[John Massaria]

I have been using my UD-301 for a few years and can say it is warm and wonderful sounding- it greatly improved when i spent some money for a PASS Class A heaphone amp with the ability to swap op amps out - I have the OPA627, LM833N, OPA2107AP - my favorite is the OPA627 by far- LM833N is warm tube, OPA2107AP is more detailed still and the 627 is like opening up a window surpassing any op amp I ever heard. The TEAC301 easily allows me to hear the difference of the PASS Amp- so that should tell you how good it is a stand allone dac. As a heapdhone amp (UD301) its is whisper quiet dead silent- but lacks the dynamics and rtythem compared to my PASS headphone amp. The DAC does DSD and any high res files I can throw at it- I dont like or use MQA as this is a lossy codec so that is a non issue for me. The Burr brown DACs in the TEAC are wonderfully musical. You will be hard pressed to find better unless you buy the Topping D90 which I just did at $700++

 

[John Massaria]

I just got the UD-301 yesterday, and I'm promptly returning it today. It was one of the worst sounding pieces of audio gear I've ever owed over the last 20 years and is only the 2nd piece of gear i've ever felt was bad enough to return along with a cheap sony avr. The sound it put out was biased towards the highs and came off piercing and shrill. Very disappointed in this product.

You definely have a problem with it- NO WAY it sounds anything but very musical. I have mine and it reveals all the reality in the recordings without ever being aggressive- it is virtually impossible for a burr brown chip to sound bad unless of course its broken.

 

[garfieldso]

I just made a mod replacing the 8920 with OPA627AP, the sound stage is better and the bass sound more solid.

 

[John Massaria]

That’s an incredible op amp I have in in my PASS WHAMMY and it’s a huge improvement
How hard was it to clip the old op amp out and put in adapter?

 

[garfieldso]

That’s an incredible op amp I have in in my PASS WHAMMY and it’s a huge improvement
How hard was it to clip the old op amp out and put in adapter?

I used to add solder to all 4 pins and pull out one side of IC, then do the other side. After then by using desoldering wick to absorb/clean up all the exceeded lead on circuit board. By the way it should be used desoldering pump to suck out the solder is probably, but I haven't got one in hand.

 

[garfieldso]

I also tried out some op amp in hand making comparison, may be the orginal op amp in 301 is pure for audio buffer/amplifying, therefore most op amp are having good result. Even NE5534 performed all-round unexpectedly. I tried muses 8890, LME49710, 49720HA, 49722, OPA627AP, NE5534. All of them, the different are not significant. Finally I adopted LME49720HA as its bloom wider, brighten, and less bloomy in compared with OPA627AP (OPA627AP in this 301 DAC seemed exaggerated in bass a little bit).

 

[John Massaria]

I also tried out some op amp in hand making comparison, may be the orginal op amp in 301 is pure for audio buffer/amplifying, therefore most op amp are having good result. Even NE5534 performed all-round unexpectedly. I tried muses 8890, LME49710, 49720HA, 49722, OPA627AP, NE5534. All of them, the different are not significant. Finally I adopted LME49720HA as its bloom wider, brighten, and less bloomy in compared with OPA627AP (OPA627AP in this 301 DAC seemed exaggerated in bass a little bit).

Awesome work!

 

[omegaorgun]

I also tried out some op amp in hand making comparison, may be the orginal op amp in 301 is pure for audio buffer/amplifying, therefore most op amp are having good result. Even NE5534 performed all-round unexpectedly. I tried muses 8890, LME49710, 49720HA, 49722, OPA627AP, NE5534. All of them, the different are not significant. Finally I adopted LME49720HA as its bloom wider, brighten, and less bloomy in compared with OPA627AP (OPA627AP in this 301 DAC seemed exaggerated in bass a little bit).

I have the dual single to double adapters. I got two ad797an, the ad797b is supposed to be better.

Definitely want to mod it to sockets just to have some options. This DAC actually goes well with a 789.

 

[garfieldso]

I have the dual single to double adapters. I got two ad797an, the ad797b is supposed to be better.

Definitely want to mod it to sockets just to have some options. This DAC actually goes well with a 789.

Great! good work. All my op amps in hand are in old age, purchased some ten years ago. I will try your suggestion, thanks.

 

[omegaorgun]

Great! good work. All my op amps in hand are in old age, purchased some ten years ago. I will try your suggestion, thanks.

I can highly recommend opa1656's.p

 

[garfieldso]

I also tried to install the Teac HR player app from Google store, to my android phone and Fiio M11 pro dac. This free version locked those DSD 2.8 5.6 function. However if you USB plugged to external Teac UD-301 DAC, the DSD function will be unlocked. Those DSD files .dsf can now be synced to DAC to lite on 2.8Mhz on screen. Even those you can upsampling all 44.1k to 5.8Mhz to enjoy your listening.

 

[arjuna93]

By the way has anyone tried Airbow mod of this DAC (Airbow AI301 Special)?

 

[billbillw]

Hate to bump an old thread, but I've been using one of these now for 6+ years and I've been happy with it for mostly playback to my 2-ch stereo from my server using Daphile. Headphones occasionally get used, but this is mostly used as a DAC.

I'm curious though, regarding the DAC portion, how far have things advanced since this came out? I know there was some major development in DACs through the mid-2010s, but I haven't kept up with reviews. Is there a lot of room for improvement over the UD-301 in something that is under $500 (new or used)?

Like I said, I have been happy with it. I don't really play the game of upgrading every year when some new product comes out that is marginally better. I wouldn't make the change unless it was a very noticeable improvement. Anything to replace it would also need to have decent headphone output.