has anyone heard of that IC?
I have it, and I think it sounds wonderful as a preamp.
It´s current output is a relatively weak -20mA-, but there is certain ¨something¨ in the way it delivers music... very smooth.
I wish to read about your opinions, and how you compare it with opa 604, opa134 and opa627.
And yes, I´m a BB fan...
I have it, and I think it sounds wonderful as a preamp.
It´s current output is a relatively weak -20mA-, but there is certain ¨something¨ in the way it delivers music... very smooth.
I wish to read about your opinions, and how you compare it with opa 604, opa134 and opa627.
And yes, I´m a BB fan...
OPA602
I have used them for years in measuring instruments and also tried them for audio. They are very good opamps (quite fast and able to drive capacitive load), the only problem is phase inversion after clipping in non-inverting mode.
Regarding your question, i would prefer (best to worst) OPA627, OPA134, OPA602, OPA604.
I have used them for years in measuring instruments and also tried them for audio. They are very good opamps (quite fast and able to drive capacitive load), the only problem is phase inversion after clipping in non-inverting mode.
Regarding your question, i would prefer (best to worst) OPA627, OPA134, OPA602, OPA604.
Thank you very much for your reply, Pavel.
I have tried it alone -noninverting configuration, gain +6, ps:+/-15volts-, and liked it a lot.
Now I´m trying it in something very similar to your audio buffer, but without r12 and without the 200 pF cap.
I have noticed a slight hardening of the sound in such configuration. I don´t know, maybe the BUF634 could be responsible...
When I leave the BUF in normal mode, the sound gets warmer and fuller, more in the line of the sound of the chip alone. But when I connect the BUF in wide bandwidth mode the sound gets harder.
I have noticed that trend with other opas too, in the same configuration. Have you any idea about that paradoxical behaviour of the composite amp, sounding mellower in normal mode?
I have tried it alone -noninverting configuration, gain +6, ps:+/-15volts-, and liked it a lot.
Now I´m trying it in something very similar to your audio buffer, but without r12 and without the 200 pF cap.
I have noticed a slight hardening of the sound in such configuration. I don´t know, maybe the BUF634 could be responsible...
When I leave the BUF in normal mode, the sound gets warmer and fuller, more in the line of the sound of the chip alone. But when I connect the BUF in wide bandwidth mode the sound gets harder.
I have noticed that trend with other opas too, in the same configuration. Have you any idea about that paradoxical behaviour of the composite amp, sounding mellower in normal mode?
Hello Federico,
your question is not easy to reply. Firstly I would like to ask you if the R12 was connected at the end of output cable. It should not be connected directly behind R10. R12 is the cable terminating resistor. When used in the beginning of the cable then its function is incorrect.
Now about influence of R12 properly connected (at the end of the cable). Compared to typical low power voltage transfer (R12 not used) the bass is more tough, not so "full" and "lazy", but better "readable" and more natural. The mids and treble loose grain. The "cable sound" is highly supressed. The sound seems to be less loud (compared to same voltage level without R12), but more dynamic and lively. All of the phenomena described can be heard on good quality audio chain. The kind of sound with R12 properly connected would be highly appreciated when listenning to the classical music. It is all about HF interference, signal power and about cable phenomena, they have not been satisfactorily explained yet.
Once more I would like to emphasize the correct R12 position - it is at the end of the buffer output cable, not at the buffer output.
Pavel
your question is not easy to reply. Firstly I would like to ask you if the R12 was connected at the end of output cable. It should not be connected directly behind R10. R12 is the cable terminating resistor. When used in the beginning of the cable then its function is incorrect.
Now about influence of R12 properly connected (at the end of the cable). Compared to typical low power voltage transfer (R12 not used) the bass is more tough, not so "full" and "lazy", but better "readable" and more natural. The mids and treble loose grain. The "cable sound" is highly supressed. The sound seems to be less loud (compared to same voltage level without R12), but more dynamic and lively. All of the phenomena described can be heard on good quality audio chain. The kind of sound with R12 properly connected would be highly appreciated when listenning to the classical music. It is all about HF interference, signal power and about cable phenomena, they have not been satisfactorily explained yet.
Once more I would like to emphasize the correct R12 position - it is at the end of the buffer output cable, not at the buffer output.
Pavel
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