[machine]

Is it possible to use OPA627 in the Bugle?

I think it would take 6 of these vs. 3 of the OPA2134PA.

I only ask because I came upon a quantity of these and am looking for a project.

I have a Cornet2 to build and would if possible try the Bugle first so I don't mess up on the Cornet2.

Thanks!

[PatOMalley]

you need not put the 627's in  U1 & U2. You can put a set in an adapter in U3 which would set the sound signature there effectively.

ReferenceAudioMods has plug and play modules:  http://www.referenceaudiomods.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=RAM&Category_Code=OPAMPS

I was considering doing the 825 until I read about the Burson 'opamp':
http://www.bursonaudio.com/Burson_HDAM_Module.htm
I have yet to try the Burson but it looks promising and you can return it if it doesn't work out.

my opamp history=> http://home.comcast.net/~omaille/bugle/opamp.html

[dhollister]

I was considering doing the 825 until I read about the Burson 'opamp':
http://www.bursonaudio.com/Burson_HDAM_Module.htm
I have yet to try the Burson but it looks promising and you can return it if it doesn't work out.

I've been following your threads here and in audioasylum and am quite interested to hear the outcome.  I am considering rolling some op-amps in my two bugles as well.

Cheers,
David

[Occam]

For a minimalist approach (both economically and effort), you might consider the opa2107 (and/or the OPA2111) as a drop in substitute. These are lovely opamps, di-fet input like the 627, but duals which wouldn't require an Brown Dog adapter board.
One might also consider the National LM4562. Not as stereotypically 'Burr Brown' sounding. As its bipolar input (albeit low offset) Jim might opine as to its suitability for the various positions.
http://www.audiocircle.com/index.php?topic=30052.msg302684#msg302684

FWIW,
Paul

[hagtech]

The bipolars are fine in all positions.  I have a problem with them as a first stage because of the possibility of rectifying AM radio.  That's one drawback of the bipolar differential pair.  They turn into diodes at RF.  Sometimes this can demodulate an AM or shortwave broadcast at the input stage, which results in a baseband component.  When you have a phonostage that picks up radio stations, it is most likely a bipolar input type.

Now, that's not to say it will always happen.  Just a trend.  It doesn't mean that FET input opamps are immune, either.  Some designs better than others. 

It's not the input bias current I was worried about.

jh

[Folsom]

I am using the original in the first socket and 2604's in the second two and liking it. They pick up a tiny bit more noise but when playing something do not notice it.