[ziplock]

Does anyone have experience modifying this humble little DAC?

It uses the Phillips UDA1321T which is not too terrible of a chip in comparison to the BB PCM2702.

You can view the datasheet here:

http://www.alldatasheet.net/datashee.../UDA1321T.html

It has a low voltage rail-to-rail op amp on the output side which I think could be swapped for say an 8620. To get started, you would have to bypass the measly usb power with an external source to supply the proper voltage.

Other possible mods include the voltage regulator and capacitors to further reduce noise..

I think this little guy has loads of room for improvement.

What do you guys think?

~Zip

 

[oicdn]

Bump for a good question

 

[ziplock]

For those interested.

Well I finally got around to modding this thing. Instead of the 8620 and power mod I had suggested, I decided to go with a compatible out of the box op amp. OK, I'm lazy!

I replaced the National LMV358 with a TI OPA2365 and the results are very good! It has a very soft sweet sound, laid back, not very aggressive. The overall noise level is considerably lower. Soundstage has opened up a good deal and I'm really grooving to this plastic cheapy! I started my listening session with some vocal trance and later played some chillout ambient style stuff. Very pleasing!

I did have to fiddle with the volume and bass / treble controls to get the sound I was looking for. The Phillips part is a curious DAC. Instead of the tone being completely linear, the tone is mixed/faded at various volume levels. Example, at 50% volume, the tone controls are much more sensitive to change. Where as starting at 70% the tonal effect is less pronounced. At 100% volume the DAC will produce a flat response where the tone controls are disabled completely.

I realize that for some people this DAC's output level will not be satisfactory. To make up for the shortcomings, I recommend using an amp with a high gain setting and higher efficiency headphones. The result is very good.

My current setup at work is Xitel --> Go-Vibe V6M --> Sony MDR-V6. I will experiment with some Senns and AKGs when I get home.

Looking forward to additional mods after I get used to the new sound signature. Stay tuned.

~Zip

 

[oicdn]

What would you recommend doing to it to get an aggro sound? I listen to faster music, so laid back don't synergize well.

Hmm...think you can mod one for me?

 

[ziplock]

Quote:

Originally Posted by oicdn /img/forum/go_quote.gif What would you recommend doing to it to get an aggro sound? I listen to faster music, so laid back don't synergize well. Hmm...think you can mod one for me?

I was recently talking with Filburt regarding these low powered op amps. He suggested a AD8397 for a more aggressive sound.

You can look at it here:

http://www.analog.com/en/prod/0,,759_786_AD8397,00.html

I suppose I could mod it for you. Supply me with the part and shipping costs and I'll do it for free. PM me if you are actually serious about this.

~Zip

 

[scottiebabie]

yup i bought a xitel mini-link for 10 bucks used so its a great deal. i modded mine by essentially bypassing all the crap (includ opamp) and did a DAC direct to mini jack out utilizing a pair of tantalums as signal coupling caps. so far so good!

stock the mini-link was better than my onboard soundmax (AD1985 or something rather). modded to DAC direct out, resolution is definetly increased with all accompanying high resolution superlatives including deeper bottom, much more microdetailed, better soundstage, etc... i think as of now, its on par with an imod interms of SQ. i think a pair of Blackgates to replace the tantalums will move the SQ up a notch and will prolly try that soon.

best news is that installation is a cinch. windows xp recognized it instantly as another usb soundcard and i was able to use it immediately with itunes, foobar and windows media player. highly recommend as a very cheap alternative to any lappies onboard sound

 

[ziplock]

Quote:

Originally Posted by scottiebabie /img/forum/go_quote.gif yup i bought a xitel mini-link for 10 bucks used so its a great deal. i modded mine by essentially bypassing all the crap (includ opamp) and did a DAC direct to mini jack out utilizing a pair of tantalums as signal coupling caps. so far so good! stock the mini-link was better than my onboard soundmax (AD1985 or something rather). modded to DAC direct out, resolution is definetly increased with all accompanying high resolution superlatives including deeper bottom, much more microdetailed, better soundstage, etc... i think as of now, its on par with an imod interms of SQ. i think a pair of Blackgates to replace the tantalums will move the SQ up a notch and will prolly try that soon. best news is that installation is a cinch. windows xp recognized it instantly as another usb soundcard and i was able to use it immediately with itunes, foobar and windows media player. highly recommend as a very cheap alternative to any lappies onboard sound

Hmm, that is interesting. I may have to pick up another so I can have two with different configurations.

I have been considering changing the various caps littered about the board. Mine currently uses bargain bin licon caps, yuck! I was considering black gate or perhaps a high-end series from rubycon.

DC power on a PC is always noisy, not well suited for audio applications. I think it would be a good idea to mod the power section of the DAC. One solution would be to bypass the PC's supply with a wall wort solution from Elpac or the like.

It will be fun finding out how good we can make this Phillips chip sound!

 

[scottiebabie]

zipdude, if u can get your hands on another hifi-link cheap, i'l highly recommend the imod-type DAC direct to minijack mod. to be frank, im seriously understating the improvement in SQ as i'd rather not be accused of viral marketing or such!

i too have done the same DAC direct mod to my 5g 'pod (i named it the Gmod after the gentleman whose skills actually made it happen) and my modded mini-link sounds identical to my Gmod, to my ears that is.

another benefit is that its also possible to "tune" the sound depending on the type and value of the post DAC signal coupling cap. im currently using a pair of 47uf sharp tantalums in the mini-link and the sound is very good with deep impactful bass with a nice decay, clear forward mids with superb extension and micro details up top. i've tried it with a smaller value and it does change the (quickens) PRaT so one can truly tune it for their individual rigs and tastes.

i definatly wont be modding the power section to an external DC source as it would defeat my intentions for a small, portable and from the looks/feel of it, a bulletproof lappie SQ solution. perhaps it mite improve SQ via more stable DC power but im getting a zero noise black background as of now. replacing some components pre DAC seems a valid proposition though. however like me, u mite be totally stoked by the SQ just doing the DAC direct mod and would let sleeping dogs lie.

warning: signal coupling caps must be used to eliminate DC offset voltages else downstream components could be damaged if u should so do the DAC direct mod. another bummer is that an external amp must be used. goodluck and let me know how it goes. im surprized and stoked that a cheapie usb DAC like the pc-lini/mini-link can be made to sound so good. if i may say so, both my modded mini-link DAC and gmod 'pod trumps my ex home rig of marantz67SE + mod Zhaolu D2 combo by a fair margin!

 

[ziplock]

Hey there scottie.

Alright, I'm definitely picking up a second one for experimentation. You have perked the curiosity in me!

What amp are you using to juice up the signal? Is it one from your signature? Stock, it is obvious amplification is a must for these little guys. How much more with this particular mod concerns me. I'm afraid my V6M may not be adequate.

I wonder if all of the Xitel products discussed thus far use the same DAC chip from Phillips? Can you check yours and read off the part number?

 

[scottiebabie]

at home im generally use a diy PPAv2 (3xbb627opa) while on the road, i use either a GV6 (ad8620) or a tomahawk. on a side note, have u tried to power your GV6 with a linear reg. 24psu? u mite be pleasantly surprized by the SQ improvements. if it were me, i'd do that 1st before thinking about another amp as i find the 24v powered GV6 to be plenty fine but not as portable ofcoz.

my mini-link also utilize the ubiquitous philips uda1321p DAC and IIRC, all the xitel usb DACs use the same chip. my mini-link belongs to the 1st series while yours is the latest edition with a lengthy mini-RCA cable included and hence the moniker, hifi-link. to be honest, i find philips chips generally have a brighter and more analytical sound siggies so downstream components matching is highly recommended. in my case, i tried a few coupling caps before finding very good synergy with the current sharp tantalums. i have some Blackgate HX HiQs coming in shortly so will give those a shot too.

all in all, its was a very worthwhile mod esp. for the price i initially paid for the xitel plus the mod virtually costs nothing too. let me how it turns out for u.

 

[ziplock]

Just performed the "direct dac" mod with coupling caps on the output...

All I can say is wow, what a difference! This is going to be fun listening.

I'm going to try and compare the modded Xitel to my Fubar II after a few weeks.

~Zip

 

[robert1325]

How does the stock xitel compare to a Creative audigy 2 value? Does it support Asio? kernel streaming?

And these Direct Dac mods, are they a lot of work? I wouldn't know where to start but I have some experience modding my amplifier (t-amp) ... another pot and coupling caps.

Thanks

Robert

 

[ziplock]

Quote:

Originally Posted by robert1325 /img/forum/go_quote.gif How does the stock xitel compare to a Creative audigy 2 value? Does it support Asio? kernel streaming? And these Direct Dac mods, are they a lot of work? I wouldn't know where to start but I have some experience modding my amplifier (t-amp) ... another pot and coupling caps. Thanks Robert

I had an Audigy 2 zs platinum for a while; it was OK. Considerable background hiss and mediocre SQ. It got the job done during its time.

Currently my "reference" is a Fubar II USB DAC with OPA627s. It's good, really good! The Audigy is no comparison. However, the modified Xitel is giving the Fubar a run for its money! The SQ is amazing and I enjoy listening to it.

The Xitel is supported by ASIO and if properly configured, provides bit perfect output. Not so sure about kernel streaming. I have not had time to test it. Other things I can tell you about the DAC is support for hardware mixing, 24Bit output, and I2C compatibility for other possible mods.

The Direct DAC mod is really not that difficult. If you can read a data sheet and follow pcb traces it should be a piece of cake. I would suggest researching possible decoupling capacitors, some have better results than others.

I hope this info was helpful. Good luck and feel free to ask more questions.

~Zip

 

[robert1325]

Thanks for that clear answer,

I have some coupling caps from my trends ta-10 amp that I don't use now... they're quite good and I could always order some extra oil -caps. Not sure if I can read data sheets... I guess I'll need to know the output points of the dac chip and connect it straight to the connector ( trough the caps ofcourse)

I'm on a tight student budget at the moment, and a little weary of spending or wasting money on stuff like this. ( used to own a Bolder modded squeezebox)

 

[thomaskuhn]

This is pretty cool! I have had my hifi-link sitting in a drawer for a while. Time to play. What values for the caps are you using?

Tom