pedal board woes... CF input buffer is the answer?

[Manic]

Hey guys,

I been doing battle with My pedal board. Basically its ruining My guitars tone. Its the usual suspects. True bypass pedals suck tone because of cable capacitance. Boss, Ibanez, and most any pedals that I own have AWFUL sounding buffers. Basicly what Im hearing with the run of the mill pedal buffer is that it wrecks the top end. The cheap buffers make it brittle, thin, its just gross.

The best buffer on My pedal board at the moment is the one in My Chandler Tube Driver (rack version). Its just OK sounding. It sure beats the pedals though.

I use the Tube Driver as My first "pedal" currently.
From what I have heard through hours of testing is the the first buffer on the pedal board set the "tone" for the entire pedal board.

I see that there are buffer pedals out there for a pedal boards input i.e.

http://this1smyne.com/Pedals.html

http://www.axess-electronics.com/sc/BS2-Guitar-Audio-Buffer-Splitter-p-16133.html

http://www.petecornish.co.uk/SAELD-1.html

I'm just not a big fan of solid state devices, although I do use a few FX pedals.

So, I had an idea to build a tube CF buffer to plug My guitar into and drive My pedal board with.

Maybe I could build the input stage to a Umble FX loop? or maybe this...

 http://www.freewebs.com/valvewizard/accf.html .

I was also considering building a full blown DC coupled cathode follower in a pedal like this one....

http://www.freewebs.com/valvewizard1/dccf.htm .

What Do You all think? I would love to hear some ideas You all might have.

Thanks much, C. Smith

[Manic]

This guys product sounds like its on the right track for what I want to do.....

http://www.amprepair.com/kanuter_vtpb1.htm

I may not need the output buffer that his board has.

[tubesornothing]

I was thinking of going a different direction:  a pedal switch board. Voodoo labs is OK, although you have to buy a command and then the pedal switcher.  There are some others around.

[Manic]

My findings have been that even when a true bypass pedal is engaged the buffer in them messes the tone up bad.

The first buffer is what is making the difference on My board. Thats why I thought a good tube buffer would be cool.

[thermion]

i don't think you need a tube buffer, there are some (really) good solid state buffers out there.

suck tone because of cable capacitance

this will be a factor no matter what pedals/ buffers you use.

cheap buffers make it brittle, thin, its just gross

when a true bypass pedal is engaged the buffer in them messes the tone up bad

agreed. maybe just tear out the buffer? for a pedal board that you never rearrange and you don't plan on using the pedals individually, this is an ok option.
the pedal switchboard gives lots of flexibility but is pricey.
i ended up trying several clean boosts and picked one that I could bear to have on all the time. i tore out the front end buffers of every pedal that had one downstream of the clean boost and linked all pedals with minimal lengths of george l cable. this path sounds clean and clear to me, YMMV.

[Manic]

Thanks for the reply...

I got My buffer built. Yeah!

 Its basically the gain stage and the cathode follower stage out of an AC30. I put a high/low switch on the input jack to adjust the top end chime. 33 stopper and about a 70k leak at the input causes enough Miller capacitance to get the top end fairly "flat".  

Its got tons of gain. I used a 200k pot at the output of the follower as an output attenuator.

I also put a switch on the followers cathode resistors. Its switches from a 100k to a 47k cathode resistor.

I read at Merlin's site that lowering the cathode resistor to 47k would add compression and "warm" the tone up some. I didn't hear it. I tried it at every gain level, didn't seem to make much, if any difference.

I was wondering if anyone had any tweaks for this arrangement of tubes...

Like maybe some caps to ground somewhere or tubes and/or other would be cool things to try.

If I left it alone at this point I could live with it though.


FWIW C. Smith

[G._Hoffman]

My thoughts, for what it's worth.

First, put any time based effects in an effects loop - preferably a parallel loop.

Second, even with your nice tube buffer, make a true bypass pedal board.  It's pretty easy - or at least, the circuit is - I've been using it for other things, not a pedal board, but it is easy to make and use.  Having one button access to different combinations of FX is the way to go, and you get the load off your signal, blah. blah, blah...RG Keen has a good, easy circuit HERE.  You will probably need to add a pull down resistor (10K works, but higher might also work) to the latch enable circuit.  Oh, and I hate the layout of the 4049 Hex inv. Buffers (it's really hard to route the PCB without jumpers, at least for a novice like me!), I'm using a CD74HC540 oct. inv. buffer, and a SN74AC573 latch, which has a better layout, is cheaper than the 373 Keen suggests, and by having eight circuits on both the buffer and latch you save yourself a bit of bother.  It's quite nice to have the layout of the buffer and latch line up so easily.  I'm finding I enjoy making circuit boards - ferric chloride does things to copper that look like magic, and it is pretty easy to work with (as long as you wear gloves)!


Gabriel

[Manic]

Hey, thanks for the info G.! That looks way cool man.

I wanted to say that after hearing the followers cathode switch (100k/47k) through headphone that I can hear that it is indeed warmer and a little compression, just as The Valve Wizard suggested. 

I played a show last night and I guess My ears are still little spent.

The 47k is browner sounding.

[G._Hoffman]

Hey, thanks for the info G.! That looks way cool man.

I wanted to say that after hearing the followers cathode switch (100k/47k) through headphone that I can hear that it is indeed warmer and a little compression, just as The Valve Wizard suggested. 

I played a show last night and I guess My ears are still little spent.

The 47k is browner sounding.

Yeah, if I used more effects, I would absolutely built myself a good true bypass pedal board.  As it is, I'm using the basic circuit to do some program switching in the Digital Tap Tempo Trem I am working on. 


Gabriel

[Manic]

maybe just tear out the buffer? for a pedal board that you never rearrange and you don't plan on using the pedals individually, this is an ok option.
the pedal switchboard gives lots of flexibility but is pricey.
i ended up trying several clean boosts and picked one that I could bear to have on all the time. i tore out the front end buffers of every pedal that had one downstream of the clean boost and linked all pedals with minimal lengths of george l cable. this path sounds clean and clear to me, YMMV.

thermion I really like this idea! Unfortunately I don't know much about pedals at all, except they are killing My tone.

Could You give a few pointers as to how to remove these dreaded buffers from My pedals?

I can hardly wait to get going on this project!!!

I am currently using George L's pedal patch cables. They sound great and got rid of a lot of the hum and buzzing coming out of My board.

[Manic]

I found this... http://www.stevesmusiccenter.com/SwellG-Drive.html

Same idea basically.

[Manic]

No CF tweaks guys?

One thing I wanted to TRY was to put a marshall style voltage divider/ boost(with cap) between the plate of the first triode and the grid of the follower...

I'm not sure if that wont blow up anything or not.