Another Philosophic question - Dumbloid results

[motterpaul]

Okay - I just built the Dumbloid Special. I got it to come right up with the OPA2134 and the BC548Bs. I socketed the LED so I could try a few different types.

The only thing I did not have exact parts as written were in whether I used Log or Lin pots (values were all correct). Now, I have read in many places it doesn't matter that much which you use. Personally, I am starting to think it can make make a big difference, mostly because I was investigating the Duncan tone modeler and it indicates switching a linear for log can make a huge difference - at least where tone control pots are concerned.

So I now have a lot of new pots on order, so I can start building everything here as close to spec as possible. Now my question...

We know these layouts are based upon original schematics - so, how is it possible that so many of us can often end up with vastly different results than the original pedals, and also we all often seem to have the same things we don't like about the results.

With the Dumbloid I had the exact same results other people mentioned in the comments on that circuit. In my case, it was fizzy, and had a sputtering sound as the notes died out.

Like a lot of people there, I changed out the OP-AMP, and the LED, and the transistors. I found that when I went with a higher HFE transistor it sounded a lot better (2N5089 for example). In switching out op-amps, I actually found the OPA remained one of the better ones for me (didn't care for the TL072) but the JRC4558D actually sounded the best by a hair.

I also switched the "accent" to a 20k log, and that was an improvement.

Now my question (And PLEASE do not take this as me being negative about of this web site. I realize now that I have to very clear about this from now on - just because I have a question it does NOT mean that I don't believe the people here know what they are doing. It is just a logical question based on observations) - once again, if this is based upon the original schematic, how is it possible the original maker can build these pedals and be successful with quality control, yet when we do it we can get vastly different results? Often with many of us having different, or many of us having the same "problems?"

Is it because of choice or sourcing of parts? Is it because some of us may be substituting things we aren't mentioning, or types of components (caps, for example)?

I mean mine worked - and I even found certain tones I liked, but I also found many things about it to be unusable (like the tone knob and the Jazz/Rock switch where one side was just way too dark). I had the exact same challenges as I read other people had.

So, I was not the only person who ended up not liking the original circuit - and that is the root of my question. Why does that happen - if that is the same schematic the original makers are using successfully?

By the way - I would be posting what I found in making this circuit under its comments - but for some reason my ability to leave comments under any circuit is not working. If someone could remedy that I would be very grateful.

And being clear - I really do not know the answer to this, and would like to know what people think. I know a lot of people just buy kits and make them. If you did that, you should be getting the exact same parts as the original maker, but based on what we are doing here - that would be a bad idea because the "original" parts don't sound good to us.

Some people who sell kits put down VERO as not a great medium. Seems fine to me and I have made some great pedals, I just don't understand why some circuits seem to bring about such different results from the original demos (for example).

[motterpaul]

BTW: since I can't comment at the actual circuit, I will put some notes here on what I observed.

There is something about the way those transistors are being powered (or under-powered) where the output just clamps down when there is no signal - almost like a noise gate. With most circuits you know when it starts working, because you hear it power up. With this one, I had no idea it was even on until I hit my guitar.

That is also the main reason for the sputtering sound when the signal dies out, I am guessing. It is worse with the recommended OPA2134 and the BC248Bs. tI gets better when you change those out.

It isn't the LED - because the circuit works without it. That is just for tone and a little stability (it helps the tone sustain a little longer, less sputter), but except for the sputtering, I think the circuit actually sounds better without the LED. A larger LED is a compromise.

Yeah tho, I can't help wondering if by changing out the IC and Trannies if I have just built a different pedal. I watched Pete Thorn do a demo of this exact pedal where he (surprise, right?) really seemed to like it as a "Dumble sound for people who can't afford Dumbles."

These guys do charge $600 for this pedal with its "post it" labeling - but it also does seem to sound better that what I've got going here so far, even with my changes. I wish I knew what the secret ingredient is.

And to be clear - this is the one I did: http://2.bp.blogspot.com/-ohyeszP4TM8/U1utvm2CHII/AAAAAAAAG6Y/tZ1Ta5zStvg/s1600/Shin%27s+Music+Dumbloid+Special.png

[Chris60601]

 I think the key is "based on" the original and I would also venture to say that manufacturers of the original stomps will always get the same parts. As mentioned before - folks use a variety of parts. Some parts may not be the exact value while others may not be able to find the exact parts so we try to get there with subs and alternatives.

Then there's the whole reason why many of us get into this hobby to begin with - to learn how its done THEN, take what we have learned and modify either our original (and I'm pretty sure many of us have some stomps that are original and wont part with, for example, I have a TS9 and sparkle Drive) or create our own "sound" or "tone". It's very satisfying getting that, "Ah-Ha" moment, and actually modifying to your liking!

Nonetheless - this is the whole thing about these stomps being called clones anyways. For various reasons, they can't be the exact stomp. If you are building to get the exact or original, then you might be better served saving the money on sourcing and just buying the originals - not intended to be insulting, but sometimes there are folks that love having a nice garden and can do all the things needed to have that garden looking really nice. Then there are others that don't have the time, money or talent to do the work but expect the same results - does that make sense?

In the end, it's a garden - may not look the same, may not produce the exact flowers at the exact same time, but its still a garden :) - BTW - I loath garden work

I can't speak for all here, but this is my opinion and I have a hunch, it probably falls along the same lines as many others here :)

I know it doesn't answer all your questions, but I hope it kinda makes the muddy waters a little clearer.

Cheers
Chris

[dexxyy]

A huge number of layouts found here may not be built from the exact same schematic as the original, but will be very, very close. To explain, not all of the layouts presented here are from factory schematics, most are reverse engineered by enthusiasts who have managed to get their hands on a pedal either buying, borrowing or having one in to repair. Sometimes during this process component values or even types can be hard to identify, it is quite common for some builders to sand off markings on ic`s or transistors. While components like resistors, caps, diodes etc may be easier to recognise, sometimes markings can be obscured (components soldered so the value markings are face down on the board etc). Also in some cases someone may acquire a pedal, not have the knowhow to reverse it and post pictures for someone with the requisite skills to perform the reverse. These methods can lead to some variation to the original. As mentioned by Chris, this is then a starting point to tweak things till you can get something that sounds the way you like it. Personally I take most dirt pedal demos with a pinch of salt, the pedal is only part of the chain so if the reviewer is playing a Les Paul into a fender 65 deluxe reverb then we`re hardly likely to get the exact same results playing a strat into a peavey bandit. Besides, Andy over at PGS can make a tennis racquet plugged into a toaster sound frickin awesome.

[Beaker]

" if this is based upon the original schematic, how is it possible the original maker can build these pedals and be successful with quality control,"

Are they? Always?


"yet when we do it we can get vastly different results?"

Do we? Ten people having different issues suggests ten different mistakes when building to me.


"Is it because of choice or sourcing of parts? Is it because some of us may be substituting things we aren't mentioning, or types of components (caps, for example)? "

Possibly, probably or definitely.


"Why does that happen - if that is the same schematic the original makers are using successfully?"


Who says it is? Schems are often speculative at best - for all the reasons Dexxy points out. Even factory published schematics are sometimes just plain WRONG.


"I know a lot of people just buy kits and make them. If you did that, you should be getting the exact same parts as the original maker"

Says who? - in fact I would bet a weeks wages that not one single part in the kit is the "same" as the original maker.


"that would be a bad idea because the "original" parts don't sound good to us."

Again, says who? You might hate it, I might love it.


"Some people who sell kits put down VERO as not a great medium"

That's because their kits are PCB based.


" I just don't understand why some circuits seem to bring about such different results from the original demos (for example)."

Don't even get me started on demos...



None of this is exact science, and never will be - just too many variables. Sometimes they best you can do is to get in the same ballpark, and be happy with that.

Sometimes you can get better results than the original though, which is why there is a boutique clone industry in the first place.



"Now my question (And PLEASE do not take this as me being negative about of this web site. I realize now that I have to very clear about this from now on - just because I have a question it does NOT mean that I don't believe the people here know what they are doing."


Again, why does this need to be continually brought up? C'mon dude, just let it lie. Please.

[rocket88]

just to add to beakers comments, which i completely agree with, is that you need to remember that if someone created a circuit they know exactly what they're looking for in their parts. for instance what hfe a transistor should be, or what company made sed transistor, which can make a HUGE difference.

for example, DBA is one of those companies that do some sorta black magic, which makes it hard to get a "clone" of their effects. by black magic i mean, they have some special characteristics they're looking for in their transitors, so while we may know they used 2N5089's in an effects, you can plug different ones in and get different results. we don't know what they're looking for.

also, what is very important, is who is to say the original sounds good. there's a bunch of effects that i've build that the originals sound bad to me, and the mods i've done makes them sound better to me. some pedals people lust after, and when you play one, its just meh (the klon IMHO, which i've played a real one, and klone), so making mods to it makes it sound better to me. typically demos are made to SELL you the pedal, so they should sound great. i bought a BATW Black Sheep cause of the demos on bass, i bought one, plugged it in, started playing and brought it back 10min later, cause it sounded NOTHING like the demos. i took pics of the board, top and bottom, recorded parts values i could see so that hopefully we can reverse engineer it and i can get it to where i want. btw, my biggest problem was the lack of low end, and the cap selector switch really went from stock to more bass cut.

if multiple people build the same effect, from the same layout, using the same values they should sound the same, and if not someone has problems in their build, not the effect.

[Chris60601]

Wow! I guess I was pretty far off om some of my explanations, as the others pretty much hit the nail on he head, LOL

... still more learning to do.

[Frank_NH]

"So, I was not the only person who ended up not liking the original circuit - and that is the root of my question. Why does that happen - if that is the same schematic the original makers are using successfully?"

As was already pointed out, many of the modern/boutique effect vero layouts here are based on schematics that were derived from the circuits of the original effect (i.e. reversed by someone who owned the pedal).  In some cases, one or more components have been prescribed incorrectly, and later on a correction has been made.  I have always treated any circuit here (unless a factory schematic is available) as an experiment - even if someone has successfully built it.  And you may build a circuit entirely correctly and not like the sound - that's OK!  There have been many circuits I built but decided not to box because I didn't like the sound or it didn't sound very special to me (the OCD was one of those).  Maybe we should start a thread about "The Island of Lost Circuits" - where bad effects circuits go when they don't make the cut...

In the case of the Dumbloid, there is a big thread about this pedal at FSB.  If you subscribe there you can search their archives and find it.  I'm a member at both FSB and DIYStompboxes.com.  Searching their archives can yield a lot of great information (especially DIYStompboxes).  

[rocket88]

not at all man, i definitely think you have some great points. there are tolerences with parts that can make a difference, which is part of the reason for people going nuts over "mojo" parts liked carbon comp resistors. plus you can never really have a true clone, unless you're using all the same parts, on the same layout/pcb.

i could be wrong, but i can't agree more with your point that those of us in DIY get the joy of making it as we want. and while i'm no gardener either, but i think you're analogy is spot on.

[Beaker]

"Wow! I guess I was pretty far off om some of my explanations, as the others pretty much hit the nail on he head, LOL

... still more learning to do. "

On the contrary Chris, your reply makes perfect sense, and is absolutely spot on.

[motterpaul]

OP here. I couldn't get logged in from my phone, so I am just getting back now- thank you all for your replies.

Sorry to bring the word "noob" again - but I came into DIY pedal building thinking that there was a lot of certainty out there about the schematics out there. I mean most other things in the music world are not so "murky", right? The fact is that you can build pretty much a stock Marshall 2204 if you want - and copying a Fender Strat has been done many times. You can even build a Dumble amp - the real specs are out there. (as far as I know).

So - this brings up the question of how accurate the effect pedals schematics that are out there really are? I agree with the idea that "maybe not all pedals really sound that good" and "demos are made to sell pedals" and I especially agree about the overdrive zone as being one of the most mysterious remaining areas. It is funny, because why should a used Klon be worth $3k today? Especially when you can get an Ethos (which looks like an amazing freaking pedal) for about $600?

I understand that it isn't cool to say bad things about different pedal makers in public, so we won't go into the "schematic" graveyard.

One thing I do wonder is this - wouldn't it be easy for some of the top pedal makers to intentionally "leak" less than perfect schematics? And if the public buys into you it - they're golden, because no "clone" will ever sound as good as their original ones for sale. Furthermore - why else would top pedal makers of today, who have seen what happened to TubeScreamer, use parts that most of us DIYers don't usually keep on hand? Like how many of us hobbyists have a batch of MC33172 op amps sitting around? (For the TC Electronics Spark Boost).

This Dumbloid circuit is the one that got me thinking. I get it, that Dumbloid is just a name of a pedal that someone managed to design and sell, probably for a lot more than it is worth. It's just a funny world, that's all I am saying. First of all - it seems ironic that one can completely degoop and backwards engineer a real Dumble amp, but that a pedal call "Dumbloid" is subject to so much speculation. Then I thought about Howard Dumble, who famously talks about the "magic crystalline sound of tube harmonics" and the Dumbloid schematic appears to be based on Op-Amp over-drive. Wouldn't some kind of JFet design make more sense?

All I am saying is that it is interesting - its a real discussion to have someplace, probably not here, although just the fact that people constantly talk about changing this or that makes it an implied discussion. But if you had to put a % number on it - how many of the schematics that out there would you guess are 100% accurate?


Along the same lines, as far as whose ideas were "right or wrong" - I don't really think there are any right or wrong answers in a philosophic discussion - there is only speculation and theory based upon your perspective. Right?

[dexxyy]

I`d think that most schematics are very close to the original pedal, however having a 100% correct schematic does not guarantee a 100% clone. You need to take component tolerances into account. A pedal using metal film resistors will generally have +/- 1% tolerance which in real terms is a 2% swing so a 1m resistor can vary between 990k and 1010k. Carbon film are a +/- 5% tolerance (10% swing) and capacitors can vary anywhere between -30% to +80%. Then you get to transistor hfe and the variety is huge, measuring proper values from components on a board is well nigh impossible. If a boutique builder hand selects components and only uses exact values ( by that I mean all 100k resistors measure 99k, all 100nf caps measure 105nf etc) then randomly selecting components based on schematic values will not get you an exact copy. It will however get you in the ballpark, from here we can tweak.

"One thing I do wonder is this - wouldn't it be easy for some of the top pedal makers to intentionally "leak" less than perfect schematics? And if the public buys into you it - they're golden, because no "clone" will ever sound as good as their original ones for sale. "

Says who? The quest for tone is a very personal quest, everyone is looking for something specific to them. I`ve modded loads of layouts here to get a sound that suits my needs better, that for me is the real value in diy pedals.

[dbat69]

There is another aspect to the original pedals that has been touched on, but is often missed.
A pedal designer (cough** we leave out Lovepedal here, cough**) , puts a lot of time into their pedal, often doing a lot of trial and error work, testing and refining before finalising a design.  During this process they will hone into particular components and values which work together and compliment each other.

As already mentioned, we do not know what those tolerances are or the exact details.  However we are being a bit naive when we use a schematic and throw our cheaply sourced components in there and then expect the same results as the original pedal.  There are times this works, and works well, but there are times it doesn't.  THat is when we tweak

Take Skreddy (and others) for example.  His pedals are perfected and components are 'chosen' to get the right sound.  THere are others who hand pick components to get the right results - as we've all come across, JFETs, are notoriously difficult to get right.

We also have to rely on the good will of others, as already mentioned, to reverse engineer pedals.  Pedals which have often been 'doctored' to make such a process extremely difficult, with goop, removal of references, multi-layer PCBs etc.

BUT, this is what makes the DIY part fun, tweaking to get what WE want out of the prdal to get OUR sound - well, it does it for me anyway

I just have a BIG thank you to all the people who make this possible for me - Mark and Miro, the reverse engineer-ers, testers, and you guys who tweak and give your opinions on how to make something better or what direction to go to change the sound in particular ways - Cheers guys

[IvIark]

In the case of the Dumbloid your results sound pretty much spot on to the original to me.  Read the Dumbloid threads on TGP to see what many non DIYers think about it and a large proportion have stated their dislike for the ugly decay.  I think it's just one of those pedals that works better with some guitar and amp combinations than others.

PCBs are great.  Veros are great.  Both are only as accurate as the schematic they're derived from, and it's in the PCB sellers interest to make sure people buy into the idea that their PCBs offer something tangible over a £0.10 piece of stripboard.  

[ξεναγος νεκροπολης]

 "Besides, Andy over at PGS can make a tennis racquet plugged into a toaster sound frickin awesome."

that made me laugh man!

and that's my answer!

the "thing" is in our fingers and in our way of seeing music and making music.
if i have jimmy hedrix's guitar plugged in a 1 million dollars equipment, and can't play like him, then if i'm not insane, i could admit that that is cause i'm not jimmy hedrix.
why can't we admit the same think when we don't have an electronics factory with all same components, and 100 workers that build same effects while we can't? there are people who are living from this!they should be able to build same pedals ALL the time! even if there is only one person that makes it for living, it's nothing like what we do here.
that's not diy. we are.  i like to think that we hack the tone. not clone the tone. companies some times make it really hard for us to reverse engineer there effects even by hidden links, double boards, false schematics and other ways. did anyone of us did that? no...
here is the deference. it's not in the sound. it's in how we see things.  
does all telecasters are the same?please tell me!
do we all had the same teacher in music? do we all wear the same stings in our guitars? do we all like building 100% clones?and if some like 100%clones, do you think you can really do it?and why? where is the fun in that!
anyway...good morning!

[Beaker]

I think I can safely speak for almost everyone here on this point:

We all have a box or bin full of completed vero builds, that work perfectly, but are never going to get boxed up. Why? Simply because we don't like them. They don't sound good with our guitars and amps, they have odd or unpleasant characteristics or they are simply boring and uninspiring.

These failures, destined for Frank's "Island of lost Circuits", are probably some of the most sought after pedals on the market too - I fall for the hype until my ears tell me otherwise, and I'm sure everyone else does too.

Hands up everyone here who has built a Klon?

Built a Klon and did not like it?

Built a klon and had to modify it before they liked it?

Built a Klon and despite all attempts to modify it to sound good, ended up throwing it into the bin?

We all do it sooner or later, and we will keep on doing it. I wouldn't mind betting that for most experienced builders, the ratio of boxed builds to "IoLC" builds is around 2:1. For every build that gets boxed, two get discarded.

I think that this is perfectly normal - we know what sounds good to us, and after all, the Emperor never seems to run out of new clothes to impress us with.

[dbat69]

Thanks MP for setting a good discussion going

The good thing about DIY, IMO is that we can build an expensive pedal for peanuts, tweak the freaking hell out of it and bin it (or send it to Frank's IoLCs - I love it) without crying over how much it cost us   We might get a tad peeved that we have spent a lot of time on a particular build, like the Dumbloid (I haven't built it yet - and it is still on my list even though the comments say it is crap ) but at least it hasn't cost us £600 for the priviledge of finding out it is crap

But then again, we might find a way of making the circuit work with our gear and guitar skills (poor in my case ), maybe that is the challenge of DIY? or simply getting something we could never afford or find?

[Frank_NH]

IvIark...
"...it's in the PCB sellers interest to make sure people buy into the idea that their PCBs offer something tangible over a £0.10 piece of stripboard."

My philosophy these days is to get PCB boards for effects where one exists (such as the Britannia or the Klon), and use vero for everything else.  I've thought about doing my own DIY PCBs, but the extra steps involved aren't worth it to me unless I was making several to sell or use in builds for other people.  Pre-made PCBs go together quickly because everything is nicely labeled and the quality of the boards (from the vendors I've purchased from) is very high.  But with vero, I can go from nothing to a completed build in two or three hours.

Speaking of the Klon, I haven't built that one yet (it's on the to-do list), but I have a feeling it will be a "mmm, it's OK but nothing special" - but I won't pre-judge.  Besides I have some of those special Russian D9E diodes that will make it sing!  

dbat69...
"The good thing about DIY, IMO is that we can build an expensive pedal for peanuts..."

This is true and one of the attractions of the hobby to me.  But beyond that, once you begin to understand how the circuits work and how to mod them, you can make your box (and tone ... or should I say in my best TGP accent "toan") unique.  This is very much like hobbyists who build things like hotrod cars - those are customized to the hilt, each being a reflection of the builder's knowledge, preferences and tastes.

[dbat69]

Exactly, Frank.  
The more I read, experiment and try to understand, the more inclined I am to make a circuit work for me. And as I said, what might start out as a naff sounding pedal, once tweaked could be something worth boxing.  But equally it also could be another cast-away.

I haven't tried any ready made PCBs yet, but I'm tempted to get some from Pedal Parts UK ad give them a go

[Frank_NH]

Here's a PCB maker from the UK I highly recommend:

http://diy.thcustom.com/

I got ROG Thor and Umble PCBs from him - both top notch!  I may also get the Azabache board he makes.  Shipping to US was relatively quick too .

By the way, when you think about it, a $10 PCB is well worth it considering most of the other components are perhaps $20 - still pretty inexpensive overall.  Also, boxing the effect is greatly simplified since most all the PCBs I've purchased permit PCB mounted pots.  Once together, the entire unit can be mounted to the holes drilled in the enclosure for the pots.  The only thing is that you need to order the pots with right angle PCB mounts, but fortunately they are the same price as the solder lug pots at most suppliers.