OPA627 in 999ES coupling question

audiokid25 · 29th December 2005, 10:20 PM

Does the OPA627 need coupling caps? Or can I get away with just a resistor? I have been using AD8620 with just a 100ohm resistor on the ouputs with great success. If caps are needed, whats the best sounding route to go?

dorkus · 8th January 2006, 09:35 AM

if memory serves me right, the OPA627 is FET input, correct? the offset figures, while not as low as AD8620, are probably still very low. most any FET input opamp will be fine i think, but you will want to measure it to be sure. if it's above, oh, 10mV or so, you may want a blocking cap.

i'm using AD8620 in my modified C222ES SACD changer. it's transparent, but i think it can sound a little thin in some applications. in my Panasonic DVD player it is very bright i may want to give the OPA2132 a shot.

costiss · 9th January 2006, 09:23 PM

nope.. 50 uV worst case.. and better to my ears than 8620, at least for the dil packaged 627

dorkus · 9th January 2006, 09:52 PM

Quote:

Originally posted by costiss
nope.. 50 uV worst case.. and better to my ears than 8620, at least for the dil packaged 627

how about the OPA2132? i hear from a few of the 8620 "naysayers" that it is a bit smoother than the 8620. i'm starting to wonder if i agree with them when they say the 8620 is too "hi-fi"... it is very clear and detailed, but a bit thin and bright, at least as a drop-in replacement.

29th December 2005, 10:20 PM	#1
audiokid25 diyAudio Member Join Date: Oct 2004	OPA627 in 999ES coupling question Does the OPA627 need coupling caps? Or can I get away with just a resistor? I have been using AD8620 with just a 100ohm resistor on the ouputs with great success. If caps are needed, whats the best sounding route to go?

9th January 2006, 09:23 PM	#3
costiss diyAudio Member Join Date: Dec 2002 Location: greece	nope.. 50 uV worst case.. and better to my ears than 8620, at least for the dil packaged 627 __________________ i am currently using 60,000 uF of capacitance in my preamplifier..

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8th January 2006, 09:35 AM	#2
dorkus diyAudio Member Join Date: Jun 2001 Location: NYC	if memory serves me right, the OPA627 is FET input, correct? the offset figures, while not as low as AD8620, are probably still very low. most any FET input opamp will be fine i think, but you will want to measure it to be sure. if it's above, oh, 10mV or so, you may want a blocking cap. i'm using AD8620 in my modified C222ES SACD changer. it's transparent, but i think it can sound a little thin in some applications. in my Panasonic DVD player it is very bright i may want to give the OPA2132 a shot.

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