Wah output buffer query for non true-bypass Crybaby

[ringworm]

Apologies for adding another wah-buffer question to the board but I've searched through a lot of the topics in this area and can't seem to find the solution I'm looking for.
My question(s):
Does the option of putting in a buffer at the output of the GCB-95, still hold good if you have NOT made the true bypass mod to the wah?
I have a GCB-95 rev.H that suffers from crappy sound going into my fuzzes (I've tried it with a Russian Muff, Superfuzz clone and Great Cheddar). The only mods I have made to it are a yellow Fasel, R9 changed from 470r to 270r to increase gain, R5 from 33k to 68k for 'vocal' increase and the sweep capacitor from 0.01uF to a 0.022uF. It sounds great on it's own but suffers from all the usual symptoms of being plugged into high-gain silicon fuzzes.
If I have not bypassed the buffer in the Crybaby, which components affect it's load and can they be adjusted, without having to put in a separate buffer for example? I have the parts for a buffer, so am willing to go that way also but am not sure how to install it, the guides I have seen online are only for wahs that have had a true-bypass mod.

[ringworm]

sorry to BUMP but still can't find an answer for my queries.

[zombiwoof]

You really should put in the true bypass switch with the buffer, and remove the input buffer components (or bypass them).  The output buffer is only on when the wah effect is engaged, and off when the wah is in bypass.  This helps the wah work in front of the fuzz, and because the buffer is out of the circuit when the wah is bypassed, the fuzz will work right by itself.  The input buffer was Dunlop's solution to the tonesuck the wah causes when it's bypassed, but doesn't help with the fuzz interaction.  If you put in the output buffer and not change to true bypass, and keep the input buffer, the input buffer will still be in the circuit when you bypass the wah, which means the fuzz will not work by itself after the wah.  You don't need both buffers if you change to true bypass and install the output buffer (and remove the input buffer), the TB and output buffer fix both problems, the tonesuck in bypass and the interaction with fuzzes after the wah.  IMO that's what Dunlop should have done in the first place, but I guess they are too cheap for that.

Al

[head_spaz]

The input buffer on the newer crybabies work to eliminate the "tone suck" problems they had with the lower impedance input of the older models.
The "output buffer" (sort of a misnomer) mod goes towards isolating the output so it doesn't interact with the fuzz's input stage, and it  raises the output impedance to help prevent over-driving your fuzz box.

If you go with true bypass mod... your fuzz box will only see the guitar in bypass mode... but you'll still have a low impedence output when you switch it on.

If you remove the input buffer then you'll retrograde your unit by importing the tone sucking problem. Doesn't sound like a good idear to me.

I recommend leaving the crybaby's input buffer... and then add the output buffer mod. Bypass then becomes optional.

The Foxrox Wah Fuzz Buffer seems to be popular.

And then there is the DougH version...

[Mark Abbott]

I should point out that I am not a big fan of the input buffer on the newer Crybaby wah pedals. The ones I have seen use a Darlington transistor with low current bias. I believe this is done to get reasonable gain while not loading the guitar down too much. To my ears this arrangement doesn't sound transparent and has certain midrange qualities to it.

Several months ago I replaced the Darlingtom transistor with a J201 FET. I found the pedal sounded the same as if it had true bypass and the wah had greater clarity. The guy who owned it was most impressed.

It is a simple thing to carry out, look at the AMZ site for FET ideas and remember the FET's pin out will probably be the opposite of the Darlington transisitor.

Yours Sincerely

Mark Abbott

P.S. I will try putting a Mosfet into another friend Crybaby as he isn't too impressed with it. I believe this should be tried prior to getting a replacement inductor.   

[zombiwoof]

The input buffer on the newer crybabies work to eliminate the "tone suck" problems they had with the lower impedance input of the older models.
The "output buffer" (sort of a misnomer) mod goes towards isolating the output so it doesn't interact with the fuzz's input stage, and it  raises the output impedance to help prevent over-driving your fuzz box.

If you go with true bypass mod... your fuzz box will only see the guitar in bypass mode... but you'll still have a low impedence output when you switch it on.

If you remove the input buffer then you'll retrograde your unit by importing the tone sucking problem. Doesn't sound like a good idear to me.

I recommend leaving the crybaby's input buffer... and then add the output buffer mod. Bypass then becomes optional.

The Foxrox Wah Fuzz Buffer seems to be popular.

And then there is the DougH version...

Not true, if you want your fuzz to work alone after the wah when it's bypassed.  If you don't change the switch to TB, the input buffer will still be in the circuit when the wah is bypassed, causing problems if you use the fuzz alone.  I repeat, IMO the best thing to do is do the TB mod, add the output buffer, and disable the input buffer.  There will be no tonesucking if you remove the input buffer and do the TB mod, it's the fact that the board is still connected in bypass with the SPDT switch that causes the tonesuckage, with the TB mod it's a straight-through signal.  Then you need the output buffer, which is only switched on when the wah effect is engaged, if you want the wah to work well with fuzz after the wah.  There's two different problems to address here, and the input buffer only addresses one of them.

Al

[Mark Abbott]

Dear Al

I disagree with performing true bypass on the Crybabys with the input buffer. If a FET or Mosfet is used the input impedance of the wah is as high or higher than the input impedance of a tube amp.

Changing a transistor and two resistors (maybe add diode protect if a Mosfet is used) is a better and cheaper option than replacing the footswitch.

After all the same end is achieved and the wah pedal sounds better for the buffering in my opinion. As previously said greater clarity is achieved.

Yours Sincerely

Mark Abbott

[R.G.]

In messing with buffers, you need to keep in mind what you're trying to accomplish. The Vox-derived wah circuit is a special case.

The original has tone sucking. This is clearly an input loading issue, and a buffer helps. The buffer needs to be clean and have wide response. I posted a JFET wah input buffer here or on geofex so long ago that I can't find it now. JFET buffers sound good in that position, and do not seem to mess up the response. That cures input loading issues. The output of the Vox-derived wah is a bit of an oddity, since it comes right off the collector of the first transistor, and any loading on that point changes both the gain of the transistor and the wah range. A buffer at that point is a welcome addition in all cases except where you're driving a fuzz face derived fuzz pedal.

There are two ways to cope with this. First, you can add an unbuffered output for the times you're going to a FF derivative, which is the same as switching out the buffer, just a different implementation. Second, you can go ahead and buffer it all to prevent loading from messing with the wah, and then stick in either a resistor or resistor/inductor pickup impedance faker to driver a FF derived pedal after the wah. The input and output buffers do different things. The output buffer only matters in a limited set of situations, so those can be taken care of with a "special situation" switch if you think about it.

[Mark Abbott]

Thanks R.G.

Your words hold greater weight than mine (and rightfully so.)

I'd hate to see people doing more work to their equipment than is required.

I have a nice drop in replacement board and Halo style inductor from Stuart Castledine, the pedal with this board rivals my Teese RMC 3 wah.

Getting back to the three transistor Crybaby. Prior to replacing the Darlington transistor the Castledine Wah was clearly superior to the three transistor Crybaby, after replacing the Darlington transistor and putting the FET in. The stock Crybaby also had this clarity.

I haven't put a FET buffer into my Castledine Wah pedal yet, but it is on the to do list!

Yours Sincerely

Mark Abbott

[zombiwoof]

In messing with buffers, you need to keep in mind what you're trying to accomplish. The Vox-derived wah circuit is a special case.

The original has tone sucking. This is clearly an input loading issue, and a buffer helps. The buffer needs to be clean and have wide response. I posted a JFET wah input buffer here or on geofex so long ago that I can't find it now. JFET buffers sound good in that position, and do not seem to mess up the response. That cures input loading issues. The output of the Vox-derived wah is a bit of an oddity, since it comes right off the collector of the first transistor, and any loading on that point changes both the gain of the transistor and the wah range. A buffer at that point is a welcome addition in all cases except where you're driving a fuzz face derived fuzz pedal.

There are two ways to cope with this. First, you can add an unbuffered output for the times you're going to a FF derivative, which is the same as switching out the buffer, just a different implementation. Second, you can go ahead and buffer it all to prevent loading from messing with the wah, and then stick in either a resistor or resistor/inductor pickup impedance faker to driver a FF derived pedal after the wah. The input and output buffers do different things. The output buffer only matters in a limited set of situations, so those can be taken care of with a "special situation" switch if you think about it.

I don't understand how adding an "unbuffered output" is going to help, isn't that going to get you right back to the "tonesucking" that you are trying to avoid?.  How can you have an unbuffered output if you have an input buffer and an SPDT switch?.

What you are proposing seems to require a lot more work than just making the wah true bypass, which makes an input buffer unnecessary (and easily disabled).  No tonesucking in bypass.  Then, if you want to use the wah in front of a fuzz, you add an output buffer (similar to the FoxRox).  It just makes more sense to me.  What if you have a number of fuzz pedals to choose from, are you supposed to mod every one of them to accept the buffered signal that you would have with an input buffer and an SPDT switch?. 

I really can't understand the opposition to this, as what I am saying seems to be the popular solution.  Most players would rather just mod the wah to work in front of any fuzz they choose to use, which also would allow the fuzz to be used alone, instead of doing more complicated mods to the wah and every one of their fuzzes.

Al

[zombiwoof]

Dear Al

I disagree with performing true bypass on the Crybabys with the input buffer. If a FET or Mosfet is used the input impedance of the wah is as high or higher than the input impedance of a tube amp.

Changing a transistor and two resistors (maybe add diode protect if a Mosfet is used) is a better and cheaper option than replacing the footswitch.

After all the same end is achieved and the wah pedal sounds better for the buffering in my opinion. As previously said greater clarity is achieved.

Yours Sincerely

Mark Abbott

The same end is achieved?.  What about the output impedance when the wah is bypassed?   What happens when you have your wah in bypass, and you try to use your vintage Fuzz Face that follows the wah?.  If it is getting a buffered signal from the wah in bypass, it will not work right.  It wants to see a guitar-level signal.  And please don't tell me to mod my $1000 vintage Fuzz Face to accept the buffered signal!.  I think you're only considering the solution to the tonesucking problem that regular wahs have, and not the problem of running a vintage-type fuzz after the wah.

If your way is going to allow a fuzz after the bypassed wah to work correctly, please try to explain it to me.

Al

[Paul Marossy]

I disagree with performing true bypass on the Crybabys with the input buffer. If a FET or Mosfet is used the input impedance of the wah is as high or higher than the input impedance of a tube amp.

Changing a transistor and two resistors (maybe add diode protect if a Mosfet is used) is a better and cheaper option than replacing the footswitch.

After all the same end is achieved and the wah pedal sounds better for the buffering in my opinion. As previously said greater clarity is achieved.

This is something that I could agree with. True bypassing is NOT the answer to every problem. Sometimes it can cause more problems than it solves in certain scenarios.

[R.G.]

I don't understand how adding an "unbuffered output" is going to help, isn't that going to get you right back to the "tonesucking" that you are trying to avoid?. 

That's one of the things I was getting at in the note. buffering the input and output are two different things. Buffering the input, done properly, eliminates tone sucking - treble loss from losing top end in a guitar signal - because the input is now so high an impedance that it does not load the guitar down. But the output of the wah circuit itself is not protected from being loaded down.

How can you have an unbuffered output if you have an input buffer and an SPDT switch?.

Easy - there is no buffer helping the output drive the load that follows it. Buffers are not just for guitar pickups. It happens that the output impedance of the wah circuit is nominally about equal to the first transistor's collector resistor in parallel with the wah pot. Not exactly, but to a first approximation. While this is a lot lower than the impedance of guitar pickup, it's still high compared to the input impedance of a Fuzz Face derived fuzz. So the FF can have an effect on the wah by loading it down. Given that we have discovered one case where the wah is affected, there can be others, including cable capacitance.

What you are proposing seems to require a lot more work than just making the wah true bypass,

Maybe. But it gives you greater control. And control is the name of the game. We're well out of the era where if you had a fuzz of any kind and a wah pedal, you were by default the local guitar hero.    I lived through that era. It was not pretty.  

It just makes more sense to me.

Cool. Do it that way. There's nothing wrong with it if that's what you want. There are other alternatives that other people might like.

What if you have a number of fuzz pedals to choose from, are you supposed to mod every one of them to accept the buffered signal that you would have with an input buffer and an SPDT switch? 

Not all fuzz pedals suffer from the input peculiarities of the Fuzz Face. In fact, almost none of them do. The Fuzz Face and its copies are a special case, albeit an important one.

And I would simply mod the wah pedal to have a buffered output and an unbuffered one, or a switch between buffered and unbuffered, which amounts to one switch on the outside of the wah. I would not mod the fuzzes because (a) all but the FF-derivatives don't need it and (b) it makes the wah have more tonal possibilities. Or I would NOT mod the wah to have an unbuffered output, and I WOULD mod the FF to have an input impedance faker to be immune to low-impedance pedals driving it. Again, more flexible.

But these are all just alternatives. So is true bypass. More brushes in the paint kit.

I really can't understand the opposition to this,

Nothing to understand. I don't oppose it. Just providing options.

instead of doing more complicated mods to the wah and every one of their fuzzes.

That's not what's needed.

[earthtonesaudio]

If you want "it all," it would be nice to have it set up so that you have:

Buffered wah when using wah alone,
Buffered input, plus specially-formulated fuzz-friendly output buffered wah when using first-wah-then-fuzz in series,
and true bypass path direct from guitar to fuzz, when using fuzz alone.


That would require some fancy switching (maybe a toe switch and a heel switch) and would probably be too much work to have to remember live, but certainly doable.  If it was me I'd opt for an all-in-one unit with both fuzz and wah, with a digitally controlled switching matrix to handle all the desired combinations without much thinking required by the player.  Of course I don't play either Crybabies or Fuzz Faces, so what do I know...

[zombiwoof]

Thanks for the replies, but I still think the solution I gave is the simplest, and will fix the OP's problem.  Even though RG says that only the FF has the loading problems when a wah is used in front of it, the OP named three different fuzzes he has (none of which, I think, is a FF type circuit) that are exhibiting these problems after his Dunlop wah.  I know that many of you guys really know a lot about this stuff, and maybe you would go for these elaborate solutions, but I think true bypass with an output buffer is the best one (or just using a buffered pedal after the wah in a loop, if you don't want to do all of the mods to the wah), and it will work with just about any fuzz you put after the wah.  It's worth noting that in the high end wahs and most of the signature wahs (which are made to the artist's specs) that Dunlop makes they use a true bypass switch in lieu of the input buffer they put in the less expensive pedals.  That tells me that these pros agree with me that TB is the best solution.  In addition, all of the wah mod pages I've read (like Stinkfoot's site, which is one of the most popular references for modding wahs for TB), suggest this is the way to go.

I didn't think this was going to turn in the long thread it has, and I hope that ringworm (the OP) has been able to get some kind of answer for his question.  I would suggest he read Stinkfoot's pages on the TB mods (if he hasn't already), I think it will be helpful to him.

http://www.stinkfoot.se/andreas/diy/articles/bypass.htm

http://www.stinkfoot.se/andreas/diy/mods/dunlop.htm

And I would really like to see if his problem is solved if he installs the output buffer without changing the switch to a TB switch, as some here have suggested.  So, ringworm, please report your results!

Al

[ringworm]

Thanks for all the replies folks! Much appreciated. Thought I was missing a singular answer somewhere that would set me straight on this but it's always good to have options!
So what am I after... Basically, i think my cry-baby sounds pants in front of my high gain silicon fuzzes; the aforementioned Muff, Superfuzz and Great Cheddar (thanks for that one RG). They're all DIY projects, no $1000 vintage boxes on my budget I'm afraid. I have a germanium FF clone (first pedal I built) but I rarely use it, what can I say, I play with the others more. I'm not aware, or overly conscious, of any drastic tone-sucking on my crybaby when disengaged, my only quibble is when engaged it sounds shrill/choppy/un-dynamic, instead of being throaty and vocal. Ideally, the less I have to mess with the wah the better, I don't think I need to start putting in switches for a myriad of different uses, I just want it to get it working in front of a high gain silicon fuzz.
I'll do things in order of simplicity I think. I'm gonna try Mark Abbott's idea of swapping out the Darlington for a J201 as I have some sitting in my box and it seems quick and recoverable. If I'm not satisfied, then I'll try the buffer on the output without the TBP and if that doesn't work I'll add in the TBP. If it's ok I may pop back for some advice on implementing the second option as there doesn't seem to be much info out there on buffering a non-TBP wah cry-baby.
Thanks again folks, I'll post back soon.

[zombiwoof]

Thanks for all the replies folks! Much appreciated. Thought I was missing a singular answer somewhere that would set me straight on this but it's always good to have options!
So what am I after... Basically, i think my cry-baby sounds pants in front of my high gain silicon fuzzes; the aforementioned Muff, Superfuzz and Great Cheddar (thanks for that one RG). They're all DIY projects, no $1000 vintage boxes on my budget I'm afraid. I have a germanium FF clone (first pedal I built) but I rarely use it, what can I say, I play with the others more. I'm not aware, or overly conscious, of any drastic tone-sucking on my crybaby when disengaged, my only quibble is when engaged it sounds shrill/choppy/un-dynamic, instead of being throaty and vocal. Ideally, the less I have to mess with the wah the better, I don't think I need to start putting in switches for a myriad of different uses, I just want it to get it working in front of a high gain silicon fuzz.
I'll do things in order of simplicity I think. I'm gonna try Mark Abbott's idea of swapping out the Darlington for a J201 as I have some sitting in my box and it seems quick and recoverable. If I'm not satisfied, then I'll try the buffer on the output without the TBP and if that doesn't work I'll add in the TBP. If it's ok I may pop back for some advice on implementing the second option as there doesn't seem to be much info out there on buffering a non-TBP wah cry-baby.
Thanks again folks, I'll post back soon.

The way the CryBaby sounds is another matter altogether, personally I don't think any of the Dunlop wahs I have had sound anything like the Vox Clyde McCoy wah I had when I was a kid, which is the benchmark for wah sound to me.  Dunlop uses high gain transistors in their wahs which have more than twice the gain as the trannies in vintage wahs, and change a couple of resistor values to try to make up for that.  My solution with my Vox 847 wah (which was made by Dunlop, and has the same transistors and resistor changes), was to refer to the schematic for a Vox Clyde McCoy wah that you can find at Fuzz Central, and change out those components for the original values (I used BC109B's for the trannies).  Many people also change out the stock Dunlop inductor for either one of the newer Fasels or one of the other good replacement inductors (like the Whipple, etc.).  You can also get into other pots, etc.  The shrillness in those Dunlops some people claim is due to the input buffer they use, maybe the suggested change to the J201 will help with that, I don't know because I've never tried it.  So, if you don't want to do much modding to the pedal as you say, you are going to have to live with the sound those Dunlops have.  You are not alone in your feelings about the sound of that wah, which is the reason for all of the mods that are going around for it.

Good luck, and let us know about your progress!

Al

[Mark Abbott]

The shrillness in those Dunlops some people claim is due to the input buffer they use, maybe the suggested change to the J201 will help with that, I don't know because I've never tried it.

I was working on a Crybaby with a buffer last night. As luck would have it or lack there of. I couldn't find a FET or Mosfet to save my life.

(As stated earlier Dunlop were MAD to use a Darlington transistor when a FET or Mosfet is the better option. I found there was signal loss and treble loss with the Darlington buffer.)

As stated above it did sound very shrill. I increased the 0.01uF cap to 0.1uF instantly the bass response was much better as I didn't have to fool with the emitter resistor of the first stage so it can be set up for maximum headroom.
(Regarding the bass mod on wah pedals I don't know why people don't use a bypass cap in series with a pot instead of reducing the whole resistor value?)

Yours Sincerely

Mark Abbott

[ringworm]

I swapped out the MPSA13 for a J201. Results: It definitely sounds smoother on my Muff (fnarr fnarr), the Great Cheddar still sounds choppy somewhere around the middle of the sweep instead of smooth and the Superfuzz squeals like mad in the heel position and wheezes up to the toe down position.
I've found a schem for the foxrox buffer and will install it when I pick up the LF351N. Would it be a good idea to install the trimmer as an external pot to adjust for different fuzzes or is that not advisable?
I only picked up the cry-baby cos I found it mint in it's box for £26 in a second-hand shop. I've made a few simple swap mods already, including the bass response but I only switched the 0.01 to 0.022. I have a bunch of BC109s around somewhere too, not sure if they're B or C though, is the HFE a factor in the transistors, any specific values prefered? I'll have a look at the Clyde McCoy too.

[zombiwoof]

I swapped out the MPSA13 for a J201. Results: It definitely sounds smoother on my Muff (fnarr fnarr), the Great Cheddar still sounds choppy somewhere around the middle of the sweep instead of smooth and the Superfuzz squeals like mad in the heel position and wheezes up to the toe down position.
I've found a schem for the foxrox buffer and will install it when I pick up the LF351N. Would it be a good idea to install the trimmer as an external pot to adjust for different fuzzes or is that not advisable?
I only picked up the cry-baby cos I found it mint in it's box for £26 in a second-hand shop. I've made a few simple swap mods already, including the bass response but I only switched the 0.01 to 0.022. I have a bunch of BC109s around somewhere too, not sure if they're B or C though, is the HFE a factor in the transistors, any specific values prefered? I'll have a look at the Clyde McCoy too.

If you look at the Fuzz Central Clyde McCoy pages, I think he says that between Hfe 350-400 is suggested, and if they are different gains, put the higher gain one in Q1.  This is from memory, though, so I would suggest checking out the site to verify.  That's what I did, and it worked out well.  You can use other NPN trannies, as they used different ones over the years, as long as they are in the same gain range.  The MPSA18's that Dunlop uses are more like Hfe 800, and they move the sound of the wah away from the original sound IMO.

http://fuzzcentral.ssguitar.com/mccoy.php

I've found these pages very helpful with my wah.  I first tried doing some of the other resistor changes, etc. that are on the net, but it really got me nowhere.  My idea was to put the way back to the Clyde specs, from there you can do any other tweaks for more bass, different range, setting the "Q", putting in trimmers, etc.  Personally, I don't want a bunch of trimmers and stuff on mine, I just want one good sound that is like what I had with my old Clyde wah.  On the Dunlop wahs, there are only a few different component values from the original circuit, so it's not hard to get it closer to the original.  Doing that should get you a good sounding wah, after that changing the pot or inductor can tune it in even more, but it's not something that is absolutely necessary.

If you decide you want to do the TB mod and possibly remove the buffer the Stinkfoot pages I linked to previously are also very helpful.  Putting in a TB switch is really not difficult.

Al