Need ideas for DS-1 switchable mods

[Guitarfreak]

I am looking for ideas for switchable mods for the BOSS DS-1.  I like the idea of having a stock vs. modded pedal at my fingertips and that's why I am looking for switchable mods.  What are some good ideas?  I've heard of Robert Keeley using Germanium diodes in one position of the switch and stock silicon in the other, but how does that work.  Can you do the same with transistors as well?

[marmora]

What kind of sound are you looking for?
Here's something a bit nontraditional if that's up your alley:
http://casperelectronics.com/finished-pieces/boss-ds-1/

[Guitarfreak]

What kind of sound are you looking for?
Here's something a bit nontraditional if that's up your alley:
http://casperelectronics.com/finished-pieces/boss-ds-1/

Not really sure what direction I want to go in with this, so I guess it files under BUMS.  I like the stock tone when used with the right amp, but I do also want to experiment with Germanium diodes and transistors and be able to switch compare side by side the tonal differences.  I think that is basically my motive here.  That and to find out if there are any well liked switchable mods for the pedal as well.

That mod sounds really cool!  Very lo-fi, reminds me of NES!  I was thinking of doing that sort of a mod to a fuzz pedal or something.  Cool idea.

[Guitarfreak]

This thread is going to get very noob.  OK so I see a lot of diodes in my pedal.  One of them is the familiar black and silver large type and the rest are see through orange and black smaller types.  How do I find out which are the clipping diodes?  Basically what I am asking is which would I have to replace if I wanted to convert the pedal from silicon to germanium via a switch?  don't kill me 

[Earthscum]

This paper has the best collection of mods I've found so far:

http://www.diystompboxes.com/smfforum/index.php?topic=76021.0

I modded mine for bass. Funny thing is, I did switchable Si-Si stock to red LED-Ge with a .47uF to REALLY crush down the high buzz. Asymmetrical crushing of the signal with a nice zap to the top end. Also modded the tone. And I did Jack Orman's Fat Mod, but reversed it after putting the decade too-large cap across the clippers. Now I'm sitting on one of the meanest bass Overdrive/Distortions I've ever played through.

Check your chips, too. Post back here with the chip... if you have the TA7136AP or the BA728N (my favorite, and I can't find more... Steve?) you are sitting good. I tried TL072 and JRC 4558 and neither sounded nearly as pristine as the BA. BTW, since you have a rectifier diode in yours, you may check the year I believe they took out that protection diode and a cap from the power supply end when they changed from the TA chips. Yours may be one of the ones that you don't want to mod... if ya don't want to trash it, I bet someone would trade ya 2 new DS-1's for it (not me, though... lol. I've had offers for mine like that, and it's nothing special.).

DS-1's are pretty popular... lots of mods for them.

BTW, that PDF has a 'close to stock' board layout that should help you a bit. The diodes you are looking for are sitting side by side, little reddish-brown glass ones. They are sitting about the center of the board closer to the op amp.

[Govmnt_Lacky]

This thread is going to get very noob.  OK so I see a lot of diodes in my pedal.  One of them is the familiar black and silver large type and the rest are see through orange and black smaller types.  How do I find out which are the clipping diodes?  Basically what I am asking is which would I have to replace if I wanted to convert the pedal from silicon to germanium via a switch?  don't kill me 

Basically, the black and silver diode is probably a 1N400X diode for voltage protection. That diode will protect the circuit incase of polarity reversal and possibly over voltage.

The ones you need to be concerned with are the "see through orange" diodes. These are probably either 1N914 or 1N4148 diodes. These diodes are most likely doing the clipping.

Of course, it would be best to somewhat trace out the circuit and find out on your own however, the "see through diodes" are your best bet for clipping.

[Guitarfreak]

This paper has the best collection of mods I've found so far:

http://www.diystompboxes.com/smfforum/index.php?topic=76021.0

I modded mine for bass. Funny thing is, I did switchable Si-Si stock to red LED-Ge with a .47uF to REALLY crush down the high buzz. Asymmetrical crushing of the signal with a nice zap to the top end. Also modded the tone. And I did Jack Orman's Fat Mod, but reversed it after putting the decade too-large cap across the clippers. Now I'm sitting on one of the meanest bass Overdrive/Distortions I've ever played through.

Check your chips, too. Post back here with the chip... if you have the TA7136AP or the BA728N (my favorite, and I can't find more... Steve?) you are sitting good. I tried TL072 and JRC 4558 and neither sounded nearly as pristine as the BA. BTW, since you have a rectifier diode in yours, you may check the year I believe they took out that protection diode and a cap from the power supply end when they changed from the TA chips. Yours may be one of the ones that you don't want to mod... if ya don't want to trash it, I bet someone would trade ya 2 new DS-1's for it (not me, though... lol. I've had offers for mine like that, and it's nothing special.).

DS-1's are pretty popular... lots of mods for them.

BTW, that PDF has a 'close to stock' board layout that should help you a bit. The diodes you are looking for are sitting side by side, little reddish-brown glass ones. They are sitting about the center of the board closer to the op amp.

The IC looks a little different than others I have seen before.  It is straight instead of 'spider' shaped if you will.  It says NJM3404AL, then under that JRC J167B.  bossarea.com has this to say about my unit "The unit with serial number xx89738 was produced January 2009. The unit is number 249738"

The power supply trace does seem to connect with another diode as well as a 100uf 16v rated cap.  I am still somewhat new to this though.

[Earthscum]

The IC looks a little different than others I have seen before.  It is straight instead of 'spider' shaped if you will.  It says NJM3404AL, then under that JRC J167B.  bossarea.com has this to say about my unit "The unit with serial number xx89738 was produced January 2009. The unit is number 249738"

The power supply trace does seem to connect with another diode as well as a 100uf 16v rated cap.  I am still somewhat new to this though.

Yar, that's the same chip as the other. One is called a SIP (Single Inline Pin) and the other is called a DIP (Dual Inline Pin). It's just different packaging. I find the SIPs easier to work with, but they are harder to find.

Smallbear Electronics should be your resource for parts. Steve sells the TA7136 chip. Also, there are a couple companies that make adapters for DIP to DIP. I made my own, with the cutout to go around the cap that I didn't want to replace, lol.

On the power supply, the cap is used for supply filtering, and the diode protects against reverse polarity... makes sure you don't fry your pedal of you use the wrong adapter, or start to try snapping your battery in backwards.

The clipping diodes are D4 and D5, and the cap that smooths out the clipping amd adds lowpass filtering is C10.

[Guitarfreak]

The IC looks a little different than others I have seen before.  It is straight instead of 'spider' shaped if you will.  It says NJM3404AL, then under that JRC J167B.  bossarea.com has this to say about my unit "The unit with serial number xx89738 was produced January 2009. The unit is number 249738"

The power supply trace does seem to connect with another diode as well as a 100uf 16v rated cap.  I am still somewhat new to this though.

Yar, that's the same chip as the other. One is called a SIP (Single Inline Pin) and the other is called a DIP (Dual Inline Pin). It's just different packaging. I find the SIPs easier to work with, but they are harder to find.

Smallbear Electronics should be your resource for parts. Steve sells the TA7136 chip. Also, there are a couple companies that make adapters for DIP to DIP. I made my own, with the cutout to go around the cap that I didn't want to replace, lol.

On the power supply, the cap is used for supply filtering, and the diode protects against reverse polarity... makes sure you don't fry your pedal of you use the wrong adapter, or start to try snapping your battery in backwards.

The clipping diodes are D4 and D5, and the cap that smooths out the clipping amd adds lowpass filtering is C10.

Thanks so much Earthscum and everyone who chimed in.  I ordered the TA chip you recommended and I'll throw that in there for good cause.  What should I expect to hear sound wise?

For the diode mod I should order a DPDT switch correct?  I have done the cap bypass mod on my Big Muff pi which should be an identical procedure, at least in my mind.  

About the power supply filtering.  I am familiar with the diode which is supposed to stop the negative voltage rush and pops and all that, but I see at least two diodes in that first trace in the same orientation.  Is the second one the rectifier diode which you mentioned?  Which I guess would indicate half wave rectification?

[Earthscum]

That PDF provided in the thread linked earlier has good diagrams on wiring the mods. It also has a bunch of info.... A+ compilation! some super crazy clipping mods I haven't tried.

[Guitarfreak]

That PDF provided in the thread linked earlier has good diagrams on wiring the mods. It also has a bunch of info.... A+ compilation! some super crazy clipping mods I haven't tried.

You are right that is clipping mod madness.  You know, of all those mods in there I don't think I saw one about germanium diodes, all silicons of different types and LED's.  Are germanium diodes not popular in DS-1's?

[WGTP]

There are many mods to the tone control that would be useful if switched.  Check those out.   

[Guitarfreak]

There are many mods to the tone control that would be useful if switched.  Check those out.   

The 'Phlat' mod seemed like it could be fun.  I did the same mod to my Big Muff pi.

[Guitarfreak]

OK, I just received the TA chip that I was recommended today and it is a 7 terminal chip and the JRC chip currently incumbent is an 8 terminal chip.  What do I do?