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Post by briankt on Apr 3, 2011 21:24:51 GMT
with Mike's help I have just installed two AD744's......wonderful sound. Thanks Mike!
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Post by PinkFloyd on Apr 3, 2011 22:50:48 GMT
with Mike's help I have just installed two AD744's......wonderful sound. Thanks Mike! Heh.... No probs Brian.... when you get bold enough you may get round to bending those legs.... If truth be told the 744 probably sounds the same with straight legs Enjoy the music man Mike.
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Post by PinkFloyd on Apr 3, 2011 22:52:50 GMT
Forgot to say....... welcome to the forum Brian All the best, Mike.
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Post by briankt on Apr 4, 2011 1:12:23 GMT
thanks Mike! very much glad to be here. thanks for taking the time to help a newbie like myself. very much appreciated. the difference was absolutely amazing. I have to say I was a little bit more than skeptical....but with your help the mod was simple and most assuredly worthwhile. waiting now on the 2107's. \
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toad
Been here a while!
I am the Super Toad, the Original Toad, the Whole Toad and nothing BUT the toad.... don't forget it!
Posts: 1,223
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Post by toad on Apr 4, 2011 8:33:32 GMT
Welcome Brian.
The Aune is a great piece of kit and represents excellent value for money. The AD744s just add to what is already an impressive little DAC/amp.
Enjoy it.
Ian
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Post by lark on May 1, 2011 7:26:36 GMT
Hello all, I'm new here (first post) and have a few questions about the Aune and opamp rolling. Firstly I'm rather ignorant when it comes to audio amplification circuits, so there are a few details I'd like to understand. I see the terms 'dual' and 'dual mono' being used, I expect this refers to the number of channels that it can be used to amplify - dual mono = 2 channels (we'll use for stereo)? Such, that if I want to use a 'non dual' opamp I'll need to use a browndog or dual to mono adapter? Or can they be used without the browndog adapter? There appears to be 2 opamps in the aune, one is used as an amplifier and the other as a buffer - not that I really know what the term buffer means in this context - what I have found through some quick research is that the buffer can help with impedance issues - but I would like to have a better understanding. What I'm wanting to understand is the function of each of the opamps and what effects I should expect when changing them - by this I mean, changing the buffer will do XXX whereas changing the other opamp with do YYY. I've just ordered a Anue DAC/AMP SE Limited edition ( cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=320682924519&ss ) (which from what I could tell (and am hoping) is this is the SE MkII with the better (?) caps, resistors and potentiometer?) I'm wanting to use this to drive my AKG k702s via USB - in the specs it shows this will drive headphones up to 600ohm impedance, this sounds like it should be enough to drive the k702 ? Any guidance will be greatly appreciated. Cheers.
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Deleted
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Post by Deleted on May 1, 2011 7:35:05 GMT
Dual mono means that both channels are completely separate, even for the power supplies.It's like having 2 separate amplifiers merely sharing the same case, and an earth connection.
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Post by lark on May 1, 2011 8:37:55 GMT
Thanks sandyk.
I see you're in Sydney. I'm in Adelaide - any hints on where to get opamps here in Australia? Most the ebay ones are being shipped from OS and postage seems to be as much as the chips... Any local suppliers that are well priced? I want to try out the AD744...
Cheers.
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Post by Deleted on May 1, 2011 9:51:41 GMT
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Post by lark on May 1, 2011 10:15:56 GMT
Thanks Alex, You're a legend.
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Post by lark on May 4, 2011 11:25:51 GMT
Ok, so I've got my Aune on the way, but I need (and want) another headphone amp (one for work, one for home).
I've been reading throught the Jaycar headphone amp thread from back in 2008 (only up to page 13 out of 98!!!! wow that's a long thread). Now I'm looking at grabbing one of these kits - Altronics seems to be the only manufacturer/distributor of these now.
My question is - how do the Jaycar amps compare to the amp in the Aune? Given that the complete Aune can be had for about $AU140 and the Jaycar kit amp is only $40 just for the amp and power supply module (and still needs other bits and a case, pot, etc) I'm wanting to know if the Jaycar amp is better than the Aune (as an amp, ignoring the DAC) .
Since the Aune has a DAC also, and it's still cheap, is it worth getting the jaycar amp?
I've build many kits and repaired many electronic devices, so chucking the kit together will be easy for me and a bit of fun...
What's your thoughts?
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Post by Deleted on May 4, 2011 11:57:13 GMT
Lark Jaycar still has them as KC-5417 and KC-5418 in their brand new 506 page 2011 catalogue. I expect that this fully modified version, assuming you can either source or make your own JLH PCB will be markedly superior to the other. Check out the "Tweaks" thread in the same area, as it is much easier to digest. Alex
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Post by lark on May 4, 2011 13:02:28 GMT
Lark Jaycar still has them as KC-5417 and KC-5418 in their brand new 506 page 2011 catalogue. I expect that this fully modified version, assuming you can either source or make your own JLH PCB will be markedly superior to the other. Thanks again for your speedy reply Alex, I rang around a few Jaycar stores today and none had stock, I then rang their supplier (Electus www.electusdistribution.com.au/ ) and they said it has been discontinued... Maybe Jaycar can still source them from elsewhere (?). I was impatient and wanted to grab one today so I didn't ask Jaycar if they can order one in.. I've found them cheaper from another place for only $25 rather than $35 from Altronics/Jaycar. I'm pretty sure they are an Altronics re-seller.. So I think they will be safe to go with.. I'm just unsure whether these will sound better/worse/same than the Aune? Any idea? If they are not as good (sonically) as the Aune, I'd probably just get another Aune (which I'm yet to hear)... I'm going to be driving K702s with then if that makes any difference to which will be better... Lark I expect that this fully modified version, assuming you can either source or make your own JLH PCB will be markedly superior to the other. Excuse my ignorance, but what is JLH ? And what is the 'other' that it will be superior to? Check out the "Tweaks" thread in the same area, as it is much easier to digest. Alex Edit - I just found the Jaycar amp section (SCHA ) - didn't even see it there before - I just stumbled upon the original thread! Thanks again, Lark.
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Post by Deleted on May 4, 2011 13:21:20 GMT
Lark It will be superior to the Aune amp if fully modified. The JLH "Ripple Eater " is a very wideband, very low impedance addon regulator with a typical noise level of around 4uV. You will find a schematic etc. in the "Tweaks" section of that area. PCBs are no longer available, but several members have etched their own, or used other methods. See also , in the power supply section users.tpg.com.au/gerskine/greg/default.htmAlex
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Post by lark on May 4, 2011 13:35:25 GMT
Great stuff alex,
Now I've found that WHOLE SCHA SECTION I've got enough reading to keep my busy and tweaking for a long time!
This is an awesome forum.. I'll be hanging around here for some time! Can't wait to get some this kit and start tweaking this baby!
Cheers.
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Post by JohnnyBlue on Jun 10, 2011 17:23:36 GMT
Following my enquiry in the Computer Audio section, I've snaffled a used Aune Mini DAC Mk2 off eBay, but I'm more than a bit confused about using it (there's no manual with it). 1) Using the USB out from my PC to the USB in, and the HP output on the front, it all works perfectly (USB/SPdif switch has to be in the USB position, obviously, and the A/D switch makes no difference). 2) Trying to use it as a stand-alone HPA: using the RCA INputs doesn't work (with, say, an MP3 player as source), but using the RCA OUTputs gives me a HP output at the front! (Again, the A/D switch makes no difference.) 3) Using the DAC as just a DAC, running from USB in, and taking an output from the rear RCAs into a separate HPA works as expected, so the RCAs in/outs must be correctly labelled. (And again, the A/D switch makes no difference.) 4) The Unlock and Power LEDs are both always on: I'm not clear what the former one does. I've read this entire thread (again!) and clearly I've got to improve the power supply (a cheap one-box solution would be ideal) but either I've got a duff Aune DAC (which I think is unlikely) or I'm not understanding how to use it properly. (That said, the main purpose for which I've got it -- as an external sound card, using the USB in and HP out -- works fine.) Any suggestions/explanations gratefully received!
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Post by lark on Jun 10, 2011 23:08:06 GMT
1) Using the USB out from my PC to the USB in, and the HP output on the front, it all works perfectly (USB/SPdif switch has to be in the USB position, obviously, and the A/D switch makes no difference). This is not correct, the A/D switch should switch from the USB/SPDIF to the Analogue input from the back.. Sounds like there's something not right on the insides... This again suggests that there is something not quite right inside.. When switched to A the RCA input should come out the front - when switched to A the SPDIF/USB switch should have no effect, but when switched to D the SPDIF/USB selects the digital source. Sounds correct, except, the A/D switch should make a difference here. The Unlock LED indicates if the unit has a SPDIF signal lock (is receiving SPDIF) and should go off when SPDIF source is attached. It is always on when no SPDIF is attached. I think this is likely given your issues. - It is possible the previous owner has made some modifications (?) or perhaps failed at making some or the unit is just faulty.. These are rather easy to open up, if you're up to it - have a quick look to see if everything looks ok... Cheers, Lark
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Post by JohnnyBlue on Jun 11, 2011 5:48:35 GMT
Lark,
Thank you for the prompt and detailed response. I'll have a look inside and see if there's any signs of tampering (I've downloaded the PDF on how to open it up, but not found a manual!).
The seller described it, somewhat ambiguosly, as "functions exactly as it did when originally purchased", so he can claim it was like that when he bought it...
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Post by lark on Jun 11, 2011 6:27:33 GMT
Yes does sound like some crafty wording...
With the skills of the crew around here, it shouldn't be too hard to work out the issue.
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Post by JohnnyBlue on Jun 11, 2011 9:51:20 GMT
Actually, on further playing around, I'm not so sure it is faulty...
I've just hooked up the Aune Mini USB DAC (which, on further reading around the web, turns out to be a Mk2 SE, judging by its green LEDs and power switch at the rear) to the only device in my house that has a S/PDIF output (a Cambridge Audio CD4 SE CD player).
Sure enough, as Lark wrote, the Unlock LED went off, but also the A/D switch started functioning normally, so that I could take the RCA output from the CD4 into the HPA input and switch back and forth between the two inputs.
Great fun! The S/PDIF input had the edge over the RCA, which I suppose is a reflection of the DAC that CA use in their cheap CD players.
So, the plot thickens!
Also, the problem of the A/D switch not apparently working has been reported by others: this is from HeadFi, "It seems there is something wrong with the A-D switch. Whenever I try to change the setting from D-A nothing happens. The DAC function of the AUNE works just fine, meaning that the switch will not let me change it to A, which in turn won't let me listen to my iPod. It makes sense. Does anyone know how to fix this switch? It seems like a real bummer to pay 40 bucks to ship it back for another replacement when I have a pretty good idea what the problem is."
For me, at least whilst using S/PDIF input, the A/D switch seems to work properly, and, in any case, I'd not intended to use the Aune as a stand-alone HPA, but to play music via USB direct from my PC, which it does very well.
I'm keen to try a bigger 18V PS, and I've rummaged around and found a Dell laptop PS that gives 19.5V, but has the wrong size plug, so I need to find a suitable line socket and 5.5 x 2.1mm plug that I can wire up (I daren't just bastardise the Dell PS, as it's for an ancient laptop that needs its backlight replacing -- I might get round to it one day!).
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Post by JohnnyBlue on Jun 15, 2011 10:57:04 GMT
Everything's now tickety-boo with my Aune Mini USB DAC: I don't know why it was playing up when I first got it, but everything's now working just as it should, after its little adventure with the S/PDIF input. I even managed to find a manual, at long last!
Just tried swapping out the 12V SMPS (actually, the one that came with the Aune Mini APE player) that I was using, for an old-fashioned, multi-voltage, proper trafo. It's unregulated and when set to 12V, it gives out 16.6V without load, and the result is a noticeable improvement in SQ over the SMPS.
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Post by lark on Jun 15, 2011 12:16:48 GMT
Everything's now tickety-boo with my Aune Mini USB DAC: I don't know why it was playing up when I first got it, but everything's now working just as it should, after its little adventure with the S/PDIF input. I even managed to find a manual, at long last! Excellent - it's always good to hear a happy ending Mine came with a 15V 1 Amp regulated power supply (not a switch mode job) so I guess I'm lucky. There are lots of comments that support improved SQ with regulated supplies over the SMPS - but I've had no experience with the latter on the Aune. Cheers, Lark
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Post by JohnnyBlue on Jun 15, 2011 12:44:24 GMT
It's proving a helluva job to find an off-the-shelf 18V transformer-based PS: the 18V PS suggested on the previous page is an SMPS, according to a response I've just had from the seller (which might explain why there was no improvement in SQ).
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Post by JohnnyBlue on Jul 5, 2011 6:30:04 GMT
When will I ever learn? I accompanied SWMBO to Tunbridge Wells yesterday so I could pop into Maplins and see what power supplies they had that might perk up the Aune a bit. Big mistake.
All the PSs over 12V were SMPSs, which I did not want, except there was one unregulated 24V jobbie, which, judging by the weight, had a trafo inside. I remembered the earlier postings here about their supplying 24V PSs with the Aune in China, and also thought since it was unregulated it'd drop down to a more sensible 20-22V under load.
Obviously I decided to check it first, so measured the output with no load and then with a 220R 3W resistor, to simulate an Aune-type load. I measured 35V and then 33V!
When I rang Maplins to complain that it was giving out too many Vs, the chappie told me that I should get a regulated power supply because, "a regulated power supply adapts itself to the voltage required by the device". Where do they find these people?
Anyway, I'm now stuck with a 35V PS that'll cost me more in petrol and parking to get my refund ("it can only be done here in-store, sir") than it cost to buy.
Like I said, when will I ever learn?
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Post by Deleted on Jul 5, 2011 7:32:31 GMT
No, when will Maplin's staff ever learn !!! There is no way a 24V supply should ever give such a high voltage with a light load.
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