to the MB Quart headphones??

Title: Re: Is it my Crack or my DAC?
Post by: Loquah on November 18, 2012, 09:17:55 PM
Just standard output, Jim.

And Grufti, thanks for your response. I agree about not getting cranky except that this is the second time I have had troubles with an NFB-5.2 (the one I currently have is my second unit due to a different issue with the first one) and the local supplier says "bring it in for thorough testing" which turns into them fumbling around before saying "we can't re-create it" or "it's not a fault". They're not setting the customer service world on fire.  :(

Title: Re: Is it my Crack or my DAC?
Post by: grufti on November 18, 2012, 09:33:43 PM

Grufti -- whatever happened to the MB Quart headphones??


I am still trying to inflict pain on the German eBay seller who misrepresented just about everything about this item. You don't want to know the gory details. I have had extremely good luck with eBay purchases for more than a decade, but not this time. I'll deal with it. Please consider yourself lucky that you have no skin in it. The only reason I'm not terribly upset is that I have done so well on eBay for such a long time.

My long silence has a lot to do with spending way more time in Germany, than I ever meant to, because of a family matter. Many of us are of an age, that makes our parents really old ... . That too is just the way you would hope it would be. Doesn't make it easier.
Title: Re: Is it my Crack or my DAC?
Post by: Jim R. on November 19, 2012, 03:32:35 AM
Hans,

Ok, thanks for the update and I completely understand.  Starting to deal with parental ageing issues myself.

Best,

Jim
Title: Re: Is it my Crack or my DAC?
Post by: Loquah on November 19, 2012, 07:06:53 PM
Turns out the issue isn't with the Crack or the DAC. The DAC was just acting as a ground to close the circuit and allow the RCAs to pick up some pretty epic noise in the area around the components. Taken out of the room, the setup sounds sweet!
Title: Re: Is it my Crack or my DAC?
Post by: earwaxxer on November 20, 2012, 03:51:43 AM
What I usually do if its not the Crack or the DAC, I check the Stack (Jack)! ::)