[pp312]

As an addendum to this apparently dead thread, I've just started using the USB input on this amp and experienced the same sort of problem as Vandhaal: slight cracking and, in my case, momentary drop-outs of the sound. Haven't experienced it with the optical input, and indeed it seems to be related to the poor fit of the USB socket. By pushing the plug right in with some force the problem can be oversome, but the fit is terrible and never firm no matter how much you push it in. Don't know what the problem is here. I won't be returning mine, but if I don't experience any problem with the optical input I may consider having the USB socket replaced at my own expense. It's obviously not up to scratch.

 

[Vandaahl]

Quote:

Originally Posted by pp312 /img/forum/go_quote.gif As an addendum to this apparently dead thread, I've just started using the USB input on this amp and experienced the same sort of problem as Vandhaal: slight cracking and, in my case, momentary drop-outs of the sound. Haven't experienced it with the optical input, and indeed it seems to be related to the poor fit of the USB socket. By pushing the plug right in with some force the problem can be oversome, but the fit is terrible and never firm no matter how much you push it in. Don't know what the problem is here. I won't be returning mine, but if I don't experience any problem with the optical input I may consider having the USB socket replaced at my own expense. It's obviously not up to scratch.

Indeed I could not insert my USB cable very deep, and was afraid to use force. In fact, the power cable did not go in deep at all, either. Maybe using more force could have solved my problem then. I still heard the noise over the optical input though, which did connect correctly.

I haven't received my money back from the Ebay seller yet, btw. I send the unit back, but it takes a while to ship something from Europe to China. I expect it should be there this coming week at the latest. Hopefully the refund will go smoothly.

 

[pp312]

Been testing the optical connection and can't provoke any crackles. I wonder if your poor USB connection could have somehow affected the optical connection?

Let us know when you get your money. The reliability of these sellers is an important issue.

 

[repeet]

I also had problems with distorted sound on mine. I opened it up to look for bad solder joints and discovered the opamps are now socketed. Upon investigating in the Aune dac thread, I discovered that the 2 opamps were in the wrong position. I swapped them over and now everything sounds great. Hope this helps. Its easy to check. OPA2604 OPAMP should be closer to the front switch panel, OPA2134 near the middle of the board.

 

[pp312]

That's interesting. I just looked inside mine and discovered the op amps aren't socketted. Not only that, the markings on them are so faint--I tried a magnifying glass--it's impossible to tell if they're correctly placed.

 

[Vandaahl]

Finally got my refund for the Muse I got from Ebay seller shmily1820082008. It had distorted sound so I send it back. It took a while before I finally got the refund. I'm not sure why, because the seller was not able to explain the reason for the delay in any form of English I could understand. But at least he replied to all my inquiries quickly (although the answers are very short), and I got a refund in the end, so this seller is pretty trustworthy as far as I'm concerned. Just don't expect any help should there be a problem with your Muse (your options are a replacement or a refund).

 

[pp312]

I don't expect any help with anything I buy overseas, including a refund. When I buy, I always consider what I can sell the unit for on Ebay should I not like it. As far as a faulty unit goes, I would hope for a refund, but if the seller won't refund the postage, as he's not obliged to do, and you have to pay postage back, it's not worth it for cheap items like the Muse. Calculated risk really. You've been lucky.

 

[Vandaahl]

He did refund the original postage costs actually. Not the postage back, but that's understandable.

 

[daydesiang]

I own this DAC/AMP too... the sound is really coloured... certain frequency just disappear? Lack of mids... boost bass nicely and highs are sparking clear... IMO this amp are made for headphones like AT... if pair it with Sennheiser... worst part become worst!

 

[pp312]

Quote:

I own this DAC/AMP too... the sound is really coloured... certain frequency just disappear? Lack of mids... boost bass nicely and highs are sparking clear... IMO this amp are made for headphones like AT... if pair it with Sennheiser... worst part become worst!
 
 

Well, I opened mine up and immediately discovered that one of the 220uf capacitors was reversed and just about to blow--that was how I spotted it. Can't say I noticed much difference in sound quality after correcting the problem, but it would seem these units have very poor quality control, and I would hesitate to comment on sound quality without checking that everything is soldered into the right place. Certainly your description of the sound doesn't resemble what I hear, which is quite an even, neutral sound.
 

 

[dorkus]

i'm thinking of ordering the Muse from eBay seller "forexman" - will take it apart and let you guys now how the current production units are looking.

 

[Vandaahl]

That would be interesting!

 

[aroldan]

I got the Muse DAC/Amp six months ago and after some changes it sounds just great with my Sennheiser HD595.
 
With the stock op amps (OPA2604 and OPA2134) the sound was distorted as someone stated (I had to make a gstreamer preamp to the volume). I then bought a couple OPA2111 and another of OPA2107 and the crackling was gone. With OPA2111 on both sockets the sound is more bassy but not just as detailed as with OPA2107. I therefore recommend the opamp rolling if you want to buy this DAC/Amp.

 

[pp312]

 As far as changing op amps, mine aren't socketted.

 

[dorkus]

the latest pictures from the eBay listing show SMD opamps, with alternate holes for a standard DIP. so it would not be hard to remove the SMD device and install a socket... seems rather non-optimal though, either the layout should be optimized for SMD or DIP. you really want to have the decoupling caps as close as possible to the device pins, though this is more easily accomplished with hard wiring anyway.