BOSS DS-1 Mods Questions

[petemoore]

I am in possible buying position for a DS-1.
 First, when I looked at Fuzz Central DS-1 mods, Phillip 'requires' the M5223AL chip be in the board for the mods there.
 Also the chip in the PIC at Fuzz Central looks like a 14 or so pin chip, is that what would be in the DS-1's factory boards?
 I wonder how much taking apart these need to see the chips' #...or whether I'll be allowed to do 'that' at the music store.
 K has anyone modded a 'modern' DS-1? .. or know the reasons for the earlier ones being the ones to mod?
 Off to make my rounds... any comments?

[Arn C.]

Petemoore,
    I have modded both and have both schematics with the mods.  They both sound great with the mods,  really quite simple also!

Peace!
Arn C.

[petemoore]

Thank you for the timely response, just before I left !!!
 I should be back here with a DS-1 pretty soon !!!
 It works, first thing I'll do is try it out for a minute, probably open her right up and take a look at doin' some mods Yupp///

[phillip]

I think that all the new DS-1s that Boss is building are equipped with the M5223AL.  It's a SIP-8 dual opamp...not much different than any other IC.  There are a couple of other ICs that could be popped in there for a better sound, but I haven't tried them.

Boss has used at least 4 different ICs in the DS-1, and as a result, the part numbers that are printed on the circuit board aren't always the same because parts have been added and taken away from model to model.  I just put that warning there so that I don't get any of those "Help it doesn't work!" emails...or if I do, I'll at least be able to say that I warned them

Phillip

[petemoore]

Well I copped this thing with a 0.$ trade [Tronics OVERDRIVE], for ten flat. [Excellent]. Slight beatness to it, everything works right, no scritchy pots.
 This ones not bad, and compared [from memory] to the other two I had, this one's closer to [but still a little different than] the 1rst one I had, which was pretty good sounding.
 Still the treble knob doesn't sound too good much above 10:30 Oclock, nice heavy distortion, not a huge drive, but plenty good boost.
 It'll be interesting to try some of the well documented mods for this unit !!

[petemoore]

Because I saw no mention of Opamp swaps at Fuzz Central, I'm assuming the Mitsubishi chip is pretty good?
 Funny I ask, I'll probably have to socket that anyway at some point.
 I think I'll start with revoicing the caps, if the OA is deemed 'acceptable' in terms of OA noise/sound quality.  
 I never looked at one of these closely from the inside or the outside from a DIY viewpoint, it'll be interesting to see if I can fit sockets in it here and there.

[phillip]

Yeah the Mitsu. chip is pretty good...sometimes a little harsh sounding.  There's a JRC (NJR) SIP8 chip that Analog Mike installs in the pedal in his mods.  I think Mouser carries a SIP8 JFET input dual opamp that has the same pinout as the Mitsu.

I think this is it...

513-NJM5532L

"NJR Operational Amplifiers - High Performance SIP-8 Dual Low Noise"

Phillip

[petemoore]

It pays to call back. He had a 25 dollar sign on there, I'm on the callback list for cheep, Boss Distortions there.
 I'ts got to be one of the most extensively researched circuits around.
 Should be interesting, heck of a deal on parts, and they're all in a properly working unit !!!  Not Bad !!
   

[StoNe]

Hi,

***I only recommend these modifications for the newest version of the Boss DS-1, which comes with the Mitsubishi M5223AL IC. There are other versions that use different ICs, so they have a few different components. Performing these modifications on an earlier version may not work well. Before beginning modifications, make sure that yours has the M5223AL and the components on the board match the values of the components on the schematic of the unmodified pedal***

I checked all my parts and I have all of them are good. But I have a different IC: BA728N (545 H55).
Does anybody know if I can do all the modifactions given at Fuzz Central with this IC?

Thanx alot
Ravian

[StoNe]

I found the datasheet:

http://www.alldatasheet.com/datasheet-pdf/pdf1/ROHM/BA728N.pdf

[Hal]

petemoore - PM!

[Blue Calx]

I just got done following the (very intuitive, thank you, by the way) instructions on fuzz central for modding the DS-1.  Everything seemed to go pretty smoothly - I used a solder wick and was really careful to not hold the iron to the board for too long, and I checked for continuity each time with a tester...

The result?  Well, the pedal sounds SUPER beefy... when it works.  It's pretty intermittant, and i usually have to hold the pedal down to get it to continue working.  Also, the  high end is pretty choppy and "farty" if that makes any sense, and the signal becomes weak on and off.

So, er, is there any easy diagnosis, can someone narrow down my problem, or is this just gonna be  "hunt and peck" troubleshooting time for me :-(

[Hal]

reflow each of ure solder joints.  Start with ones taht look messy or dont look shiney.  See if you catch it there.  

If its intermittent, odds are u wont see it with a meter.

First check the obvious, though!  (wires to battery, to jacks, plastic plate on bottom, etc.)

[petemoore]

You used a socket  for the Opamp
?

[Blue Calx]

I didn't mess with the op amp - and I was real quick with the iron so as not to fry anything....  I'mm'a have someone who knows their stuff look at it - thanks for the suggestions.