Op Amp Upgrade In Audio Alchemy Ditb D/a

[arupg]

The Audio Alchemy DITB has OP275 Op Amp fitted as stock. What would be the most desirable upgrade of this Op Amp?

My power supply is not the Audio Alchemy wall wart but the upgraded Power Station 1 (PS1).

Thanks in advance for your suggestions!

 

[ash_dac]

Hi,

See:- http://www.1388.com/doctor/jonopinion/14022001/ for notes.


I considered buying one a while back but decided on tda1541a!

Never heard an analodue devices chip!


Kind regards,

Ashley.

 

[arupg]

Hi,

Thanks for your post. I've read in this Forum that replacing the OP-AMP in the Audio Alchemy DAC-in-the-box may provide quite a bit of a performance boost - hence my earlier post as to what would be the IDEAL Op-Amp in today's market?

Any reommendations will be most appreciated!

Thanks!

 

[adinica]

Try the EL2244 op-amp from Elantec/Intersil USA. It's very musical sounding and perhaps better than op275. Good luck.

 

[arupg]

Thanks! adinica

From your other posts, I find that you have preferred the EL2244 over OPA2134, 2132,2604, OP275 & NE5532.

I have a NAD C540 that uses OPA2604 & also a NAD C521BEE that uses the NE5532.

As for replacement of the OP275 in the Audio Alchemy DAC, can it be a simple Op-Amp replacement with the EL2244?

What about the NAD C521BEE with 5532?

 

[D0Hbert]

You can try changing it for opa2604, 2132 and 2134. Opa 275 is mono, so you need a brown dog adapter for this. Another upgrade is increasing the line voltage, I think I changed the default 5volts of the dac to 12volts, and it definitely give the sound more power and slam

 

[georgehifi]

The OP275 is a very "Tube" like sounding opamp (by the way it's a dual opamp), little fat but ho so sweet, if you want that sweetness but with tones of detail and rock like solid bass and stunning dynamics, go for the AD825, they are smd singles but you can get them mounted, 2off on Brown Dog converter boards, well worth the trouble, the cheapest place I've found (send email) is http://www.rageaudio.com.au/
far cheaper than LC Audio or Soundlabs or anyone else I've come across.

Cheers George

 

[arupg]

Hello DoHbert,

Thanks for your suggestions. As far as I recall, the supply inputs are +/- 12V since I use the upgraded power supply Model PS-1 of Audio Alchemy which is a +/- 15V @ 250mA.

I also replaced the voltage regulators (both 5V & 12V) to 1A TO220 versions.

Regards

 

[Fin]

Just got a BITB without power supply...so now I need to get or make one. In the attached info about modding it, he recommends changing the +/-5V regs for the analogue section to +/-12V regs. This will raise the voltage to the opamp and the analogue side of the dac chips. The dac chips then need heatsinks to help dissipate the extra heat.

What about this as an alternative?
Build an external regulated +/-12V supply.....optimised for the opamp.....then divert the supply to the opamp around the existing +/-5V regs. This way the opamp gets +/-12V and the dac get +/-5V.....and there are no heat issues or risk of damaging the dac chips.

Actually, the external power supply could be regulated at a higher voltage, which might be beneficial for the performance of the opamp.....maybe +/-15V.

Any comments or thoughts would be appreciated.

 

[arupg]

Fin - You have a good alternative option. Maybe the results would be interesting....

I have now been using my DITB with the higher voltage fed to the Op-amp & the analog side of the DAC chips for almost a year now and must report that the heat issues have been NO PROBLEM esp in a hot country like India where I am & throughout the Indian summers at ambient in-room temperatures over 38 deg C. Just make sure that the addt. heatsink (suggested in the mods) mounted on the DAC chips are there & glued well.

The sonic improvement of the DITB is astonshing........ to a point one really feels that such an inexpensive DAC can give such wonderful results......

The last upgrade I feel could be the Op-amp itself. My one came with OP-275. Any suggestions if the latest modern Op-amps substituted could yield better results would be much welcomed. There are a lot of Op-amp gurus on this forum who could shed their views & will be highly appreciated.


---------------------------------
Regards
Arup

 

[Fin]

Hi Arup

Thanks for your reply and update on your results.

Maybe the way you have done it is better after all. That way, everything get double regulation and maybe the dac chips perform better at 12V.....who knows?

I think that the main problem with my idea is that the supply to the opamp could pick up interference on the cable leading to the DITB....and it is not undergoing any further regulation inside the DITB.

I'm not sure whether mine has AD712 or OP275.....haven't opened it yet. The serial number on mine is: 16754. Comparing it to your serial number might give me a clue before I even decide to open it........................

I also noticed that the coxial input on mine is different to some of the others I've seen. Maybe it's already been modified.

 

[Fin]

Hi Arup

Just wondering.....how does your DITB compare to some of you other equipment?

Have you compared it to an integrated CD player?

Also - do you know what the frequency of the oscillator is?

 

[arupg]

Dear Fin
After the upgrade, the DITB sounds hell-of-a-lot different. W better than any integrated CDP of NAD, Rotel, Marantz, Denon, Arcam, Cambridge Audio etc. variety by a large margin.

Infact, I did a head-to-head comparison with a high-end DAC, i.e. Theta Pro Gen Va costing some $6000 and must say my digital replay outfit (NAD C-540 CDP with heavily damped chassis, professional 3 set cones under), (Theta TLC as a jitter attenuator), (DITB - modded) - all connected using 2pcs XLO Signature digital cable sounds almost 80% of the Theta ProGen Va except in the extreme low bass where the Theta just wins hands down. The DITB excels in mindboggling soundstaging, showing layering on top-notch recordings as well as lots of air. Always open sounding, it does great justice to all types of well recorded acoustic music and vocals.

Do note that rest of my replay system is: Precision Audio Synthesis dual mono Passive-pre (Shallco/Vishay bulk foil/WBT/Siltech wire), Jeff Rowland Model 7 Mono 350watts power amps & B&W Matrix 802s (biwired using XLO Ultra12 for Bass/Signature 5.1 for mids & highs). All interconnects are van-den-hul first ultimate. Room is totally treated while AC power s off a fully regulated/filtered source of 8kVA.

Hope this input helps. Should you need further details, please do not hesitate to mail me at arupg@yahoo.com

Cheers!!
Arup

 

[Fin]

Thanks for that Arup

It really helps put it all in perspective and gives me a good idea of what is possible. I've been struggling a bit with trying to figure out how far to try and go with this little DAC....and if putting a lot of effort into it would be going over the top. However, from what you say, it seems like it would be well worth the effort etc.

My initial thought was to just build a nice external power supply for it and do the basic mods as outlined by Kal Rubinson - and similar to what you have done. Then use it to improve the sound of my DVD player.

BUT....now due to your comments....I think something more interesting is in order. I have a Tentlabs XO DAC looking for a home - but a rebox would be required to use this as it would be hardwired inside the DAC case. This should have a similar effect to your Theta TLC. That was the real stumbling block for me:- whether to bother addressing the jitter issue with this little dac or not. Have you tried it without the Thets TLC?

BTW - impressive system!

 

[arupg]

Dear Fin

Thanks for the quick post and your kind omments. U must work on the DITB and also a jitter attenuator. Do take your time if u have to.

With the Theta TLC, the depth of the soundstage collapses, blacks are grey, i.e. higher noise floor, dynamics less impressive and upper mids to top coarse. Insert the Jitter chrusher and WOW! What a difference.

Arup

 

[arupg]

Sorry correction:

WITHOUT the Theta TLC, the depth of the soundstage collapses, blacks are grey, i.e. higher noise floor, dynamics less impressive and upper mids to top coarse. Insert the Jitter chrusher and WOW! What a difference.

 

[Fin]

OK Arup....

...you have convinced me.....I will use the Tentlabs XO DAC with this DITB.....and do all of the mods I can find and think up....all inside a new larger case.

I just need to find out the correct oscillator frequency to order from Guido Tent. My feeling is that it is 11,2896mHz - but I would like to know for sure.