Transistor question: IRF9610 vs SFP9610?

PolishedSteel · 16th June 2006, 10:22 AM

Hello, finally the first part of my components for an Aleph 5 arrived, including 20 pieces of 9610 series Transistors. Now I actually specified IRF9610s and made the comment on my order that I'd love to have them from the same lot, but in any case from International rectifiers, but what I actually received were nevertheless Fairchild SFP9610. My question now: Are they also suitable for use (of course they are in a technical sense, since they are the same transistor type, but what about the musical qualities?), or should I return them without looking back?

Thanks a lot in advance,

Chris

Nelson Pass · 16th June 2006, 06:58 PM

My experience is that the Fairchild P channel devices are superior
to the IR (and seem to be equivalent for N channel). I don't see
any reason you shouldn't use them.

PolishedSteel · 16th June 2006, 07:02 PM

Ok, thanks a lot... So I think I will start to get into the business of matching them now!

Chris

wrenchone · 16th June 2006, 07:07 PM

Nelson, are you referring to the "funny" (we're not laughing) linear region behavior you documented for some of the IR devices? Is this behavior unique to IR?

flg · 16th June 2006, 11:23 PM

I thought I had a bk-mrk of that thread, the exchange with N.P. and a couple other "Guru's" of the subject... Very interesting reading. I'll look more later.
I have never heard an IR 610 part

I always get Faichild... If I remember correctly, the gain of the Fairchild 610 is a tad higher and C a tad lower??? Everything I ever expected, always worked just like I expect. Or maybe more correctly, Just like N.P. said... But I also wonder about the P ch weirdness thing??? I have a few of those 9610s still in a bag...

Mad_K · 19th June 2006, 05:50 PM

I have used Fairchild SFP9610 for Aleph 3, and they worked very nicely

Nelson Pass · 19th June 2006, 06:17 PM

Quote:

Originally posted by wrenchone
Nelson, are you referring to the "funny" (we're not laughing) linear region behavior you documented for some of the IR devices? Is this behavior unique to IR?

Yes. The IR P channel parts have a slightly odd gain shelving
behaviour. It's not a big deal, but the Fairchild and others
don't have it, so they get the nod in Common Source applications.

yup · 15th November 2006, 08:08 PM

Well, now the Fairchild part has been discontinued...

They list the FQP3P20 as a replacement. Unfortunately I do not have the ability to measure the frequency response of this device.

Can anyone make any reccomendations or have any experience with this part (or another brand)?

I am building the Aleph-x with the 044's (slightly dark top end), so I am guessing that the frequency response of the IRF9610 is not a good compliment.

Thanks,
Jeff

Nelson Pass · 15th November 2006, 08:26 PM

We used them successfully for years, but the Harris or
Fairchild versions have proven to have a little less distortion
as input devices. It is not at all a given that the amp will sound
darker.

This could change at any time if IR changes its process, as
no other mfr seems to have this phenomenon on what are
supposed to be the same parts.

mpmarino · 17th November 2006, 03:23 AM

On the same topic I grabbed a tube of IRF9610 with the Samsung 3 star logo (-Korea-) a while back.

Junk?

Edit: Oh, a quick search turns up that Fairchild bought the semi stuff from samsung ~1998. All good I guess.

16th June 2006, 10:22 AM	#1
PolishedSteel diyAudio Member Join Date: Jun 2006	Transistor question: IRF9610 vs SFP9610? Hello, finally the first part of my components for an Aleph 5 arrived, including 20 pieces of 9610 series Transistors. Now I actually specified IRF9610s and made the comment on my order that I'd love to have them from the same lot, but in any case from International rectifiers, but what I actually received were nevertheless Fairchild SFP9610. My question now: Are they also suitable for use (of course they are in a technical sense, since they are the same transistor type, but what about the musical qualities?), or should I return them without looking back? Thanks a lot in advance, Chris

19th June 2006, 05:50 PM	#6
Mad_K diyAudio Member Join Date: Sep 2002 Location: Norway	I have used Fairchild SFP9610 for Aleph 3, and they worked very nicely __________________ Mads K

17th November 2006, 03:23 AM	#10
mpmarino diyAudio Member Join Date: Jun 2004 Location: Crunchville, where I don't fit in.	On the same topic I grabbed a tube of IRF9610 with the Samsung 3 star logo (-Korea-) a while back. Junk? Edit: Oh, a quick search turns up that Fairchild bought the semi stuff from samsung ~1998. All good I guess. __________________ Crazy Yankee.

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16th June 2006, 06:58 PM	#2
Nelson Pass The one and only Join Date: Mar 2001	My experience is that the Fairchild P channel devices are superior to the IR (and seem to be equivalent for N channel). I don't see any reason you shouldn't use them.

16th June 2006, 07:02 PM	#3
PolishedSteel diyAudio Member Join Date: Jun 2006	Ok, thanks a lot... So I think I will start to get into the business of matching them now! Chris

16th June 2006, 07:07 PM	#4
wrenchone diyAudio Member Join Date: Feb 2004 Location: Silicon Valley	Nelson, are you referring to the "funny" (we're not laughing) linear region behavior you documented for some of the IR devices? Is this behavior unique to IR?

16th June 2006, 11:23 PM	#5
flg diyAudio Member Join Date: Jul 2005 Location: North East	I thought I had a bk-mrk of that thread, the exchange with N.P. and a couple other "Guru's" of the subject... Very interesting reading. I'll look more later. I have never heard an IR 610 part I always get Faichild... If I remember correctly, the gain of the Fairchild 610 is a tad higher and C a tad lower??? Everything I ever expected, always worked just like I expect. Or maybe more correctly, Just like N.P. said... But I also wonder about the P ch weirdness thing??? I have a few of those 9610s still in a bag...

15th November 2006, 08:08 PM	#8
yup diyAudio Member Join Date: Oct 2002 Location: Atlanta, GA	Well, now the Fairchild part has been discontinued... They list the FQP3P20 as a replacement. Unfortunately I do not have the ability to measure the frequency response of this device. Can anyone make any reccomendations or have any experience with this part (or another brand)? I am building the Aleph-x with the 044's (slightly dark top end), so I am guessing that the frequency response of the IRF9610 is not a good compliment. Thanks, Jeff

15th November 2006, 08:26 PM	#9
Nelson Pass The one and only Join Date: Mar 2001	We used them successfully for years, but the Harris or Fairchild versions have proven to have a little less distortion as input devices. It is not at all a given that the amp will sound darker. This could change at any time if IR changes its process, as no other mfr seems to have this phenomenon on what are supposed to be the same parts.

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