# Sourcing LM301AN



## steppenbar (Jul 29, 2022)

Got a Cattle Driver PCB and was wondering if there was any good source for the LM301AN? or what is a good alternative. Haven't had much luck googling the usual parts websites. Hope this is the right forum for this type of thread. Thanks!


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## Cybercow (Jul 29, 2022)

All of these are pin-for-pin compatible single opamps that should work just fine in place of an LM301

LM201 - Slew = variable; BJT
LM301 - Slew = variable; BJT
LM308 - Slew = 0.3V/µs; BJT
LM148 - Slew = ~0.5V/µs;BJT
LM4250 - Slew = variable; BJT
LM709 - Slew = 0.25V/µs; BJT
LM741 - Slew = 0.5V/µs; BJT
LM748 - Slew = 0.5V/µs; BJT
OP07 - Slew = 0.3V/µs; BJT

If you want the LM301AN, Jameco LM301AN has them . . . .


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## Alan W (Jul 29, 2022)

I got a few at Mouser about two weeks ago, but they are SMT, so you need to solder them onto the small adapter boards that are available in the pedalpcb shop.


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## benny_profane (Jul 29, 2022)

IC LM301AH
					

Small Bear Electronics DIY Parts




					smallbear-electronics.mybigcommerce.com
				




The -H package is metal can instead of DIP8.


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## manfesto (Jul 30, 2022)

Op-Amp - AS301AN, Alfa, Single, 8-Pin DIP | Amplified Parts
					

The AS301AN is Alfa’s version of the LM301A in an 8 pin DIP package. The AS301A is a general purpose operational amplifier. This amplifier offers many features which make its application nearly foolproof: overload protection on the input and output, no latch-up when the common mode range is...




					www.amplifiedparts.com
				




This is an interesting alternative, not sure exactly what the deal with Alfa is (anybody who has the scoop I’d love to hear!) but they do “version”s of the LM301 in both DIP8 and metal can formats, and they also do their “version” of a CA3080.

I bought some AS301s with my last order from AmplifiedParts and just built a Rat with one, and it did the Rat thing.

For $2 I’ll for sure pick up some more


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## derevaun (Jul 30, 2022)

I recently got some from Jameco for US$3.95. I haven't tested them in a circuit yet. Good luck!


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## ICTRock (Jul 30, 2022)

honestly, if you aren't going with the lm308, just go with a 741and skip c12. there's nothing special about the 301 other than it is a poor substitute for the 308 in rat-like circuits


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## steppenbar (Jul 30, 2022)

ICTRock said:


> honestly, if you aren't going with the lm308, just go with a 741and skip c12. there's nothing special about the 301 other than it is a poor substitute for the 308 in rat-like circuits


I do have a couple of 308s!


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## steppenbar (Jul 30, 2022)

manfesto said:


> Op-Amp - AS301AN, Alfa, Single, 8-Pin DIP | Amplified Parts
> 
> 
> The AS301AN is Alfa’s version of the LM301A in an 8 pin DIP package. The AS301A is a general purpose operational amplifier. This amplifier offers many features which make its application nearly foolproof: overload protection on the input and output, no latch-up when the common mode range is...
> ...


Thanks for the heads up, I forgot about amplified parts. I think I'll stick with my 308s but definitely want to try their CA3080s


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## steppenbar (Jul 30, 2022)

Cybercow said:


> All of these are pin-for-pin compatible single opamps that should work just fine in place of an LM301
> 
> LM201 - Slew = variable; BJT
> LM301 - Slew = variable; BJT
> ...


That's super informative! I do have a few 308s and 741s


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## manfesto (Jul 30, 2022)

steppenbar said:


> That's super informative! I do have a few 308s and 741s


If they’re legit 308s I’d save them since they’re getting rare and go with a cheaper alternative


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## Chuck D. Bones (Jul 31, 2022)

derevaun said:


> I recently got some from Jameco for US$3.95. I haven't tested them in a circuit yet. Good luck!


You better test them because Jameco is known to sell bad parts and their customer service policy is "tough shit."

TL071 is a good sub for LM301 in this pedal.  You definitely want a low-noise opamp.


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## steppenbar (Jul 31, 2022)

manfesto said:


> If they’re legit 308s I’d save them since they’re getting rare and go with a cheaper alternative


I have like 5 but I'll be socketing and will experiment to see how they work. But yeah they're getting expensive.


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## steppenbar (Jul 31, 2022)

Chuck D. Bones said:


> You better test them because Jameco is known to sell bad parts and their customer service policy is "tough shit."
> 
> TL071 is a good sub for LM301 in this pedal.  You definitely want a low-noise opamp.


I'll check it out! Also thanks for the heads up on Jameco. I'm still a newbie so I'm not very familiar with a lot of things yet.


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## MattG (Sep 21, 2022)

ICTRock said:


> honestly, if you aren't going with the lm308, just go with a 741and skip c12. there's nothing special about the 301 other than it is a poor substitute for the 308 in rat-like circuits



So C12 is the compensation cap between pins 1 and 8 on lm301/308, OP07, etc.

What happens if you have C12 populated with an opamp like the LM741 or TL071 that doesn't need a compensation cap?  At least with the LM471 and TL071, pin8 is "NC", the datasheet says "do not connect".  I know you're _supposed_ to leave that pin open, but if it's _internally_ not-connected, it shouldn't matter, right?  Pin1 (again for the LM741 and TL071) is offset null voltage.




Chuck D. Bones said:


> TL071 is a good sub for LM301 in this pedal.  You definitely want a low-noise opamp.



The TL071 has a much higher slew rate (13U/usec for the TL071CP), dramatically higher than e.g. LM308.  My understanding (quite possibly incorrect!) is that, at least with the Rat, part of the tonal character comes from that super-slow slew rate.  The Cattle Driver clipping arrangement is different than a Rat though (soft clipping in feedback loop vs hard clipping to ground).

FWIW, I actually have two Cattle Drivers.  They both have LM308N in them (if I'm not mistaken, that's what the Buffalo TD-X has).  In one of my builds, I swapped out the LM308N for a TL071CP.  Side by side, there was definitely a difference.  To me, with the TL071, the max "overdriven-ness" ceiling seemed a little lower, and and it also seemed a little "crispier" with a little more emphasis in the highs.  I was afraid to leave it in there, though, per my question above, I'm not sure if it's a problem to have the 47pF across pins 1 and 8 on the TL071.


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## MichaelW (Sep 21, 2022)

MattG said:


> So C12 is the compensation cap between pins 1 and 8 on lm301/308, OP07, etc.
> 
> What happens if you have C12 populated with an opamp like the LM741 or TL071 that doesn't need a compensation cap?  At least with the LM471 and TL071, pin8 is "NC", the datasheet says "do not connect".  I know you're _supposed_ to leave that pin open, but if it's _internally_ not-connected, it shouldn't matter, right?  Pin1 (again for the LM741 and TL071) is offset null voltage.
> 
> ...


Hmmm interesting, I have a TL071 in mine, but I do have a 308 gifted to me by @swelchy. I was saving it for a rainy day I can't hear the difference between a 308 and OP07 in my Rat, I might have to try it in the Cattle Driver.


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## ICTRock (Sep 21, 2022)

If you want the Pepsi challenge on the 308 vs the OP07 in a rat, remove the clipping diodes.


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## Chuck D. Bones (Sep 21, 2022)

An LM301 will not slew-rate limit in the Cattle Driver.  The soft clipping diodes don't allow the output voltage to swing far enough to slew-rate limit in the audio freq range.  I don't doubt you hear a difference between the TL071 & LM301A, I just can't explain why you're hearing it.    

The gutshot of the TD-X I found online shows an LM301A.


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## MattG (Sep 21, 2022)

Chuck D. Bones said:


> The gutshot of the TD-X I found online shows an LM301A.



Back when I built my first (of three total) Cattle Drivers, I had some issues, and @music6000 was helping me debug it.  He said he has an actual TD-X, and it has an LM308N.  Presumably both (possibly even others) were used during production.

Nice looking guts on that TD-X though!




Chuck D. Bones said:


> An LM301 will not slew-rate limit in the Cattle Driver.  The soft clipping diodes don't allow the output voltage to swing far enough to slew-rate limit in the audio freq range.  I don't doubt you hear a difference between the TL071 & LM301A, I just can't explain why you're hearing it.



My LM308Ns came from eBay, so it's quite possible I have fakes.  My TL071CP is TI-branded from Digi-Key, so reasonable chance of being legit.  I have LM301A as well, but those are also eBay sourced.  <shrug>


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## Chuck D. Bones (Sep 21, 2022)

Not everything from eBay is .  

An easy test to see if an opamp is even in the ballpark is to measure the current into the +power pin.  Connect the -input to the output, connect the +input to 1/2 Vcc.  LM308's are low power. Their typical power supply current is between 250uA and 300uA when powered from 9V.  Fakes will draw more current than that.

DigiKey, Avnet, Arrow & Mouser are authorized distributors.  They guarantee the authenticity of the parts they sell.


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## Feral Feline (Sep 22, 2022)

MattG said:


> So C12 is the compensation cap between pins 1 and 8 on lm301/308, OP07, etc.
> 
> What happens if you have C12 populated with an opamp like the LM741 or TL071 that doesn't need a compensation cap?  At least with the LM471 and TL071, pin8 is "NC", the datasheet says "do not connect".  I know you're _supposed_ to leave that pin open, but if it's _internally_ not-connected, it shouldn't matter, right?  Pin1 (again for the LM741 and TL071) is offset null voltage.
> 
> ...


That's what sockets are for. 

Socket not only the op-amp, but the compensation cap, too. Then you can also experiment with different size caps, 22p, 30p, up to... check the data sheet, I think you can go as high as 60-ish. 

Another option is trim-caps. Like trimmer-resistors, you can get trimmer-caps in the PF range. I don't recall the exact values of my pF caps, but I've got a bunch of different sizes of adjustable caps from about 5pF up to 120pF. 







Install a trimmer-cap and just dial it down to zero, see if anything bleeds through; again, check the datasheets of the trim-caps, variable capacitors may have a minimum setting that still bleeds through a bit, in which case...

... back to sockets.


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