Dipthonizer builders: mods?

[Morocotopo]

Hi fellow builders. All of you who made a Dipthonizer, I have some questions for you. I used Madbean´s Honey Dripper schem but made my own layout.

Schem here:

http://www.madbeanpedals.com/projects/HoneyDripper/docs/HoneyDripper.pdf

I built mine, works, but there´s some things I´d like to improve:

- The sweep control only has effect in the last quarter of the rotation, the rest of the pot´s travel just leaves the filters static. And the response to picking strength feels kind of "hard", like you have to really whack it to get the filters to move.
- With a mildly hot single coil it sweeps MORE than with a humbucker... odd, supposedly a humbucker has more output and will generate a stronger signal/envelope?
- The filter´s peaks are a little bit too sharp, too much resonance I believe, gets a little tiring to the ear.
- The thing is noisy... but I believe the original was too, not that I ever heard one in person.

Well, anyone has some experience with this? I want to get it to perform at it´s best, really nice effect. When you hit it just right it makes the funniest/greatest vowels!

[pinkjimiphoton]

hi ari,
it is what it is...

it likes strats best, humbuckers tend to make it overdrive too much.

what you're describing with the sweep is typical, too... i've built three of 'em, all the same. they're almost microphonic!!

what ya gotta do, is put fuzz in front of it, overdrive after.

turn the distortion pot down a little bit, maybe half way up.

turn your sensitivity down... how you actually PLAY and how you *think* you actually play are two different things.

start with the sensitivity up about half way.

turn your guitar down a little.

now BEAT ON IT. then play extremely dynamically soft. you'll notice some settings work better than others do.

i actually "sweep" my guitar up and down, that's what controls the sensitivity... the pot on the unit just kinda adjusts the "range" of sensitivity, and what you're describing is exactly what i encountered at first. it's obnoxious..

but once you get used to it, it really sounds great!!

some of the "vowel" settings work much better than others... some guitars/p'ups will only work with one setting.

but fuzz before, and overdrive after, really will help bring this thing to life.

did you see my stupid pedal trick for this?

it's on my youtube

youtube.com/666pinkster

keep me posted bro!!

peace out

jimi

[Morocotopo]

Jimi!! Hi there.

Yeah, I saw your vid on the pedal, actually that inspired me to build this!

So, as per your description, mine works as intended... the only thing I haven´t tried is putting fuzzes/etc. before and after. Will do.

I built the thing, boxed and finished it. But after some use I became dissatisfied, so I breadboarded a second one, so now I have the boxed one and the breadboard one, wich I´ll use to experiment and see if I can make it better. If I make any improvement then I´ll apply that to the boxed one.

One thing I´ve already worked out is, the opamp IC5A on madbean´s schem was oscillating at some settings, making a whine/whistle and/or excessive hiss. As suggested by someone somewhere, I replaced C16 for a 1uF one, and the whine is gone.

On to the work then.

Cheers

[Mark Hammer]

- The sweep control only has effect in the last quarter of the rotation, the rest of the pot´s travel just leaves the filters static. And the response to picking strength feels kind of "hard", like you have to really whack it to get the filters to move.

If the last bit of rotation does what you need, then there is no need to change the gain of anything.  You can simply use a different taper Sweep pot, or swap the 10k for a 5k with a 4k7 or 5k1 added to the ground leg of the pot.  If you still can't get enough sweep, then consider changing the value of R6 to 220k for a little more zip.

- With a mildly hot single coil it sweeps MORE than with a humbucker... odd, supposedly a humbucker has more output and will generate a stronger signal/envelope

You can play with the bandwidth of the gain stage built around IC1b or IC1c (although b is easier).  So, you could insert an RC network in parallel with R4 to give a little more gain above a certai range, and/or stick a cap in parallel with R6 to tame the gain at higher frequencies.

- The filter´s peaks are a little bit too sharp, too much resonance I believe, gets a little tiring to the ear.

Reducing the value of R14 and/or R16 should reduce the Q, though whether you want to reduce them both is a matter of taste.  Note, as well, that dropping their Q will also shift their range, so don't monkey too much, or you lose the vowel quality.

- The thing is noisy... but I believe the original was too, not that I ever heard one in person.

Stick a TL074 in place of the LM324, and a TL072 in place of the 4558.

[pinkjimiphoton]

great advice from mark,
especially the opamps. i think i used a TL084 in mine.

i wouldn't mess with the pots too much, cuz they really DO need the full range depending on the dc resistance of the pickups driving it.
old-school low gain p'ups probably needed it all to do their thing.

another thing i found, was it seemed to *sound* better with ALL ceramic chips, but it makes it kinda microphonic. the first one i built with mostly chicklets,
the next was a mix of chiclets and ceramics, the last one all ceramic.. had more of an "edge" to it, and a bit grainier which really seemed to help the vowels.

in the end, it kinda "is what it is"... i didn't think mine even worked at first, cuz i had the pots cranked, and it sounded kinda like a %^&*ed wah stuck in the high mids.
turning them down helped a lot. but fuzz before and overdrive after really seems to bring it to life.

i haven't used mine in a while now, it lives on my live board but due to back issues, i've been using a multi and a couple outboard pedals live the last month or two.

i'll revisit it soon tho, my band is starting to gig again, and i use the full gospel business with them. when hosting jams/open nites, i don't need as much firepower.

oh yah, another thing.. play with the clipping diodes, to me it sounded best with ge on one side and si on the other.. i think i used to 1n34a's in series on on the lower half and an 1n914 on the top of the wave. sockets, bro.

i think once you get used to it's peccadillos, you'll really dig it!

i love it with a strat, cuz i can adjust the sensitivity up or down with my volume knob, effectively being able to have full wah-like control just with my hands. 

[Morocotopo]

Guys, thanks for the suggestions, working on it right now.

One thing that baffles me: wich one is the "envelope voltage cap"? Or this thing doesn´t have one? I don´t quite understand the env generator, this is not the simple Meatball type. I think.

I ask this because it seems to me that the "dipthong" could be more pronounced/audible if I shorten a bit the env decay time, seems to me it lingers a bit too much so it loses movement at the note´s tail. but I can´t find the decay R!

I mean, nobody says "auuuuuuto" or "queeeestion"...

[bluesdevil]

Finished mine up a few weeks ago. A mod I did was to parallel the 10k resistor that effects the depth with another 10k using a toggle. Some of the vowel positions really benefit from it.
Speaking of vowel positions: I seem to get distortion in the second setting more easily than others, but I'm pretty happy with how it turned out.

[Ronan]

There's some mods to soften the sharpness of the high filter in the last post here, worked very well for me, YMMV.
http://www.diystompboxes.com/smfforum/index.php?topic=99045.0

[pinkjimiphoton]

if you need less sensitivity/sustain, try turning down the guitar a little, that's worked for me so far.

[Morocotopo]

OK guys, I finished modding this. I made the following changes (always referring to the Madbean schematic):

- R5: 220K for a bit more drive
- Sweep pot: replaced with a 5KB with a 4K7 R from leg 1 to ground. Makes the sweep a bit more controllable. I suspect a 2K5 pot with a 8K2 or so R would be even better, but I don´t have a 2K5 pot.
- C2: 1n
- R21: 1K. Not much variation changing this R value.
- C16: 1uF, to tame oscillation in IC5A that was whistling in some vowel positions.
- R17: 8K2, to lower the second filter output a bit.
- R18: 1K5 to lower a bit the output level, because it seemed to me that the FX was a bit above unity, possibly because the resonant peaks make it seem louder to perception.
- R1: 1M, 100k seemed a bit too low impedance for the input, specially if driven directly from  the guitar.

Also, I added a 4.7 pico cap to the LT1054 from pin 2 to pin 7 to increase the switching frequency, because I thought the whistling I was getting came from the charge pump, but it seems it wasn´t so.

So, those are my mods. Working good now. Thanks guys for the suggestions.

[pinkjimiphoton]

OK guys, I finished modding this. I made the following changes (always referring to the Madbean schematic):

- R5: 220K for a bit more drive
- Sweep pot: replaced with a 5KB with a 4K7 R from leg 1 to ground. Makes the sweep a bit more controllable. I suspect a 2K5 pot with a 8K2 or so R would be even better, but I don´t have a 2K5 pot.
- C2: 1n
- R21: 1K. Not much variation changing this R value.
- C16: 1uF, to tame oscillation in IC5A that was whistling in some vowel positions.
- R17: 8K2, to lower the second filter output a bit.
- R18: 1K5 to lower a bit the output level, because it seemed to me that the FX was a bit above unity, possibly because the resonant peaks make it seem louder to perception.
- R1: 1M, 100k seemed a bit too low impedance for the input, specially if driven directly from  the guitar.

Also, I added a 4.7 pico cap to the LT1054 from pin 2 to pin 7 to increase the switching frequency, because I thought the whistling I was getting came from the charge pump, but it seems it wasn´t so.

So, those are my mods. Working good now. Thanks guys for the suggestions.

thank YOU  bro for sharing your results!!! some of those fixes i am gonna try, too, thanks !!!

[Morocotopo]

- No, thank you...
- No, thank YOU...
- no, YOU, thank YOU!



Glad it helps someone Jimi. What I have yet to try is replacing IC´s 1 and 4 for TL074 and 072, to see if I can tame the hiss a bit.

[pinkjimiphoton]

try tl082/4, i used 'em in mine.

[Morocotopo]

Jimi, I don´t have 084/082 but used 074/072. Reduced the hiss quite a bit, still is noisy but less so.
I´m testing the thing with my mods, works good, better (in my opinion) than before. But yesterday I tried it with a tremolo before it. Wow! very nice, sort of a "vowel phaser". The envelope still works, I mean, it raises and falls with the note´s envelope but the tremolo adds "pulsating vowels", if that makes any sense...

[digi2t]

But yesterday I tried it with a tremolo before it. Wow! very nice, sort of a "vowel phaser". The envelope still works, I mean, it raises and falls with the note´s envelope but the tremolo adds "pulsating vowels", if that makes any sense

Really?? Hmm... think I`ll try to marry the Ludwig to the Tau Pipe phaser, and see if any fireworks happen there. 

If anything mind-blowing happens, I`ll Youtube it.

[aquataur]

I see people change the value of C16 a lot. Can anybody explain the function of this cap? I have never before seen a cap in that position, unless this were some hard and fast compensation mechanism for ICs long gone.

Normally, a cap on the output of a +1 buffer is something to be avoided, since the op-amp has to permanently charge and discharge the cap with huge currents. A cap there may also lead to oscillation due to excessive phase shift. Is this the reason for a cap there - phase shift? If yes, this is a very crude method and potentially instable. If it is meant to limit bandwith - awkward method. If it is meant to suppress supply noise - wrong place. If it is meant to introduce phase shift - what about people using a cap 10 times bigger?

Also, the resistor (R30) in front of this buffer is strange. To my understanding, IC5b maintains its potential and will not be impressed by a 1M load to a supply rail.
Is this a remnant of a preceding debugging period?

Looking at the circuit, all other parts were explainable and logical.

thanks,
-helmut

[aquataur]

bump. No ideas?

[aquataur]

Folks.

I have made a LM13x00 version of it. It is well documented on my site.
I encountered all the "problems" mentioned above, except the squealing. As for C16, I left it away, because there is strong indication that this is the cause of what it prentends to prevent. In other words,  capacity on the output to a +1 buffer will make it oscillate rather than prevent oscillation in the wrong circumstances.
There is evidence on my web pages.

Ronan, I tried the expression pedal method. Pluggin in a TRS type exp pedal disables the auto mode and gives control to the pedal. Works great, but depends on the quirky pot law of the pedal.

Jimi, a FF in front improves things, but IMHO my BOR is even sweeter.

have fun,

-helmut

[Morocotopo]

Hey Helmut!

Nice findings on this circuit. It´s been a while since I used this pedal, but might try your suggestions.

Nice page, interesting stuff about the FSH, since I have made one of those and suffered the S/H problems, I´ll try your solution to the problem.

Cheers!

[pinkjimiphoton]

man, nice to revisit this all these years later and find relevent info...

i just sold mine, the one in the vid.

so time to dig another one