# Boss DS-1?



## bengarland (May 10, 2020)

Are any of the PedalPCBboards directly comparable to a Boss DS-1 Distortion?


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## Robert (May 10, 2020)

The Defouler is _close_, but not 100% identical.

I've been meaning to work up a DS-1 inspired board for a while, I'll see what I can do.


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## UnusedPortion (Jul 24, 2020)

@PedalPCB are you still planning on putting out a DS-1 board?


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## Barry (Jul 24, 2020)

One of my favorites to do mods on


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## Chuck D. Bones (Jul 24, 2020)

Indeed.  Picked mine up at a garage sale several years ago for $5, needed a new tone pot.  Ended up putting in most of the Keeley mods.


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## UnusedPortion (Jul 24, 2020)

@Barry @Chuck D. Bones  Curious as to your take on the differences between the DF-2 and DS-1 distortion circuits.  How close are they?  Is the DF-2 circuit an improvement on the DS-1 circuit?


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## Barry (Jul 24, 2020)

UnusedPortion said:


> @Barry @Chuck D. Bones  Curious as to your take on the differences between the DF-2 and DS-1 distortion circuits.  How close are they?  Is the DF-2 circuit an improvement on the DS-1 circuit?


I've never looked at a DF-2, I studied many different DS-1 mods to develop the ones I was doing, a lot of what the Boutique modelers change are just fluff to make it look like a bigger mod than it is


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## Barry (Jul 24, 2020)

Chuck D. Bones said:


> Indeed.  Picked mine up at a garage sale several years ago for $5, needed a new tone pot.  Ended up putting in most of the Keeley mods.


I used to run WTB's on Craigslist for broken pedals for $10, I figured if I couldn't fix them I could repurpose the enclosures and some of the parts


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## Chuck D. Bones (Jul 24, 2020)

UnusedPortion said:


> @Barry @Chuck D. Bones  Curious as to your take on the differences between the DF-2 and DS-1 distortion circuits.  How close are they?  Is the DF-2 circuit an improvement on the DS-1 circuit?



The Defouler is one piece of the Boss DF-2 Feedbacker.  The Defouler is pretty much the same as a DS-1.  C22 in the Defouler is 1uF; it's 470nF in the DS-1.  The Boss DS-1 has emitter-follower buffers on the input and output.  The Defoulfer uses opamp unity-gain buffers.  Not much, if any, sonic difference.  The Defouler has a spare opamp that is used as a Vref buffer. Again, no sonic difference.  The thing that does make a difference is the choice of opamps.  The original Made in Japan Boss DS-1s had a TA7136 single opamp that has been out of production for a long time.  Some folks will pay a premium for a MiJ DS-1.  Later models have an M5223A dual opamp. The "spare" opamp is wired as a unity gain buffer.  The Defouler uses a pair of TL072s.  The TL072 gain stage will sound different from the TA7136 or the M5223A when driven to saturation.  How much difference?  Which sounds better?  It's kinda up to the individual which is "best."  If you're going to build a Defouler, you might want to socket IC2 so you can experiment with different opamps in the distortion stage.  IC1 is just buffers, I wouldn't bother swapping that one.  You might also want to consider the myriad mods that exist, most are just component value changes.  

The mods fall into three general categories:

Altering the gain, bias and/or freq response of the transistor gain stage (Q2).  This has a major influence on the sound.  If you think it resembles the input stage of a BMP, you're not wrong.
Altering the clipping diodes for more/less compression and/or asymmetry.
Retuning the Tone control to eliminate the mid scoop.


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## Barry (Jul 24, 2020)

Chuck D. Bones said:


> The Defouler is one piece of the Boss DF-2 Feedbacker.  The Defouler is pretty much the same as a DS-1.  C22 in the Defouler is 1uF; it's 470nF in the DS-1.  The Boss DS-1 has emitter-follower buffers on the input and output.  The Defoulfer uses opamp unity-gain buffers.  Not much, if any, sonic difference.  The Defouler has a spare opamp that is used as a Vref buffer. Again, no sonic difference.  The thing that does make a difference is the choice of opamps.  The original Made in Japan Boss DS-1s had a TA7136 single opamp that has been out of production for a long time.  Some folks will pay a premium for a MiJ DS-1.  Later models have an M5223A dual opamp. The "spare" opamp is wired as a unity gain buffer.  The Defouler uses a pair of TL072s.  The TL072 gain stage will sound different from the TA7136 or the M5223A when driven to saturation.  How much difference?  Which sounds better?  It's kinda up to the individual which is "best."  If you're going to build a Defouler, you might want to socket IC2 so you can experiment with different opamps in the distortion stage.  IC1 is just buffers, I wouldn't bother swapping that one.  You might also want to consider the myriad mods that exist, most are just component value changes.
> 
> The mods fall into three general categories:
> 
> ...


I got to fix an original Japan DS-1 for a buddy, I feared it was the IC, but it was the distortion pot, it had got stomped, but it sounded awesome once I got it fixed


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## UnusedPortion (Jul 24, 2020)

Chuck D. Bones said:


> The Defouler is one piece of the Boss DF-2 Feedbacker.  The Defouler is pretty much the same as a DS-1.  C22 in the Defouler is 1uF; it's 470nF in the DS-1.  The Boss DS-1 has emitter-follower buffers on the input and output.  The Defoulfer uses opamp unity-gain buffers.  Not much, if any, sonic difference.  The Defouler has a spare opamp that is used as a Vref buffer. Again, no sonic difference.  The thing that does make a difference is the choice of opamps.  The original Made in Japan Boss DS-1s had a TA7136 single opamp that has been out of production for a long time.  Some folks will pay a premium for a MiJ DS-1.  Later models have an M5223A dual opamp. The "spare" opamp is wired as a unity gain buffer.  The Defouler uses a pair of TL072s.  The TL072 gain stage will sound different from the TA7136 or the M5223A when driven to saturation.  How much difference?  Which sounds better?  It's kinda up to the individual which is "best."  If you're going to build a Defouler, you might want to socket IC2 so you can experiment with different opamps in the distortion stage.  IC1 is just buffers, I wouldn't bother swapping that one.  You might also want to consider the myriad mods that exist, most are just component value changes.
> 
> The mods fall into three general categories:
> 
> ...


Thanks a lot, @Chuck D. Bones for taking the time to give such a thorough response.  I really appreciate it!


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