Jrc 4558d(x)

[antichef]

I pays to read the DIY forum!

I took Somnium7 up on his offer for the old opamps he pulled out of the RX-7

Now back in the day, I played metal using an Ibanez Tube Screamer TS10, and I thought it sounded fantastic. I stomped it to death. A couple of years ago, I tried to reclaim the sound by picking up a TS10 on the bay. To my dismay, it sounded awful with my amp (the same one).

Anyway, I opened it up, and the opamp in the TS-10 is a 4558D JRC with the number 0183B. I pulled it out and put in a socket. Then I put in one of Somnium7's - it's a 4558DX JRC with the number 1249 --- and I GOT MY SOUND BACK!!! I'm doing backflips. I don't know what was in the old one.

Now I'm eyballing my [son's] Fulltone Fulldrive 2, which has a 4558D JRC with the number 2062B, but it's not socketed. Don't know if I have the cojones to take the iron that unit, but it wasn't too hard with the TS10. It already sounds pretty good, but it's hard to stop once you start doing this, isn't it?

[dementedchord]

those secondary numbers are production date codes... good luck... if you're carefull with the desoldering in particular you'll be ok... too much heat on a pin can lift the associated pad and then the horror stories begin...

[mshilarious]

Cut the old opamp out before you desolder, much easier that way. Of course you have to be sure you don't want the old opamp!

If you have a good desoldering tool, you can do without that, I think Somnium's desolder gun is $200 or so

[dgatwood]

Originally Posted by mshilarious

Cut the old opamp out before you desolder, much easier that way. Of course you have to be sure you don't want the old opamp!

If you have a good desoldering tool, you can do without that, I think Somnium's desolder gun is $200 or so

Eh. Use a solder wick to remove the solder and you shouldn't have trouble lifting traces. Where I usually lift traces is putting the new parts into the holes because they aren't clean, not pulling the old ones out....

[antichef]

I've got the $8 plastic spring loaded solder sucker. It actually worked like a champ on the Ibanez pedal. The thing about the Fulltone is that it already sounds good -- at least with the Ibanez, if I destroyed it, it was no big loss

[Somnium7]

Originally Posted by antichef

Then I put in one of Somnium7's - it's a 4558DX JRC with the number 1249 --- and I GOT MY SOUND BACK!!! I'm doing backflips. I don't know what was in the old one.

Glad to hear that worked out alright.

I never was able to find any documentation or datasheet that says anything about the DX version of this IC. I can only imagine it is a higher voltage version of the original since they can be powered from +/- 22V. If that is the case there is a chance a different manufacturing process was used on this series.

Would love to know the true story though....

They are nice sounding devices and surprisingly quiet. They have a pronounced smear to the upper mids and a considerable roll-off on highs but even these sonic flaws sound good in certain situations.
This is why I will leave these installed for a certain number of my input channels. I love the huge improvement in sound quality I'm getting with my upgraded channels but it's nice to have that vintage tone too.

[dgatwood]

Originally Posted by antichef

I've got the $8 plastic spring loaded solder sucker. It actually worked like a champ on the Ibanez pedal.

I freaking hate those things. It's such a pain in the backside to get the tip down close enough to suck off the solder before the solder cools to the point that it is no longer liquid. Once you try a solder wick, you'll never go back to those nightmarish contraptions.

With a solder wick, you place it beside the solder joint and heat the joint. As the solder liquifies, it flows right off the joint onto the wick and you are left with bare metal and a solder-coated strip of wick. Nothing could be more painless. I've used solder wicks to desolder 7-point potentiometers (three signal contacts and four metal frame structural "contacts") in seconds.

[altitude909]

Originally Posted by dgatwood

I freaking hate those things. It's such a pain in the backside to get the tip down close enough to suck off the solder before the solder cools to the point that it is no longer liquid. Once you try a solder wick, you'll never go back to those nightmarish contraptions.

With a solder wick, you place it beside the solder joint and heat the joint. As the solder liquifies, it flows right off the joint onto the wick and you are left with bare metal and a solder-coated strip of wick. Nothing could be more painless. I've used solder wicks to desolder 7-point potentiometers (three signal contacts and four metal frame structural "contacts") in seconds.

+1 on the solder wick (aka desoldering braid), you can get it fluxed also so it really sops it up

http://www.techspray.com/newinfo/prowick.pdf

[antichef]

I also use that copper braided desoldering ribbon stuff -- is that different from a wick? I actually had a good easy, worked-on-the-first-try type of experience with the $8 sucker along with my $8 soldering iron. I had a much worse experience doing similar things on my Art Tube MP preamp - I think that was a difference in the circuit board ... it was a nightmare, but the I did get through it.

[antichef]

Well, the Fulldrive2 is safe from me - the circuit board is mounted on posts, and someone wrote his/her initials on it and put clear glue over it, sort of like a personal seal -- I'm not going to break the seal

[mshilarious]

Originally Posted by antichef

I also use that copper braided desoldering ribbon stuff -- is that different from a wick? I actually had a good easy, worked-on-the-first-try type of experience with the $8 sucker along with my $8 soldering iron. I had a much worse experience doing similar things on my Art Tube MP preamp - I think that was a difference in the circuit board ... it was a nightmare, but the I did get through it.

That has plated-through holes. Good for assembly, not so good for desoldering But it usually makes the hole pretty tough, so it is much less likely to lift traces. On the other hand, an IC may require enough to heat to desolder that it could harm the chip . . .

[dgatwood]

Originally Posted by mshilarious

That has plated-through holes. Good for assembly, not so good for desoldering But it usually makes the hole pretty tough, so it is much less likely to lift traces. On the other hand, an IC may require enough to heat to desolder that it could harm the chip . . .

Oh, yeah. The only way I've ever found to deal with plated vias is to have one person grab the component with pliers while a second person heats the leads. I guess it saves the manufacturer from having to drill an extra hole (one for the via, one for the solder pad), but... what a pain.

I had to recap a graphite Airport base station once, and it used plated vias. It took about three hours to replace four caps (twice because I misread the board markings and put them all in backwards), but it has been working for almost six years since, so I can't complain. (Okay, I can, but.... ) If I were doing it again, I probably would just yank the body off the cap and solder the new part to the exposed electrodes....