The notorious TL604CP ic

[Mars Amp Repair]

I Decided to bring start a new post on this one.
I did a search for postings on this IC, but didn't find anything, tho I know I've seen previous posts. So decided to start a new one.

I've heard talk of these discontinued tl604's & how Peavey has a replacement in the form of a small pcb for like $20. I've done some searching on the web for this IC & have found a few sources, but would like to know if anyone has had any reliable luck with any particular supplier.

I found one (vancebaldwin.com) that sells them for around $6 for the original TL604CP, but they have no means on their site to contact them. That makes me suspicious. Others must know about the Peavey replacement, as they sell for about $14 ea.
Anyone had any luck with a source for the originals?

Thanx, glen

[Mark Black]

I didn't have any luck finding originals either.

The preferred replacement seems to be a DG419 (or ADG419 depending on the maker). They are not pin-for-pin compatible though, and you need to create a voltage divider resistor string to feed one of the pins.

Here's a blurb on the changeover courtesy of Gallien Krueger...

Hey I see you are near Denver. Don't know if you're old enough but do you remember...

Mr. Lucky's
M-80's
Tulips
Casa Bonita

(Road trip memories from days of old...)

Oh yeah - your next post should make you a "Senior Member"!

[Mars Amp Repair]

Hey Mark,
Thanx for the info...there are suppliers abounding with tons of the TL604's...just got a quote from one company online www.iso-comp.com for $20ea for 10 or $12.xx ea for $20. The verbage sounded like they're definitely not a USA Co.

I'm still waiting for a quote from another site for $5.00 ea. So they're out there. Not certain I need 10 or 20 for that matter. Just do a search for TL604CP. I'll let ya-all know if I come up with anything.

Anyway as far as Denver sites...yeah I'm a senior member of Denver, too. I remember Mr. Lucky's memory serves, which is amazing these days, it was a disco club. I think Tulips was the joint that became The Proof of the Pudding and who ever visited Denver & didn't got to Casa Bonita!!

funny you mentioned that. WAAAy back in like '74, I visited here with a band from S.F. & we played for 2weeks at a sleazy bar across the street from Casa Bonita called 'Freddies Lounge'. Funnier still is that we stayed at this equally sleazy motel next door called 'The Bugs Bunny Motel'. About 15yrs ago Disney finally made them change the name. I don't think the bar or the motel are still there.

Senior member on the site, huh...sounds cool to me...that would be for my brilliance, right?!!! g

[Enzo]

I'm not a fan of NOS ICs, and PV was nice enough to make the work around to support their thousands of amps that use it. Why not just order one from PV and be done with it? Buy one for the repair, charge the customer for the part, and let him have his amp back.

[Steve Conner]

Yeah, special function ICs are like sushi, and you wouldn't want to eat NOS vintage sushi

Seriously, NOS TL604s would probably work fine, but I think the Peavey replacement board is a more elegant idea. That's assuming that it will work in other manufacturers' circuits. It's possible that different designers applied the TL604 in different ways, and maybe Peavey's board won't work in, say, a Fender London Reverb. I opened one of these the other day, saw it was stuffed full of TL604s, and that made me think of that PV replacement thingy, though none of them was actually bad.

[Mars Amp Repair]

I ordered some of these IC's

Folks,
I just ordered 5 of these IC's from www.vancebaldwin.com. They're supposed to be original Panasonic. I'll let you know of the outcome when I receive them in a few days. They were only $6.33 ea with no minimum order.

I originally found them at another supplier for around $13.99 ea, given the Peavey price, I was willing to give that try, but they wanted stinkin' $18 to ship them....what are they thinking

Also by the Chinglish in their e-mail, I also thought I could be dealing with the counterfeit issue, too.

glen

[Mars Amp Repair]

the tl604's

Well as fate would have it, Vance Baldwin came back with the tl604's discontinued.
I ended up using my Peavey replacement board for this GK 800fb (I think that's the model).
I'd still like to find some place that has a stash of the originals, but most companies want you to buy a crapload of them to get a decent price.

glen

[mark dc]

Tl604cp

I Decided to bring start a new post on this one.
I did a search for postings on this IC, but didn't find anything, tho I know I've seen previous posts. So decided to start a new one.

I've heard talk of these discontinued tl604's & how Peavey has a replacement in the form of a small pcb for like $20. I've done some searching on the web for this IC & have found a few sources, but would like to know if anyone has had any reliable luck with any particular supplier.

I found one (vancebaldwin.com) that sells them for around $6 for the original TL604CP, but they have no means on their site to contact them. That makes me suspicious. Others must know about the Peavey replacement, as they sell for about $14 ea.
Anyone had any luck with a source for the originals?

Thanx, glen

I HAVE IC TL604CP QTY-100 email ma4fu@netzero.net

[Mars Amp Repair]

Wow,
Been so long...I think I figured a way to make another IC work...as I recall, there was a mod to make a different IC work in there...can't really recall now. Thanx for the reply & info for all. glen

[Marina]

Just wanted to see if I understand, or if anyone knows... Is this Peavy substitute something like the DG419 mod premade, and would it fit into the socket?

[Enzo]

It is a small board with legs sticking down, so it should plug right into place.

[Marina]

Well, the price is right, $3.95. Can't beat that.

The DG419 crossover courtesy of Gallien Krueger doesn't look like it would work for my application. I have pin 7 as an input and pins 3 & 4 as an output. The DG419 mod sheet shows pin 7 going nowhere. I did a search on the datasheet for the DG419, and didn't see any amp stage in it, only to throw the switch.

I'm not having a problem with the LED switching part of it. That part seems to be working. The LEDs are fed on one side from pin 7 of a 4558. The LEDs are paralleled in opposite directions, with one LED's anode and the other's cathode tied to pin 7 (the output) of the 4558 op amp, and the other end of the parallel combination is tied together to pins 1 & 6 of the TL604. These lights are controlled by the footswitch which feeds into the input of the 4558 op amp.

Maybe I'm not interpreting the schematic correctly, but it looks like pin 7 has to be the input and pins 3 & 4 the output of a gain stage. I have signal to pin 7 and nothing coming out. The symptom of the amp I'm working on is low front end gain. I can jump across this stage and get a little more gain but not enough, I don't think. So I'm assuming there's a gain stage in there. Does anybody know if that's the case?

[Marina]

One Post

I HAVE IC TL604CP QTY-100 email ma4fu@netzero.net

Just curious if anyone has successfully done business with Mr. Funk. The exact replacement is preferable to me, but this guy has only posted once to the forum, so I was just wondering.

[Enzo]

I don't offhand recall just what Peavey put on their little fix, but Peavey is above and beyond all reproach. They will sell you a little part that will work.

[Marina]

Thanks Enzo,
After looking at the datasheet for the TL604, it doesn't appear that it has an amplifying stage in it. I think it's just a switch, so now I'm not even sure if that's the problem. I'm going to have to look at it again.
I trust Peavey. So if I need one, I'll try their mod.
Thanks Again,
Marina