[francisdemarte]

Quote:

Originally Posted by Fidelity /img/forum/go_quote.gif I ordered the aune unit with the opamps socketed, does anyone know of a place online that will ship to the EU where I can order 2x AD744 with the correct dual socket adaptor? Edit: Is this the correct adaptor for fitting pair of AD744s? 2x Dual to Mono Opamp PCB OPA2604 NE5532 LM358 > OPA627 on eBay (end time 23-Jan-10 14:27:50 GMT)

That will work. I have the Brown Dog adapter, not sure if they ship to the EU:

Single-to-dual Op-AMP Adapter - DIP version (p/n 021001)

 

[Fidelity]

Quote:

Originally Posted by francisdemarte /img/forum/go_quote.gif That will work. I have the Brown Dog adapter, not sure if they ship to the EU: Single-to-dual Op-AMP Adapter - DIP version (p/n 021001)

They indeed do international shipping!

Now I just need to find the cheapest place that also ships to the EU that stock the AD744s.

Thanks for the link.

 

[rayk]

So I have swapped out the default OPA2604AP with a dual OPA627BP, sounds nicer

! I think this should be the default config.

Nice unit overall, not mind blowing but good for the price. Haven't done any thorough testing yet.

 

[devast]

Quote:

Originally Posted by rayk /img/forum/go_quote.gif So I have swapped out the default OPA2604AP with a dual OPA627BP, sounds nicer ! I think this should be the default config. Nice unit overall, not mind blowing but good for the price. Haven't done any thorough testing yet.

Leave the opa2604 there for now. And replace the 2134 with your opa627. It will be much better.

 

[francisdemarte]

If you haven't already, I recommend that you upgrade your power supply to something around 18v-20v regulated, it's another nice bump in quality.

 

[stwert]

I recently bought this dac/amp. Really happy with it (FLAC audio with Senn HD555), and though I'm not that experienced with amps and dacs, it seems very good for the price.

In regards to a power supply, I was wondering if someone with more electrical knowledge could point me to a '18v-20v regulated' power supply that will work with this dac (in North America). Would this also eliminate the need for the awkward adapter?

Thanks

 

[francisdemarte]

If your handy with a soldering iron and multimeter you can build your own. Just follow the link in my sig for an example that I built. I used Tangent's THREAD kit, a toroidal transformer, and parts from Radio Shack Product Details

I've never used it before but a lot of headfi'ers like Elpac power adapters:

Digi-Key - EPS374-ND (Manufacturer - FWC1818-760F)

Both items will replace the bulky adapter and power converter that came with the Aune.

 

[rayk]

Quote:

Originally Posted by devast /img/forum/go_quote.gif Leave the opa2604 there for now. And replace the 2134 with your opa627. It will be much better.

I read an earlier post that swapping 2134 wasn't recommended.

"I would avoid replacing the 2134 in this DAC - it is part of an active LPF circuit, so normal rules of rolling do not apply. "

Quote:

Originally Posted by francisdemarte /img/forum/go_quote.gif I've never used it before but a lot of headfi'ers like Elpac power adapters: Digi-Key - EPS374-ND (Manufacturer - FWC1818-760F)

That thing has Voltage - Input 85 ~ 264VAC , so I assume it's compatible with AUS? Yeah agree the standard wall wart is quite clunky.

 

[JMIJohn]

Will this drive 600 ohm Beyer dt990 (2005)'s?
And what is all this about how the stock power supply is bad? What should I get, specifically, to maximize performance. i don't want to go buying some power conditioner, just something that outputs the right voltage if the stock is incorrect/inferior.

Thanks.

 

[devast]

Quote:

Originally Posted by rayk /img/forum/go_quote.gif I read an earlier post that swapping 2134 wasn't recommended. "I would avoid replacing the 2134 in this DAC - it is part of an active LPF circuit, so normal rules of rolling do not apply. " That thing has Voltage - Input 85 ~ 264VAC , so I assume it's compatible with AUS? Yeah agree the standard wall wart is quite clunky.

I don't know who wrote that, but that's bs. The lowpass filter has way bigger impact on the sound then the headamp. Just make sure the opamp you insert there is unity gain stable. And i personally don't like the 2134.

 

[francisdemarte]

Should I move my AD744 to replace the 2134 instead of the OPA2604? I believe they are unity gain stable.

Quote:

Originally Posted by devast /img/forum/go_quote.gif I don't know who wrote that, but that's bs. The lowpass filter has way bigger impact on the sound then the headamp. Just make sure the opamp you insert there is unity gain stable. And i personally don't like the 2134.

 

[devast]

Quote:

Originally Posted by francisdemarte /img/forum/go_quote.gif Should I move my AD744 to replace the 2134 instead of the OPA2604? I believe they are unity gain stable.

Try it, if it's not getting really hot then it's ok. If it does, then i recommend placing a 0,1uF film cap underside the pcb between the opamp pins v+ and v-(or 2 caps between v+ and gnd, v- and gnd pics) if you can do it.

 

[devast]

Quote:

Originally Posted by JMIJohn /img/forum/go_quote.gif Will this drive 600 ohm Beyer dt990 (2005)'s? And what is all this about how the stock power supply is bad? What should I get, specifically, to maximize performance. i don't want to go buying some power conditioner, just something that outputs the right voltage if the stock is incorrect/inferior. Thanks.

The first one is a question i can't answer unfortunately, i don't own any 600ohm phones. Theoretically, it will work. But how well, that's the thing i don't know. About the stock psu: it's not bad, but it could be better. There's the elpac psu, there's a psu specifically made for this unit here if you can negotiate with the seller to get a custom aune with this psu that would be great too, and of course you can build your own regulated linear power supply using a thread, a transformer and a case with some connectors.

 

[francisdemarte]

Quote:

Originally Posted by devast /img/forum/go_quote.gif Try it, if it's not getting really hot then it's ok. If it does, then i recommend placing a 0,1uF film cap underside the pcb between the opamp pins v+ and v-(or 2 caps between v+ and gnd, v- and gnd pics) if you can do it.

I just replaced the OPA2134 with a pair of AD744 and put the OPA2604 back into the headphone amp socket. This seems to be mellowed treble a bit, a its a little less bright, very subtle difference. I'm not sure if I like it with my headphones.

On the upside the AD744's did not get hot at all.


Quote:

Originally Posted by devast /img/forum/go_quote.gif The first one is a question i can't answer unfortunately, i don't own any 600ohm phones. Theoretically, it will work. But how well, that's the thing i don't know. About the stock psu: it's not bad, but it could be better. There's the elpac psu, there's a psu specifically made for this unit here if you can negotiate with the seller to get a custom aune with this psu that would be great too, and of course you can build your own regulated linear power supply using a thread, a transformer and a case with some connectors.

I think I like the look of my PSU better

I noticed that they removed the regulator that is in the Aune. Is there any benefit to this?

 

[devast]

Quote:

Originally Posted by francisdemarte /img/forum/go_quote.gif I think I like the look of my PSU better I noticed that they removed the regulator that is in the Aune. Is there any benefit to this?

I think it's the virtual ground splitter you're talking about. If you use a dual (+/-12V and a GND for example, 3 wires) power supply, the virtual ground splitter is not necessary.