mesmer
Well-known member
Anybody ever seen this opamp?It has a framiliar footprint.
http://www.surplussales.com/Semiconductors/SemiC-Audio.html
Peter
http://www.surplussales.com/Semiconductors/SemiC-Audio.html
Peter
Can anyone identify this opamp?
- Thread starter mesmer
- Start date
Help Support GroupDIY Audio Forum:
:shock:
Mark Burnley
Well-known member
Hi Peter,
These look like very old stock- this package was a standard discrete op-amp module package, and whilst it looks similar to some "famous" audio op-amp modules, I should imagine it'd be a very poor performer. As Jakob alluded to- if it has characteristics "similar to a 741" then it would struggle with quality audio in most apps.
Before the IC fab processes became cheap, high-yielding, and accurate, the only option was to build discretely- and many specialist op-amps were built this way. At the time they would have been state-of-the-art and expensive!. I've got some old Analog Devices potted DOA's at home. Out of curiousity I e-mailed AD and got the datasheet (1974!!). The specs were actually quite funny w.r.t the price- it made me realise that we live in a remarkable age when we can buy incredibly specced IC's for peanuts and get them to do a good job.
>sensible electronics hat taken off<
BUT...if you found the datasheet for them, or if you get an op-amp like this for not a lot of money, by all means use them as an effect stage- the GBW product would be low I should imagine, as well as the slew rate. Offset currents may be measured in mA...etc etc, but that may be just what you need. And they'd sure look cool inside a project
There's always something to be gained from experimenting :thumb:
...I'm sure PRR guided someone through a project like this with success...Bluebird? I can't remember...
Mark
These look like very old stock- this package was a standard discrete op-amp module package, and whilst it looks similar to some "famous" audio op-amp modules, I should imagine it'd be a very poor performer. As Jakob alluded to- if it has characteristics "similar to a 741" then it would struggle with quality audio in most apps.
Before the IC fab processes became cheap, high-yielding, and accurate, the only option was to build discretely- and many specialist op-amps were built this way. At the time they would have been state-of-the-art and expensive!. I've got some old Analog Devices potted DOA's at home. Out of curiousity I e-mailed AD and got the datasheet (1974!!). The specs were actually quite funny w.r.t the price- it made me realise that we live in a remarkable age when we can buy incredibly specced IC's for peanuts and get them to do a good job.
>sensible electronics hat taken off<
BUT...if you found the datasheet for them, or if you get an op-amp like this for not a lot of money, by all means use them as an effect stage- the GBW product would be low I should imagine, as well as the slew rate. Offset currents may be measured in mA...etc etc, but that may be just what you need. And they'd sure look cool inside a project
There's always something to be gained from experimenting :thumb:
...I'm sure PRR guided someone through a project like this with success...Bluebird? I can't remember...
Mark
clintrubber
Well-known member
from Mark Burnley:
Right ! For that price you might even add some of these modules and let some todays SMD-opamp that's mounted underneath do the actual job :wink:
Right ! For that price you might even add some of these modules and let some todays SMD-opamp that's mounted underneath do the actual job :wink:
MikoKensington
Well-known member
That does look marvelous. :grin:
I actually bought one of those. I thought it would be similar to a 2520 but I couldn't get it to pass decent audio. I bread-boarded it a few different ways using schematics like the 312 and even just a simple inverting input setup. But just got distortion.
It does have trim, and I wasn't sure what to do with it but everything I tried didn't work, then Peter C gave me the layout for the 1731 in the same footprint--- built a few and then I never played with it again.
It does look promising as a audio op-amp, same size same footprint, but it didn't work for me. Give it a go. You may have luck with it.
Vetsen
It does have trim, and I wasn't sure what to do with it but everything I tried didn't work, then Peter C gave me the layout for the 1731 in the same footprint--- built a few and then I never played with it again.
It does look promising as a audio op-amp, same size same footprint, but it didn't work for me. Give it a go. You may have luck with it.
Vetsen
CJ
Well-known member
"Paper jam! there is now paper jam!"
"We need you to move your desk back another three feet."
=
"Has anybody seen my red stapler?"
We did this befor once, didn't we?
Must be Friday! :guinness: :guinness: :guinness: :guinness:
"We need you to move your desk back another three feet."
=
"Has anybody seen my red stapler?"
We did this befor once, didn't we?
Must be Friday! :guinness: :guinness: :guinness: :guinness:
SSLtech
Well-known member
Rr-iii-iii-iii-ght...
yeah, I'm gonna have to go ahead and disagree with you there... ...'kay?
Keef
yeah, I'm gonna have to go ahead and disagree with you there... ...'kay?
Keef
SonsOfThunder
Well-known member
yeeeeeah, umm, I'm gonna need you to come in on Saturday, yeah, that'd be greeeeat. Possibly Sunday too...
I'd say the movie has a crappy plot, and terrible acting. But it is very funny. We joke about this one all the time where I work.
Peece!
I'd say the movie has a crappy plot, and terrible acting. But it is very funny. We joke about this one all the time where I work.
Peece!
********s!
peter purpose
Well-known member
peter purpose
Well-known member
Sure thing,
Tis an EQ based on this from Rod Elliots...
I'm yet to fire it up (not sure if the intechs will take 18V), but as them orange blocks are apparently ***** at passing quality audio, I'm using them as simulated inductors.
pp
Tis an EQ based on this from Rod Elliots...
I'm yet to fire it up (not sure if the intechs will take 18V), but as them orange blocks are apparently ***** at passing quality audio, I'm using them as simulated inductors.
pp
MikoKensington
Well-known member
Hmmm. Neato. I can't wait to know the outcome of your listening tests.
peter purpose
Well-known member
Well,
The best thing about this EQ is the high frequency shelf.... which is the only bit of the circuit that goes nowhere near those orange blocks..!!
It was worth a punt. :sad:
The best thing about this EQ is the high frequency shelf.... which is the only bit of the circuit that goes nowhere near those orange blocks..!!
It was worth a punt. :sad:
peter purpose
Well-known member
Nope... About as much use as a tit on a bull :roll:
