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DIY Stompboxes => Building your own stompbox => Topic started by: g3rmanium on April 01, 2007, 07:14:46 AM

Title: Revised Kay Fuzz Tone schematic
Post by: g3rmanium on April 01, 2007, 07:14:46 AM
Hello,

I've promised over and over again (:icon_redface:) to trace the schematic of my Kay Fuzz Tone, so here it is:

(http://img112.imageshack.us/img112/83/kayfuzztonegf6.th.png) (http://img112.imageshack.us/my.php?image=kayfuzztonegf6.png)

From the schematics published here (http://diystompboxes.com/pedals/kayf1.JPG), the 0.0022 cap is missing and the pot is 250 K instead of 50 K. There are some other changes to the tone stack, I think.
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Sir H C on April 02, 2007, 11:11:41 AM
Some guts shots (the schematic here I think has been debunked several times over)

(http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/kay-circuit-diagram.jpg)

(http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/kay-circuit.jpg)
Title: Re: Revised Kay Fuzz Tone schematic
Post by: g3rmanium on April 02, 2007, 02:26:04 PM
Some guts shots (the schematic here I think has been debunked several times over)

Yeah, gut shots!  :icon_biggrin: Just made these:

(http://farm1.static.flickr.com/238/443844334_2dc1cc74a0.jpg) (http://www.flickr.com/photos/germanium/443844334/)

(http://farm1.static.flickr.com/221/443844314_a373ac7f0e.jpg) (http://www.flickr.com/photos/germanium/443844314/)

(http://farm1.static.flickr.com/244/443844298_8fb29c60cb.jpg) (http://www.flickr.com/photos/germanium/443844298/)
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Meanderthal on April 02, 2007, 03:06:39 PM
 I just noticed it's a wah type control for the gain. Interesting!
Title: Re: Revised Kay Fuzz Tone schematic
Post by: g3rmanium on April 02, 2007, 03:31:19 PM
I just noticed it's a wah type control for the gain. Interesting!

Hm? Gain is fixed, the treadle just blends between two different sounds.
Title: Re: Revised Kay Fuzz Tone schematic
Post by: puretube on April 02, 2007, 03:58:19 PM
 :icon_biggrin:
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Meanderthal on April 02, 2007, 05:37:26 PM
 Ummm. Oh! :icon_redface: Makes much more sense now! From the perspective of a foot control being useful mid-song anyway...
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Dan N on April 02, 2007, 08:42:22 PM
Thanks for the nice photos!

Interesting about that .0022 cap being gone. It was used on one we saw here a while back.

I'm pretty sure you missed the big 0.1 cap on your drawing. It goes to ground from a 22K resistor. Bottom right corner of your drawing (next to the diodes).

How does yours sound? Losing that .0022 cap might make it raunchier.

Title: Re: Revised Kay Fuzz Tone schematic
Post by: analogguru on April 02, 2007, 11:15:46 PM
Quote
the schematic here I think has been debunked several times over

but never really good....

If the valu is 2n2, this cap can be seen on the picture from Sir H C  and also on the 2nd picture of g3rmanium.
this cap is located between the base and collector of the FIRST transistor.

On every schematic this is shown incorrect.  Itīs the same with the collector resistor of the 3rd/4th transistor.  This is definitely a 10k and NOT a 100k.

also the 100n-cap can be seen on both pictures and it was on every picture I have seen before.
It doesnīt make any sense without that cap.

compare it with the Univox superfuzz, Royal Fuzz, Ace Tone FM-2, Ibanez standard-fuzz or any similar unit like the foxx tone-machine or fender blender.

The kay seems to be the PMS:  "poor-manīs superfuzz".

The schematic is also incorrect in the way, that there is not shown the true-bybass slider-switch.

so I wouldnīt trust the schematic shown.

analogguru
Title: Re: Revised Kay Fuzz Tone schematic
Post by: analogguru on April 03, 2007, 12:18:59 AM
Ok, here is the link to the:

"Revised" Kay F-1 Fuzz Tone schematic (http://analogguru.an.funpic.de/schematics/Kay_F-1_FuzzTone.gif)

enjoy !

analogguru
Title: Re: Revised Kay Fuzz Tone schematic
Post by: g3rmanium on April 03, 2007, 04:40:39 AM
Thanks for the nice photos!

No problem :icon_biggrin:

I'm pretty sure you missed the big 0.1 cap on your drawing. It goes to ground from a 22K resistor. Bottom right corner of your drawing (next to the diodes).

Hm, I will check again but I went over the circuit and counted the parts and they matched the Photoshop drawing.

How does yours sound? Losing that .0022 cap might make it raunchier.

Mine doesn't have much sustain and also is not really loud, but the octave-up sound is cool. Not sure if the other ones are louder. There's this guy on TGP that has modded his Kay Fuzz Tone to sound incredible (Mr. Sage or so is his nick), he told me he put some Germanium diodes in it.
Title: Re: Revised Kay Fuzz Tone schematic
Post by: g3rmanium on April 03, 2007, 04:59:42 AM
If the valu is 2n2, this cap can be seen on the picture from Sir H C  and also on the 2nd picture of g3rmanium.
this cap is located between the base and collector of the FIRST transistor.

Ah, I guess I know now what you mean. It could be that I overlooked this cap. I will check this.

also the 100n-cap can be seen on both pictures and it was on every picture I have seen before.
It doesnīt make any sense without that cap.

Ok, I'll try to find this one as well.

Title: Re: Revised Kay Fuzz Tone schematic
Post by: mattpocket on April 03, 2007, 09:57:32 AM
I still dont get what the wah pot type set-up is for?

Is this pedal in a wah enclosure?! Does it have a stomp switch and a wah pedal?

EXPLAIN! I'm intrigued.
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Sir H C on April 03, 2007, 11:03:32 AM
To switch it on and off, there is a slider switch on the top.  No stomp switch.  Kay put several things in different colored wah enclosures, tremolo, wah, and a bass booster.

(http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/kay-fuzz-top.jpg)

Here is the wah circuit:

(http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/kay-wah-sch.jpg)
Title: Re: Revised Kay Fuzz Tone schematic
Post by: mattpocket on April 03, 2007, 11:12:41 AM
So the fuzz is controlled by the wah pedal?
Title: Re: Revised Kay Fuzz Tone schematic
Post by: analogguru on April 03, 2007, 11:47:58 AM
Quote
So the fuzz is controlled by the wah pedal?

@mattpocket
this is a pedal, not a "wah-pedal"... a wah-pedal is a pedal which produces a wah-sound.

The fuzz is not controlled by the pedal, only the output volume of the fuzz (and the tone-color a bit).

@Sir HC
you make me really curious:

you have close-up-pictures of the component-side of the wah ?

also you mention the bass-boost ? any guts ?

and a nice picture of the tremolo-components would be helpful to clear the question if the resistor which comes from the collector of the oszillator and feeds the to opposite-trannies is 68k or 10k.

analogguru
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Sir H C on April 03, 2007, 12:13:18 PM
I am lacking a bass boost, I will have to dig out the trem to get some pictures of it, but here is one of the Wah:

(http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/kay-wah-ckt-close.jpg)
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Mark Hammer on April 03, 2007, 12:34:43 PM
Look at the schematics for the Foxx Tone Machine, Univox Superfuzz,  Honey Fuzz, Ace-Tone Fuzz, and a bunch of others and you'll see many similarities.  There is the phase splitter (transistor with equal-value emitter and collector resistors, providing two opposite-phase outputs), the  diode pair to ground, and the notch/scoop filter on the output.

The big differences between the Kay and these others lies in the input stage.  You will note the absence of any network linking the base of the input transistor and the emitter of the phase splitter (Q1 and Q2, respectively).  I don't know a lot about discrete circuits, but I take it that this network has the function of providing more boost for certain portions of the spectrum, and especially boosting the fundamentals that are likely to make up the doubled frequencies.  The Kay is a simpler circuit that omits this element, which, in principle ought to make for a thicker fuzz with a less obvious octave up (hence no means for selecting/deselecting it).

C9/C10, R14/R15 make up the traditional midscoop filter in these pedals.  The values are fairly similar to those seen on the Superfuzz except that the value of C9 is substantially larger, allowing more mids through to the output.  You will note that C9 sort of steps over the pot directly to the output, such that mid/treble content is generally uninfluenced by the setting of the pot.  I wouldn't say completely uninfluenced, since you will note that the output of C9 has two direct paths to ground: one through R16 and the other via the pot wiper through the ground leg of P1.  Place those two resistances in parallel and that resistance plus the value of C9 forms a kind of crude variable highpass filter.

At the same time, consider that R14/15/16 form a kind of fixed voltage divider, kind of like a 132k pot turned down partway (32k on one side, 100k on the other).  But whoops, once again we have this "other" path to ground that places the ground leg of P1 in parallel with R16. We also have another path whereby R14 and C10 form a lowpass filter with a corner frequency of 72hz and P1 simply attenuates that output.

So, P1 seems to play multiple roles that involve attenuating the bass, shifting the highpass corner frequency, and attenuating the overall signal level.  As noted, moving the pot around, whether by fingers or foot, will produce equal parts volume and tonal change.  Not having used one of these, I have no idea what the effect-vs-bypass volume shift is.  Given the complete absence of any post-filter gain recovery stage, such as found on both the Superfuzz and Tone Machine, my sense is that the output will be a bit louder than bypass, but not by much, making the pot more of a tonal change than anything else.  This is likely part of why it is situated in a treadle mechanism like a wah rather than a panel-mounted pot.  If the volume won't change much then the player won't get themselves into trouble by turning up too loud and risking feedback.

This pot is actually a nifty little control, and entirely capable of being implemented on many designs that use a gain recovery stage.  For instance, the Superfuzz has a 100k terminating resistor on the output stage.  That could easily be converted into a 100k log pot for volume control, and the volume pot normally situated before the output stage co-opted into functioning like this little-bit-of-this-n-that control found on the Kay.  It might actually make for a more interesting tone control than the stock one found on the Superfuzz.
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Jackie Treehorn on April 03, 2007, 01:46:40 PM
Well, I'm not so sure about that 10k on the tied transistors.  When I built this circuit, I noticed that the best sounding value in that spot shifted a bit with the battery.  I ended up using a 50k pot and a 47k resistor to adjust between 47-97k and I think there's a sweet spot in there to get the Lanois style sound.  The initial output was less than the bypassed output, so I tried to reduce some resistors here and there.  I've got a .0022 in the tone section.  As I recall, smaller values tended to give a brighter/harsher tone but there was more volume loss heel down.  I ended up with a 100k pot, but with a 120k resistor between the ground connection.  The amount of sustain seemed to depend on the gain of the transistors.

Here is a movie I made of the pedal in action.... http://theinside.net/misc/Kay Fuzz/Kay Fuzz.MPG (http://theinside.net/misc/Kay Fuzz/Kay Fuzz.MPG)

I have a vero layout I did based on the old schematic, but maybe that would just lead to more confusion!

Oh and pulling one of the tied transistors gets a pretty nice straight fuzz, too...
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Mark Hammer on April 03, 2007, 02:21:16 PM
Very nice tone, and nice demonstration of the effect of the pot.  The huge bottom is a consequence of the midscoop filter.  As expected, there was very little variation in volume.  The octave is more pronounced than I was expecting, but then the octave effects varies with the tone setting in the Superfuzz, so there is no reason to expect it not to vary with pot setting here.  And since you mentioned that the pot value was replaced by a pot/resistor combo that essentially restricted the pot's range of influence, I gather the pot has more effect in a stock unit.

You don't have to pull the transistor to get the fuzz.  I gather you can simply lift the connection between the 1uf cap and the base of the relevant transistor to do the same.  This is essentially what is used on the Foxx Tone Machine.
Title: Re: Revised Kay Fuzz Tone schematic
Post by: analogguru on April 03, 2007, 02:48:03 PM
(http://analogguru.an.funpic.de/pictures/Kay_Fuzztone_11resistor.jpg)

The green circled resistor is the one in doubt.  if you compare it to the red circled resistor, you can see that its definitely a 10k.

Concerning the input filter:
If you look at the schematic of  the Ibanez Standard Fuzz (and clones like Bruno Fuzz Machine):

Ibanez Standard Fuzz Schematic (http://analogguru.an.funpic.de/schematics/Ibanez_StandardFuzz.gif)

you will notice, that there is also no input-filter.

And donīt forget the 100n (C3) on the emitter of the first transistor (will produce less gain at lower frequencies) and the large value of 2n2 (C2) between collector and base of the first transistor (will reduce gain at higher frequencies) which is also acting like a bandpass-filter.

I assume that the Kay is an absolutely minimized version for the reason that they even did not use the base resistors (470 E or 1k) or a footswitch.  IMHO this is more a novelty.

Fender used in the Blender also a pot in the filter-section as a tone control.

analogguru
Title: Re: Revised Kay Fuzz Tone schematic
Post by: g3rmanium on April 03, 2007, 03:21:49 PM
Here is a movie I made of the pedal in action.... http://theinside.net/misc/Kay Fuzz/Kay Fuzz.MPG (http://theinside.net/misc/Kay Fuzz/Kay Fuzz.MPG)

That sounds great. Like mine should sound like, I guess. Maybe I should record some clips as well.
Title: Re: Revised Kay Fuzz Tone schematic
Post by: g3rmanium on April 03, 2007, 04:07:21 PM
More gut shots!

(http://farm1.static.flickr.com/216/445248232_1a7197ea44.jpg) (http://www.flickr.com/photos/germanium/445248232/)

(http://farm1.static.flickr.com/239/445248204_7e6605fda6.jpg) (http://www.flickr.com/photos/germanium/445248204/)
Title: Re: Revised Kay Fuzz Tone schematic
Post by: g3rmanium on April 03, 2007, 04:13:58 PM
Here is the updated diagram:

(http://img524.imageshack.us/img524/2414/kayfuzztonedc0.th.png) (http://img524.imageshack.us/my.php?image=kayfuzztonedc0.png)
Title: Re: Revised Kay Fuzz Tone schematic
Post by: g3rmanium on April 03, 2007, 05:11:30 PM
Here are the original blog posts:

Revised Kay Fuzz Tone schematics (http://johannburkard.de/blablog/music/effects/2007/04/01/Revised-Kay-Fuzz-Tone-schematics.html?page=comments)

and

Revised revised Kay Fuzz Tone schematics (http://johannburkard.de/blablog/music/effects/2007/04/03/Revised-revised-Kay-Fuzz-Tone-schematics.html?page=comments).

The last one contains clips (mp3 (http://johannburkard.de/resources/Johann/kay_fuzz_tone_clip.mp3), ogg (http://johannburkard.de/resources/Johann/kay_fuzz_tone_clip.ogg)).
Title: Re: Revised Kay Fuzz Tone schematic
Post by: ustompsteve on April 03, 2007, 07:10:42 PM
On the schematic on my site that Spaceshot helped me with there is a 50k pot with a 200k resistor after it. I am pretty sure he got that from a real unit. Maybe some were different.

Any idea what moving the 2n2 C2 from between Q1 and Q2 to before Q1 would change? Also the changing of the 10k to 100k?

I will try and change mine in the next few days.

I really like the way mine sounds as is. That would be great if it ends up sounding even better.

--Steve
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Jackie Treehorn on April 03, 2007, 07:28:12 PM
Thanks for the kind words guys.  I really like g3rmanium's clip, too.

I put 2n4401's in the octave section and I remember spending some time testing and matching to get a strong octave.  I think Lanois' pedal in "Orange Kay" has a pretty strong octave.  I am going to have to put a switch where Mark suggests to cut the octave.  Thanks for the tip.

It does look like a 10k.  I was more or less implying that it sounds better to me with the 2n4401 transistors to use a value in the 47k-100k range.  Sorry for the confusion!
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Joe Kramer on April 03, 2007, 07:47:51 PM
. . .  I dig the way you do business, Jackie. . . .
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Dan N on April 03, 2007, 09:07:30 PM
Tip of the cap to Analogguru! I never noticed that cap was on Q1. I wonder how it affected the proper function of Q2, the phase splitter. Has every clone been f**ked from the get go?

Looks like they messed with the pot. 50K + a 200K resistor the begin with (original schematic and spaceshot's), them just went with 250K (Roger Lavallee and g3rmanium). I wonder which Sir HC has?

Argh!

Thanks again for your photos, g3rmanium and Sir H C! Thanks for the (hopefully) final schematic, analogguru!

Title: Re: Revised Kay Fuzz Tone schematic
Post by: g3rmanium on April 04, 2007, 03:40:41 AM
Looks like they messed with the pot. 50K + a 200K resistor the begin with (original schematic and spaceshot's), them just went with 250K (Roger Lavallee and g3rmanium). I wonder which Sir HC
has?

I measured the resistance between pin 1 and pin 2. With the pedal all the way up, it was around 8 KOhm. With the pedal all the way down it was close to zero. Maybe this helps? The treadle has a really short sweep anyway.
Title: Re: Revised Kay Fuzz Tone schematic
Post by: ustompsteve on April 04, 2007, 02:21:34 PM
I updated the schematic and layout on the http://ustomp.com site with the updates/changes.

I left the 50k pot w/ the 200k resistor. This could be replaced with a 250k pot and a jumper depending on which way you want to go.

--steve
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Dragonfly on April 04, 2007, 11:31:59 PM
you might try doing a layout utilizing a transistor array like the CA3086
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Arn C. on April 05, 2007, 08:27:06 AM
I like your thinking Dragonfly!  I have a few of those IC's!!!!


Peace!
Arn C.
Title: Re: Revised Kay Fuzz Tone schematic
Post by: Sir H C on April 05, 2007, 10:11:14 AM
you might try doing a layout utilizing a transistor array like the CA3086

Great for places where you need a matched pair (such as the octave devices).
Title: Re: Revised Kay Fuzz Tone schematic
Post by: burningman on May 30, 2007, 12:58:13 AM
I have a couple of questions, that I thought maybe someone could answer. First, which would you say is more suitable for this project, a log or linear pot? Right now I am using a 100k Crybaby hot potz ecb24. I was also wondering what audible difference should there be when I drop the 200k resistor for a 150k to make up the 250k resistance to ground with the 100k hot potz? I've tried this already but haven't heard any difference.
Thanks
Title: Re: Revised Kay Fuzz Tone schematic
Post by: roseblood11 on July 13, 2009, 10:10:08 PM
Hi,

could anybody post a verified layout please? some of the links in this thread are dead...

Title: Re: Revised Kay Fuzz Tone schematic
Post by: roseblood11 on July 24, 2009, 05:57:12 PM
ups, I meant to say "veroboard layout"... Of course I know the pcb layout on ustomp.com