Boss DS-1 MIJ spec - do the diodes matter?

[sirlemonhead]

Hi,

I bought a MIT DS-1 but it's from the era where the internals were still Japanese spec.

I had a look inside the other night and noticed the D4 and D5 had been removed at some point in its past. I didn't even realise (I was using it as a boost!)

I'd like to return it to stock as much as possible so I've got some 1N4148s on the way. I've been reading up on this though and saw that the original run of pedals used different types of diodes - yellow band ones, blue band ones.. Mine has black band diodes in positions... D6 and D7 I think? Which I think are some variation of the blues by another manufacturer..

Anyway, to cut to the point Is there any real point in sourcing the original spec diodes, from the point of making it sound 'better' than the 1N4148s or would I really not notice?

It doesn't seem to have any other major mods (I did the ACA -> PSA mod a few years back and didn't spot the missing diodes then...) and it has that original spec Opamp in there.

[bigtone23]

I will humbly offer my opinion, there are more accurate and informed details that many on here will have from direct comparisons of various components (like diodes) used for various revisions. I do have a pretty good, critical ears, but they are not the golden ears of a cork sniffer.

Short answer about the diodes? I would say as long as they are the same spec, they will pretty much sound the same.

First, I find BOSS-as a whole-does a good job keeping their products sounding pretty consistent through the revisions and generally find that the DS1 sound is pretty consistent through the years and revisions-anything that sounds too different is the design from another orange/distortion pedal, like the DS2, DF2, OS2, etc.. Of course, there are various tweaks that change (like the chip, the MIT circuit and component changes around '94, the general 'sum of the part tolerances within the circuit,' etc... But in the end, it still sounds like a DS1.

This is a great page about the DS1. https://www.electrosmash.com/boss-ds1-analysis

I have a stock 86 MIJ DS1, had a stock 89 MIT DS1 (which was virtually identical to the 86 for part values, though the suppliers were different), and a 11 MIT that was stock when I got it (purchased with the intention to be wildly modded).

When I directly compared the 86 to the 89, I honestly couldn't tell them apart. Both have black band diodes.
When I compared the 86 to the 11, they also sounded 90% the same-the 11 was a touch brighter. Don't remember the diodes in the 11.
The first mod I did to the 11 was the 'pre 94' mod (3 cap changes). This was enough to make them sound pretty much the same. That was enough for me to confirm my belief in the consistency of DS1 tonality. I then did continued on with the JCM800 mod to the 11. It's wholly a different animal now.

86 MIJ on the left, 89 MIT on the right...

[sirlemonhead]

Hi,

Thanks so much for replying, that's all really helpful

I'd say my ears definitely fall into the 'I wouldn't notice a difference' category but I'm still humming and hawing over this - a weird obligation to make this stock with the right parts, to 'restore' it. My DS-1 is a weird one in that almost like the top layer of paint is peeling off in some places - it's generally duller and darker than the orange of my second DS-1, 2000's era MIT but in some spots the paint is almost coming away and I see the brighter orange underneath! Anyway!...

I think I will do the 3 cap mod to my second DS-1 based on what you said - that one is in pristine condition.. It's such a cheap change to swap some caps and now it's got me thinking of buying a 3rd to do additional mods to (I'll check out that JCM 800 mod!).... maybe a 4th to do the 'no diodes' mod to

I ordered some 1N4148 diodes so I'll probably just put them in the first DS-1 and call it a day for that. I've also since read that 1N4150 diodes give a forward voltage that's similar to the original parts and 1N4150s are cheap so I've got those saved in a Mouser basket for when I next put an order in there. Worth trying out! Sourcing the original diodes seems a bit difficult now because it looks like there's a lot of knockoff ones up on ebay and I probably couldn't trust anything is legit at this stage...

Thanks

[zentropa]

I have had over 100 DS-1 since I used to mod them quite often.

There are 5 iterations of the DS-1 circuit (6 if you include the op amp change compared to V4 for the 40th Anniversary and BK version, 7 if you include Waza) that all have slightly different qualities, although versions 2 (94-00), 3 (00-06), 4 (06-15), 5 (16-present), 6 (2017) sound pretty close to one another. Version 1 definitely is the most organic feeling and sounding, although with 15 years of production, there can be a lot of variance in compression and how much dry signal is in the mix e.g. ~1983 and older tend to have more dry signal and less compression. The early MIT DS-1 tend to have less dry signal in the mix than most of the MIJ and a higher noise floor, but the playfeel is fairly similar to MIJ. I had a lot of trouble with versions 2 and 3 getting to unity volume with hot humbuckers without being modded. I found V5 to have the least note articulation of any of them. My own personal ranking order goes V1 > V6 > V4 >= V2 > V3 > V5. I would rank V2 above V4 and V6 if not for the volume issues.

In general I would say that the clipping diodes are really important for the pedal's base character, although the huge changes tend to occur if you go to a completely different class of diode, e.g. 1N4001 or LED. I would have to believe that going with 1N4148 or 1N4150 will not yield major changes compared to the stock ones. It will probably be slight, mostly affecting the compression/playfeel and how much fizziness there is in the distortion (I don't consider fizz to be inherently bad, so I'm not stating this negatively).

I hope this helps.

I can say that I found it funny that when I tried to a bunch of "recommended" MT-2 mods, they usually made them sound like a DS-1 with a more versatile tone stack.

[bigtone23]

Hi,

Thanks so much for replying, that's all really helpful

I'd say my ears definitely fall into the 'I wouldn't notice a difference' category but I'm still humming and hawing over this - a weird obligation to make this stock with the right parts, to 'restore' it. My DS-1 is a weird one in that almost like the top layer of paint is peeling off in some places - it's generally duller and darker than the orange of my second DS-1, 2000's era MIT but in some spots the paint is almost coming away and I see the brighter orange underneath! Anyway!...

I think I will do the 3 cap mod to my second DS-1 based on what you said - that one is in pristine condition.. It's such a cheap change to swap some caps and now it's got me thinking of buying a 3rd to do additional mods to (I'll check out that JCM 800 mod!).... maybe a 4th to do the 'no diodes' mod to

I ordered some 1N4148 diodes so I'll probably just put them in the first DS-1 and call it a day for that. I've also since read that 1N4150 diodes give a forward voltage that's similar to the original parts and 1N4150s are cheap so I've got those saved in a Mouser basket for when I next put an order in there. Worth trying out! Sourcing the original diodes seems a bit difficult now because it looks like there's a lot of knockoff ones up on ebay and I probably couldn't trust anything is legit at this stage...

Thanks

Yeah, it can be a rabbit hole when it comes to modding the DS1. The good thing is there are still a lot of stock late 20th/early 21st Century MIT through-holes out there for cheap. I picked up a '02 Garmopat modded DS1 for $50. It has three modes, two of which are wildly different sounding from stock, and one mode is sort of close to stock, but has less gain and scoop. Looking inside, there are several changed caps and resistors, and the 3-way switch mostly addresses diode vs LED clipping. One mode seems to be like the Keeley Seeing Eye Mod, as it also has the LED peeking through the O of Tone.

Here's a post for what the '11 DS1 went through.
viewtopic.php?f=6&t=566&p=5068&hilit=jcm800+mod#p5068
This article snowballed the desire to mod a DS1...
https://www.premierguitar.com/diy/pedal ... -ds-1-mods
This page was also great...
https://mrfuriousrecords.com/audio/jack ... -ds-1-mod/

[bigtone23]

I have had over 100 DS-1 since I used to mod them quite often.

There are 5 iterations of the DS-1 circuit (6 if you include the op amp change compared to V4 for the 40th Anniversary and BK version, 7 if you include Waza) that all have slightly different qualities, although versions 2 (94-00), 3 (00-06), 4 (06-15), 5 (16-present), 6 (2017) sound pretty close to one another. Version 1 definitely is the most organic feeling and sounding, although with 15 years of production, there can be a lot of variance in compression and how much dry signal is in the mix e.g. ~1983 and older tend to have more dry signal and less compression. The early MIT DS-1 tend to have less dry signal in the mix than most of the MIJ and a higher noise floor, but the playfeel is fairly similar to MIJ. I had a lot of trouble with versions 2 and 3 getting to unity volume with hot humbuckers without being modded. I found V5 to have the least note articulation of any of them. My own personal ranking order goes V1 > V6 > V4 >= V2 > V3 > V5. I would rank V2 above V4 and V6 if not for the volume issues.

In general I would say that the clipping diodes are really important for the pedal's base character, although the huge changes tend to occur if you go to a completely different class of diode, e.g. 1N4001 or LED. I would have to believe that going with 1N4148 or 1N4150 will not yield major changes compared to the stock ones. It will probably be slight, mostly affecting the compression/playfeel and how much fizziness there is in the distortion (I don't consider fizz to be inherently bad, so I'm not stating this negatively).

I hope this helps.

I can say that I found it funny that when I tried to a bunch of "recommended" MT-2 mods, they usually made them sound like a DS-1 with a more versatile tone stack.

This is cool info. As always, you have really great info based on your experiences!

I have a MT2W, and 'Custom' Mode kind of makes it more DS1-ish. Less slicy, more punchy.

[zentropa]

I have a MT2W, and 'Custom' Mode kind of makes it more DS1-ish. Less slicy, more punchy.

I like the MT-2W's custom mode a lot. I use it in the same role that I use my Ibanez SM9 in, as a dirty boost into dirty amps