DS-1

That's what I was thinking.

It's also easier to create an adapter to fit a DIL IC in a SIL footprint than the other way around.
 
OK, so the bonehead maneuver I made was...

Wait for it...

I didn't plug anything into the Input jack. I forgot that most commercial pedals use that jack as a power switch. It's not necessary to switch the external power that way, but that's how Boss did it.
 
Chuck D. Bones said:
OK, so the bonehead maneuver I made was...

Wait for it...

I didn't plug anything into the Input jack. I forgot that most commercial pedals use that jack as a power switch. It's not necessary to switch the external power that way, but that's how Boss did it.
Click to expand...
Ah the memories! That’s how I used to save battery life!!!
 
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Bricksnbeatles said:
I’d say SIL pre-94, just because SIL is fun and “SILly”, and pre-94 because if you call it a ‘vintage-spec’ DS1 PCB more people will be interested in it than if it’s a ‘modern’ one
Click to expand...

If you want to be true to the vintage design, then you need buffered bypass and soft switching too. It's a slippery slope.

Even without soft switching, the input buffer is essential.
 
I've been there a time or two. :ROFLMAO:

I keep a bunch of 1/4" adapters laying around to use as dummy plugs for that reason, and when tracing a pedal where the jacks short the tip to ground when nothing is plugged in.
 
Chuck D. Bones said:
If you want to be true to the vintage design, then you need buffered bypass and soft switching too. It's a slippery slope.

Even without soft switching, the input buffer is essential.
Click to expand...
True, but most of the people I’ve seen using vintage DS-1s either have them modded for true bypass or are using it in a loop switcher, in which case the soft switching and buffered bypass isn’t a factor anymore. The input buffer would be part of the PCB that’s currently in development though anyway I would assume
 
I'm not hard over one way or the other on soft switching, buffered bypass or true bypass. The only thing I strongly prefer in my pedals is that they do not load the input in bypass mode.
 
I vote for pre-1994, since the post circuits are pretty common. It would also be nice to pick between the various mods…once we find out what they are.
 
I’d vote pre-1994, but is there a SIP-to-DIP converter for the (7-pin) TA7136AP?
I get that would be possible for the 8-pin post-1994 version.
 
Where are you going to get TA7136's? China?

I think it makes more sense to put in two foorprints:
  • 7-pin SIP for TA7136
  • 8-pin DIP for a single opamp since that's what the original circuit had. For some reason that eludes me, Roland replaced the single opamp TA7136 with a dual opamp and wired one as a unity gain follower.
 
peccary said:
I've got one from the early 2000's that I think I've used once, maybe. Got it for free when I bought my very first bass and hated it, so it's just been kicking around in a drawer for close to 20 years. I just pulled it out to take a look at it and it had a 20 year old battery in it 😬 Had to cut it out.
Click to expand...
BTW, Peccary, I know how to mod a DS-1 so that it lets bass notes thru.
 
Here's the stock schematic for mine, it's Made in Taiwan. Has the M5223AL SIP dual opamp. Note the typo on the schematic: C7 is actually 100pF.

C2 and C3 choke off the bass end of the spectrum, so we'll make those bigger. Change C2 to 2.2μF. I used tantalum of course. This pedal is full of aluminum electrolytics, so those are ok to use for C2 if that's all you have. Change C3 to 1μF film. That's really all it takes to get a large dose of bass frequencies into the circuit.

C8 limits the low-freq response at high DISTORTION settings. You can make that larger, but unless you're running with DISTORTION wide open, it's not necessary to change it. Lotta people increase C9, I didn't on mine.

I retuned the TONE control, completely optional, by raising C11 to 47nF and reducing R16 to 3.9K. No more midrange notch.

I did like Keeley and replaced D5 with a 3mm red LED. If you want the "seeing eye," then drill a 3mm hole thru the O in TONE and mount it there.
There are tons of other mods, most of which I think are bogus. One popular mod is changing the biasing & gain on Q2. I did my own version of that. I increased R9 to 470Ω, then I added a SPDT on-off-on switch that connected either a 2.2μF, 22μF or nothing in parallel with R9. With nothing in parallel with R9, Q2's gain is reduced, making it run cleaner and flattens the freq response a bit. Adding the 2.2μF cap increases the gain in the upper mids and treble range but leaves a tight bottom end. Connecting the 22μF cap boosts the gain at all frequencies for nice fat tone. If all you want is the ultra fat tone, then leave Q2 alone.

The LEVEL control should really be A-taper, not B-taper. As soon as I obtain a 9mm A100K knurled pot, I'll change mine out.

I did not do any of the "boutique" mods like replacing the two disk ceramic caps with silver-mica, or replacing all of the film caps with WIMA. IMO, it's "good enough."

Boss DS-1-schematic.png

DS-1 cb mod 02.jpg
 
Chuck D. Bones said:
Here's the stock schematic for mine, it's Made in Taiwan. Has the M5223AL SIP dual opamp. Note the typo on the schematic: C7 is actually 100pF.

C2 and C3 choke off the bass end of the spectrum, so we'll make those bigger. Change C2 to 2.2μF. I used tantalum of course. This pedal is full of aluminum electrolytics, so those are ok to use for C2 if that's all you have. Change C3 to 1μF film. That's really all it takes to get a large dose of bass frequencies into the circuit.

C8 limits the low-freq response at high DISTORTION settings. You can make that larger, but unless you're running with DISTORTION wide open, it's not necessary to change it. Lotta people increase C9, I didn't on mine.

I retuned the TONE control, completely optional, by raising C11 to 47nF and reducing R16 to 3.9K. No more midrange notch.

I did like Keeley and replaced D5 with a 3mm red LED. If you want the "seeing eye," then drill a 3mm hole thru the O in TONE and mount it there.
There are tons of other mods, most of which I think are bogus. One popular mod is changing the biasing & gain on Q2. I did my own version of that. I increased R9 to 470Ω, then I added a SPDT on-off-on switch that connected either a 2.2μF, 22μF or nothing in parallel with R9. With nothing in parallel with R9, Q2's gain is reduced, making it run cleaner and flattens the freq response a bit. Adding the 2.2μF cap increases the gain in the upper mids and treble range but leaves a tight bottom end. Connecting the 22μF cap boosts the gain at all frequencies for nice fat tone. If all you want is the ultra fat tone, then leave Q2 alone.

The LEVEL control should really be A-taper, not B-taper. As soon as I obtain a 9mm A100K knurled pot, I'll change mine out.

I did not do any of the "boutique" mods like replacing the two disk ceramic caps with silver-mica, or replacing all of the film caps with WIMA. IMO, it's "good enough."

View attachment 13294

View attachment 13295
Click to expand...

Thanks, Chuck. I have bookmarked your post and will let you know how it turns out when I get to it.
 
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