Crybaby Mods? JH1-S

[uncleauzzie]

Hi there,

I'm new to the board, and modding as well. I recently installed a mod kit in a Valve Junior and now I'm pretty much hooked!

My knowledge of electronics is sub-par at best, but I do remember Ohm's law! ha!

At any rate, I'm joining the forum in an effort to learn more about some common mods, electronics, and hopefully wind up building an analog delay of my own from scratch!

I have a few questions about Crybaby mods, specifically the Dunlop JH-1S (Thomas Organ Hendrix Special Wah).

I wasn't sure what the actual difference between the standard JH-1, and the JH-1S so I emailed Dunlop. Here is what one of their techs had to say:

"The difference between the JH-1 and the JH-1S is that that JH-1S has a slightly different pot with an audio taper allowing for easier control of the sweep range."
Can anyone elaborate on this? Audio taper pot vs what? Can anyone confirm which pot came stock in this pedal?

What I'm after for a mod, is a bigger "scoop" and true bypass.

Should I swap in a new pot, and new inductor such as a red Fasel?

I'm open to any and all suggestions.

Cheers!



I've been told Carling DPDT's are choice for truebypass mods.

Can anyone provide some advice or provide a walk-thru?

[joegagan]

Welcome.
I was not aware that there was a jh1 model during the thomas organ era, but i am always learning.
If you could take some clear interior pics this would help, as true bypass methods vary by era.
Also, the jh1s that i have seen have gone through various part changes. The earlier ones had 470k pots in place of the standard 100k.  Dunlop's answer to your q was interesting. The jh1 pots i have measured had essentially the same taper as their 100k,exc 470k. I wouldn't call it audio, it has dead zones at both ends and a rapid kink in the sweep. However, their claim that the jh1 pot gives better control is correct, the 470k seems to extend the usable mid and slightly lower the q. Some eras of jh1s had a few other component diffs from the std wahs, others had almost no changes.

Once we see the guts of your wah we can make some suugestions and take it from there. Don't order any pots or inductors, yours may be fine.

[uncleauzzie]

Thanks for the quick reply!

Here are a couple pictures.

I do not believe it is an original thomas design so much as it is "based" on an original thomas design. Correct me if I am wrong.

Switch not pictured, but it is the standard stock SPDT.

Serial # AA-22K827

MFG Date: June 9 1994

[joegagan]

Ok. Looks good. Check the pot, see if it has a date code and R designation. This will help tell whether the pot is original. This is the era that usually had 470k.

Is the pot scratchy?

Dunlop inductors from this era usually sound very good . To me, a red fasel would not be an improvement.

For tru bypass instructions, do a search for " stinkfoot wah", match up your board, he has specific instructions for the various iterations. Most people use the commonly available 3 pdt since they have become cheaper than the dpdts.

Overall, i really like the sound of the jh1 from this era stock. You may find you like it a little better with the buffer removed, but be warned that you may lose a little top end. Stinkfoot also tells how to bypass the buffer should you choose to try that. He also lists a few component changes that alter the sweep, feel, etc.

Will be able to tell a little more once we know what the pot is.

[zombiwoof]

As I recall, the regular JH-1 of this era had the 470k HotPotz, and the JH-1S had the standard 100k HotPotz.  The circuits were slightly different, the regular version being voiced for a lower range.  The circuit differences from the standard Dunlop Crybaby of that time were very slight, only a couple of component value changes.  The "S" stood for "special".  At some point I think they added the buffer circuit to those Hendrix models (and also an adapter jack, which wasn't in the first versions), there were a couple of revisions.  I wish I could remember the exact differences, but I remember I liked the "S" version better (and had one for a while).

Al

[joegagan]

alan, i've never seen that S before. dunlop never ceases to amaze. in my side by side comparos, the jh1s from this era sound a little more vintage-y old voxey than their normal early mid 90s CB. a little warmer, a little less high end. more mid emphasis on the pot sweep. we couldn't find any cap or resistor differences, so i assumed dunlop used the 470k as a very simple way to warm up the tone.

the one i would like to see, but i think probably never existed, is the 'clav-wah' that is listed on the dunlop factory schem that also contains the jh1.

[uncleauzzie]

The pot is not scratchy.

The only marking on the pot reads as follows:

Dunlop Mfg CH00245

NL6187-116A
Mexico
9514SL

[joegagan]

Wow, i'm stumped. Those numbers don't mean anything to me. Maybe they used an audio taper pot from their high gain volume pedal or something. Now the response you got from dunlop is making more sense.

So , since the pot is good i would suggest you do some searches here, all the mods for late model dunlops will apply to yours. Stinkfoot has excellent descriptions of what the various changes do. And he has good photos that explain how to do them.

When you say 'bigger scoop' , do you mean wider range? The sweep cap .01 can be increased to bring the voicing lower for example.

Or if you want more growl you can decrease the value of the emitter R off Q1.

I am gona have to look out and find one of these so i can measure the pot and get to the bottom of this.

[uncleauzzie]

If you can explain the proper measuring process, and if the measurements can be obtained from a simple multimeter, I would be happy to measure this pot.

[joegagan]

Ok. The normal method requires removing the pot from the wah.

Make a radial chart with markings at five degree increments. As in pic. Place the pot with back of pot on chart. Orient pot so that you have full cw at approx 5 oclock, ccw at approx 7.  Hook up test leads to the center and right contact ( cw and center ). Move the pot at 5 degree increments and mark the R reading at each. (note - there is a lot of data on this little sheet if you can decipher it!)




I have a method that measures pot in actual treadle movement , but it requires making a carboard rig with a stick and a gauge.

[joegagan]

if you don't want to draw your own protractor like i did, here is one you can print:

http://api.ning.com/files/RgvbmV5ued2zEIzCxE4oyrNnMso18GLQyKwu2e462mTw6*vgS5a5joTSBXdSj8nhtZ8jgLlWpNMaSsjymA8sIaunsoZkRWqf/2000pxProtractor1.svg.png

you can make a thick paper pointer and use two sided tape to attach to the end of pot shaft to extend indicator out to 5 degree lines.

[zombiwoof]

Thanks for the quick reply!

Here are a couple pictures.

I do not believe it is an original thomas design so much as it is "based" on an original thomas design. Correct me if I am wrong.

Switch not pictured, but it is the standard stock SPDT.

Serial # AA-22K827

MFG Date: June 9 1994

That's one of the later revisions for sure, as it has the adapter jack.  The earliest were battery powered only, and had no battery access door on the bottom (you had to take off the bottom plate to change the battery, as in the older CryBaby's).  Also, as I recall, the early version had the older metal-case HotPotz (HotPotz-1?), later they changed to the sealed type like the one in yours.

I don't really think that wah had an audio taper pot, I think it had the regular 100k HotPotz pot that was in the other CryBaby's.  As I said, the regular JH-1 had the lowered tonal range using the 470k pot with component changes from the regular CryBaby,  and the Special version just had a couple of component changes from the regular Crybaby specs and the 100k HotPotz (I'm pretty sure about this).  I don't think that guy at Dunlop knows what he's talking about, IMO.  By the way, they made both versions of the JH-1 at the same time, not sure why they felt the need to have two different versions.
To answer your questions, yes you can swap out the pot and inductor for any of the ones that are around now, you could use a Fasel inductor or one of the good "Halo" clones like the Area 51, also the Whipple inductor is reportedly a really good Halo clone inductor.  For the pot, there are many "Icar" taper clones out there, those are supposed to duplicate the sound of the early Halo inductor in the original Vox wahs, Small Bear has the Blacktop pot, the guy that makes the Whipple inductor also sells a nice CTS Icar taper pot, and Area 51 also has an Icar taper CTS pot.  I didn't like the Fulltone pot myself (which I believe is made by "Diva", it seemed flimsier in construction than the CTS Icar types to me).

I would also add that claims by Dunlop that any of their CryBaby's are based on the Thomas Organ Co. wahs is stretching the truth a bit.  Dunlop uses much higher gain transistors in all of their wahs, and several component value changes from the old Vox/Crybaby wah circuits.  There are several schematics of the different eras of Vox and Crybaby wahs on the net, where they show the slight component value differences over the years, and you can compare that to a schematic of a typical Dunlop CryBaby and see where they changed the values of some resistors and a cap or two, probably to make up for the fact they are using transistors (MPSA18 in every Dunlop wah I've seen) that are too high gain for the vintage sound.

Al

[joegagan]

good info, alan.

after looking at my various hotpotz, i am pretty sure the date code on uncleauzzie's pot is 14th week of 95.

i also stumbled into a 470k hotpotz2 that is factory 470k, so it must have come from a jh1 wah or possibly a high gain volume pedal by dunlop.

some high gain volume pedals had a 470k hotpotz2 with attached little circ board with terminals for 4 wire clip, ealrier versions may have differed. i have some of these circ board pots here. am going to measure to see if there were two different taper hotpotz2 470ks, one for volume peds , one for jh1 wah. more to come.

[zombiwoof]

Just noticed a big error in my post above, when I was talking about the "Icar" taper pots, somehow in editing as I wrote the reply I mistakenly said the Icar pots attempt to duplicate the sound of the early "Halo inductors".  Obviously I meant that the Icar clone pots attempt to match the taper of the Icar POTS that were in the early Vox wahs.  Got my inductors and pots confused as I was typing, the part about the Halo inductors was supposed to go with the inductor info.  It's too late to edit the post now, so wanted to clear up my brain fart there.

Al