Hello,
I could not find any reference to this schematic on the DIYAUDIO forum. The mentioned schematic is published in AD797 datasheet on page 16 (Figure 50. A General-Purpose ATE/Instrumentation I/O Driver). This is a link to the document:
http://www.analog.com/static/imported-files/data_sheets/AD797.pdf
I found the same schematic reference in "Composite ideas" section on this website :
AnalogOutputBuffer < Main < Foswiki
I cannot understand the circuit purpose from published descriptions. I would like to build AD797/AD811 based preamplifier. I thought about use of
+/- 15V power supply. The preamplifier would be used with CD player as the music source. It would be great if I can also use it as headphone amplifier with headphone impedance >32 Ohms.
Can I use the published circuit for this purpose with listed component values? Or .... I need to change them. My main purpose would be to use it as preamplifier with volume control at the input.
Thank you very much for the help.
I could not find any reference to this schematic on the DIYAUDIO forum. The mentioned schematic is published in AD797 datasheet on page 16 (Figure 50. A General-Purpose ATE/Instrumentation I/O Driver). This is a link to the document:
http://www.analog.com/static/imported-files/data_sheets/AD797.pdf
I found the same schematic reference in "Composite ideas" section on this website :
AnalogOutputBuffer < Main < Foswiki
I cannot understand the circuit purpose from published descriptions. I would like to build AD797/AD811 based preamplifier. I thought about use of
+/- 15V power supply. The preamplifier would be used with CD player as the music source. It would be great if I can also use it as headphone amplifier with headphone impedance >32 Ohms.
Can I use the published circuit for this purpose with listed component values? Or .... I need to change them. My main purpose would be to use it as preamplifier with volume control at the input.
Thank you very much for the help.
A line level preamp doesn't need a very low noise opamp like AD797. You'll be making a rod for your own back to use such a chip in this application. Try something like AD8065 instead of AD797 - it has lower input bias currents and therefore suits being fed from a high impedance source (volume pot). A composite architecture for a preamp is a good idea though.
Thanks for replies.
Well, it looks like AD797 has its own problem based on comments on this forum. On the other hand this chip has been implemented in some good sounding applications ( I had a chance to auditions is once in Norh ACA preamplifier ). Since, I have quite few of these chips I would like to experiment with single chip circuit:
Jos jedan preamp - Solid State - diyAudio.rs
And buffered one.
Abraxalito: can you explain meaning of "composite architecture"
Hitsware: youtube clip is great !!!!! It looks like bottle of beer has helped a lot...
Well, it looks like AD797 has its own problem based on comments on this forum. On the other hand this chip has been implemented in some good sounding applications ( I had a chance to auditions is once in Norh ACA preamplifier ). Since, I have quite few of these chips I would like to experiment with single chip circuit:
Jos jedan preamp - Solid State - diyAudio.rs
And buffered one.
Abraxalito: can you explain meaning of "composite architecture"
Hitsware: youtube clip is great !!!!! It looks like bottle of beer has helped a lot...
By 'composite architecture' I meant using two chips in a loop rather than a single one. It gives the advantage that the output current can come from a separate supply to that powering the gain stage thus giving better overall immunity to self-generated power supply noise.
Incidentally you could consider AD815 instead of AD811 if you didn't fancy a trafo - its happy with a 25R load.
Incidentally you could consider AD815 instead of AD811 if you didn't fancy a trafo - its happy with a 25R load.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.