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DIY Stompboxes => Building your own stompbox => Topic started by: no one ever on September 04, 2005, 05:07:38 PM

Title: Mod: JRC4558's
Post by: no one ever on September 04, 2005, 05:07:38 PM
anyone else notice that in the boss hf-2 there are 2 (count em) JRC4558DD chips?

I'm thinking of pulling one out and replacing the chip in my ts9dx... and then using the other one for a friends. how much should i charge?  :twisted:  :?:

I just read up on these... people are saying "it's hard to find a worse opamp chip..." why is this so popular then?
Title: Mod: JRC4558's
Post by: AL on September 04, 2005, 05:41:07 PM
Quotepeople are saying "it's hard to find a worse opamp chip..." why is this so popular then?

Hype

AL
Title: Mod: JRC4558's
Post by: nelson on September 04, 2005, 06:10:56 PM
Quote from: AL
Quotepeople are saying "it's hard to find a worse opamp chip..." why is this so popular then?

Hype

AL


because (insert your favourite guitarist here) had the original 80's JRC4558D opamp in his (insert overhyped pedal here).

its a bog standard dual opamp.

many prefer the sound of others.

TL072 is lower noise....

I use TL072 for my duals...

the OPA series from TI is supposed to be great and burr brown chips are also well loved around here.
Title: Mod: JRC4558's
Post by: no one ever on September 04, 2005, 06:15:41 PM
alrighty then. i'll buy a bunch of chips and a socket and compare em.


maybe i'll post clips.
Title: Mod: JRC4558's
Post by: sir_modulus on September 04, 2005, 06:38:26 PM
I'm a burr brown man...though I do have to say the JRC4558DD's sound really nice in my marshall practice amp (I've tried some RC4558's in there...sounds different...but very close). It's all a matter of slight taste IMO.

Cheers,

Nish
Title: Mod: JRC4558's
Post by: no one ever on September 04, 2005, 09:16:24 PM
is there a difference between JRC4558D and DD's?
Title: Mod: JRC4558's
Post by: nelson on September 04, 2005, 09:36:51 PM
the DD attract groupies with bigger boobies...........


seriously though I think it has to do with temp tolerance although I aint sure.
Title: Mod: JRC4558's
Post by: KE4NYV on September 04, 2005, 09:48:04 PM
Oooh!  Did someone say big boobies???

Seriously, I just ordered 10 of these on friday...

http://www.mouser.com/index.cfm?handler=displayproduct&lstdispproductid=525647&e_categoryid=268&e_pcodeid=51303

A Mouser search for the JRC part came up with these as a cross-ref part.  When I get them in I'll try them out and see what kind of grainy dist I can get out of these.  Has anyone else tried these out?  Are they similar to the JRC part or a poor re-issue of sorts?
Title: Mod: JRC4558's
Post by: no one ever on September 04, 2005, 09:59:01 PM
Quote from: KE4NYVOooh!  Did someone say big boobies???

Seriously, I just ordered 10 of these on friday...

http://www.mouser.com/index.cfm?handler=displayproduct&lstdispproductid=525647&e_categoryid=268&e_pcodeid=51303

A Mouser search for the JRC part came up with these as a cross-ref part.  When I get them in I'll try them out and see what kind of grainy dist I can get out of these.  Has anyone else tried these out?  Are they similar to the JRC part or a poor re-issue of sorts?

wow .18! not to deter anyone from the great service and supply at small bear, but they're .40 there...

i wonder how these DD's are used in my flanger...
Title: Mod: JRC4558's
Post by: Mark F on September 04, 2005, 10:20:00 PM
Quote from: no one everalrighty then. i'll buy a bunch of chips and a socket and compare em.
That..........is the best thing you could do! Then You will know what sounds better to You and not just what you heard or read about a certain chip etc. And just think of all the fun you'll have learning about different op-amps. :)
Title: Mod: JRC4558's
Post by: no one ever on September 04, 2005, 11:26:08 PM
Quote from: Mark F
Quote from: no one everalrighty then. i'll buy a bunch of chips and a socket and compare em.
That..........is the best thing you could do! Then You will know what sounds better to You and not just what you heard or read about a certain chip etc. And just think of all the fun you'll have learning about different op-amps. :)

thank you! i could use a few suggestions though for a chip compatible with the ts9dx...
Title: Mod: JRC4558's
Post by: nelson on September 05, 2005, 12:46:52 PM
any dual opamp with the same pinout.
Title: Mod: JRC4558's
Post by: no one ever on September 05, 2005, 03:01:21 PM
Quote from: nelsonany dual opamp with the same pinout.

where's a resource for pinouts?
Title: Mod: JRC4558's
Post by: nelson on September 05, 2005, 03:22:24 PM
you get pinouts on datasheets. Most dual opamps share the same pinout ie V+ on pin 8 and V-/ground on pin 4.

Whenever I need to check a datasheet I just google "Partnumber datasheet"

www.alldatasheet.com usually comes up with it.