Boss SD-1 japan/taiwan Differences

[cosmitron]

Hi. I know questions from newbies may be annoying, espacially if they have been already asked.

So please, excuse me for my zero electronic knowledge, and my poor english. :oops:
OK now the question.


I just bought a used (and abused) Boss SD-1 made in taiwan. I been said those peddles were not as warm as the japanese ones... especially because of a different chip in it.

So I've register this site to know how to 'downgrade' the Sd1 to its original form (and sound)... As I opened the lovely relic stompbox, I've seen this famous chip in it: the JCR4558DD.

So the questions are:
Is it the right chip? the same chip we found in the japanese ones?
Are there different chips on last 'SD1'?
Does they drastically sound different?
Will you apologize my unknowledge and bad english?

thanx you all passionate people. :wink:

[phillip]

The MIJ and MIT SD-1s are basically identical.  They both use the JRC4558 IC (I believe).  The Taiwanese version uses the JRC4558DD, which I think is supposed to be lower noise compared to the JRC4558D.  

Basically, you won't hear any differences in the two pedals since the circuits are identical...I couldn't tell any difference when I had a chance to try a MIJ model.  Even Boss has denied the rumors that the MIJ and MIT pedals sound different from each other.

Phillip

[G Kresge]

I've had 2 MIJ SD1s and several MIT SD1s. I haven't noticed any significant difference in tone or noise between the Japanese and Taiwanese models. Some things I've read on various sites claim that the 4558DD is inferior to the 4558D, but I haven't heard a noticable difference after replacing a 4558DD with the 4558D.

[cosmitron]

Thanks! What a great news!!!
BTW I have a friend who has a SD1 MIT too. But one of the latest ones.
The dude opened it, not especiallly readily , but he did.
He told me his brand new SD1 got a JRC1123B in it.
Now he wants to know if some of you have it and tasted differences... :wink:

Thanks.

[stinkfoot]

"1123B" is most likely the date code - if you tell your friend to take another look, he should see "4558DD" written on there as well. The way JRC (now NJR) marks their IC:s are as follows: model - maker - date code, which can be a little confusing. Your friend's IC probably reads:

4558DD
JRC
1123B

/Andreas

[G Kresge]

On that note, how does the date-coding work on the JRC chips? Any way to tell the date of manufacture by the date-stamp?

[AgentDouble]

About the JRC chip dating, i believe that the first digit is the year code. In that case 1 would mean 1991, 2001, or 2011. The next three digit along with the letter are batch number. Correct me if i'm wrong.