colorsound wah values?

[MovingInSloMo]

Did me a search and yes there are several threads on the 'ol colorsound but no values. Though admittedly I didn't spend an hour digging. Some wah n00b questions:

1.) I have decided to just build my dream wah from scratch and I want the colorsound wah. I am using a weener board from madbean. Is there a value list for a colorsound wah out there?

2.) POTS! The colorsound uses a 100k linear with that cam thing. I have three pots at my disposal, an icar taper pot from whipple, a hot potz I and a hot potz II. Would any of those allow the sweep the wah is famous for?

3.) There is no Q resistor?

4.) Inductors. I have a whipple and TDK inductors available. would either of those suffice? I have read (here) that 500k is a good value?

[Rob Strand]

This is all I have,

[MovingInSloMo]

where are the wah experts when you need them

[zombiwoof]

Joe Gagan might be able to help.
Al

[ElectricDruid]

where are the wah experts when you need them

They cried off?

I'll get my coat...

[MovingInSloMo]

where are the wah experts when you need them

They cried off?

I'll get my coat...

BAH-DUM TSSSSSSH! har. You only get one har. That's a one har quip.

[Rob Strand]

New info:

Early 70's Colorsound units:
T26 material, ui = 2200
P14x8 pot core, gapless with hole
AL = 2100 nH/t^2

Wire 38 AWG, bobbin fairly full so be reasonably neat.

L = 500mH +/- 20mH
RDC  = 27.5 ohm to 28.0 ohm

About 488 turns.

Modern material is N48.
Lower loss than T26 so try adding 100k in parallel with inductor.

For some reason there's not a lot of *precise* info on the Colorsound.
----------------
Pot Core

Core               P 14 x 8 (gapless with hole)  ; 14mm x 8mm
Material:       Siemens N22 (ui=2300)
Inductance   500mH                    ; nominal not measured
Wire              40 AWG                    ; guessed/assumed? not confirmed from DCR

Note:
I have seen:
   T26 material (Siemens ,ui =2200, used for transformers)
   Technically this would require 4.5% more turns.
----------------
Siemens Data

Matl         Pot Core Spec
N22   ui = 2300
N48   ui = 2300      ue=1340      AL = 2100 nH
T16   ui = 2200
----------------
Turns Calculation

For 500mH:
- Calculation based on AL,  N = 488 turns
  (bobbin is only 43% full, AL might be 0.5% lower)
- Someone said they used 460
----------------
P14 x 8 Bobbin:

d  = 7.1 +/- 0.2 mm
D  = 11.5 +/- 0.2     (max)
b  = 4.4mm
----------------
Resistance Estimate:

40AWG (dw=0.0787mm)                             *** assumed not confirmed by any measurement ***
(Ka=0.57 = wire area / bobbin cross-section)
460 turns   , 40.93 ohms, Do = 8.88mm, lw ~ 11549mm
488 turns, 43.72 ohms, Do = 8.99mm, lw ~ 12336mm

Bobbin is not full of copper.

[Actual wire was 38AWG]
----------------
These resistance results imply the inductor is close to:
(IIRC most of these are on a P14 x 8 core.)
- 1968/9 Vox (Italy) "stack of dimes"
- 1970's Thomas (U.S.) "stack of dimes"
- 1970's Fasel
----------------
Whipple     30ohms
TDK 5103  japan marking 40ohms
TDK 5103  no japan marking 19 ohms
----------------

[MovingInSloMo]

ok this thread is now moot, bought a Joe Gagan Joe-Sonic drop in board on reverb. Let the man himself do it and source the parts.

[zombiwoof]

ok this thread is now moot, bought a Joe Gagan Joe-Sonic drop in board on reverb. Let the man himself do it and source the parts.

Joe Gagan is now officially The Man when it comes to wah stuff.  He puts out some great parts and pedals, I remember he was the authority on wah matters when he used to be on the forum.  Is he still here?.
Al

[MovingInSloMo]

He popped in OT last week.  I was going to send a him PM, then I was browsing on reverb wondering how much original ones go for and I saw his drop in board and went "why am I wasting time?"

Still going to populate the weener board as a clyde style for future housing in another shell.

[Joncaster]

I had this same kinda thought process about building a decent wah for myself.
So I looked at shipping in an inductor, pot, decent parts, and finding a good shell (have an 845, so a bit weak feeling, can't find used ones easily here for cheap).

I actually bought a whipple and pot months ago, but it got lost in our postal system:( might not ever arrive.

Besides, once I start tuning a wah, I have no doubt it would be a bit of a black hole, I think it's almost a dark art (especially with no decent wah's readily available around here to test against)

After thinking about it on and off for the last year, I've just gone the full hog and ordered an Italia from Joe.
I listen to clips of wahs for months, and that one stood out.
I thought it would make a nice present to myself.
Let's see when it arrives (chose a better method of shipment this time, hopefully).

[Paul Marossy]

Yes, the Colorsound inductor based wah pedals did not have a Q resistor. That's partly why they have such a wide range of sound if you will (and also because of the crazy amount of treadle travel). You can get this real synthy sounding thing in the heel down position. That's basically the two secret ingredients of the Colorsound wah pedal.

I made a full blown clone of the Colorsound wah shell so I could get an accurate sounding Colorsound inductorless wah pedal, with the cam and all. Did it just for the heck of it. You can see video here if interested:

[zombiwoof]

Yes, the Colorsound inductor based wah pedals did not have a Q resistor. That's partly why they have such a wide range of sound if you will (and also because of the crazy amount of treadle travel). You can get this real synthy sounding thing in the heel down position. That's basically the two secret ingredients of the Colorsound wah pedal.

I made a full blown clone of the Colorsound wah shell so I could get an accurate sounding Colorsound inductorless wah pedal, with the cam and all. Did it just for the heck of it. You can see video here if interested:

Great, but how does it sound?.  I thought you would play through it at the end!.
Al

[Paul Marossy]

Great, but how does it sound?.  I thought you would play through it at the end!.
Al

Sounds like a wah pedal. I don't have a way to get good sound quality recordings, so I don't do them. The point of the video was how I constructed the thing.

[MovingInSloMo]

Does the inductorless one sound as full as the original inductor model?

[Rob Strand]

I made a full blown clone of the Colorsound wah shell so I could get an accurate sounding Colorsound inductorless wah pedal, with the cam and all. Did it just for the heck of it. You can see video here if interested

What final values did you end up using?

I've got this schematic which I believe John Lyons drew up based on "nirvanas silence"'s  info in an old thread:



I'm pretty sure the 10nF input and output caps are correct.

The value I still dispute is the 5M7 resistor.

I've looked at a few boards and I see 3M3 in that position more often that not.  I suspect 5M7 is actually a misread 2M7, which is close to 3M3.

The thing about using 3M3 is the biasing tends to suit a generic 2N3904 transistor more than the commonly quoted 2N5088.   More than likely the actual transistors were generic BCxxx types such as those used on the inductored Colorsound Wahs.     Like it could be that the transistor is deliberately biased with a slightly lower VC in order to get more gain out of the stage.

Another missing piece of info is the Wah pot taper.

[mac]

Does the inductorless one sound as full as the original inductor model?

The inductorless version has more punch at the middle of the sweep.
25k to 50k B are ok to go from low to high.

It is not like the inductor version, but I love it.

IIRC Joe Gagan posted a video some ago.

mac

[Rob Strand]

Using a high gain transistor definitely helps give stronger peaks.   The biasing isn't bad with the high gain transistor + 3.3M resistor.  So it's still a possibility the real unit used a high gain transistor.
The difference in tone between a 2N3904 and a 2N5088 will be noticeable, however both will "work".

The 5.7M, which I consider a mod, further increases the peaks.   I guess this is where modding to suit your taste and what the off-the-shelf unit actually is part ways.

Other ways of getting similar results is to increase the collector resistor. Or to decrease the 33k in series with the 15nF cap; although this mod changes the frequency.  There's many possible mods.

[mac]

Or to decrease the 33k in series with the 15nF cap; although this mod changes the frequency.  There's many possible mods.

That's what I did, I put a 25kB pot and a resistor in series instead of the 33k. Note that if you lower the 33k too much it will howl badly.
A switch to change the 15nf cap is fine too.

mac

[mac]

I posted this in the simulation section,

https://www.diystompboxes.com/smfforum/index.php?topic=99448

mac