OPA2107 !!!! WOW!!!

[Sean H]

I agree, I just got three of them for my Zhaolu 2.0 and they are very nice sounding indeed. I find they are of the classic BB sound and it seems like they fall somewhere between an OPA2604 and OPA627 in my experience. Don't have a lot of experience with BB opamps ouside of 627/637/2604. I am hearing greater detail and resolution compared to the 2604 (which is a opamp I like) with a bit tighter bass that's also noticeably deeper. The treble is well open and airy and reminds me more of the 627 being liquid and smoother but tends to be just a bit less focused than the 2604 it seems - not 100% sure yet on that though. Air, space, ambiance and tonal character is quite nice. Seems to sit right at home with my Zhaolu, Mapletree Ear+ Purist and HF-1's.

 

[Tachikoma]

Quote:

Originally Posted by Andrea For unbuffered amps the OPA627/637 are no good.

Will they be decent for usage in a DAC's analogue output stage, with a +/-15V power supply? I'm looking for a lusher sound to compliment my electrostats, but without bloating up the bass; would an OPA2107 give me that?

 

[ppl]

Quote:

Originally Posted by Sean H I agree, I just got three of them for my Zhaolu 2.0 and they are very nice sounding indeed. I find they are of the classic BB sound and it seems like they fall somewhere between an OPA2604 and OPA627 in my experience. Don't have a lot of experience with BB opamps ouside of 627/637/2604. I am hearing greater detail and resolution compared to the 2604 (which is a opamp I like) with a bit tighter bass that's also noticeably deeper. The treble is well open and airy and reminds me more of the 627 being liquid and smoother but tends to be just a bit less focused than the 2604 it seems - not 100% sure yet on that though. Air, space, ambiance and tonal character is quite nice. Seems to sit right at home with my Zhaolu, Mapletree Ear+ Purist and HF-1's.

Hello Sean nice to see you posting again. My self i am not a big fan of the OPA2604 Dual or the OPA604 sing. This OPA ranks as one of the worst sounding opamps i have ever heard and i have tried them in all kinds of circuits. The OPA2107 is a dielectrically isolated op amp and IMHO it don't get any better than that Burr Brown opamps that have Fet inputs and are fabricated with Dielectric isolation are called Difet. The OPA627 and opa637 are two popular Difet devices. The OPA2604 like the OPA213X series are made with the Junction isolation Process and as such are more limited in there maximum performance because of the High Leakage currents within the die and thus are more thermally sensitive have lower bandwidth vs the amount of current consumed.

Analog devices have used Junction isolation with great success as evidenced by the wonderful AD744 and AD712 series. The Newer Ad devices like the popular AD8610/20 AD8065/66 are dielectrically isolated and ADI again exploits this process to the max.

The only Burr Brown Opamps i now consider are dielectrically isolated types.

 

[Andrea]

Quote:

Originally Posted by Tachikoma Will they be decent for usage in a DAC's analogue output stage, with a +/-15V power supply? I'm looking for a lusher sound to compliment my electrostats, but without bloating up the bass; would an OPA2107 give me that?

Yes, sure, they should give you what you're after, both the OPA627 (not the 637 that's not stable at unity or low gains, thus isn't adequate for a DAC's output stage) and the OPA2107.



Btw, the OPA627 isn't good for driving headphones directly because it doesn't like heavy capacitive loads.

 

[Filburt]

627 drives my headphones just fine...just need to know how to work with it ;D

 

[Andrea]

Hmm, perhaps that strong ringing ultimately sounds good

Or it may be fixed with just a small resistor in series with the output (?)

 

[Filburt]

Quote:

Originally Posted by Andrea Hmm, perhaps that strong ringing ultimately sounds good Or it may be fixed with just a small resistor in series with the output (?)

Are you getting strong ringing? Have you actually tried it or are you just speculating? The issue of driving a capacitive load with this chip pertains more to frequencies outside of the audio band.

 

[Andrea]

I remember that head-fi member fewtch lamented some evident and unnatural midrange glare in the sound of the OPA627 in the Go-Vibe that he didn't get with any other op-amp (AD8620, AD8066, OPA2227 etc. if I remember correctly).

That aside, I was "just" speculating. I have a couple of them OPA627s, now that you got me thinking of it I'll give 'em a try in my (incoming) XM3 and I'll let you know if fewtch was right or not. (if I like them, then thank you for the hint

)

 

[Sean H]

Quote:

Originally Posted by ppl Hello Sean nice to see you posting again. My self i am not a big fan of the OPA2604 Dual or the OPA604 sing. This OPA ranks as one of the worst sounding opamps i have ever heard and i have tried them in all kinds of circuits. The OPA2107 is a dielectrically isolated op amp and IMHO it don't get any better than that Burr Brown opamps that have Fet inputs and are fabricated with Dielectric isolation are called Difet. The OPA627 and opa637 are two popular Difet devices. The OPA2604 like the OPA213X series are made with the Junction isolation Process and as such are more limited in there maximum performance because of the High Leakage currents within the die and thus are more thermally sensitive have lower bandwidth vs the amount of current consumed. Analog devices have used Junction isolation with great success as evidenced by the wonderful AD744 and AD712 series. The Newer Ad devices like the popular AD8610/20 AD8065/66 are dielectrically isolated and ADI again exploits this process to the max. The only Burr Brown Opamps i now consider are dielectrically isolated types.

Hi ppl - I've been hanging out in the Digital forum quite a lot lately I guess.

I knew you weren't a big fan of the OPA2604 and when I wrote the above where I mentioned I liked that opamp I almost put in parenthesis "Sorry ppl."

It's funny but I tend to prefer a sound that is more bassy and even a hair on the darker side and am less prone to certain distortions. Somehow I like the 2604 in my Zhaolu DAC, it seems to work. I do like the 2107's a lot so far and they seem superior. Interesting your description of the design behind them. I have thought about trying 8065's but I would need two have several of them and mounted on Brown Dog single to dual adapters and it would get a tad spendy as the Zhaolu uses three dual opamps. I've seen your comments on the AD712 (dual) and I'd like to give them a try. Thanks.

 

[Filburt]

Quote:

Originally Posted by Andrea I remember that head-fi member fewtch lamented some evident and unnatural midrange glare in the sound of the OPA627 in the Go-Vibe that he didn't get with any other op-amp (AD8620, AD8066, OPA2227 etc. if I remember correctly). That aside, I was "just" speculating. I have a couple of them OPA627s, now that you got me thinking of it I'll give 'em a try in my (incoming) XM3 and I'll let you know if fewtch was right or not. (if I like them, then thank you for the hint )

Well, it could just be I work with these chips better than I thought. I shared my test box with a few folks at a mini meet and it seemed to be well liked by pretty much everyone; no comments about glare or ringing.

 

[yellafella321]

is that the little chip we tried on sunday?

That thing sounded great! Very smooth and warm, excellent paired with grado's.

 

[Andrea]

Fliburt,

for the OPA627, did you use series resistors on the output, and if yes, what value, and inside or outside the feedback loop? Also, did you use any bypassing caps on the power rails? Thanks

 

[Audioexcels]

Anyone else want to try one? I have some if so...

 

[adhoc]

Anyone have any idea how the following opamps stack up to the OPA2107?

AD712
AD744
AD797
AD843
AD845
AD8620

Any impressions anyone could give me on ANY of the above opamps would be much appreciated. I'd hate to spend so much money on opamps that I won't use.

Thanks!

 

[Andrea]

The AD8620 is somewhat harsh in mid/treble transients and doesn't have the most 'weighty' midrange. Other than that it's fine. I'm not sure that I'd place it ahead of BB's OPA2134 for overall sound quality.