Author Topic: Fun With OP AMPS (Read 4557 times)

Elliot · « **on:** May 11, 2007, 07:59:04 PM »

Just for fun I did an experiement with different op amps in my HBE Powerscreamer - I picked them all up at an electronics fair for about £5.

New production JRC4558D - Came with the HBE, but I swapped in another one - Nice smooth tone - classic TS808 type sound.
RC4558P Portugal - similar but gritier than above,
JRC 5532D - Good distortion (rather than OD) tone, nice and thick,
Early 1980s JRC4558D - taken from an old clock radio I took apart to practice soldering PCBs - no different from the new production JRC4558 to my ears - not worth the £40 they go for on ebay.
TL072CN - Good tone, tubey, but a bit darker than the 4558 series.
Burr Brown OPA2124PA - too clean, too Hi Fi no harmonics - in my view the worst of the bunch.
Burr Brown OPA2604AP - the clear winner - richer that the JRC, a bit louder and more presence but still with a distortion kick - raises the mid range hump in the eq to make it more singing in quality.

All in all great fun - unfortunately one of the resistors is a bit black after putting in a chip the wrong way round but a test with a multimeter shows it still to be working.

dave_mc · « **Reply #1 on:** May 11, 2007, 09:52:55 PM »

haha, cool! i like people a/b-ing stuff.

:drink:

Brow · « **Reply #2 on:** May 13, 2007, 12:01:11 PM »

Thanks for the info.

I've recently bought a HBE Power Screamer myself and have also just ordered a couple of those Burr Brown Op Amps to try in the Power Screamer and the Big D I've just ordered too :)

Should be fun when it all arrives :)

_tom_ · « **Reply #3 on:** May 13, 2007, 12:04:22 PM »

Someone on HC is trading their Power Screamer for my Crunch Box, I might try one of those Burrs (the good one!) in it if I'm feeling a bit daring :lol:

Pierre · « **Reply #4 on:** May 14, 2007, 10:50:09 AM »

So far my favorite is the TL072. To me the 4558 is garbage. I want to try the LF833 and the LM353 too.

JJretroTONEGOD · « **Reply #5 on:** May 14, 2007, 10:54:55 PM »

the keeley pedals come with that very chip inside it as far as I know! www.robertkeeley.com

Elliot · « **Reply #6 on:** May 14, 2007, 11:10:42 PM »

Its a bit strong to say a 4558 is garbage - a tube screamer tone has its place - but I agree the other chips have a bit more to them.

By the way the Award-Session JD10 (a great stomp box boost/od/distortion/buffer/recording pre-amp) is based on three TL072s wired up like a Bassman/JTM45 pre-amp circuit. Don't let the Jerry Donahue thing put you off, that mutha can kick out hard core distortion as well as great bluesy tones.

gwEm · « **Reply #7 on:** May 15, 2007, 09:43:16 AM »

nice comparison elliot :)

i agree with other opinions here, i also like the TL072.

in general, i couldn't believe there was so much different in sound when i was experimenting with changing opamps. although, i didn't try all the ones you did!

_tom_ · « **Reply #8 on:** May 15, 2007, 11:29:32 AM »

I got my Power Screamer today, it sounds great stock! The only thing I would say I dont like is that it can sound a bit too thick/smooth at times for me. Where do you get the "Burr Brown OPA2604AP" and is it easy to swap em? I fancy trying it if its not too in depth.

edit - heres a quick clip with my LP with Mules, first with it off (laneys preamp gain is on about 3.5, master on just above 1). As you can see, its a bit fuzzy/muddy on lower strings, but I really like the tone anyway.

http://www.netmusicians.org/files/44-power%20screamer.mp3