Volume Pedal Question

[lbpesq]

Ernie Ball makes both 250K volume pedals for passive instruments, and 25K VPs for active instruments.  So what happens if you use a 250K for an Alembic or a 25K for a passive guitar?  And does it make a difference if the VP is placed last in the chain, AFTER all the effects?  I know there's some techy people around here who know a lot more about this stuff than I do.  (one of the many reasons I LOVE hanging out around here).
 
Bill, tgo

[5a_quilt_top]

I use EB passive mono volume pedals for my bass and guitar pedal boards. I place them either first in the chain for bass or second in the chain (with my Fulltone Deja-vibe first) on my guitar board.
 
First off - yes - they will work with Alembic instruments. I now have several Alembic basses and, as of two weeks ago, a guitar and have noticed no issues with either.
 
I view a volume pedal as a floor-mounted volume control for the instrument and also a a means to tune silently as I have a Boss pedal tuner running off the tuner out jack on volume pedal on each board.
 
Placing it first will cause it to behave very much like your instrument's volume control in that the signal is decreased BEFORE it hits the rest of the chain.
 
Placing it later in the chain or at the end will allow it to govern the overall volume for everything that precedes it.
 
Depending upon what you are trying to achieve, this may or may not be desirable.
 
Some folks I know prefer it last so they can set up a raging overdrive tone and control its overall volume before it hits the amp.
 
Because I use low-power tube guitar amps with the basic tone set pretty clean, I prefer to have that raging OD pedal tone hit the amp as hard as possible to drive the power tubes.

[keith_h]

You would generally want to place the volume pedal after pedals that depend upon signal strength for their settings. An envelope filter is one example of modulation effects where changing the input signal strength will affect the device settings. Overdrive effects are another class of device where input signal levels can affect the device settings. Things like delays and reverb can go before or after the volume pedal depending upon what you like.  
 
Volume pedals themselves are just another volume pot and will affect the highs when used. To this end if you are not running a buffer or buffered effects before the volume pedal or in the effects loop of the amp you would would want to use the 250K pedal. If you are using a buffer or buffered effect in front of the volume pedal or using an effect loop you would want to use the 25K pedal.
 
Using a 25K pedal with a passive guitar without a buffer will result in the loss of more highs than the 250K. For an Alembic or other active instrument I would expect it to not make any difference. To have the most flexibility I would suggest the 250K pedal as it can be used in the input chain, with buffers or in the effects loop with either passive or active instruments.
 
Keith

[lbpesq]

I guess I didn't make myself clear.  There are no issues about where to place the pedal in the chain.  I use the volume pedal to obtain the same benefits of an OBEL without the extra cord.  I keep my guitar on 10 just about all the time, so the pedals see the same consistent signal, (the whole purpose behind the OBEL), and place my volume pedal last in the chain.  I play mostly Alembic and Alembic equipped guitars, but may play the occasional passive guitar.  Even then, I have an Xotic EP Booster that is a buffer.  So what is the difference between having the 250K vs. 25K VP at the end of the chain?
 
Bill, tgo

[JuancarlinBass]

Quite interesting. I have been tweaking with some home-made circuitry, for a W/D/W setup for recording. I am splitting the signal on my guitar rack, once it exits the (Mono, Dry) preamps section (First a BBE381solid state preamp, then the dry section of a Roland GP-8 processor -out through its loop insert-, then a Chandler Tube Driver rack), so it can feed on one hand a miked guitar amp inside an iso box (Fender Champ) for dry tone (which I can also send to another amp which is not isolated), and then the other hand feeds the DSP (Mono to Stereo) section, for all the effects that are later run into the mixing console. So I?ve built a passive splitter box, with a couple switches to toggle on and off the two amps (Iso and non-iso), and a potentiometer for the one in the iso box (the Champ), so I can control the amount of hotness of the signal being sent to it. Thing is, some friend insisted on putting in there a 1 Meg-Ohm pot, and I find it cuts the highs terribly once I start to tame the signal down. When I was testing possibilities before building this splitter box, I achieved this gain-taming by placing (uncomfortably so) a really old, heavy, metal-built sturdy Roland volume pedal from a friend, and highs were not killed so much, but then I could not check the values for its pot. I guess the answer would be simple for those of you more experienced with this, so... Should I replace the 1 Meg ohm pot with a 250K one? A 25K one? Thank you very, very, very much!

[keith_h]

If your last effect before the volume pedal is high impedance or you use a passive guitar using a 25K pedal will result in a loss of high frequencies (i.e. tone suck). Even a 250K pedal will kill some highs just not as bad. If you use a 250K after a low impedance effect the pedal sweep might not be satisfactory. Whether you will notice or not only you will be able to tell.  
 
Keith

[dfung60]

Bill -  
 
You'll have (slightly) better results with the 25K volume pedal.  Your Alembics have buffered, active electronics and presumably all your effects pedals also have an active preamp, so the 25K volume pedal should give best results.  
 
If you use a 250K volume pedal after your effects or after your Alembic output and before your effects, it will also work, but you'll probably find that the volume control action will happen more abruptly at the end of the pedal travel vs. the 25K pedal.  You'll still get gradation, just not as much resolution.
 
The only configuration where the 250K volume pedal will be noticeably better is if it receives the signal directly out of a guitar with passive pickups (e.g. before any effects).  In this case, you may find that when you rock the 25K pedal back you'll get a lot of treble cut.
 
If the volume pedal is normally wide open or closed, it won't matter which pedal you use.  You will probably hear subtle tonal differences if you play with it rocked to a mid position.
 
David Fung

[pace]

Try one of these:
 
http://www.tpa-az.com/page8.htm