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zentropa
Gold Member
USA
837 Posts |
 Posted - 06/06/2009 : 18:02:02
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my quick chime in on mods...
imo, mods should be considered based upon what strengths and weaknesses pedals have and how you want to tweak things.
op amp swaps tend to change the bite and boost feel. clipping diodes change the gain flavor. caps/resistors change the eq tailoring, clarity, and volume. i differentiate between bite/cut and volume as i consider them to be very different things.
for example, to get more cut from an SD-1, something that swaps the op amp down to a JRC4588D (or equivalent) will increase the cutting power by a wide margin over a JRC4558DD. a TS-808, OD-1, or Full Drive 2 conversion will help in these regards.
The current version of the keeley mod on the SD-1 both increases the boost feel but decreases the gain.
the FD-2 conversion will add boost/bite and make the gain chunkier with more drive.
basically, for clipping diodes:
-LED's decrease gain but increase bite/drive. Think class A type break-up.
-germanium diodes significantly decrease gain but smooth things out.
-silicon rectifier diodes increase the gain, grit, and drive by a large margin but can be a bit harsh.
-MOSFET's generally add fuzz without adding a lot of drive.
-silicon zener diodes are the standard and are basically middle ground in terms of gain and drive.
upgrading tone components with metal film components (resistors, caps, etc.) basically makes a pedal more hifi, which can be both good or bad depending upon what you want. it increases the tonal representation of your actual sound but at the same time it steals some of the organic behaviors/nuances of the pedal.
i'm kind of a tone whore and people have said i have hawk ears when it comes to tone/timbre.
from my experiences, the order of importance for tone overall:
0. hands
1. amp head
2. guitar body wood
3. guitar fretboard wood
4. pickup voicing and magnets
5. effects pedals
6. instrument cable quality
7. speaker types
8. cabinet design
overall, i feel many people jump on modded pedals because they're supposed to have great tone but they often don't have enough experience with the stock pedal in order to understand the pedal's inadequacies that the mods are supposed to fix. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 06/06/2009 : 18:27:52
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quote:
Originally posted by zentropa
0. hands
1. amp head
Bravo! |
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IM28
Copper Member
26 Posts |
Posted - 06/07/2009 : 16:45:44
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As a technician I have the opportunity to listen to both stock and modded pedals that come in for repair or mods. I have noticed an increase over the last two years of pedals with bad or incomplete mods, usually by DIYs. There seems to be a corresponding increase of broken/modded pedals on eBay being sold even by reputable modders.
When ever I get a modded pedal in hand I try to A/B it with a stock one.
With the SD-1 I had an opportunity to test a Keeley mod against a MIJ and MIT versions. The differences between the Keeley pedal and the stock version were fairly subtle. At the end of the testing I still preferred the MIJ tone over the Keeley and the MIT. This is purely subjective but I think most Boss pedals are well engineered and most mods don't provide enough bang for the buck (unless you do it yourself). |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 06/07/2009 : 16:58:30
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quote:
Originally posted by IM28
I have noticed an increase over the last two years of pedals with bad or incomplete mods, usually by DIYs. There seems to be a corresponding increase of broken/modded pedals on eBay
For the "hobby" technicians (myself), this trend is actually pretty good value! As long as the thing isn't too destroyed by the 5,000,000W iron that's generally used, buying and reviving these pedals is a cheap way of increasing the collection.
quote:
I think most Boss pedals are well engineered and most mods don't provide enough bang for the buck (unless you do it yourself).
I'm kind of intentionally misreading your reply... I'm guessing you mean "having the ocommercial modder do the mod", but i think what you say applies even to the mod design itself. My experience with a "store bought" mod (a kit from a well known modder that I installed) was fairly unspectacular. I found the instructions to the SEM on the Keeley site and I did like what it did to my MIT DS-1, but when I tried to find a mod for my MT-2 I tried everything in the book (several books) and the mods just didn't do much. Took me about 6 months of tinkering and a bunch of help from folks in this forum (thanks Moonwatcher!) to come up with a mod that changed the pedal enough (to something good enough) to make the effort of modding it worthwhile.
PS: WELCOME to the forum! If you don't mind me asking, what is your technical background? I have a degree in Electrical Engineering, but hadn't done any hands-on electronics for maybe 20 years before I started seriously collecting pedals. Strictly a management type at work these days, but don't hold that against me  Hence I call myself a "hobby" techie. |
Edited by - Laurie on 06/07/2009 17:01:11 |
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zentropa
Gold Member
USA
837 Posts |
Posted - 06/07/2009 : 18:26:36
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quote:
I'm kind of intentionally misreading your reply... I'm guessing you mean "having the ocommercial modder do the mod", but i think what you say applies even to the mod design itself. My experience with a "store bought" mod (a kit from a well known modder that I installed) was fairly unspectacular. I found the instructions to the SEM on the Keeley site and I did like what it did to my MIT DS-1, but when I tried to find a mod for my MT-2 I tried everything in the book (several books) and the mods just didn't do much. Took me about 6 months of tinkering and a bunch of help from folks in this forum (thanks Moonwatcher!) to come up with a mod that changed the pedal enough (to something good enough) to make the effort of modding it worthwhile.
i generally put mods into 3 categories. 1. enhancements. 2. fixes. 3. conversions.
it seems most of the mods out there are focused around enhancements. boosting volume, increasing the sweep of the tone knob, making the pedal lower noise and more hifi, etc. while these may make the tone "better," usually it isn't significantly better where it's worth the cost of the mod (e.g. $5 better vs. $50 better).
fixes basically fix an inherent flaw in the pedal, such as the sd-1 bleed problem. since most pedals wouldn't have made standard production if the flaw was massive, these mods again fall into the subtle range.
conversions on the other hand take a pedal and turn it into another pedal or an entirely new animal (often including many of the enhancement mods). these usually have the greatest tonal effect but at the same time, conversions that do similar replacements (usually clipping diodes) often yield a load of different pedals that overlap in tone.
e.g. i did the indyguitarist JCM mods on both a DS-1 and an MT-2 and ended up with 2 pedals that sounded nearly identical but the MT-2 yielded slightly more gain and a bit more eq control.
it seems that mods that don't use clipping diodes to perform a significant change to the gain structure don't seem to do anything major in terms of changing the pedal's characteristics (e.g. they have to involve an LED, rectifier diode, etc. in the clippers). |
Edited by - zentropa on 06/07/2009 18:27:53 |
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IM28
Copper Member
26 Posts |
Posted - 06/07/2009 : 22:54:21
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quote:
Originally posted by Laurie
For the "hobby" technicians (myself), this trend is actually pretty good value! As long as the thing isn't too destroyed by the 5,000,000W iron that's generally used, buying and reviving these pedals is a cheap way of increasing the collection.
I'm kind of intentionally misreading your reply... I'm guessing you mean "having the ocommercial modder do the mod", but i think what you say applies even to the mod design itself. My experience with a "store bought" mod (a kit from a well known modder that I installed) was fairly unspectacular. I found the instructions to the SEM on the Keeley site and I did like what it did to my MIT DS-1, but when I tried to find a mod for my MT-2 I tried everything in the book (several books) and the mods just didn't do much. Took me about 6 months of tinkering and a bunch of help from folks in this forum (thanks Moonwatcher!) to come up with a mod that changed the pedal enough (to something good enough) to make the effort of modding it worthwhile.
PS: WELCOME to the forum! If you don't mind me asking, what is your technical background? I have a degree in Electrical Engineering, but hadn't done any hands-on electronics for maybe 20 years before I started seriously collecting pedals. Strictly a management type at work these days, but don't hold that against me Hence I call myself a "hobby" techie.
LOL  I know exactly what you mean I have a pile of pedals waiting to be "rescued", a DD-3, PH-3, TW-1,3 SD-1,MT-2 plus other DOD and MXR vintage pedals. It is a great way to sharpen your repair skills, try the pedal out maybe even add it to the collection or sell it.
I completely agree about the design aspect of the mod kits and even some of the "pro" mod services just seem to be variations on the mods that are publicly available. I am sure a lot of mods are developed by emperical means rather than actually reading the schematic and applying some basic engineering. On the other hand here are some knowledgable DIYs out there actively publishing mods (Brett Miller for example)that are well documented and designed.
When I was in school for EE I got my first job at a music store as a tech. Lots of guitar repairs and Peavey, Marshall and Fender warranty work. I did a stint as a bench tech at a now defunct stereo chain working on consumer audio/video stuff. I also had the priviledge of some part time tech work for Kinder. I've also worked on Industrial type microprocessor control (Z80) and automation stuff.
For a couple of years I developed and wrote database application software and I am now a engineer for a IT virtualization company.
Of course during this entire time I have been playing guitar, building and fixing effects and amps(sometimes for profit)
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MoonWatcher
Bronze Member
USA
98 Posts |
Posted - 06/08/2009 : 05:25:55
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quote:
Originally posted by zentropa
conversions on the other hand take a pedal and turn it into another pedal or an entirely new animal (often including many of the enhancement mods).
For right or wrong, this tends to be what floats my boat.
Enhancements just don't pique my interest enough, although if requested I'll do them for someone else. And if I'm going in to deal with a fix issue, it's usually not sufficient in itself. I've got a hacked pedal right now that some misguided modder clearly replaced a log drive pot with a linear one. I'm just not sure as to what way I might want to "convert" the rest of it.
As far as pedals that have been buggered up by someone else, I just don't sweat that at all. I've got both a DS-1 and a Daddy-O with severly crippled pcb's that work fine. The traces had to be jumpered all to hell and they'd be a PITA if I ever wanted to alter anything on them (not that I do), but they work just fine. |
Edited by - MoonWatcher on 06/08/2009 05:41:57 |
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MoonWatcher
Bronze Member
USA
98 Posts |
Posted - 06/08/2009 : 05:41:22
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quote:
Originally posted by IM28
I am sure a lot of mods are developed by emperical means rather than actually reading the schematic and applying some basic engineering.
I don't get the empirical method at all, as it is such a stone age technique at this point.
I'm not suggesting that modders go out and get a degree in electronics design and engineering just for the purposes of tweaking a little 9V analog (and sometimes digital) device, but we live in an age where there's a wealth of information at our fingertips. And pedals are simple enough that you can cobble together some information and then proceed with modifications based on logic, theory, concepts, and goals.
...But part of the missing piece of the puzzle is the artistic or creative aspect. If it's just an exercise in mechanics, a mod will most likely never amount to much. If someone is bound by the confines of a status quo circuit or even basic electronic principles, they'll never even get close to the edge of the envelope. Not that many are consciously trying to get there, but some (like myself) are.
I always think of the Rush song Hemispheres when it comes to pedal modding. You've got the engineering types who know what will happen on paper, know the math, know the logic, etc. You've got the creative types who are purposely trying to overload part of a circuit, get it to oscillate, get it to distort at specific frequencies (that they are typically unaware of the exact quantifiable measure of). But you rarely get someone who can balance the two hemispheres. And I think that this is a great reflection of a large number of mods and by extension even many pedal designs.
It's really hard to meld it all into a coherent design, especially if your mind favors one over the other. I'm fortunate enough to be schooled in both science and art, but it's still a challenge, oftentimes. |
Edited by - MoonWatcher on 06/08/2009 05:42:16 |
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gmreszel
Copper Member
USA
32 Posts |
Posted - 06/09/2009 : 19:34:50
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| Just another note of thanks for the responses on this thread. The pool of knowledge here is really impressive. I've read the whole thing a few times and must admit I have more questions I have to resolve than answers but that's not a bad thing - just part of the ed-uh-kashun process. |
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zentropa
Gold Member
USA
837 Posts |
Posted - 06/11/2009 : 07:04:01
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you'd be surprised as to how much can be discovered "by ear."
there's a lot of qualitative characteristics of sound that can't really be measured by equipment.
that being said, the engineering aspect of it can save lots of time/effort, but there's lots of things that may look perfect on paper but may have varying results in actual practice. the TR-2 R9 mod is a good example of this. replacing the 10K resistor with 6.8K = unity on the volume, but due to the nature of the effect, something in the 5.5-6.2K range is needed to avoid a perceived volume drop.
while people can say that tone is preference, guitar has been around long enough now to where there's some pretty standardized formulas of "good tone" (many of which i agree with). one of the things that makes modding interesting to me is that it's often the low-fi, noisy components that yield the warmest and most organic tone (even if their measured sound reproduction quality is low). |
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gmreszel
Copper Member
USA
32 Posts |
Posted - 06/11/2009 : 14:34:55
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quote:
Originally posted by zentropa
you'd be surprised as to how much can be discovered "by ear."
there's a lot of qualitative characteristics of sound that can't really be measured by equipment.
I agree. When I was in high school I hung with a group of audiophile geeks and we'd go around to the shops and collect literature on this amp or that speaker or fancy turntable. We thought that the ones with the lowest harmonic and intermodulation distortion, etc specs were the best but in the end you just had to hear it.
With that thinking of lo-fi then, I'm surprised I see a lot of mods where they hi-fi it; particularly I was noticing that with Allums mods. |
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IM28
Copper Member
26 Posts |
Posted - 06/11/2009 : 20:10:47
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quote:
Originally posted by MoonWatcher
quote:
Originally posted by IM28
I am sure a lot of mods are developed by emperical means rather than actually reading the schematic and applying some basic engineering.
I don't get the empirical method at all, as it is such a stone age technique at this point.
I'm not suggesting that modders go out and get a degree in electronics design and engineering just for the purposes of tweaking a little 9V analog (and sometimes digital) device, but we live in an age where there's a wealth of information at our fingertips. And pedals are simple enough that you can cobble together some information and then proceed with modifications based on logic, theory, concepts, and goals.
...But part of the missing piece of the puzzle is the artistic or creative aspect. If it's just an exercise in mechanics, a mod will most likely never amount to much. If someone is bound by the confines of a status quo circuit or even basic electronic principles, they'll never even get close to the edge of the envelope. Not that many are consciously trying to get there, but some (like myself) are.
I always think of the Rush song Hemispheres when it comes to pedal modding. You've got the engineering types who know what will happen on paper, know the math, know the logic, etc. You've got the creative types who are purposely trying to overload part of a circuit, get it to oscillate, get it to distort at specific frequencies (that they are typically unaware of the exact quantifiable measure of). But you rarely get someone who can balance the two hemispheres. And I think that this is a great reflection of a large number of mods and by extension even many pedal designs.
It's really hard to meld it all into a coherent design, especially if your mind favors one over the other. I'm fortunate enough to be schooled in both science and art, but it's still a challenge, oftentimes.
I should qualify my comments about the emperical method.
What I have an issue with is blindly changing components without knowledge of the function within a particular circuit. I have read comments by modders that actualy state that this was their method and claiming it to be better than getting hung up on "engineering" modifications. Actual empirical testing and subjective listening as a way of deciding whether a mod sounds "good" is really the only tool we have to make those decisions. Our ears are the final test instrument. There is a pitfall in simply changing components and listening in that we are subject to our own expectations as to whether there actually was a change in what we are hearing. This change/listen process should be founded in a basic understanding of what the circuit/component is actually doing. We also need to know from a functional perspective if the component is really the one we should be changing to achive a particular result.
MI circuits are unique in that we don't engineer them for typical low distotion HiFi specs (its funny seeing mods labeled as "HiFi" ) Effects and amps are tools and we want them to distort and warp the basic sounds of the instrument to achieve a personal, unique signature of our own. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 06/11/2009 : 20:29:52
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quote:
Originally posted by IM28
I have read comments by modders that actualy state that this was their method and claiming it to be better than getting hung up on "engineering" modifications.
Oh... you beat me to that! One very visible modder makes this statement on his web site - he is speaking of his early days, as he has a great reputation now. But it did astound me when I read it the first time. Lucky the average modern opamp is fairly forgiving, eh?
I've always taken the same approach as IM28 - gain a basic understanding then "fiddle around" - you never know when something will just sound right. That's the reason that the final low-pass filter in my MT-2 Stormchaser mod uses a 1k resistor and a big cap - higher resistance and lower cap (to give the exact same calculated 3dB point for the filter) just didn't sound as good. Can't explain why this should be so, other than the opamp must "like" driving the lower impedance load, even though on paper it shouldn't matter at audio frequencies. |
Edited by - Laurie on 06/11/2009 20:30:57 |
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cctsim
Silver Member
United Kingdom
418 Posts |
Posted - 06/11/2009 : 21:31:29
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quote:
Originally posted by Laurie
[quote]Originally posted by IM28
That's the reason that the final low-pass filter in my MT-2 Stormchaser mod uses a 1k resistor and a big cap - higher resistance and lower cap (to give the exact same calculated 3dB point for the filter) just didn't sound as good. Can't explain why this should be so, other than the opamp must "like" driving the lower impedance load, even though on paper it shouldn't matter at audio frequencies.
This effect is similar to a technique used in power supply filtering where you put in parallel a large electrolytic capacitor with a small ceramic or metal film (100n or so).
Although on paper it shouldn't make a difference given the 10-20% tolerance of electrolytic capacitors in practice it does.
It is related to the mechanical construction of capacitors, apparently they have an operational frequency sweet spot, e.g. we should not force theoretical cut off frequencies using high resistor values.
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 06/11/2009 : 22:12:42
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quote:
Originally posted by cctsim
[quote]
This effect is similar to a technique used in power supply filtering where you put in parallel a large electrolytic capacitor with a small ceramic or metal film (100n or so).
Although on paper it shouldn't make a difference given the 10-20% tolerance of electrolytic capacitors in practice it does.
It is related to the mechanical construction of capacitors, apparently they have an operational frequency sweet spot, e.g. we should not force theoretical cut off frequencies using high resistor values.
Yep. The same filter 3dB point implemented with a 100k resistor and a mono capacitor (rather than the 1k resistor and larger poly capacitor) has a completely different character. |
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Opinions on mods, keeley, allums, et al
