Legit LM308n ?

djmiyta said:
Has anybody recently purchased any legit lm308n chips? If so from where ? I want a few not just for the rat but a couple other builds I'd like to try. Took 2 gambles on it so far First Ali express ( I knew it was a crap shoot gamble from the start) and 1 from good ol Flea bay also a no go.. Both were a few years back so I imagine the supply is much less.
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I finished a rat clone in July (Build Report) using an LM308N DIP purchased from Jameco (Link).
I never really thought about whether this was real or not, so I went and pulled the chip. Using the test posted by @Chuck D. Bones, I found the supply current for my chip is 740-750 µA, which looks to be at the high end, but within spec for this chip. (Assuming that measuring the current into the LM308N at pin 7 is the supply current). This is lower than the supply current for any other chip that I had readily at hand to check (including OP07D and LT1115).

This chip is pictured below, it is laser-marked, not printed, which I believe (google search) was in use by National by 1993 (when the code suggests the chip was made, if I interpret it correctly).

So, while not a low current chip, the data suggests this Jameco purchase was authentic.

IMG_7919.jpeg
 
gtfields13 said:
I finished a rat clone in July (Build Report) using an LM308N DIP purchased from Jameco (Link).
I never really thought about whether this was real or not, so I went and pulled the chip. Using the test posted by @Chuck D. Bones, I found the supply current for my chip is 740-750 µA, which looks to be at the high end, but within spec for this chip. (Assuming that measuring the current into the LM308N at pin 7 is the supply current). This is lower than the supply current for any other chip that I had readily at hand to check (including OP07D and LT1115).

This chip is pictured below, it is laser-marked, not printed, which I believe (google search) was in use by National by 1993 (when the code suggests the chip was made, if I interpret it correctly).

So, while not a low current chip, the data suggests this Jameco purchase was authentic.

View attachment 102954
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As a slight aside: I was breadboarding up my own version of the Rat circuit (what happens when the board is out of stock, @Robert ) and actively exploring alternatives to the LM308 for my future Rat builds. With only minor tuning I can't hear or see (ADC into Max/MSP and FFT) the difference between the LM308 and OP07D, nor the UA741ACP, which I expected to be different. The only swap that was a very different sound when I dropped in was an LM301AN (with compensation added) that I think I picked up in the mid-90's.
 
This thread got me to thinking. What is the chip in my 6 clipping style BYOC Rat pedal? I built this over 10 years ago, and behold it looks like a legit National Semiconductor LM308N chip from the 80's according to the batch/manufacturer's number (this was found on an old forum from over 15 years ago). The chip posted about has the same the batch/manufacturer's number as mine. Very versatile Rat pedal with Standard (1N4148 post Opamp Diodes), Turbo (2 Red post Opamp LED's), Asymmetrical Distortion (1N4148 plus two 1N4001 post Opamp Diodes), Symmetrical OD (two 1N4148 Diodes), Asymmetrical OD (1N4148 plus two 1N4001 Diodes) and MOSFET (BS170). My LM308N looks exactly like the one below> unnamed.jpg
 
rpaul2 said:
This thread got me to thinking. What is the chip in my 6 clipping style BYOC Rat pedal? I built this over 10 years ago, and behold it looks like a legit National Semiconductor LM308N chip from the 80's according to the batch/manufacturer's number (this was found on an old forum from over 15 years ago). The chip posted about has the same the batch/manufacturer's number as mine. Very versatile Rat pedal with Standard (1N4148 post Opamp Diodes), Turbo (2 Red post Opamp LED's), Asymmetrical Distortion (1N4148 plus two 1N4001 post Opamp Diodes), Symmetrical OD (two 1N4148 Diodes), Asymmetrical OD (1N4148 plus two 1N4001 Diodes) and MOSFET (BS170). My LM308N looks exactly like the one below>View attachment 102975
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This is indeed legit
 
Stickman393 said:
DIP-14s anybody?

View attachment 103066


The Motorola is from Jameco. Haven't tested, seems legit.

This is a DIP-8 from Jameco:

View attachment 103067

Need to test it. On the plus side, Jameco is about an hours drive from my place. So I can go down there and collectively whip some ass if they turn out to be fakes.
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I got some chinese lm308 from aliexpress some years ago since I did know nothing about the industry but they definitely look like the DIP-8 from Jameco
 
ivandelado said:
I got some chinese lm308 from aliexpress some years ago since I did know nothing about the industry but they definitely look like the DIP-8 from Jameco
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I got mine around the same time as @gtfields13. Our date codes match, which isn't *super* surprising if Jameco is sitting on a bunch of NOS chips.

Trying to keep an open mind here: if the chips from AliExpress have the same date codes marked on em, they're likely from the same counterfeit source.

BUT...this is also where I'm kinda wishy-washy on how important that is.

Cause, like...the new coolaudio and xvive BBDs are knockoffs. Copies. I'm thrilled that we have those, though. If they function identically, it's a boon to the DIY community.

It's true that knockoffs from China can be of inferior quality. My "Motorola" AC128s are proof of that. But I made that determination after testing, not before.

So...imma see what this fucker does.
 
Stickman393 said:
BUT...this is also where I'm kinda wishy-washy on how important that is.

Cause, like...the new coolaudio and xvive BBDs are knockoffs. Copies. I'm thrilled that we have those, though. If they function identically, it's a boon to the DIY community.
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That's a rosy way of looking at it, one that would be more applicable if these copies were not marked up to real part mojo prices.

It's a bummer there are less trusted sources each year as us old fucks die off or retire. Like, for example, Steve from Small Bear. I'm sure there are still troves to be found, I would just say be cautious or at least be aware it's a gamble rather than a outright purchase.
 
Hal Harvey said:
That's a rosy way of looking at it, one that would be more applicable if these copies were not marked up to real part mojo prices.

It's a bummer there are less trusted sources each year as us old fucks die off or retire. Like, for example, Steve from Small Bear. I'm sure there are still troves to be found, I would just say be cautious or at least be aware it's a gamble rather than a outright purchase.
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Call me and optimist.

Go ahead. Do it. See what happens
*clutches knife by the blade, blood dripping from his fist*
 
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