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Post by samtheman on Feb 4, 2010 23:21:28 GMT
Hi everyone and in particular PinkFloyd who inspired me with this thread to buy my first ever Dac/headphone amp - the Aune. I'm completely new to this - having just baught an Aune and HD650 headphones, learnt about downloading flacs, and wrapped my head arround 'bit perfect' sound It's been an absolute revelation and I'm in love with music all over again!! I've taken advice from this thread and updated my power supply to 18v regulated (20v seemed a little harsh to my fledgling ears). I'm now intrigued by the concept of opamp rolling - could someone advise me please? is the ad-744 the way to go? And if so can i buy it from here: cgi.ebay.ie/AD744JN-AD744-BiFET-Op-Amp-8-pin-DIP-IC_W0QQitemZ200405374637QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2ea91756adI've rarely even picked up a soldering iron so would be very gratefull if someone would walk me through buying and installing the ad-744 (if that's the best one to go for). Thank you!!
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matt7941
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Post by matt7941 on Feb 5, 2010 11:16:54 GMT
Good morning and welcome samtheman! Re the AD744s and opamp rolling. It really is quite simple in the Aune and is a great way to start tweaking. Be careful though, it soon becomes an obsession. I wouldn't purchase from the link to ebay you posted. Firstly, it seems a little expensive and secondly there is always the chance they may not be genuine. Some of the Hong Kong/China sellers are known to sell fake goods. Try this link for the AD744s (of which you will require 2): uk.farnell.com/analog-devices/ad744jnz/op-amp-bifet-precision-dip8-744/dp/9604847At least from Farnell's you are guaranteed that they are genuine. You will also need a Browndog adaptor, available from here: cimarrontechnology.com/single-to-dualop-ampadapter-dipversionpn021001.aspxIf you're not confident with a soldering iron opt for the adaptor with the DIP sockets already installed. The AD744s are then literally just a push fit. The postage is very reasonable and service is very good. It'll be with you within 10 days from across the pond (I presume you are in Eire from the ebay listing). Whilst you're about things, you might as well swap the opa2134 for an opa2107. This, as Mike stated, is a very worthwhile step. You can obtain one of these from here: cgi.ebay.co.uk/OPA2107-dual-Low-Noise-Difet-OpAmp-Pro-audio-HiFi-DIP8_W0QQitemZ180464456851QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2a04851493I have personally ordered from here and can confirm they are not fake, plus again the service is really good. The opa2107 is a direct swap fro the opa2134 so no adaptor is needed. (BTW this is a bit of a bargain considering Farnell's are asking £19.98 plus VAT! The opa2107 is not a cheap opamp.) When you've got the opamps/adaptor come back to us and we'll walk you through the opamp swap. If you've any other queries just post them here and someone will not doubt respond with an answer. Cheers Matt
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Post by samtheman on Feb 6, 2010 1:23:08 GMT
Hi Matt Well - what can i say - thankyou so much. I really apreciate you taking the time to post such a detailed responce. I've ordered all the parts you reccomended and will let you know when they arrive. If you or someone else is willing to help me install them - the least i can do, is post a review from my perspective on the SQ changes they have made. I think that this thread is an example of the wonderfull potential of the internet - and I offer my sincere thanks!! All the best, Sam
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matt7941
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Post by matt7941 on Feb 6, 2010 11:50:50 GMT
No problem. It's what this forum is all about, there's no snobbery and very little ego here. I've received more than enough help over the last 18 months on here. If you want me to guide you through the swaps send me a PM or just post on here. There's also a good guide on the ebay listing on how to disassemble the Aune: coolfungadget.com/ebayimg/aune_mini_usb_dac/Mini_USB_DAC_Dispart_Guide.pdfCheers Matt
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Post by samtheman on Feb 8, 2010 12:08:40 GMT
Thanks again Matt - your help is very much appreciated. I read the pdf on how to dissemble the Aune and gave it a try last night - worked perfectly and serboob - I can confirm the Aune comes with adapters for the op-amps fitted as standard (mine was and i didn't ask for it at time of ordering). Matt - would you suggest I try the class a mod on the 2 AD744's? - Is is easy to bend those pins without breaking them and does it make a big SQ difference? Once modded I assume they push into the BB adapter which in turn is pushed into the board. If it's then just a case of replacing the other op-amp with the OPA2107 - then I reckon I'm good to go without taking any more of your time Matt Cant wait for the op-amps to arrive (your right - this is addictive!) Thanks again, Sam
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matt7941
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Post by matt7941 on Feb 8, 2010 19:26:35 GMT
Good evening Sam.
Yes, bending the legs of the 744s is quite straightforward as they are relatively "soft", but be gentle as they are reasonably delicate. Remove pin 6 as close to the body of the opamp as possible and bend pin 5 to fit in pin 6's socket on the adaptor (Mike's picture on page 9 of this thread is how they should end up looking). A miniature pair of snipe nose pliers is ideal if you have them to bend the legs. This mod. is actually the OB (output bypass) mod and not the class A modification. The class A mod involves soldering a resistor between pin 7 and the bent pin 5 to bias the output to class A. However, the class A mod is potentially damaging as mentioned elsewhere by other esteemed members. Stick to just the OB mod and you won't go far wrong. It is certainly worthwhile in this application with decent gains in overall sound quality.
Once you've done the OB mod. on both the 744s you are quite correct that they just push in to the adaptor's sockets which in turn is pushed in to the socket on the Aune.
Re. replacing the OPA2134 with the OPA2107, it simply is just a case of extracting the OPA2134 from the socket and inserting the OPA2107.
As with any opamp swap, just ensure you insert them the correct way round. Pin 1 is usually marked with a little dot or depression next to the appropriate leg on the topside of the opamp's body. Otherwise, it will have a "D" shaped notch on the top surface at the pin1 end of the opamp. If I remember correctly the Browndog adaptor is also marked up to show the correct orientation for fitting the opamps.
Glad to hear that you got in to the Aune ok. Reassembly should be straightforward as long as you heed the advice on the PDF.
Good luck.
Cheers,
Matt
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Post by rosewind on Feb 15, 2010 20:40:35 GMT
Hi there.
I have ordered an Aune amp - (not the SE version, though). I'll have a listen, pop the case open, and then see if I have the guts to do the opamp rolling. I found a Danish store that carries the three opams (2 x AD744 / 1 x OPA2107). I am still looking for the browndog adapter for the two AD744s as the store didn't seem to carry that particular browndog adapter.
To go with the Aune, I have bought a set of Superlux HD 660 - I hope this is going to sound better than my defunct Sennheiser HD490s.
Great forum!
Best wishes, Peter
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Post by clausdk on Feb 15, 2010 20:52:39 GMT
Hi there. I have ordered an Aune amp - (not the SE version, though). I'll have a listen, pop the case open, and then see if I have the guts to do the opamp rolling. I found a Danish store that carries the three opams (2 x AD744 / 1 x OPA2107). I am still looking for the browndog adapter for the two AD744s as the store didn't seem to carry that particular browndog adapter. To go with the Aune, I have bought a set of Superlux HD 660 - I hope this is going to sound better than my defunct Sennheiser HD490s. Great forum! Best wishes, Peter Hi Peter Good to see a fellow dane on the forum, Welcome..
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Post by PinkFloyd on Feb 15, 2010 22:00:07 GMT
Hi there. I have ordered an Aune amp - (not the SE version, though). I'll have a listen, pop the case open, and then see if I have the guts to do the opamp rolling. I found a Danish store that carries the three opams (2 x AD744 / 1 x OPA2107). I am still looking for the browndog adapter for the two AD744s as the store didn't seem to carry that particular browndog adapter. To go with the Aune, I have bought a set of Superlux HD 660 - I hope this is going to sound better than my defunct Sennheiser HD490s. Great forum! Best wishes, Peter Hi Peter, Welcome to the forum Just out of interest, what is the Danish shop charging for the OPA 2107? I have quite a few of these in stock and charge £9 each for them. Do try the OPA2107 in place of the AD-744 too.... the OPA2107 is also excellent in this position.... well worth trying Mike.
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Post by PinkFloyd on Feb 15, 2010 22:14:01 GMT
Nice guide Matt but it's not necessary to remove the knob.... just undo the four screws on the front, that's all that is required.
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Post by PinkFloyd on Feb 15, 2010 22:16:26 GMT
Matt.... try the 2107 in place of the 744's.... let me know what you think.
Mike.
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Post by paradigm on Feb 16, 2010 9:41:10 GMT
Hey guys been awhile. Hey mike, this look like a nice amp/dac compo, wonder how well it stacks up with my O1 DAC, or when i had the GS novo?
Nathan
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Post by rosewind on Feb 16, 2010 13:29:06 GMT
Clausdk and Mike.
Thanks for the welcomes!
Mike.
The Danish supplier charges ... the double of what you do it seems. If I wanted to test the 2107 against the 744s, would I need just one extra 2107?
And would you be able to supply me with 2 x AD 744 + the browndog adapter (for the two AD744s)?
And what would shipping to Denmark be?
Thanks!
Peter
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toad
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Post by toad on Feb 16, 2010 14:36:33 GMT
Hey guys been awhile. Hey mike, this look like a nice amp/dac compo, wonder how well it stacks up with my O1 DAC, or when i had the GS novo? Nathan Hi Nathan, Nice to see you back on here. To quote myself from earlier in the thread: Ok I've had the AD744s in the Aune for a few days now and I really like them. The Aune now has a warm and rich sound that reminds me of the GS Novo with less soundstage. Hope that helps Ian
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Post by paradigm on Feb 16, 2010 16:40:11 GMT
Thanks Ian, I recommended this to a friend to get them into Headphone Amps. Nice cheap start. Hope to share some music with you guys soon. Hope to make a shpongled type track Nathan
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Post by rosewind on Feb 18, 2010 15:51:31 GMT
What are the exact part numbers of the AD744 and Opa2107? I have seen AD744s with different extensions (i.e. aD744jnz) and the Opa2107 seems to have been made by two manufacturers, one of which is Burr Brown. Any help would be appreciated Peter
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Post by PinkFloyd on Feb 18, 2010 21:30:29 GMT
What are the exact part numbers of the AD744 and Opa2107? I have seen AD744s with different extensions (i.e. aD744jnz) and the Opa2107 seems to have been made by two manufacturers, one of which is Burr Brown. Any help would be appreciated Peter I don't keep stock of the AD-744 (run out) you are looking for dip8 versions AD744JN or JNZ are fine. The OPA2107 you can try in BOTH positions in the Aune.... just shuffle things about (ie: Remove the 2604 and try a 2107 in it's place.... remove the 2134 and try an OPA 2107 in it's place) There are no hard and fast rules.... whatever sounds best to your ears. I can do you 1 OPA2107 for £9 or two for £15. Shipping will be £3 Mike.
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Post by rosewind on Feb 19, 2010 0:44:57 GMT
Mike. I'll take two Opa2107s then. I cannot get the AD744s in Denmark, as I need to be registered as a company to shop ... The same applies it seems to Germany and the UK. So ... what to do? However, I just ordered a browndog adapter in the US, so that's taken care of. And I just got a set of nice Superlux HD-660s which I expect will sound superbly with the Aune ... Thanks! Peter
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matt7941
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Post by matt7941 on Feb 19, 2010 16:20:05 GMT
Good afternoon Mike.
Sorry I didn't respond to your post sooner, I've had a bit of a hectic week or so.
Unfortunately I won't be rolling the 2107 in to the "2604" position in the Aune, because I've removed the 2107 from the "2134" position and placed them in my X-24K (my only pair). Sadly, as far as the Aune goes, they suit the X-24K (in the buffer position) so well (with LM49720HAs as I/V) that there is no way they're coming out. They are so sweet and melodious. I've rolled the opa2111s that were in the DAC in to the Aune but they don't suit it whatsoever. The bass is overblown and muddy, the separation has been replaced by congestion and the top end sweetness has all but gone walkabout. The first chance I get the AD744s are going back in and I'll pick up another couple of 2107s. However, it won't be for a while yet as I've so many other things on the go at the moment.
How is it sounding to you now the opa2107 has been in for a while?
Cheers
Matt
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Post by antigeek1 on Feb 19, 2010 21:14:27 GMT
Just Replaced the original opa2604 with one of the OPA2107 chips that arrived in the post this morning.
Even from cold the OPA2107 is quite a decent upgrade over the opa2604 . Its more natural, detailed and musical.
The AD744 upgrade is also an amazing improvement over stock and well worth doing.
I will say that the amplifier stage of the Aune is in a higher league than its internal DAC.
The Aune makes a very worthy headphone amplfier in its own right and coupled with my newly constructed Buffalo Sabre 32 DAC works a treat!
Well done on unleashing its potential Mike!
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toad
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Post by toad on Feb 19, 2010 21:27:14 GMT
I will say that the amplifier stage of the Aune is in a higher league than its internal DAC. Couldn't agree more. Good value all the same though
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Post by PinkFloyd on Feb 19, 2010 21:55:45 GMT
Just Replaced the original opa2604 with one of the OPA2107 chips that arrived in the post this morning. Even from cold the OPA2107 is quite a decent upgrade over the opa2604 . Its more natural, detailed and musical. The AD744 upgrade is also an amazing improvement over stock and well worth doing. I will say that the amplifier stage of the Aune is in a higher league than its internal DAC. The Aune makes a very worthy headphone amplfier in its own right and coupled with my newly constructed Buffalo Sabre 32 DAC works a treat! Well done on unleashing its potential Mike! Look at the OPA2107 as a "dual" version of the OPA627.... the "specs" may differ slightly but there is definitely a link sonically..... I have always classed the 2107 as a dual 627 ..... Glad you like it
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Post by antigeek1 on Feb 19, 2010 22:02:22 GMT
I'm loving it. Its a smoking hot combination! Definelty a huge performance boost. Even the bass has been perked up nicely!
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Post by antigeek1 on Feb 19, 2010 22:04:28 GMT
Have a spare OPA2107 if anyone needs it..
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matt7941
100+
Mmmmmmm... Pork scratchings.....
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Post by matt7941 on Feb 19, 2010 22:33:07 GMT
If the opa2107's still going spare can I take it off your hands?
Let me know how much you want for it or I have various other opamps etc going spare if you want to sort out a swap?
Cheers
Matt
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