ebay DAC

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al newall
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#46

Post by al newall »

Neal wrote:Detail, tone and texture all better on the Biscuit DAC than the AK at the moment....the AK will be tweaked over the break to see how it improves. Waist line already expanding!
I find that quite intriguing, because although i can't compare the two side by side, i know that i'm hearing things now that weren't obvious before.

My Cirrus DAC was heavily tweaked, and the new one is only partly modded.
Much to learn there is.
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floppybootstomp
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#47

Post by floppybootstomp »

Have been listening to mine for the past few hours and yes, it does make a difference, I was actually wondering about that ;)

The two things that struck me immediately were a tighter bass and more detail. I'm using this with my media computer, medium priced Asus motherboard with onboard evverything including Nvidia 8200 graphics.

Toslink out to converter to co-ax, into the DAC and onto switcher.

I bought from Here cost £44.84 inc postage, parcel marked as gift so no import duty.

I chose that one from lots of 'em simply because it seemed to be the cheapest. Ordered on the 16th, arrived 23rd, pretty good, one week delivery.

The transformer lists two 9V rails as the pair of blues and the pair of whites but in fact the only combination of those wires to give me 9V was the pair of whites. The blues gave 5V, not that it mattered much.

So, 45 quid for board & TX; a tenner for the Toslink/coax converter; twelve pounds for a case from maplins and about four quid for sockets and mains cable make total cost about £71.00.

You can buy a ready made one in a case for around 85 but their case is silver and I wanted a black one. I will probably fly the onboard power LED to the front of the case and add a power switch.

Apart from lots of FLAC files also listened to the first part of 'Echoes' from the Pink Floyd at Pompeii film from an avi file on the computer and that sounded quite marvellous. I do love that track in the film, always gets me tingly, Pink Floyd get funky and oooooo, weren't they young back then? My goodness.
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colin.hepburn
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#48

Post by colin.hepburn »

Hi All
Now that I have acquired two AK4396 dacs the plan for now is to leave one as standard apart from the already changed op amp

So for the other AK dac I want two add a Valve output Stage to it but which valve to use anyone got any ideas for the valve output stage and a schematic if possible thanks :)
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#49

Post by colin.hepburn »

Hi all this may help get a response to my Question on a good valve buffer for the eBay AK4396 DAC
This is the possible psu using the said TXs Hammond 229B230 12VA 230CT@50mA More details on TX here http://www.hammondmfg.com/229.htm
Heater TX is a Tamura PL20.28.130B 14volt @1.5Amp so 12.6 volt heaters
So any suggestions on a valve buffer to go with this psu HT 200/250volt would be helpfully
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andrew Ivimey
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#50

Post by andrew Ivimey »

The lampucera DAC is louder than the AK (imho) - this almost always makes things sound better.

I've built two of these AK Dacs - never again! all those fiddly components - bah! One day I will add a valve stage to one of my DACs but it takes so very looooooonnnnnnnnnnnnnnnggggggggggggg to do anything.

I'm using different output i.c.s and I'm still not convinced they are better than the supplied NE5332s - whihc, on paper are inferior; different but not necessarily better. One day I will decide.
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al newall
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#51

Post by al newall »

andrew Ivimey wrote:The lampucera DAC is louder than the AK (imho) - this almost always makes things sound better.
You may be right about that, but i hadn't noticed much difference in the volume knob position.
If you are right, that could explain the dynamics thing i've been missing.
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pre65
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#52

Post by pre65 »

My "other" e-bay DAC has a 3v output, so will of course sound louder. It also has two separate op-amps.

Unlike Andrew I found changing the NE5532 op amps (for LM4562) a noticeable positive experience. :)
Last edited by pre65 on Fri Dec 30, 2011 8:40 pm, edited 2 times in total.
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colin.hepburn
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#53

Post by colin.hepburn »

Yep I noticed a change as well when I changed the NE 5532 out for the LM 4562NA in a tighter bass and a bit more lower Detail with cleaner mids But i also want to try a valve buffer on the other AK Dac plus upgrade some of the caps for Oscon and silmic types maybe :)
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Paul Barker
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#54

Post by Paul Barker »

It boils down to the other elements in the chain requiring the fix / revealing the improvement. Insert the one which doesn't offend you reader. But a difference between opamps is clear to some.
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#55

Post by Max N »

OTOH, Andrew doesn't say which op amps he has fitted. Maybe the ones he has tried aren't 4562?
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andrew Ivimey
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#56

Post by andrew Ivimey »

On the two AK DACs I have side by side compared NE5532s ith OPA627s. They sound different but I haven't decided which is actually better.
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#57

Post by Neal »

Biscuit DAC is finished...loads of room to add bits...found an unused ALWSR so will pop it in and then leave it as is for comparison to the AK DAC....which has had no mods yet.

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Just counted up I've got 7 DACs in the house....I must be mad :?
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#58

Post by Mike H »

andrew Ivimey wrote:On the two AK DACs I have side by side compared NE5532s ith OPA627s. They sound different but I haven't decided which is actually better.
Your post bit old now but if you get a chance, when using NE5532 might try connecting 3.3k resistors between o/p's and negative rail, see if that does anything. :D I'm assuming your op-amp supply rails are 12 - 15V. :?:
 
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#59

Post by colin.hepburn »

Ok after some confusion with double sided pcbs boards I have had the Ebay FET Buffer up and running the last copual of weeks

As far as the sound improvements go well I would say it's about the same as the step up from the stock NE5532P was to the 4562NA op-amp in my view the 4562NA was a bit more open airy more space between instruments and more detailed a round vocals
Adding the FET buffer kept what the 4562NA op amp was doing but sounded smoother with more width and depth to the sound stage so is a worthy upgrade to the Ebay 2496 Dac fother upgrades to this dac with be the input cap and a couple of oscon caps in the digital psu plus maybe some better Low Impedance 2200uf 63volt
Buffer PSU
Is a Rod Elliott. Project 05 Rev-A LM317/337 regulators
Which has an uneven voltage outputs
17.7v out from the 337
14.9v out from 317
This maybe my oversight in not checking if the two 2,2k resistors on the LM337 side were matched
The FET
Seems to work ok with the voltage difference on the LM 337
The Dac appears to have 2.5volts offset on its output from the Dac chip i first added 1uf poly caps to the dac output this killed the bass and sounded thin change to the Russian K42Y-2 0.22uF PIO capacitor excellent sounding caps and this sorted it out and got it back to the description above I have a match pair of the Russian FT-2 0.1uF teflon capacitor to try i have a second 2496 Dac which i will add a valve buffer too 8)
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The Regulator schematic

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colin.hepburn
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#60

Post by colin.hepburn »

Well The Ebay AK4396 Dac is sounding good at low volumes but a big problem now that it's running in to the 6L6 amp

I have lost the gain from the dac I got from the JE. KT66 so now I have lost that magic the KT66 gave the 6L6 just starts to sound grainy and to much gain over sensitive with vinyl :(

At some point I get the WAD Pre2 CF setup which may help but I don't really want to put the dac through the pre any ideas on how to sort out the gain from the Dac
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