Phono preamplifier using OPAMPS.

binspaul · 18th November 2009, 04:07 AM

Hi,

See the Phono preamp implementation using National LM833. Please have a look at the Figure: 3 and Figure: 4 for the circuit and the performance. This is an old app note, created in 1985, but quite helpful.

Best regards,
Bins.

peranders · 18th November 2009, 09:58 AM

Do you want to show us or do you ask something?

binspaul · 18th November 2009, 12:46 PM

Hi,

I wanted to collect the opinion on that implementation. Also, what is the idea of replacing the LM833 with the LM4562 or LME49710 ?

Best regards,
Bins.

binspaul · 18th November 2009, 12:52 PM

Hi,

The Linear Technology LT1115 is also being used in phono stages. See the attached file. Which one will be better (when compared to National LM833 implementation) ?

Best regards,
Bins.

Tolu · 18th November 2009, 12:58 PM

why don't you take the schematics of the passive RIAA from the datasheet of the LME49720?

Conrad Hoffman · 18th November 2009, 01:03 PM

It's definetely a useful app note for the equations but I think you'd be far better off with the circuits and parts used in their AN-1651 app note, available here-
Audio App Notes

CH

binspaul · 18th November 2009, 01:06 PM

Hi,

What is the idea on Twisted Pear Audio - RETRO ? Will the symmetrical arrangement yield benefits ?

Best regards,
Bins.

Andrea: · 18th November 2009, 01:14 PM

Quote:

Originally Posted by binspaul

Hi,

The Linear Technology LT1115 is also being used in phono stages. See the attached file. Which one will be better (when compared to National LM833 implementation) ?

Best regards,
Bins.

LT1028 better than LT1115 better than LM833

binspaul · 18th November 2009, 01:28 PM

Hi,

What about the RETRO from twisted pear audio ? (We have got a thread here for this at: Retro - A fully symetrical phono stage with RIAA filter)

Please suggest.

Best regards,
Bins.

Conrad Hoffman · 18th November 2009, 03:28 PM

I like balanced and instrumentation amps, but you have to compare the actual measured performance of that design vs. some other design. I believe (could be wrong) that differential amp systems like that one are at an inherent noise disadvantage over single ended. Other benefits may make up for it. IMO, the performance of the LME opamps is so good that only a fairly complex discrete design can compete with it. It is, however, a high speed part and poorly laid out or poorly bypassed, it won't do its best. The commercial instrumentation amps I've seen don't come close on noise and distortion, but I haven't used 'em all.

CH

18th November 2009, 09:58 AM	#2
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	Do you want to show us or do you ask something? __________________ /Per-Anders (my first name) or P-A as my friends call me

18th November 2009, 01:03 PM	#6
Conrad Hoffman diyAudio Member Join Date: Mar 2007 Location: Canandaigua, NY USA	It's definetely a useful app note for the equations but I think you'd be far better off with the circuits and parts used in their AN-1651 app note, available here- Audio App Notes CH __________________ I used to be an audiophool like you but then I took an arrow to the knee.

18th November 2009, 03:28 PM	#10
Conrad Hoffman diyAudio Member Join Date: Mar 2007 Location: Canandaigua, NY USA	I like balanced and instrumentation amps, but you have to compare the actual measured performance of that design vs. some other design. I believe (could be wrong) that differential amp systems like that one are at an inherent noise disadvantage over single ended. Other benefits may make up for it. IMO, the performance of the LME opamps is so good that only a fairly complex discrete design can compete with it. It is, however, a high speed part and poorly laid out or poorly bypassed, it won't do its best. The commercial instrumentation amps I've seen don't come close on noise and distortion, but I haven't used 'em all. CH __________________ I used to be an audiophool like you but then I took an arrow to the knee.

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18th November 2009, 12:46 PM	#3
binspaul diyAudio Member Join Date: Feb 2009 Location: Cochin, Kerala, India	Hi, I wanted to collect the opinion on that implementation. Also, what is the idea of replacing the LM833 with the LM4562 or LME49710 ? Best regards, Bins.

18th November 2009, 12:58 PM	#5
Tolu diyAudio Member Join Date: Mar 2007	why don't you take the schematics of the passive RIAA from the datasheet of the LME49720?

18th November 2009, 01:06 PM	#7
binspaul diyAudio Member Join Date: Feb 2009 Location: Cochin, Kerala, India	Hi, What is the idea on Twisted Pear Audio - RETRO ? Will the symmetrical arrangement yield benefits ? Best regards, Bins.

18th November 2009, 01:28 PM	#9
binspaul diyAudio Member Join Date: Feb 2009 Location: Cochin, Kerala, India	Hi, What about the RETRO from twisted pear audio ? (We have got a thread here for this at: Retro - A fully symetrical phono stage with RIAA filter) Please suggest. Best regards, Bins.

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