Can anyone recommend a direct replacement for the op amps on my audio labs 8000m they are TL071CP ?
Almost same slew rate, and circuit may need alteration.
Anything over 8 V/us slew rate is enough for audio.
TL071 is above that, 13-16 IIRC.
134, is similar to 2134 with 20 V/us?
Noise figures may be better.
Anything over 8 V/us slew rate is enough for audio.
TL071 is above that, 13-16 IIRC.
134, is similar to 2134 with 20 V/us?
Noise figures may be better.
https://www.edn.com/sam-groners-op-amp-distortion-study/
Yes you might need to disconnect a compensation capacitor lead. Otherwise i'll let people make their own mind through Samuel Groner study.
Yes you might need to disconnect a compensation capacitor lead. Otherwise i'll let people make their own mind through Samuel Groner study.
You have an issue with it?
Many recording studios still use 4558s and 5532s... some prefer JRC made NJM series for those part numbers.
Those are relatively slower, and have been standard for decades.
So read up, like suggested above, and take an informed decision.
Remember this topic invites strong opinions.
Also, you must have some technical knowledge, to be able to modify circuits, and to decide how to do that by listening.
Or build another, just for fun.
Also read up on op amp rolling, that is enjoyable.
Many recording studios still use 4558s and 5532s... some prefer JRC made NJM series for those part numbers.
Those are relatively slower, and have been standard for decades.
So read up, like suggested above, and take an informed decision.
Remember this topic invites strong opinions.
Also, you must have some technical knowledge, to be able to modify circuits, and to decide how to do that by listening.
Or build another, just for fun.
Also read up on op amp rolling, that is enjoyable.
Last edited:
That.
In any case, they are parts of a system, matched from day one to a ton other components; not sure you will "improve" anything and there´s danger of creating instability where there was none before.
In any case, they are parts of a system, matched from day one to a ton other components; not sure you will "improve" anything and there´s danger of creating instability where there was none before.
My first thought as well. The circuit I have for the 8000 shows they are used as a DC servo... in which case the TL071 is perfect.
Thanks for the quick response people the thing is I am not to well versed or experienced at modifications and I have no circuit diagrams. I can solder and follow diagrams so not a complete novice it’s just I was reading an article that recommended the ops 627 as a replacement to greatly improve the sound and wondered if anyone had experience of this . I do understand the controversy over op amps so this makes me unsure I do not know where in the signal path of if it is in the dc servo with no drawing I cannot say.
It is not in the audio path. The servo provides a DC correction voltage to maintain the DC offset close to zero. The TL071 really is perfect for this.
Thank you all for your response cleared up that problem, just one more thing I would like to learn more about audio amplifiers and how they work can anyone recommend a book or any other form of learning to do this.
You need first to understand general basic circuitry and resistors, caps and coils work, and then look at semiconductors (diodes and transistors) and progress from that looking at simple 1 transistor amplifiers and the basic transistor configurations.
Probably be good to build a Pass ACA or any of the simplest designs and learn what each component does, and you end up with a great amp when done.
Bill
Bill
I have seen 6dB betterment of noise floor in the DCG3 preamp with OPA134 vs TL071 due to much better nVrtHz spec in the servo but I would not know if as fruitful here also.
On the other hand installing an IC socket and trying out a better JFET input type chip to judge for yourself isn't a big deal. Easy to access the back of the board if that amp is serviceable via a removable bottom panel.
On the other hand installing an IC socket and trying out a better JFET input type chip to judge for yourself isn't a big deal. Easy to access the back of the board if that amp is serviceable via a removable bottom panel.