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I've just bought an oddball one. Its a Nov-1981 [long dash black screw]. Its not arrived yet, but the seller has outlined in his advert certain mods "done by a previous owner"

to wit:

IC PREAMP TOSHIBA TA7136AP changed to TA7136P

C1 CAPACITOR 473K value 47nF changed to 104J 0.1uF

D4 and D5 1N4148 diodes changed to 1S2473

R2 RESISTOR 0.47 ohm changed to 0.22 ohm

The original parts are included with the pedal, but I doubt I will retrofit them. It will be good enough just to have those parts rather than have further re-soldering done. And I am slowly rebuilding my stock of DS-1s having sold all of them off except my favourite (an '85 version) so I have a few different flavours, and this will be another different flavour, no doubt

Is anyone aware of the sort of differences these modifications are likely to make?

some info on the TOSHIBA TA7136AP versus TA7136P here, thanks to old_iron

http://www.bossareaforum.com/Forum/viewtopic.php?t=562

Luke Drifter wrote: ↑

Fri Feb 17, 2023 4:09 am

IC PREAMP TOSHIBA TA7136AP changed to TA7136P

It will be considered sacrilege by some, but I can't imagine this would cause an audible difference.

Luke Drifter wrote: ↑

Fri Feb 17, 2023 4:09 am

C1 CAPACITOR 473K value 47nF changed to 104J 0.1uF

Opens up the bass response - lets more bottom end through the pedal.

Luke Drifter wrote: ↑

Fri Feb 17, 2023 4:09 am

D4 and D5 1N4148 diodes changed to 1S2473

Again, it will be considered sacrilege by some, but I can't imagine this would cause much of an audible difference. Both diodes are glass packaged, fast switching silicon.

Luke Drifter wrote: ↑

Fri Feb 17, 2023 4:09 am

R2 RESISTOR 0.47 ohm changed to 0.22 ohm

R2 is showing as 470k on the schematic that I have. Did you mean 470k to 220k? If so, I can't see why they would do this. It is the bias-point setting resistor for Q1. Perhaps they wanted to drive the bias point closer to 4.5V to accommodate a hotter input signal? In a distortion pedal that doesn't make much sense to me. And if so it would be done at the expense of making the R24/R25 voltage divider a bit more "unsettled".

Thanks Laurie, for your detailed answer. It arrived today - and yes, it is a touch bassier (not a bad thing with my Telecaster) - and a bit less gainey at the top of the range (i use them with dist on minimum as a general rule) and a bit quieter maybe. Largely the same sound overall, and i doubt a drunk audience member could ever tell the difference. The collection grows .. i would still call the '85 (second from left) my favourite, though.

hopefully higher res photo. L->R: Nov 81, Jul 85, Dec 86, Nov 93 (MIT)

Nice collection there mate!

i'm building it up again. I had 7 or 8 a few years ago. Sold them off (too cheap of course) I think these 4 will do me for a while

At the height of my collection in 2012 I had 11 of them

I'm down to two now:

• A 40th anniversary with a Seeing Eye mod

• A fully stock 40th anniversary

I've been keeping an eye out locally for a 1980's version, but nothing has come up in the last year.

I've got another odd-ball one

another 50 dollar MIT black label. It had non-boss knobs on it (not any more) and has a serial number that I cant decode [B954987]

Luke Drifter wrote: ↑

Tue May 02, 2023 1:45 am

I've got another odd-ball one

another 50 dollar MIT black label. It had non-boss knobs on it (not any more) and has a serial number that I cant decode [B954987]

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Try the batch number without the B.
http://www.bossareaforum.com/Forum/viewtopic.php?t=464