Source for 708N chip to upgrade Rat 2?

[Steve A.]

EDIT: I got the numbers mixed up- it is the LM308N chips that I was wondering about. I apologize for the confusion created.

I've been searching the web for 708N chips and found 2 sources that are a bit pricey. Just wondering if there is a good source for them. Also, are these useful to have around for anything beside Proco Rat pedals?

Thanks

Steve Ahola

[g1]

Do you mean LM308 ?

[Chuck H]

That's the one I'm familiar with. Still cheap enough in bulk but spendy as hell individually. I had a mid 80's RAT! Bought it new when I was only sixteen! I must admit, it was pretty cool! If I though there was enough of a following I would buy the LM308 in bulk and build pedals! Though it hasn't worked out for anyone else so far. In fact the only pedal I would buy that uses that chip would be the ProCo reissue! The "White Face RAT". The side by side comparison with an actual vintage unit on Youtube is VERY convincing. I can't say how much the LM308 actually had do with it, but the reissue with that chip is the only pedal I've heard that does THAT sound. I cut my teeth playing through a RAT! Sadly I don't even know what ever happened to that pedal. Probably stolen. Later in life I bought a "Vintage RAT" and I NEVER use it. It's just not there. The later models, "Turbo RAT", RAT II" and any other incarnation just don't do it either. Many known recordings have been made through original LM308 RAT's. Three Franklin's will get you into a bona fide reissue!!! Small price for honest mojo IMHO. I haven't done it yet though. Either my priorities are off or my budget is. I don't really wish to examine which at any given time.

[Steve A.]

It looks like there are new LM708N's being made in China- very inexpensive with free shipping. However I wonder how they compare to the original ones.



5 Pcs LM308N DIP 8 LM308 308N Operational Amplifiers | eBay

Steve

P.S. I noticed a few auctions on eBay selling the new chips at NOS prices. Let the buyer beware!

http://www.ebay.com/itm/LM308N-IC-OP...item25856724dc

[Chuck H]

Indeed! The newest chips could be a similar amplifier erroneously marked!!! We've seen that sort of thing. The original RAT chips were made by Motorola (or made for Motorola by ???) and had an "M" in a circle in the markings. I've never seen one of these for sale. The oldest ones around are made by National Semiconductor and may also have been made in china but modders report good results with these.

[g1]

It looks like there are new LM708N's being made in China- very inexpensive with free shipping. However I wonder how they compare to the original ones.

[ATTACH=CONFIG]26600[/ATTACH]

Sorry to keep harping on this, but there you go calling them 708's again,

[doctor]

Sorry to keep harping on this, but there you go calling them 708's again,

It is necessary to distinguish between two approaches.

1. The client is a snob and he wants to get an authentic product.
For example, Botticelli fresco not restores using modern paints,
because it will not be the work of Botticelli.
If so, then you need to look for the chip of the same manufacturer
and the same year production.

2. The client wants to obtain a fixed device that sounds the same.
In this case the same chip manufactured by any manufacturer is suitable.
Such replacement will not lead to any sound changes.

The same chip manufactured by different manufacturers has both the
same internal schematic and identical parameters. Compare the LM308
manufactured by Linear, National Semi and Texas Instruments.

[g1]

Doctor, I was not referring to the brand or prefix, rather the typo of 708 instead of 308.

[Jerry]

Steve, If you are looking for LM308 chip, build your own clone has them listed on their site.

[doctor]

g-one, you are right.

My remark is of a general nature.

[Steve A.]

Sorry to keep harping on this, but there you go calling them 708's again,

I called them LM708's in the post that you just quoted. When I researching sources for this chip it looked like some of the mfg's used their own prefix instead of the LM, although it is possible that those chips were entirely different. BTW in both of your posts you omitted the N suffix which indicates the case type (I believe that the LM708AN is basically the same chip but in a can.) Yes, I am a stickler for details, too.

So does anyone recognize the logo in that picture?

Steve

[Steve A.]

Steve, If you are looking for LM308 chip, build your own clone has them listed on their site.

Thanks! I checked that site earlier using the search box and did not find them. However going through the menu I did find them there. $5 each plus $4.07 shipping- very reasonable.

There is a whole batch of ridiculously cheap LM708N's on eBay from China, HK and Taiwan, like this auction- 10 chips at $6.99 w/ free shipping. Kinda strange- it did not come up in a site search or a google search. And when I searched Google for "lm708n rat" the only hit I just got was to this thread!

10 Pcs LM308N DIP 8 LM308 308N Operational Amplifiers | eBay

And when I searched Google for "lm708n rat" the only hit I just got was to this thread! What the heck is going on???

https://www.google.com/search?q=lm70...en-US:official

Steve

[g1]

It's 3!!! THREE!!! Not SEVEN!!! OK??? I'll stop yelling now, I'm not really losing it (or am I ).

edit: to be clear: there is no such thing as a 708 op amp, be it LM or any other prefix. It is 308, as in LM308 .
The only reason I ever brought it up was that I saw the title of the post and was scratching my head thinking "what's a 708 chip". I thought others may also wonder, or just not respond to the post.

[Steve A.]

to be clear: there is no such thing as a 708 op amp, be it LM or any other prefix. It is 308, as in LM308 .
The only reason I ever brought it up was that I saw the title of the post and was scratching my head thinking "what's a 708 chip". I thought others may also wonder, or just not respond to the post.

I don't have the time to reinvestigate this right now but I did find referrals to 708N chips with different prefixes the other day so I used the generic term "708N" to refer to the same chip made by other vendors who may have used a different prefix. Perhaps I should have referred to it as an "xx708N" chip with "xx" defined as a two letter prefix.

The title "Source for 708N chip to upgrade Rat 2?" should make perfect sense to the people familiar with RATs and the IC's used in them who would probably be the people most likely to give me useful advice (a big thanks to Chuck H. and Jerry!)

Steve

[Jazz P Bass]

Pro Rat 2 schematic