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Post by Deleted on Nov 21, 2009 1:03:17 GMT
Matt Use the old NE55xx warhorses in properly optimised gear, with decent power supplies, and I mean low noise and low impedance,and they will certainly show their age. Power supplies seem to be taken for granted by many people. They should be taken every bit as seriously as the rest of the design. Look at all the attention to PSU that Leo and Will are giving to their Buffalo DACs as an example.Also look at the attention to PSU detail that Robert gave in his version of the SC HA. Robert is a qualified engineer too. Alex
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Post by Deleted on Nov 21, 2009 14:19:03 GMT
Do you other guys find the USB input better than the rca?
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toad
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I am the Super Toad, the Original Toad, the Whole Toad and nothing BUT the toad.... don't forget it!
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Post by toad on Nov 21, 2009 15:03:37 GMT
Personally I get a far better results from RCA but the DACs in my Arcam are better than the Aune so that's no surprise.
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Post by PinkFloyd on Nov 21, 2009 21:36:06 GMT
After a brief spell with the opa1612 under the bonnet (which I absolutely hated btw....) it's back in with the AD-744 and they are literally a breath of fresh air That lovely, airy, bassy, spacious, flowing sound is back and I won't be popping the hood again for a good while! (well, not until the B'dogs for the OPA827 arrive anyway ) Anyways.... when I had the AD-744 out I thought I'd take a few pics of how to go about performing the "OB" tweaks, direct to the chip itself. It's not that clear on Xin's site as a lot of his instructions are directed at the "socket" and not the chip. Anyways, here goes...... I hope I've got this right First off remove pin 6. Carefully bend over pin 5 to substitute pin 6: That's the OB.
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Post by PinkFloyd on Nov 21, 2009 21:59:43 GMT
Do you other guys find the USB input better than the rca? Well.... I am using the amp as a dedicated headamp / DAC so USB is my preference (some say SPDIF is a lot better).... I didn't buy the aune to be used as a standalone amp (I have dozens of them) I bought it to plug into the USB port of my computer and play Apple Lossless files which it does beautifully.... Simples!
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Post by namklak on Dec 1, 2009 17:13:19 GMT
The ad-744 does appear to be a fine chip, and the mod suggested above bypasses the class AB output stage (I'm all for that). But the final headphone driver stage topology in the Aune is class AB, and not even monolithic (nor constant-current driven DC bias) like the bypassed ad-744 class AB stage. So you've peeled one layer of the onion, but you still have an onion. Some year I'm hoping to spend the time necessary to delete the non-monolithic (aka unmatched) Aune class AB output stage. Or fix it. But fixing class AB is a little like fixing a soup with too much salt...
As mentioned just above, I don't think enough has been said about the power supply, specifically the one shipped with the Aune. Hopefully before Christmas I can measure what voltage the shipped supply dips to (which I'm betting is below my claimed mandatory 16V) and then see how the Aune behaves with a Tread at 18-20V. -BobK
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Post by PinkFloyd on Dec 1, 2009 21:52:49 GMT
At last..... the SOIC single to dual DIP sockets arrived and I have mounted a couple of OPA-827: Very early days but my first impressions were "the bass! Wow...." not Boomy bass either, just plenty of it with great extension underpinning things, not dominating. OPA827 has thrown up a few surprises already.... I am hearing subtle things I didn't know existed on Yello's latest album "touch Yello".... I'm not "listening" to the "chip", instead am relaxing listening to the album, as usual, and there have been a good few "ooh! never noticed THAT before" moments.... All very well and good as long as you don't have a "where has that trumpet gone?" moment.... none of that with the OPA-827.... everything is where it should be with more to boot! The sonic signature is quite similar to the classic OPA-627 though more vibrant.... not quite as chocolaty as the OPA627..... and, as I've said, the bass is just incredible.... think of OPA-627 with a built in "subwoofer" and you're getting the picture I'll give her a good week or so to stabilize in the circuit and will report back.... out of the box, though, she's good..... she's very good
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Post by PinkFloyd on Dec 18, 2009 23:03:40 GMT
The OPA 827 has been onboard for a few weeks now and it's a very good "general purpose" chip in the sense that it does nothing spectacularly but does everything acceptably.... there is the typical Burr Brown chocolaty "haze".... like listening with rose tinted spectacles on..... definitely musical, definitely enjoyable but, compared to the AD-744, lacks definition and that sense of "space".... with the AD-744 we are talking crystal clear clarity, the OPA-827 conveys the same "general" message but with an added coating of treacle. I like it as a "background" chip.... ie: one that you can listen to music all day through without having to sit up an get "involved" in the music..... it's like having Radio 2 on in the background whilst you're working....... enjoyable but nothing really reaches out and grabs you by the balls.... some may even find the OPA-827 a euphonic listen, and just what the doctor ordered, but I, personally, prefer a bit more bite and snap. Overall, the OPA-827 has a nice bouncy bass (boing boing boing).... energetic and typically "car sub woofer like" in nature (as I say, "generally pleasing / voiced for the masses") the mids are silk screened allowing a modicum of detail through but it's hard to cut through the haze if you really try to home in on any particular aspect of the mix..... the treble, again, is inoffensive and easy to listen to (smooth, silky, "acceptable") Not a lot more I can say really.... a bloody good chip for "easy listening" but not my cup of tea.... I'd rather an OPA-2107 (or even an OPA2227) over this any day..... the OPA-827 is certainly NOT an OPA-627 killer either! I've read a few reports suggesting this to be the case but, to my ears.... no way! The OPA-827 is closer to the OPA-2604 sonically and, if I had to choose, would go OPA-2604 (in this application anyway). Anyways.... back in with the AD-744 tomorrow..... I'm sending Toad a couple of mounted 744's to try in his Aune, hopefully he will report here once installed I'll give the 744 a week in circuit and will then "power roll" everything I have in my opamp armoury over the Christmas period..... I'm sure the 744 is not the only one that can make music in this amp
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Post by clausdk on Dec 18, 2009 23:36:57 GMT
Have you tried it with the GD-modules ??
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Post by PinkFloyd on Dec 19, 2009 13:37:04 GMT
Have you tried it with the GD-modules ?? I would love to Clause but they are far too big to fit in
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Post by clausdk on Dec 19, 2009 14:33:16 GMT
Have you tried it with the GD-modules ?? I would love to Clause but they are far too big to fit in I got an extensioncord for them, du you want to borrow it ?? I can send it toogether with the red leather pads
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Post by Deleted on Dec 19, 2009 14:46:53 GMT
Awh, go on Mike, you just need a silo hatch ala Dave (insomniac). Do you think the NG27 could drive one?(Sun) I hadn't thought to try until now ( I have 2 now ensconced in the main amp but a spare left from the SCHA )
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Post by rayg on Dec 19, 2009 15:45:46 GMT
Thanks for the review, Mike. I was browsing around looking to pick one up on ebay and came across this question on the auction listing, which leaves me a little bit confused:
Q: Is it possible to use this unit as a DAC AND amp at the same time? A: Yes. But only for the configuration below: DAC: COAX-in or USB-in -> Back line-out AMP: Back line-in -> Front headphone-out A/D Switch: A USB/SPDIF Switch: SPDIF
Does this mean you need to connect the "line in" and "line out" (using RCA's) in the back? And switch it to "A" and "SPDIF" in front even if you are listening to your PC using a USB connection?
Also, has anyone compared this to the Zero DAC/AMP?
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Post by PinkFloyd on Dec 19, 2009 21:43:58 GMT
Awh, go on Mike, you just need a silo hatch ala Dave (insomniac). Do you think the NG27 could drive one?(Sun) I hadn't thought to try until now ( I have 2 now ensconced in the main amp but a spare left from the SCHA ) Already thought about it Chris but the opamp socket is butted up too close to the ALPS pot for the Sun to fit in..... of course, we could fit the extension leads and carve up the top of the enclosure but is it worth totally shagging the appearance of the amp up? I think not. I will be trying the earth, sun and moon in the Aune over the Christmas period though (on extension leads) and may, yet, end up bastardizing the enclosure to accomodate one should they outperform the AD-744 Yes, I do think the sun would be fine in the NG27.... just be sure to check the DC offset before plugging your 'phones in..... actually man, I'll try a sun in my NG27 on Monday, I'll let you know how I get on
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Post by PinkFloyd on Dec 19, 2009 21:51:10 GMT
Thanks for the review, Mike. I was browsing around looking to pick one up on ebay and came across this question on the auction listing, which leaves me a little bit confused: Q: Is it possible to use this unit as a DAC AND amp at the same time? YES! You simply connect a USB cable to your computer. On the front panel you flick one switch to "USB" and the other to "D" that's that the signal is now going through the DAC and being amped If you are using a SPDIF connection you simply flick the switch to "SPDIF" and the other to "D" If you want to use the Aune as a standalone amp connected to the analogue in (ie: with CD as a source connected to the phono inputs) then you flick the switch to "A" (which stands for analogue) Hope this answers your question?
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Post by rayg on Dec 20, 2009 0:37:04 GMT
Yes. That is how I had understood it. The "Q & A" on the auction page just had me confused!
Thanks.
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Post by proximo on Dec 20, 2009 4:41:08 GMT
I've had the OPA-627 in my Aune for the last few weeks and like it very much. Today, I finally got around to trying the AD744 with OB/CA mod (as per your example a few posts back) and wow. Very nice. I've only had it in a few hours but so far it's the best I've heard with my Senn HD-650s. I noticed when looking at your post on how to do the OB/CA mods that you've removed the photos showing the resistor soldered between pins 5 and 7. Any reason for this? The OPA 827 has been onboard for a few weeks now and it's a very good "general purpose" chip in the sense that it does nothing spectacularly but does everything acceptably.... there is the typical Burr Brown chocolaty "haze".... like listening with rose tinted spectacles on..... definitely musical, definitely enjoyable but, compared to the AD-744, lacks definition and that sense of "space".... with the AD-744 we are talking crystal clear clarity, the OPA-827 conveys the same "general" message but with an added coating of treacle. I like it as a "background" chip.... ie: one that you can listen to music all day through without having to sit up an get "involved" in the music..... it's like having Radio 2 on in the background whilst you're working....... enjoyable but nothing really reaches out and grabs you by the balls.... some may even find the OPA-827 a euphonic listen, and just what the doctor ordered, but I, personally, prefer a bit more bite and snap. Overall, the OPA-827 has a nice bouncy bass (boing boing boing).... energetic and typically "car sub woofer like" in nature (as I say, "generally pleasing / voiced for the masses") the mids are silk screened allowing a modicum of detail through but it's hard to cut through the haze if you really try to home in on any particular aspect of the mix..... the treble, again, is inoffensive and easy to listen to (smooth, silky, "acceptable") Not a lot more I can say really.... a bloody good chip for "easy listening" but not my cup of tea.... I'd rather an OPA-2107 (or even an OPA2227) over this any day..... the OPA-827 is certainly NOT an OPA-627 killer either! I've read a few reports suggesting this to be the case but, to my ears.... no way! The OPA-827 is closer to the OPA-2604 sonically and, if I had to choose, would go OPA-2604 (in this application anyway). Anyways.... back in with the AD-744 tomorrow..... I'm sending Toad a couple of mounted 744's to try in his Aune, hopefully he will report here once installed I'll give the 744 a week in circuit and will then "power roll" everything I have in my opamp armoury over the Christmas period..... I'm sure the 744 is not the only one that can make music in this amp
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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!
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Post by toad on Dec 20, 2009 9:21:47 GMT
I'm sending Toad a couple of mounted 744's to try in his Aune, hopefully he will report here once installed Looking forward to listening to them Mike. Of course I'll post my impressions. You know me... I never shut up
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Post by PinkFloyd on Dec 20, 2009 11:50:28 GMT
I noticed when looking at your post on how to do the OB/CA mods that you've removed the photos showing the resistor soldered between pins 5 and 7. Any reason for this? Yes, A few guys here felt the resistor would put too much strain on the 744 so it's best to run the chip without the resitor in situ. Mike.
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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 Dec 24, 2009 17:19:21 GMT
The 744s arrived today. I've put them in the Aune and initial impressions are very good. Definately the best sound the Aune has produced for me. I'll post more in a few days as I'm busy with Family and Friends etc but that'll give the chips a chance to cook anyway. Things are definately promising though
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Post by PinkFloyd on Dec 24, 2009 20:45:49 GMT
The 744s arrived today. I've put them in the Aune and initial impressions are very good. Definately the best sound the Aune has produced for me. I'll post more in a few days as I'm busy with Family and Friends etc but that'll give the chips a chance to cook anyway. Things are definately promising though Glad they arrived before Christmas Ian If you find you "really" like them and they are keepers then, at a later date, it's best to remove the dil8 socket from the Aune and solder the 744 module onto the board direct.... this will also bring about subtle improvements. All the best, Mike.
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Post by fidelity on Dec 25, 2009 3:27:25 GMT
Any links to the best/cheapest place to order the AD744 from? I've not opened up my Aune MKII SE yet, ordered it with both opamps socketed...
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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 Dec 30, 2009 10:55:44 GMT
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. Personally I like a wide soundstage but there's something about the Aune with AD744s that makes me want to grab my headphones and slam out some rock. Electronic stuff sounds great too.
The bass on the Aune has improved no end. As you know I'm not a fan of bloated bass and although the Aune has plenty, it doesn't sound bloated. There's certainly a weight to the bass that wasn't there before the AD744s went in.
Mids are nice. Rich and warm but voices are a little more recessed than my Solo and Novo.
Highs are clear and there is good detail. Again not quite as good to my ears as my Novo or Solo but we're not talking huge differences here.
Overall the Aune sounds great. The AD744s really do suit it and I'm sure many of my minor quibbles are due to the soundstage and seperation. They could maybe be improved by a better power supply than the laptop PSU I'm currently using. I'm certainly more likely to try a better PSU now that's for sure.
Although the Aune is my secondary home amp used mainly for listening sessions when my partner wants to listen with me, when she's not about I am sure I'll be firing up the Aune to listen to Rock and Electronic stuff.
Cheers for the AD744s Mike, they really have improved the Aune no end.
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Post by PinkFloyd on Dec 31, 2009 22:30:31 GMT
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. Personally I like a wide soundstage but there's something about the Aune with AD744s that makes me want to grab my headphones and slam out some rock. Electronic stuff sounds great too. The bass on the Aune has improved no end. As you know I'm not a fan of bloated bass and although the Aune has plenty, it doesn't sound bloated. There's certainly a weight to the bass that wasn't there before the AD744s went in. Mids are nice. Rich and warm but voices are a little more recessed than my Solo and Novo. Highs are clear and there is good detail. Again not quite as good to my ears as my Novo or Solo but we're not talking huge differences here. Overall the Aune sounds great. The AD744s really do suit it and I'm sure many of my minor quibbles are due to the soundstage and seperation. They could maybe be improved by a better power supply than the laptop PSU I'm currently using. I'm certainly more likely to try a better PSU now that's for sure. Although the Aune is my secondary home amp used mainly for listening sessions when my partner wants to listen with me, when she's not about I am sure I'll be firing up the Aune to listen to Rock and Electronic stuff. Cheers for the AD744s Mike, they really have improved the Aune no end. Ian, Glad you like the 744 man. The real "bottleneck" in the Aune is the SMPS wallwart.... feed it a decent 20V of regulated DC and you'll get another 100% improvement in SQ, guaranteed..... The "soundstage and seperation" you comment on becomes reality with a half decent supply. This really is an amp / DAC that responds well to simple things like different opamps / power supply changes.... spend another, say, £100 on it and it will easily surpass amp / DACS costing a lot more. It's also essential that you feed it high quality lossless files (I use apple lossless through itunes) from a good quality computer (ie: not some old thing that's been kicking about in the workplace for a few years).... spend a bit of time getting it right and the Aune has the potential to amaze you. Mike.
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Post by rayg on Jan 9, 2010 16:46:39 GMT
Been enjoying the AUNE, and now I am itching to try building a DIY PSU for it. Anyone know of a good DIY kit and transformer (and whatever else is needed) from a US souuce that would match well with the AUNE?
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