Weird imbalance on a Lite Audio DAC-39

[That Dude]

I've recently bought a Lite DAC-39 second hand. At that time I did not have a proper coaxial line-out cable so I substituted it with a box-standard rca cable. I got imbalanced sound. So I bought a Zu audio Firemine and I thought the problem went away. But upon closer analysis, the problem persists in a different form.

The left channel of the unbalanced output sounds "out of phase" the highs are pretty decent but the mids and bass are washed out. The right channel on the other hand is full bodied and sounds fantastic. I've troubleshooted my entire system and the problem definitely lies with the DAC. Both coaxial and optical inputs produce the same imbalance. I have already had the DAC with me for over 2 months, so I guess the seller would be less than willing to believe me when I say I've just noticed the problem. (Even though I did, cause I've been doing casual listening on my speakers and simply chalked up the imbalance to mastering, since the vocals are still dead centre)

I need help guys. Thanks.

[nikongod]

Have you tried swapping the gain tubes on your amp (assuming you still have the DV332) from left to right? If the imbalance follows the tube replace BOTH of them.

Where is the attenuator on your amp parked? If its less than 1/3 spin (1/3 of the way above the lowest volume) what you are describing is not uncommon unless you have a stepper.

If neither of those things explains/solves the problem here is a last ditch test: Do you have a multimeter that can measure ~1 or 2vac? what are the output levels from the DAC playing a mono 1khz tone?

Edited August 25, 2010 by nikongod

[That Dude]

I've tried swapping the tubes but the imbalanced persisted on the left channel.

My attenuator is parked at around 10 O'clock, but, I've removed my DV332 and connected the DAC directly to my tomahawk. Hence, ruling out my amp being the problem child.

I could try the multimeter test, but any ideas on where to get the 1kHz tone?

Thanks!

[Pars]

The digital in (coaxial or optical S/PDIF) has both channel's information in a single bitstream, so the cable could not possibly be the problem. It could be a problem in the DAC (output stage?). Or possibly in the transport (not sure what you are using).

[That Dude]

^If the problem is the DAC, I have no idea where to go for assistance. The only place I can think of is Pacific Valve but shipping from Singapore would cost my remaining arm and leg.

[grawk]

that's one of hte big drawbacks to buying cheap gear from a long way away. It's basically disposable.

[That Dude]

^I guess, but I bought it in Singapore, 2nd hand. So I'm beating myself up for not checking thoroughly enough within the 7 days warranty the seller provided.

[The Monkey]

Smash it into little tiny pieces and start over. You'll feel better.

[NekoAudio]

The left channel of the unbalanced output sounds "out of phase" the highs are pretty decent but the mids and bass are washed out.

If you listen to _only_ the left channel does it still sound this way? (Disconnect your right channel.) If so, then you've probably got a high pass filter being created somewhere.

If you run the DAC left channel into your amp right channel and it still happens, which is implied when you say you've isolated it to the DAC, then the high pass may be occurring due to the cable or something strange having happened at the output stage. Those would be my first two guesses at least. So if the cable isn't the problem, then you've got something odd inside.

A bad or disconnected component in the analog output stage, or a wire that has shorted or disconnected, might be the cause. If you're willing to open it up you could look inside to see if you can identify any such problem.