Legit LM308n ?

djmiyta

djmiyta

Well-known member
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.
 
I've had decent luck with jameco.... Some were legit... some were questionable but not obvious fakes..
 
swelchy said:
I've had decent luck with jameco.... Some were legit... some were questionable but not obvious fakes..
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Haven't bought any of the PDIP versions from Jameco, but IIRC @jwin615 has and they were all fakes. The TO99 cans I've gotten have been, by all testing anyway, legit*. I've also gotten a few (very reasonably priced) from trusted ebay sellers, but they sold out quick.

They are thin on the ground, and fakes are rife. Be wary.

*Looking back at my purchase history, I've received two types: legit Motorola cans, and one National Semiconductor one which may most likely be fake. i.e. caveat emptor
 
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Anyone bought from these folks?

www.tubedepot.com

80s/90s Style LM308N RAT Op-Amp Chip

Arguably, this is the most debated Rat chip ever. Conversations have dragged on for years about the quintessential "Rat" sound and what components comprise its ubiquitous distorted characteristics. One thing is certain: The LM308 is always in the conversation. The LM308 chip is the same style used
www.tubedepot.com www.tubedepot.com

I haven't, and I'm not in the market, just one of the first search results that comes up. I haven't bought anything from Tube Depot, but they look like a legit operation, not some sketchy fly by night ebay seller.

Edit: Just to clarify - Not to say that I think No BS ebay guy is sketchy. I bought some of those a while back and they sounded good to me.
 
Erik S said:
Again, I have no skin in this game, but it does look like there were different versions of that logo over time.

View attachment 102724
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I know that some cans were produced concurrent with plastic pdip, but yeah, looking again (bought a while ago) in starting to doubt this Jameco(?) one.
1000010084.jpg
The fatness…


This one is from a trusted eBay seller. It's an old Intersil logo/mark . 1757605376302.png
1000010085.jpg
 
Fairly certain all the Jameco ones were fakes.
They also keep reupping the stock.
The LT1008 is an easily obtainable sub, though a bit pricey. Most tight low end in my shoot out. Of course, that's all subjective.
jwin615 said:
View attachment 98334
Rat opamp shootout
Findings playing a loop through an EL ACHE build max gain, filter wide open
1)Harris HA2-5130-2 best note articulation, good low end, nearing unobtanium, not a CA5130 varriant
2)Linear LT1008 close second, a little less saturated but full tight low end
3)LM308 yep
4)Raytheon RV4077FDE a little less saturation, less fizz/sizzle than a 308 but bottom extension is lacking but what is there is tight
5)OP07 ... There's a weird ice pick 1khz harmonic, boxy low end, less harmonics but more crossover distortion?
6)OP02 meh fizzy, less balls, flubby bottom

1 2 and 4 are all improved OP07 types, per the datasheets
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I looked at Jameco during my recent hunt.

I am by no means an expert, someone might tell me my entire haul is fake (I sure hope not), but combined with some of the reviews here there were just too many red flags.

The printing just looks off in the photo. Maybe I'm wrong.

The confidence that more will be in stock in 7 weeks is at least a little off-putting. Maybe it's just a placeholder for parts that are configured as replenishable in the system, it has said 7 weeks for at least two weeks, regardless, I was suspicious.....


1757609927539.png

Let me clarify that this is not a negative review. I've never personally had any bad experiences with Jameco.
(I don't think that I've ever actually ordered anything from them)
 
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Robert said:
The printing just looks off in the photo. Maybe I'm wrong.
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the one above is one I got from Jameco: NatSemi logo is too fat around the ascender and descender of the N, and I question whether they were still doing cans concurrently with PDIPs 😕
1000010084-jpg.102725

1000010091.jpg 1000010090.jpg 1000010089.jpg

If memory serves, I also got Motorola branded ones from Jameco, and those were sufficiently "old" and matched the patters of those from a group buy a while back.
 
Play test it against an OP07. I can definitely tell a difference between one of those and the verified (as best as possible) group of LM308s I got from Small Bear. The LM308 sounds chunkier, tighter and less fuzzy around the edges, IMO.
 
A few years ago, I bought some that look like this. They have a brownish tint. I haven't seen many like them but they are legit.
4707.jpg
 
I got some PDIP LM308 from this seller a couple years ago: https://www.ebay.com/str/intergalacticsemiconductor. They were pulls, with mangled legs and a variety of markings.

I tested them in a Rat circuit on the breadboard, along with some Motorola metal cans, some УД1408А, a NTE 938, and a metal can from the no china bs shithead. Using a couple measures gleaned from @Chuck D. Bones, most tested legit and also sounded like each other. So did a LM108. Fails were a PDIP from Jameco, and an Ebay purchase from more than a decade ago. They sounded different, drew different current, had different 1-8 resistance, and didn't react to pulling the 30pF capacitor.

I have private doubts about any markings being dispositive on their own (other than codes that match image search results). Testing was fun and easy, and it matched my ears. Conventional wisdom about Jameco and Ebay was the best external guide.

FWIW, I'd look into getting some Soviet УД1408А, which are analogous. I can't hear a difference, and they tested like the legit 308s. Also AS301, which are new production? They sound really, really close.
 
derevaun said:
FWIW, I'd look into getting some Soviet УД1408А, which are analogous. I can't hear a difference, and they tested like the legit 308s. Also AS301, which are new production? They sound really, really close.
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Interesting, I can't really find any sources to buy them online though. Or I found some Ukrainian site where they were dirt cheap but I don't think they ship abroad, and possibly a bunch of russian sites I'm not touching with a ten foot pole.
 
Fama said:
Interesting, I can't really find any sources to buy them online though. Or I found some Ukrainian site where they were dirt cheap but I don't think they ship abroad, and possibly a bunch of russian sites I'm not touching with a ten foot pole.
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I was getting mine from alexer1 / SOVCOM on eBay, but he hasn't seemed to have much in the way of opamps lately.

It's been a while since I ordered anything, but I've bought a ton of stuff from DSMCZ. The search function on the site blows, so be prepared to browse. Shipping used to be reasonable, and would show up quicker than expected. But it's been at least a year since my last order.
 
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