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It's Taylor DAC v2.0

Thanks Andy - and I mis-refer to pin20 when I mean pin 7.

It was probably gin actually -accuracy & verbosity in inverse relation to %ABV ;)
 
Maybe - better is better and all that. Actually I find the mixer makes-or-breaks it; minimise your dialectric absorption ;)
 
Andy,
excellent info (as usual).
Regarding bypassing the electrolytes, I have some Sibatit caps (100nF & 33nF), would you reckon they are OK for this?
I also wonder which caps I could use for the 3300pF-Pin-20-to-21 connection; I have Styroflex caps of the right capacity at hand, would they do the job or should I get some ceramics?

Kit,
I am quite curious about your opinion on this DAC; my own implementation (based on a DDDac board) is half-finished, and my expectations might be too high already. I guess my question would have to be: does it sound musically involving? I can deal with a lot of shortcomings, but the sheer boredom that my NAD exposes has to be bettered. If it sounded like a Sony PSX I'd call this little project a success, no kidding.

Best regards,

Oliver
 
Originally posted by coredump
I am quite curious about your opinion on this DAC; my own implementation (based on a DDDac board) is half-finished, and my expectations might be too high already. I guess my question would have to be: does it sound musically involving? I can deal with a lot of shortcomings, but the sheer boredom that my NAD exposes has to be bettered. If it sounded like a Sony PSX I'd call this little project a success, no kidding.

As always, don't believe the hype :)

I think it sounds great, but it has a very particular sound I've become attuned to over time that might sound weird to fresh ears.

What's seems to have happened is that energy from the top and upper middle has been shunted down into the mid bass. The dac sounds rich, atmospheric and kicks like a mule. To my ears this is more like live music than anything I've heard. BUT...there is a certain something that's not there, some sort of magical aura that might bother some by its absence.

The thing to remember is that whilst the DAC is very simple, a massive array of sounds can be achieved just by swapping components. It's easy and fun to build, but the tuning is the real work.

But hey, if you don't like it you're free to buy a £6,000 dac instead of building a £60 one :)
 
One thing I'm going to try with the next dac version is decoupling solely with ceramic SMD caps. These are small enough to wedge between the body of the CS8412 and the supply pins, the closest possible connection.

I've tried swapped the digital decoupling for a single 4.7uF / 16V / Y5V / 1206, which seems to have loosened and opened things up a bit. The simplicity and smallness is ideologically gratifying too.

Regards the PLL filter cap, is film the definite best type? A ceramic SMD would keep things neat, though they're a bugger to try and solder onto a foil groundplane.
 
egards the PLL filter cap, is film the definite best type? A ceramic SMD would keep things neat, though they're a bugger to try and solder onto a foil groundplane

You want something non-microphonic here, so some good SMD ceramics will be fine (NP0?).

Maybe better still try PPS in SMD, but be VERY careful with the iron - they damage easily.

Andy.
 
Thanks Andy. Any kind of PPS SMD you can recommend, or indeed any special SMD soldeing iron?

Right about melting. All the film caps I've used have been slightly resculpted by my good self :)
 
Digital and analogue decoupling caps on the CS8412 are now both 4.7uf SMD ceramics only.

Quite a striking change. Bigger, smoother, looser, a lot more physical and dynamic, less pacy but pitch and timing is all there. Sounds very loud, with instruments having a tendancy to drown one another out.

Jolly good if you ask me.
 
I'm told Y5V caps are very microphonic. With this in mind, would it be best to solder them directly onto the IC pins or the regulator pins?

Given that the regulator is big with long leads, does it add resonance or acts as a vibration sink.

The sound is still improving, though I find just leaving the dac to idle makes more difference than 24/7 burn in.

I was worried the dac has a synthetic character, perhaps due to compression or distortion. What seems to be happening is that the dac is incredibly revealing of the character of a recording, whereas I'm used to my CDs sounding pretty much the same qualitatively and varying only on quite quantivtative technical grounds, ie degree of FUBAR'd-ness.

I've said this before but it's really true this time :). Listening to the (superb) first volume of Prince's greatest hits, the early 80s songs have a very analogue dry and crisp quality, whilst it's very obvious that the later stuff has had loads of technology applied to it. Compare "When U Were Mine" to "Pink Cashmere," and the latter is technically impressive but very artificial.
 
I took the Pony's advice and invested in a 12 pack of Harp and the mighty Quo's greatest hits (12 Gold Bars). I'm not sure which caused the problem but I had to inspect the household ceramics at close proximity after the 10th can of Harp and during the middle 8 of Down Down.

Can anybody shed any light on this?
 
Modding continues apace.

Swapped the decoupling on the TDA1543 for a single 4.7uf SMD ceramic. Bit disappointing compared to the improvements these caps made to the CS8412. Sound became a little veiled and artificial, with noticeable glassy ringing in the upper mid. More snap, though.

I've separated the analogue and digital grounds. Pin 21 and 23 now connect to pin 22 (A gnd) via insulated silver wire, as does the loopfilter on pin 20. The cap on this is now 2.2uf Wima polyester.

Quite a dramatic change. The sound has lost its ludicrous power and hugeness, but is now very crisp and precise. I've heard this effect before when usinging jitterboxes with other dacs, the difference is that Taylor DAC sounds lush and harmonically rich rather than dry and pinched. Notably, basslines are much more textured (hear the fingers on the strings etc), with more of mid bass emphasis that does unfortunately seem to interact more with the room.

Keith Hudson's classic Pick a Dub is a good case study. I'd heard this as a tough, boisterous dub album all intent on blasting me with mighty sonic booms. Through Taylor DAC it sounds extremely sparse and eerie.
 
Before I start, WARNING!: make sure you stack the TDA1543 ontop of the CS8412 in the correct orientation. I sppent ages building a dac only to put the 1543 on back to front and fry the whole shebang. Pin 1 is the one nearest the notched end of the 1543, and should connect to pin 12 of the 8412.

Right then. The newest addition to the family is setup as before, with the following unique features:

Four 30mm foamed butyl rubber feet, so it can sit directly on the shelf of my rack.

75R Welwyn RC55 on each digital output pin

The loop filter is a 499R Welwyn RC55 followed by a 4.7uf Y5V 1206 ceramic.

Good old Sanyo 220uf OSCON G-type for coupling cap. The difference is that I've peeled them, which some say makes for a more natural sound.

The TDA1543 is bypassed with the quadruplet discussed previously.

Each LM78XX is bypassed with a Rubycon ZA 10uf 35v on the input, and a 100nf X7R 0612 ceramic on the output.

This cap combo is also sued to bypass the Rubycon ZL 3300uf 16v that provides local filtering.

I'm slumming it with Welwyn RC55 I/V resistors, as I've buggered the Audio Note tantalums. I'm using Peter Daniel's recommended 3k0 value, rather than the 2k3 value theory calculates for an 8v supply.

It's hardly had any run-in yet so the treble sounds like sand and glass, but it's the best "from cold" sound I've heard yet. Ultra dynamic, the tom toms and kick drum on Morphine's excellent Cure for Pain feel like I'm going to poo my pants!

Subject to some minor revisions, I think this is the one.

Woo!
 
Originally posted by Kit Taylor

feel like I'm going to poo my pants!

Know the feeling Man!

After about 10 cans and a good couple of hours stomping to the quo, I DID POO MY PANTS.
I put this down to the fact that I rushed my tea, (a Chicken Vindaloo) drank far too much, and then stomped on a full stomach.

Won't be doing that again. Well, not until this Saturday.
 
Back to the Audio Tant resistors for I/V. Chunkier and groovier, smooth without lacking grunt.

The Welwyns are rubbish for I/V, sharp and grainy. I do use one for Vref, its smallness makes for easier construction.
 
Does anyone know where to buy the SN75179BP buffer chip? I remember reading about how spdif signal boosting just before CS8412 could substantially improve the sound.

Sounding good here. The speakers are 5m apart and toed in about 60 degrees, and the image is as stable as the recording allows (some mixes seem decidely wobbly).

I've changed the interconnect between the L200 and HX1.2 from Chord Anthem to a zero connector silver, and this little amateur project is starting to sound seriously professional.

What's interesting now is that the better the recording the more superficially soft and indistinct the sound. My cheapo Scientist ....Meets the Space Invaders sounds very tough and steely, but Chick Corea's Return to Forever seems to have had all the deges filed off. Thing is though, the cymbals are loaded with harmonics and the murky, down in the mix bass has strummed chords and all sorts of interesting new embellishments.
 
Originally posted by Kit Taylor
Does anyone know where to buy the SN75179BP buffer chip?

I managed to find some McCains chips in my local supermarket, I found them to be very stable but quite hot after 3 minutes in the microwave, not sure how they'd work in the DAC tho' as they are not some much of a buffer chip but more a chip buttie.
 


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