Hi all
Some of you might have seen my message last week or the week before, i'm in the process of starting a Gilmore Class-A Dynmaic Heapdhone ampifier.
I've come across a hitch with the OP27. As far as I understand this chip feeds the output into the DC offset with a little voltage gain so the amp runs in class A??? Is that right i'm not sure, i don't normally work with discreet amps.
The problem is i'm on a really low budget, and find the OP27 and it's high retail price a bit expensive. Also i have no easy supply of opamps so i'll need to order from texas instruments, so add shipping costs and i definatly can't afford it.
Texas Instruments offers samples of most of their chips (inc Burr Brown chips), and the OP27 is not one of thoes chips.
Is there a substitute i can use instead of the OP27, which is availuable from Texas Instruments, or is cheaper, and doesn't compromise sound quality? It doesn't matter if they don't have the same pinout i can easily modify the design.
Some of you might have seen my message last week or the week before, i'm in the process of starting a Gilmore Class-A Dynmaic Heapdhone ampifier.
I've come across a hitch with the OP27. As far as I understand this chip feeds the output into the DC offset with a little voltage gain so the amp runs in class A??? Is that right i'm not sure, i don't normally work with discreet amps.
The problem is i'm on a really low budget, and find the OP27 and it's high retail price a bit expensive. Also i have no easy supply of opamps so i'll need to order from texas instruments, so add shipping costs and i definatly can't afford it.
Texas Instruments offers samples of most of their chips (inc Burr Brown chips), and the OP27 is not one of thoes chips.
Is there a substitute i can use instead of the OP27, which is availuable from Texas Instruments, or is cheaper, and doesn't compromise sound quality? It doesn't matter if they don't have the same pinout i can easily modify the design.
I don't mean to sound discouraging, but most of the questions that could possibly be asked regarding this amplifier have already been asked and answered on the Headwize forum.
I know it's hard using the search function when you don't know for sure that your question's been asked, but there really is a lot of information there.
http://headwize2.powerpill.org/ubb/showpage5.php?fnum=3&tid=3705&fdays=20&srch=gilmore;opamp;
http://headwize2.powerpill.org/ubb/showpage5.php?fnum=3&tid=2184&fdays=20&srch=gilmore;opamp;
I know it's hard using the search function when you don't know for sure that your question's been asked, but there really is a lot of information there.
http://headwize2.powerpill.org/ubb/showpage5.php?fnum=3&tid=3705&fdays=20&srch=gilmore;opamp;
http://headwize2.powerpill.org/ubb/showpage5.php?fnum=3&tid=2184&fdays=20&srch=gilmore;opamp;
Garbz, the opamp is used as DC-servo and virtually any good audio opamp will fit because the application isn't very critical. Just pick an opamp and I can tell you if it's good or not.
sorry i did try searching op27 replacement in both forums but came up with nadda. Thanks for the links.
I've got opa134, opa627, opa637, on hand.
I can easily get TL071, LF351, LM301, LM308, lm747, ne5534n, ne5534an.
I'm gonna use the opa134 (cheap = win)
Also mad_k don't know where u find the Gp but i can only see the GB, and no samples availuable and 10usd + god knows for delivery.
I've got opa134, opa627, opa637, on hand.
I can easily get TL071, LF351, LM301, LM308, lm747, ne5534n, ne5534an.
I'm gonna use the opa134 (cheap = win)
Also mad_k don't know where u find the Gp but i can only see the GB, and no samples availuable and 10usd + god knows for delivery.
I've built this amp. I use the OP27 in it, but others have used the OPA227. Those are the two most commonly used in the servo. The OPA132 you have will work. I say don't waste an OPA627 in there as it won't impact sound at all.
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