Where to get (old) LM 741 and RCA 741?

Website · Post by **Lonkero** » 27 May 2010, 11:24

I live in Finland, where there are only a few store selling op-amps. I've been trying to find the LM741 and RCA metal can version (which is supposed to be quieter) but don't know which would be good place to buy them? In my country the few shops sell only new ua741 op-amps.

Even better would be if I could obtain some original 30+ year old 741 op-amps to my dod 250 project. Maybe somebody can help me?

mictester · Post by **mictester** » 27 May 2010, 12:34

Lonkero wrote:I live in Finland, where there are only a few store selling op-amps. I've been trying to find the LM741 and RCA metal can version (which is supposed to be quieter) but don't know which would be good place to buy them? In my country the few shops sell only new ua741 op-amps.

Even better would be if I could obtain some original 30+ year old 741 op-amps to my dod 250 project. Maybe somebody can help me?

Why? Do you like hiss?

The 741 was one of the noisiest op-amps ever made, and wasn't really designed for audio use. If you use an NE5534 instead, your pedal will sound exactly the same as an original one, but without the hiss.

The 741 doesn't have any mystical musical properties, and you'll just be wasting your money if you're suckered into buying "NOS" parts!

Website · Post by **Lonkero** » 27 May 2010, 12:45

mictester wrote:
Lonkero wrote:I live in Finland, where there are only a few store selling op-amps. I've been trying to find the LM741 and RCA metal can version (which is supposed to be quieter) but don't know which would be good place to buy them? In my country the few shops sell only new ua741 op-amps.

Even better would be if I could obtain some original 30+ year old 741 op-amps to my dod 250 project. Maybe somebody can help me?
Why? Do you like hiss?

The 741 was one of the noisiest op-amps ever made, and wasn't really designed for audio use. If you use an NE5534 instead, your pedal will sound exactly the same as an original one, but without the hiss.

The 741 doesn't have any mystical musical properties, and you'll just be wasting your money if you're suckered into buying "NOS" parts!

When it comes to some things, I have a purist in me

Noise ain't a problem cause I run NS-2 with all the dod pedals. Even the YJM 308 which has the KA4558 is supposed to be low-noise op-amp but it ain't. Hiss is as loud in it too.

I've learned that there all are the great new improvements which suppose to replace the olds, but if they're so great why are not everyone using the new stuff? Cause there are differences which some of us can hear

Enough offtopic, lets keep focusing on the parts obtaining!

uncleboko · Post by **uncleboko** » 27 May 2010, 13:18

DeanM · Post by **DeanM** » 27 May 2010, 13:30

Well with the 741s in old DOD250's it wasnt the NOS chips that made the sound. it was just that they took advantage of the poor specs of the 741. 741's have a pretty bad slew rate and so were slow to react to higher frequencies and that led to a smoother top end than with other faster chips. so it worked well in that simple circuit.

I remember seeing RCA 741's online somewhere!! and it was within the last two weeks i saw em!! cant remember where the hell i saw em tho!! il try remember and if it comes back to me il let you know!

sadrew · Post by **sadrew** » 27 May 2010, 14:28

ebay has plenty... do a search for LM741 TO-99

roseblood11 · Post by **roseblood11** » 27 May 2010, 22:11

I´m sure that a NS-2 kills more tone than any old super-duper mojo IC can deliver...

JOHNO · Post by **JOHNO** » 27 May 2010, 23:52

Wiki says that RCA became defunct in 1986 when GE brought them out. I have about 50 used RCA CA741 opamps. These are from the late 60's or early 70's i'm not sure. Now if you check the RCA data sheet you will notice that it says on the first page that the CA741 is identical in specification to the LM741. If you would really like one of these opamps I'd be happy to satisfy your need for this "mojo chip" if that is what you want to call it, and send you one in the mail. But I've built 250's with these CA741 chip's, and your garden variety LM741 chips and the results are the same. But if you really want one pm me your address and I'll send you one.
Johno

Website · Post by **Lonkero** » 28 May 2010, 11:14

JOHNO wrote: But if you really want one pm me your address and I'll send you one.
Johno

That would be great! PM Sent

marin · Post by **marin** » 20 Aug 2010, 15:16

as Dean said, the 741 has limited bandwidth but wether that could be called smooth is another thing. having in mind that those and these adjectives are arbitrary i say that dod250 with 741 gets additional distortion to the notes after 12th fret E. it does sound bold and great. with 741 you have a thing not dissimilar to exciter. if not aural than certainly audible.

there is NO more hiss than with 4558 variety.

snmavronis · Post by **snmavronis** » 21 Aug 2010, 01:23

The closest I got ahold of to the RCA 741 IC chip is this:

JOHNO wrote:Wiki says that RCA became defunct in 1986 when GE brought them out. I have about 50 used RCA CA741 opamps. These are from the late 60's or early 70's i'm not sure. Now if you check the RCA data sheet you will notice that it says on the first page that the CA741 is identical in specification to the LM741.

Does this mean that my CA741 metal can is from the 19th week of 1979 according to the date code 919 at the bottom if I'm reading it correctly? The only reason I might use it is that it could be from the same period (1979-1980) that my DOD is based on.

You're right though it sounds no different when I compared this than the 84' Motorolla LM741CN dip version that I'm using anyway. I think the datasheet says the DIP version has a higher temperature range than the Metal Can version.

leeknpotatosoup · Post by **leeknpotatosoup** » 21 Aug 2010, 23:14

At my university we have heaps of them just lying around everywhere haha

snmavronis · Post by **snmavronis** » 21 Aug 2010, 23:25

leeknpotatosoup wrote:At my university we have heaps of them just lying around everywhere haha

What does your university have an op amp graveyard? LOL.

I know using vintage parts doesn't really make anything sound better, but it adds a certain coolness factor to your clone especially if it is from the same time period as your subject is.

marin · Post by **marin** » 22 Aug 2010, 13:36

I'll PM you leeknpotatosoup.

leeknpotatosoup · Post by **leeknpotatosoup** » 23 Aug 2010, 03:13

snmavronis wrote: What does your university have an op amp graveyard? LOL.

I know using vintage parts doesn't really make anything sound better, but it adds a certain coolness factor to your clone especially if it is from the same time period as your subject is.

Yeah we were using old parts to look at the noise in op-amps, turns out they're pretty noisy compared to the modern versions, but still not bad.

If anyones keen I could send some in an envelope for free.