VINTAGE JRC4558DD??

Started by Yoshi, April 02, 2023, 01:04:11 PM

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bluelagoon

#40
Here's some 4558 op amps from a 1980's loaded PCB, likely a mixer. marked as JRC4558DV, with 1986 date codes. Just had a second look at my own and they are in fact DV suffixed identically the same JRC4558DV including the stripe and all.
They sold all 20 of them he had on Reverb 4 years back at $15 USD each = $23 AUD each.
I have 50 of them, seems more money to be made and less convoluted to sell them as op amps rather than in effect pedals, But where's the fun in that? then again may be the most prudential route to take. we shall see.

https://reverb.com/item/17712664-jrc-japan-radio-company-jrc4558-dv-op-amp-1986-shiny-black




bluelagoon

#41
Another Guy presently on Reverb has a good stash of what appear to be early 90's  and some later into the 2000's , at around $3.50 each which includes postage. You get to take your pick of what he has and you get 10 pieces in the purchase lot.

https://reverb.com/au/item/65598326-jrc-10-pcs-genuine-jrc-4558d-4558dd-pulled-tested-parts-tr808-re808

although they are later production than the 80's, they all look legit.




Rob Strand

#42
Quotealthough they are later production than the 80's, they all look legit.
That's a good collection.

I've been meaning to update a few finer points on the date codes,
https://www.diystompboxes.com/smfforum/index.php?topic=130374.msg1264320#msg1264320

I wasn't sure if the last letter incremented over time, like a revision, but that
collection puts an end to that idea.  The last digit might be a machine or plant location.
Certainly a lot of B's in the early days.

A few 80's samples here, also indicates 70's but I'm not sure about that one.
I thought JRC started producing 4558's from 1977.  It's all fuzzy information
I've scraped up.
https://www.iom-stockroom.com/entry/jrc4558
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

johngreene

Quote from: Rob Strand on April 06, 2023, 06:15:04 PM
Quotealthough they are later production than the 80's, they all look legit.
That's a good collection.

I've been meaning to update a few finer points on the date codes,
https://www.diystompboxes.com/smfforum/index.php?topic=130374.msg1264320#msg1264320

I wasn't sure if the last letter incremented over time, like a revision, but that
collection puts an end to that idea.  The last digit might be a machine or plant location.
Certainly a lot of B's in the early days.

A few 80's samples here, also indicates 70's but I'm not sure about that one.
I thought JRC started producing 4558's from 1977.  It's all fuzzy information
I've scraped up.
https://www.iom-stockroom.com/entry/jrc4558
what an opportunity to do some comparative tests! 🤔
I started out with nothing... I still have most of it.

amptramp

Quote from: johngreene on April 06, 2023, 10:54:41 PMwhat an opportunity to do some comparative tests! 🤔

If you are going to do comparative tests, rather than put them in stompboxes to try and get some idea of the sound you get, try to reproduce the important spec sheet values for the op amps.  The spec sheet will often show you the test configuration, so you don't have to do much thinking.  The open loop gain at various frequency points has a lot more effect on the response, especially with high-gain circuits like the clipper stage in a Tube Screamer than the closed-loop response in the tube screamer tells you.  The feedback in the closed-loop response tends to mask the effects of open-loop response but you can always work backwards using the gain formulas to determine what effect you would get at a given closed-loop gain.

You should also be able to determine the noise performance of the device, which is not necessarily specified for a lot of popular devices.  One accomplishment I can look back on was determining the noise in nV/SQRT Hz for an LM318, which was not in the data sheet.  Many years after I measured this, National revised the data sheet to show 11 nV/SQRT Hz, exactly as I had determined.

Rob Strand

Quotewhat an opportunity to do some comparative tests! 🤔
and maybe find out they don't all behave the same  :icon_mrgreen:   Even back in the 80's I found that 741's had widely varying noise, perhaps 6dB or more variation in real circuits, with a high correlation with the manufacturer.   At least with the JRC4558's they come from the same manufacturer.
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

momo

I found this today, never seen one like that, will try soon enough.

"Alas to those who die with their song still in them."

Rob Strand

Quote from: momo on May 01, 2023, 06:14:45 PM
I found this today, never seen one like that, will try soon enough.
From the large centrally placed depression and small pin 1 dimple my guess is it's a Raytheon RC4558, maybe 70's.  The markings are a little messy though and it's not marked *RC*4558.  Also no date code.
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

Jmariner

I just went through the op-amp taste test again in a circuit I call The Death Screamer; it's not based on a tube screamer but instead the pedal I created to replace my tube screamer after I modded it to death. I had the TS7 which was a decent pedal, but noisy as hell and not much use on my cheapo solid-state amps at the time.

In a broader circuit architecture, meaning the cheapo Crate head that the TS7 had a noise war with, the 4558 in the high gain channel was obviously different than the TL072, and not subtly so. More froth and grime. A rattier texture and chiseling highs. I really liked it, but every pedal and amp I've modded or built eventually ends up with a 5532 in it. I think that's just the nature of solid-state commercial gear without more thoughtful engineering and the demand for high gain with clarity and low noise in the scheme; what I tend to seek. Cheap amps and pedals, or not so cheap, are being churned out for general use and experimentation by learning players. You can get good punk rock, country, blues, metal etc. out of them but nothing extraordinary without an outboard piece of equipment that makes drastic alterations within the signal cascade.

Some gear, the op-amp might make an obvious difference, but just as much it won't. The 4558 in my death screamer is not pleasant and an obvious mismatch, but for punk rock or country twang and snap in my vintage Crate head, it's a clear winner.

Lino22

#49
I have built two TS-808 clones, using the same values, but different types (caps mainly). All parts were brand new, nothing like NOS. One of them sounded audibly sweeter, and i did a blind test to make sure i am not fooling myself; i am fully aware that i tend to hear what i want to hear especially at the very beginning of an ear test. They both used the same chip (new production).
When the core started to glow and people started yelling, he promptly ran out the door and up a nearby hill.

FiveseveN

Quote from: R.G. on July 31, 2018, 10:34:30 PMDoes the circuit sound better when oriented to magnetic north under a pyramid?

Lino22

When the core started to glow and people started yelling, he promptly ran out the door and up a nearby hill.