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CNC Phono pre-amp, Opamp rollng and Bugle comparo-->

jimreeves said:
Great job guys!
I think the analog audio world needs more of these non-scientific head to head comparisons. It was a result of just such a test that helped us find the AD823 for dual and AD797 for single channel op amps. Well done!
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Thanks JR! I am looking forward to more comparisons... :yes:

VROBERTSON said:
Fun and informative read fellas! Well written Jim. I so do love my Bugle. :music:
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Thanks, Vince! As your Bugle has benefited from the research done on ours, I am glad it meets with your approval. :bigok:
 
Nice write up.

Do you have any plans on testing the current big buzz, the OPA1642?

I didn't see the LM4562 or LME49720HA (metal can) listed either, any plans for those?

What does your DC offset measure on the outputs of your homebuilt?

EDIT: I see your comments regarding the LM4562 in another thread.
 
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hags said:
Nice write up.

Do you have any plans on testing the current big buzz, the OPA1642?
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I haven't heard about that one yet. Is it new, or an older one that people are just now starting to favor for audio?

I forgot to mention the OPA2107, but I'm sure the OP and others are already familiar with that great op-amp.
 
Mr. Lin said:
I haven't heard about that one yet. Is it new, or an older one that people are just now starting to favor for audio?

I forgot to mention the OPA2107, but I'm sure the OP and others are already familiar with that great op-amp.
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Data sheet says Dec. '09, so it's relatively new. Also, I haven't seen the
OPA2132UA mentioned.
 
Fasterdamnit said:
I will gladly review any and all chips you fella's would like to send me. :thmbsp:
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Ha! Yeah, I was interested only for curiosity's sake with that particular circuit. I have experimented with all the ICs mentioned in my AN346 pre amp. It uses both active and inactive RIAA eq. I built mine sans the coupling capacitor between gain stages as with the more modern, lower offset ICs it's not needed.

I've had it head to head with a Bugle I owned as well a the Acoustech PH-1. In both instances it threw a noticably wider soundstage, a much deeper sound stage, went lower in the low end and was quieter than both, especially the comparatively noisy PH-1. I used a high quality shunt PSU based on the Borbely design on the AN346 and Bugle. Both the Bugle and and the Acoustech have been sold. So yeah, I'd say these application note pre amps, as simple as they are, are pretty good.

What is the DC offset on yours?
 
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Did somebody need a pair of OPA2134's? I have a pair I'm sure will never get used. Not my cup o' tea.

EDIT: they're spoken for by Dodog.
 
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G'day all, I love the OPA2134! Here are my eight remaining spares! Regards, Felix aka catman.
 

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At the risk of showing my ignorance ....again..... I'll ask how the favored combo OPA2134/OPA2134 sounds compared to the AD823/AD823 from the CNC design & build thread?
Ron
 
Renron said:
At the risk of showing my ignorance ....again..... I'll ask how the favored combo OPA2134/OPA2134 sounds compared to the AD823/AD823 from the CNC design & build thread?
Ron
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Chalk and cheese Ron.

The OPA2134 has the typical Burr Brown sound, warm, pleasing and laid back.

The AD823 has more detail, more controlled bass and a wider soundstage IMO.

YMMV
 
HypnoToad said:
Chalk and cheese Ron.

The OPA2134 has the typical Burr Brown sound, warm, pleasing and laid back.

The AD823 has more detail, more controlled bass and a wider soundstage IMO.

YMMV
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I found the 823 to have a bit of a hard edge so I do not like to listen to them for any extended time. I prefer the 2134's. You would have to listen for yourself to decide. :yes:
 
I may have suggested previously that the $38 E-Bay phono board be included here just for gigglz. It's actually pretty good.
 
If we are using a battery supply when looking at Op Amp data sheets, you can look at slew rate, bandwidth etc, but one thing we should be looking at is the Current Supply.

For example:

OPA27GP has a current draw of 3.3ma.

OPA134 has a current draw of 4.0ma.

AD797 has a current draw of 8.2ma.

Looking at the current supply of each we can see not a lot of difference with the first two but the AD797 draws over twice as much which means running on batteries it will drain them more than twice as fast as the others.

Just something to consider when using a battery supply.
 
Good posts, thank you all.
My speakers (small Thors) are already right on the edge of razor sharp treble, looks like I'll be rolling some OpAmps. :) once I finish all the projects I have going.....sheesh.
Rebuild Rek-o-Kut Rondine deluxe.
Finish building Schroeder tonearm Clone then install in above.
Build CNC phono pre
Then the fun begins.

Thank you for your information.
Ron
 
From my opamp rolling experimentation, the paired performance, using same opamps on both input & output sockets, beats the mixed combo.

So far, paired performance of LME49990 tested in CNC & HTMCPS comes up at the top in my system when tested against OPA2134 or LME49720.

I would love to try out the paired OPA637's, though, but those aren't cheap just to play around.
 
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