# NPD - Boss DF-2



## YellowChecker (Jun 10, 2021)

I know it's old but I got my hands on a Boss DF-2 super feedbacker & distortion from 1985! It looks almost brand new!!
Just wish I wasn't doing overtime this week so I could try it out properly.
It's probably not the best distortion out there, but I got it because I started playing guitar around that time and it was the 1st pedal I ever tried.








Had to share, sorry if it's boring


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## CathodeRay (Jan 12, 2018)

Nice find.

Considering the condition and age, maybe it's even worth a few bucks if you wind up not liking it?


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## mhammer (Nov 30, 2007)

I also have a DF-2. Not the best, but certainly the first feedback simulator. One thing I like about it is that if you tune in the lower note as the "feedback" (control set at 7:00), and hold down the foot treadle, you can play over it and use it as a drone note. The distortion lacks any discernible personality, but that's okay. It's essentially a low-budget DS-1. There are various mods posted around, including suggestions for altering the rate at which the simulated vibrato on the overtones occurs. That vibrato doesn't jump out at you, but it's there. After all, part of what keeps a string vibrating IS finger vibrato. Nice touch on Boss's part.

Low-volume feedback emulators have come a long way since the early '80s; particularly since migrating to the digital domain, where there is more flexibility in how and when the simulated feedback gets introduced. I have a Line 6 Dr. Distorto, which provides controls for varying how the "feedback" fades in and out. My favorite, if I could find one, is the out-of-production Fender Runaway, which is not only great-sounding but also optimized for performance.


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## Chito (Feb 17, 2006)

I used that DF-2 for quite a bit in the 90s. Although I only used the distortion part of it and never used the feedbacker. At that time, I prefered the distortion part of that pedal than the DS-1. I was told they are the same thing but I find it less harsh than the DS-1. I also still have the pedal but it's nowhere near how yours look like.


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## KoskineN (Apr 19, 2007)

Cool, love those old Boss pedals. I remember a friend of mine used to have one in the 90s, and we were messing with the feedback thing a lot. I should get one to add to my small Boss pedal collection one day. Have fun!


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## mhammer (Nov 30, 2007)

Chito said:


> I used that DF-2 for quite a bit in the 90s. Although I only used the distortion part of it and never used the feedbacker. At that time, I prefered the distortion part of that pedal than the DS-1. I was told they are the same thing but I find it less harsh than the DS-1. I also still have the pedal but it's nowhere near how yours look like.


The DF-2 uses the same kind of Tone control as Big Muff. Similar to the Big Muff, one can tinker with component values in the tone control to get more pleasing sounds.


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## isoneedacoffee (Oct 31, 2014)

I had one for a bit after I realized that some of the cool, trippy, sounds that Adam Franklin from Swervedriver was generating were due to that pedal. I discovered that he had a malfunctioning DF-2, which would enter into some crazy spacey oscillation. He would use it in a very musical way. If I remember correctly, there was a guy somewhere in Ontario that was modding and selling DF-2s to match that "malfunction". I think I bought mine from him. I'll see if I can find a clip of that type of sound from Swervedriver. It's really, really, cool!

EDIT: Found a sample. It's the "siren" setting for this modded one. Skip to the 40 second mark.


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## Chito (Feb 17, 2006)

mhammer said:


> The DF-2 uses the same kind of Tone control as Big Muff. Similar to the Big Muff, one can tinker with component values in the tone control to get more pleasing sounds.


So in that sense, there would be a difference between the DS-1 and the DF-2? Am I right in making that assumption?


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## mhammer (Nov 30, 2007)

Here is the distortion "engine" of the (early issue) DS-1. The relevant parts are outlied in red.









Here is the distortion "engine of the DF-2, with the relevant portions outlined in blue.










The circuit built around Q2 in each pedal is largely the same, with one exception. The DS-1 uses a 250pf capacitor where the DF-2 uses 47pf. This should roll off some of the highs in the transistor driver stage of the DS-1, in comparison to the DF-2.

The clipping diodes, going to ground in each are the same. The DS-1 sticks the .47uf capacitor after the 2.2K resistor, where the DF-2 has in reversed. Makes no difference to the result.

The Tone control is absolutely identical in the two units. Same rolloffs on the bass and treble sides.

The other more noticeable differences are in the op-amp chips used for the gain stage in each. The DF-2 uses a 5218L op-amp which is a fairly standard one in many Boss pedals, and has low noise. The DS-1 uses a TA7136 chip, which is a little idiosyncratic. Can't think of any other Boss pedals that use them, off the top of my head. The DF-2 gain stage has a maximum gain of 54x, while the DS-1 gain stage seems to have a max gain of roughly 44x. (Keep in mind that gain is multiplicative. So, a gain of 10x followed by a gain of 10x = a combined gain of 100x.) 

It appears that the transistor stage feeding the op-amp gain stage is the same in each, with respect to how much it boosts the signal. So one would think that the DS-1 should _technically_ be a less intense-sounding pedal. BUT the DF-2 has R16 (68K). In tandem with R15 (100k), this drops the level of the transistor output feeding the op-amp by about 40%. So even though the gain stage in the DF-2 has a bit more gain on tap (55x vs 44x), the signal feeding that op-amp gain stage has been knocked down considerably, and probably more than the additional gain can compensate for.

As for the quirks of the chip the DS-1 uses that may also have some impact, I can't say. Above my pay grade.

All of this is to say that the two circuits are similar enough - with the exception of the chip - that a DF-2 could conceivably be modded to be _*more*_ like a DS-1. Change te 47pf cap to 250pf and bridge R16 so you don't lose any signal.

Hope that's not too mysterious.


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## Chito (Feb 17, 2006)

mhammer said:


> Here is the distortion "engine" of the (early issue) DS-1. The relevant parts are outlied in red.
> View attachment 371449
> 
> 
> ...


Thanks Mark! So from what I can understand from this is that, this would answer why I find the DF-2 less harsh than the DS-1. Also, it provides some credibility to what I thought I was hearing back then. Mind you these days, with my hearing loss, I probably won't be able to hear that difference anymore.


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## YellowChecker (Jun 10, 2021)

CathodeRay said:


> Nice find.
> 
> Considering the condition and age, maybe it's even worth a few bucks if you wind up not liking it?


time will tell


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## YellowChecker (Jun 10, 2021)

mhammer said:


> I also have a DF-2. Not the best, but certainly the first feedback simulator. One thing I like about it is that if you tune in the lower note as the "feedback" (control set at 7:00), and hold down the foot treadle, you can play over it and use it as a drone note. The distortion lacks any discernible personality, but that's okay. It's essentially a low-budget DS-1. There are various mods posted around, including suggestions for altering the rate at which the simulated vibrato on the overtones occurs. That vibrato doesn't jump out at you, but it's there. After all, part of what keeps a string vibrating IS finger vibrato. Nice touch on Boss's part.
> 
> Low-volume feedback emulators have come a long way since the early '80s; particularly since migrating to the digital domain, where there is more flexibility in how and when the simulated feedback gets introduced. I have a Line 6 Dr. Distorto, which provides controls for varying how the "feedback" fades in and out. My favorite, if I could find one, is the out-of-production Fender Runaway, which is not only great-sounding but also optimized for performance.


The runaway does some nice swell/feedback


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## YellowChecker (Jun 10, 2021)

isoneedacoffee said:


> I had one for a bit after I realized that some of the cool, trippy, sounds that Adam Franklin from Swervedriver was generating were due to that pedal. I discovered that he had a malfunctioning DF-2, which would enter into some crazy spacey oscillation. He would use it in a very musical way. If I remember correctly, there was a guy somewhere in Ontario that was modding and selling DF-2s to match that "malfunction". I think I bought mine from him. I'll see if I can find a clip of that type of sound from Swervedriver. It's really, really, cool!
> 
> EDIT: Found a sample. It's the "siren" setting for this modded one. Skip to the 40 second mark.


Interesting and weird! I have the EQD data corrupter and it can produce somewhat similar sounds but it can't be held indefinitely like in the video.


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## YellowChecker (Jun 10, 2021)

mhammer said:


> Here is the distortion "engine" of the (early issue) DS-1. The relevant parts are outlied in red.
> View attachment 371449
> 
> 
> ...


Really cool to know! Like Chito said I did notice a difference but that was a while ago and I don't have my ds-1 anymore to compare. Thanks for the technical breakdown!


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## Permanent Waves (Jun 2, 2020)

One of the many Boss pedals I regretted selling. I bought mine in November 1984, right after it came out back when it was called Super Distortion and Feedbacker (before DiMarzio had them change the name because they copyrighted "Super Distortion" pickups). First pedal I ever bought, with paper route money! I was going to buy a DS-1 but saw that and found the feedback feature really cool. Used it to sustain the last note at the end of the "Limelight" solo. I just kick myself for selling all my Boss stuff, especially when I see the prices now.


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## Okay Player (May 24, 2020)

mhammer said:


> I also have a DF-2. Not the best, but certainly the first feedback simulator. One thing I like about it is that if you tune in the lower note as the "feedback" (control set at 7:00), and hold down the foot treadle, you can play over it and use it as a drone note. The distortion lacks any discernible personality, but that's okay. It's essentially a low-budget DS-1. There are various mods posted around, including suggestions for altering the rate at which the simulated vibrato on the overtones occurs. That vibrato doesn't jump out at you, but it's there. After all, part of what keeps a string vibrating IS finger vibrato. Nice touch on Boss's part.
> 
> Low-volume feedback emulators have come a long way since the early '80s; particularly since migrating to the digital domain, where there is more flexibility in how and when the simulated feedback gets introduced. I have a Line 6 Dr. Distorto, which provides controls for varying how the "feedback" fades in and out. My favorite, if I could find one, is the out-of-production Fender Runaway, which is not only great-sounding but also optimized for performance.


Me: "Well, that seems interesting."
_Looks it up on Reverb_
Reverb: Fender Runaway | 6P-X Pro Audio | Reverb


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## mhammer (Nov 30, 2007)

Okay Player said:


> Me: "Well, that seems interesting."
> _Looks it up on Reverb_
> Reverb: Fender Runaway | 6P-X Pro Audio | Reverb


Holy crap!


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## fretzel (Aug 8, 2014)

I have the FB-2. While I don't use it a lot, I really like it.


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## YellowChecker (Jun 10, 2021)

Okay Player said:


> Me: "Well, that seems interesting."
> _Looks it up on Reverb_
> Reverb: Fender Runaway | 6P-X Pro Audio | Reverb


OUCH! $1,274.78CAD but there's free shipping!


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## Okay Player (May 24, 2020)

YellowChecker said:


> OUCH! $1,274.78CAD but there's free shipping!


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## mhammer (Nov 30, 2007)

Fender has had some real home runs and standing triples with their recent series of pedals. I wonder why they didn't resurrect the Runaway?


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## fretzel (Aug 8, 2014)

mhammer said:


> Fender has had some real home runs and standing triples with their recent series of pedals. I wonder why they didn't resurrect the Runaway?


A couple of years ago someone local was selling one for cheap but I didn't grab it. This weekend a Brian May pedal was up for $200. I debated it but didn't get it either. 

It would appear that I do have restraint at times.


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## YellowChecker (Jun 10, 2021)

fretzel said:


> A couple of years ago someone local was selling one for cheap but I didn't grab it. This weekend a Brian May pedal was up for $200. I debated it but didn't get it either.
> 
> It would appear that I do have restraint at times.


Restraint! that's the one thing I keep forgetting


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## mhammer (Nov 30, 2007)

fretzel said:


> A couple of years ago someone local was selling one for cheap but I didn't grab it. This weekend a Brian May pedal was up for $200. I debated it but didn't get it either.
> 
> It would appear that I do have restraint at times.


I generally set my self-restraint at $50. I've gone a little over at times, when warranted, but not by much.


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