unity gain stable single channel DIP opamp

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#2
There are literally dozens of threads on this subject, however for great sonics I still think the OPA2604 has a bit of magic about it.

You are just going to have to try a few and see what you think.
 
#3
Thanks mate - I've read dozens and dozens of threads about this type of thing over the past year or two, but it's the "unity gain stable" thing that gets me - what is the statistic on the data sheet that lets me know whether it is unity gain stable or not?
 
#6
jcx said:
how can anyone offer meaningful advice without the basics of V or Iout, what signal levels, power supply V?
Click to expand...

The OPA2604 covers most bases having a supply range of -/+4.5 to 24 volts, 600 ohm drive capability and good (it's docile to work with) stability.
As a replacement for the OPA627 (on dual adapters as the OP uses them) I feel it it should operate perfectly in a DAC whether used as I/V conversion/filter buffer etc.
If you want to retain the single devices and adapter use the OPA604
Whether the OP can hear any difference subjectively will be interesting to know.
 
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#8
OPA604 should be perfect. When you mentioned using adapters thought you meant making a dual out of two single SMD devices.

Read the last part of this data sheet "sound quality",
http://www.datasheetcatalog.org/datasheet/BurrBrown/mXyzsxss.pdf

that's Burr Browns take on it... in use I have found it offers excellent sonics, can't really say more than that... only you will know if you hear/detect/like the device.
 
#9
OK thanks, I'll give them a go. I tried out the LME49710NA (as you can read in that thread), but did not notice a huge difference, so it should be interesting to try the OPA604 and compare it with both the OPA627 and LME49710NA.

I don't think there are many other candidates there that would be suitable opamps. I'm leaving the four OPA627 in the filter stage as it's too expensive to replace all 6 chips!
 
#10
remember they also need to be bipolar input for your dac.

mooly, I recommended the BUF634 to lordearl, as I figured they were single channel opamps acting as unity gain buffers (the stock opamp is OPA134), but of course we didnt get good results as they are also taking a bipolar input
 
#11
qusp said:
remember they also need to be bipolar input for your dac.

mooly, I recommended the BUF634 to lordearl, as I figured they were single channel opamps acting as unity gain buffers (the stock opamp is OPA134), but of course we didnt get good results as they are also taking a bipolar input
Click to expand...

The BUF634 isn't an opamp as such 🙂 and certainly can not replace the OPA134.
http://www.datasheetcatalog.org/datasheet/BurrBrown/mXtxtvx.pdf

I'm using lordearls link above for the circuit post #13,
http://www.diyaudio.com/forums/digi...eived-my-wolfson-4-0-biy-dac.html#post2175263
 
#12
good timing, got some OPA604 from Farnell, playing as we speak - not really noticeable differences yet (didn't imagine there would be as the BB sound signature is widely the same across their opamps - but these are a cheap opamp, so what the hey!)

What about the LME49600 - would they work on some kind of adapter?
 
#14
Mooly said:
The BUF634 isn't an opamp as such 🙂 and certainly can not replace the OPA134.
http://www.datasheetcatalog.org/datasheet/BurrBrown/mXtxtvx.pdf

I'm using lordearls link above for the circuit post #13,
http://www.diyaudio.com/forums/digi...eived-my-wolfson-4-0-biy-dac.html#post2175263
Click to expand...

i know this, but I had made a wrong assumption that the OPA134 was being used as a buffer/line driver as it can often be found in this position (wasnt looking at the schematic). its at the output after what seemed to be the IV, but because if the 4 dac chips there is a separate summing stage I failed to think of
 
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