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volume pedal.. do i want 250k or 25k ?

popthree
October 15th, 2011, 03:57 PM
i intend to purchase a volume pedal.. i plan to put it after my compressor and dirt pedals. the compressor will always be on.. knowing that.. do i want a 25k ?

thanks

Teleworshipkid
October 15th, 2011, 04:37 PM
Only use a 25k if you have active pickups.

popthree
October 15th, 2011, 06:34 PM
i was thinking the comp being on all the time.. and the OD's being on sometimes would introduce a load like active pickups....

Teleworshipkid
October 15th, 2011, 07:31 PM
Eh... Unless you have everything on all the time, then you probably shouldn't have to worry about that...

popthree
October 15th, 2011, 08:27 PM
well like i said in my original post, i'm putting the volume pedal 'after' a compressor that will be engaged full time.

1300 E Valencia
October 15th, 2011, 11:52 PM
Between the guitar and the amp's input, use the high impedance model (250K). No, it doesn't matter how many or what kind of pedals are also in the chain.
The 25K models are for use in an effects loop.
Hope this helps :grin:

popthree
October 15th, 2011, 11:55 PM
hmm

1300 E Valencia
October 16th, 2011, 02:03 AM
Sorry, you can have a zillion pedals engaged "all the time", it still doesn't make your guitar "active".
Active pickups output a low impedance signal.
Effects loops are low impedance.
99.999% of everything else is high impedance.

Tele-phone man
October 16th, 2011, 04:44 AM
You can do it. I would recommend neither the 250k nor the 25k. Rather, I prefer a good active VP, which can usually be used in every setting. They tend to have higher input impedance than the 250k passive volume pedals, and their buffered, low-Z output can drive any impedance input.

RomanS
October 16th, 2011, 05:03 AM
Sorry, you can have a zillion pedals engaged "all the time", it still doesn't make your guitar "active".
Active pickups output a low impedance signal.
Effects loops are low impedance.
99.999% of everything else is high impedance.

Nope.
Most effects pedals (with very few exceptions) have low impedance outputs - so, if you run an effects pedal in front of your vol. pedal, and leave it on at all times (with buffered/non-true-bypass = buffered pedals - eg. a Boss TU2 - even when turned off!), you can safely use a low impedance volume pedal.
Boss specifically recommends low-Z vol. pedals for use after other effects pedals:
http://www.roland.com/products/en/_support/faq.cfm?iCncd=269&FAQ=EN31-07729&dsp=1&ln=en

That said, I personally prefer an active vol. pedal (as long as it is NOT a Morley!), as you don't have to worry about where to place it.

BTW, what compressor are you using? Once we've got the model, we could try to find out its output impedance specs...
To mention the two most popular models' output impedances:
Boss CS-3 - 1k
MXR Dynacomp - 10k
...both have low impedance outputs!

popthree
October 16th, 2011, 10:04 AM
thanks Romans.. i'm using a Marshall ED-1

i was wanting to keep my cash outlay on the low side which i why i'm considering a passive volume pedal.. looking at those ernie ball jr.s since they can be had for $80 new and less for used.

RomanS
October 16th, 2011, 03:41 PM
thanks Romans.. i'm using a Marshall ED-1



Output impedance less than 1kOhms - so it's low impedance:

http://marshallamps.com/product.asp?productCode=Compressor&pageType=SPECS

Personally, I haven't used Ernie Ball vol. pedals (though it's the choice of a lot of pro players - should work fine!) - for passive vol. pedals my favorite is the Boss FV-500 (comes in low and high impedance versions).

popthree
October 16th, 2011, 04:33 PM
Romans.. Thanks !

fly135
October 17th, 2011, 02:50 PM
Between the guitar and the amp's input, use the high impedance model (250K). No, it doesn't matter how many or what kind of pedals are also in the chain.
The 25K models are for use in an effects loop.
Hope this helps :grin:This is the correct answer. The output impedance of the compressor does allow you to put a low impedance pedal after it, but I wouldn't. If you change your mind then you may not be able to move it where you want in your chain. It's the input impedance of the device following the volume pedal that dictates if you need a low impedance volume pedal.

popthree
October 17th, 2011, 03:42 PM
its not just the compressor that will be 'before' the volume pedal. all my dirt will go before it as well.

i can't ever see putting a volume pedal before my dirt boxes...

i have read that using a 250k vol pedal 'after' comp and dirt will cause loss of highs... which is why i am thinking i need the 25k... just wanting to make sure i'm thinking correctly.

fatsound77
October 17th, 2011, 04:47 PM
SO many wrong answers and very few right ones. If you are for sure positive your compressor will stay on all the time then YES 25K. Contrary to some of the above statements, if you are feeding it a compressors low impedance buffered out then that is an active signal. BUT if you go directly from passive pups to 25K VP then you will have awful loading issues sucking away all your signal. Using a 250K after a buffered/low impedance/active signal will work, but the incorrect pairing of impedances will mess with the taper/swell rate making for a not so good nor smooth swell.


It's the input impedance of the device following the volume pedal that dictates if you need a low impedance volume pedal.

This is absolutely incorrect. It's the source signal that dictates the use of a 25K or 250K. In his case the source is not technically the passive pickups. It's the compressors output only because he's going to keep it on 100% of the time.

popthree
October 17th, 2011, 05:08 PM
thanks fatsound77.... what you and Romans have said reinforces some of the information i have read elsewhere...and what my gut is telling me... there seems to be such confusion regarding this topic ! i know i want the comp on all the time... and i want to hit my dirt with full out guitar volume so the gain is unaffected by the volume changes..

my aim is to be able to create long dramatic swells for ambient looping type stuff. i wish i had unlimited funds to buy a really nice active volume pedal but i'm always pinching pennies as i have mouths to feed !

thanks again !

fatsound77
October 17th, 2011, 05:22 PM
Yeah. I used to be anal about no active volume pedals, but my bud Justin at Thru-Tone got me hooked on his mod he does to the Ernie Ball VP's. Check him out at http://www.thru-tone.com, I wrote a quick review on here to help try and spread the good word. I won't even play without the modded VP on my board now. Definitely a worthy investment for me and just completely eliminated my headaches with these topics.

fly135
October 18th, 2011, 04:22 PM
This is absolutely incorrect. It's the source signal that dictates the use of a 25K or 250K. In his case the source is not technically the passive pickups. It's the compressors output only because he's going to keep it on 100% of the time.Sorry but you are a bit off base on your assessment of my post. Well a lot if you give "absolutely" the weight it deserves.

First of all if you have a passive pickup then there is no way the device following it will be a low impedance input. If that is the case then a brain dead monkey designed your board. I'm not suggesting you are a brain dead monkey or your board is ill-designed. So we can assume as an axiom that you will never have a low impedance input after a passive pup.

Knowing what I stated above, and knowing that anything that goes before the amp will have high impedance inputs, we can then move to other considerations. The first consideration is that it is never required to have a 25K pedal before an amp. In fact having a low impedance input following a low impedance output is not a requirement. In theory it does reduce noise, but your pedal chain is loaded with high impedance inputs so this is not a consideration. Therefore you can now see that having active pups is irrelevant in the decision process.

What is relevant is the input impedance of the device following the volume pedal. And what we find is that the 250K pedal is more versatile. You can *always* put a 250K in front of the amp. You cannot always put a 25K pedal in front. You can always put a 250K pedal in a low impedance loop and the worst you will suffer is a sweep non-linearity. That sweep non-linearity is the result of the impedance following the volume pedal and has nothing to do with the device feeding it. If you put a 250K into a 10K ohm input impedance the sweep kills the signal too fast, but it's usable.

OTOH if you put a 25K pedal anywhere that has a high impedance driver you will suffer from tone suck. Which is worse... tone suck or sweep issues? Combine that with the fact that most places to insert a pedal is a high impedance circuit (even many amp loops) and you can see the 250K is more versatile and the easiest criteria for choosing is the input impedance of the device following the pedal.

popthree
October 18th, 2011, 05:26 PM
hey fly135, i appreciate your input. it sounds to me like you are saying if i want the most versatile 'passive' volume pedal, i should get one with a 250k pot.

however, in my case, i will not be changing my mind about where the pedal goes in the chain. it will be after the dirt which is after the comp that is always engaged.

considering that criteria only, which would you use, the 25k or the 250k, and why ?

is Boss wrong ?

RomanS
October 18th, 2011, 06:02 PM
Apparently, Ernie Ball is wrong, too... :mrgreen:

http://www.ernieball.com/faq/7-Ernie-Ball-Volume-Pedals-FAQ#89

jefrs
October 18th, 2011, 06:26 PM
Typical OD pedal (Arion SOD-1)


Input Impedance - 300K ohms
Output Impedance - 10K ohms
Maximum Input Level - +5dB, 0dB = 1 V Effect Off
Maximum Output Level - -12dB, 0dB = 1 V Effect On

So -
High input impedance (suits output from pickups), similar impedance to front end of valve amp
Low output impedance (will drive low impedance input or high impedance input)

Input will accept low or medium level (less than "line") signal. A higher level won't damage it, but it doesn't sound nice.
Output medium level (less than "line") i.e. the pedal is not really suited for the amp FX loop.

This pedal is typical of most floor pedals. It might drive a 25k vol but would be happier driving 250k vol pedal. To drive a 25k one really requires a line-level signal ~1Vrms e.g. mixer (desk) or keyboards.
Vol pedals are usually first in chain, or second in chain (do experiment), and then are 250k log or 500k linear. The 500k linear will give fine control at the top of its range and not load the pickups as much as the other one. The 250k log has its best fine control at the bottom of its range, from silence, and then rises rapidly in volume to full on, but it does load the pickups more.

I have found that active vol pedals colour the sound whereas a passive one can be a tone-sucker as it loads the signal. Best to experiment with your pedal order.

popthree
October 18th, 2011, 07:30 PM
i didn't realize this was a can of worms topic

1300 E Valencia
October 18th, 2011, 07:46 PM
Buy both, return the one that doesn't work in your setup.
As we have learned today, class, you just gotta plug 'em in and try 'em out.
Your Mileage Will Vary.

fatsound77
October 18th, 2011, 10:58 PM
To Fly.

Ofcourse 250K is more versatile. No one said the contrary. But the the source driving the load is the determining factor. The standard average amp input is 1M. A 25K vs 250K in fron of this makes no difference until you determine the source signal that is driving the volume pot. In the OP case he is driving it with a low impedance signal, which makes the 25K the optimal match.

By your philosophy of the following device being the determining factor will lead to nothing but total SUCK. Passive pups to 25K = huge tone loss into an OD or fuzz makes no difference, still suck. But passive pups into a compressor outputting a low impedance signal into 25K into any pedal let alone the amp... same signal, no suck and now controllable taper.

There is two methods to proving this... Simply our friend ohms law with a pencil and paper, or simply plug these pedals in all orders and just get it simple. No can of worms, just a lot of wrong info. Low impedance = active. Two terms that relate to different situations, but mean the same thing.

RomanS
October 19th, 2011, 03:02 AM
^ ^ THIS ^ ^

fly135
October 19th, 2011, 08:58 AM
By your philosophy of the following device being the determining factor will lead to nothing but total SUCK. Passive pups to 25K = huge tone loss into an OD or fuzz makes no difference, still suck. But passive pups into a compressor outputting a low impedance signal into 25K into any pedal let alone the amp... same signal, no suck and now controllable taper.If you notice I previously said only a brain dead monkey would put a low impedance input after a passive pup.

"First of all if you have a passive pickup then there is no way the device following it will be a low impedance input. If that is the case then a brain dead monkey designed your board."

There is two methods to proving this... Simply our friend ohms law with a pencil and paper, or simply plug these pedals in all orders and just get it simple. No can of worms, just a lot of wrong info. Low impedance = active. Two terms that relate to different situations, but mean the same thing.I'm sorry but I know exactly what I'm talking about and I am well aware of how it applies. The passive is more versatile and putting it after active pup will not cause tone suck. I think you need to use ohms law to demonstrate how it can. And you will see that you can't. Get your pen and paper and support your claim.:idea:

fatsound77
October 19th, 2011, 11:21 AM
NO one said a 250K would suck tone after an active signal. Of course it wouldn't. The issue is the impedance imbalance results in a lowered taper pushing most of your volume throw to the last end of travel. It will work fine, but the OP wants to know which one will work best for him. Stop trolling the thread and going off tangent. The solution has been supplied to the OP's issue and you are in here stating incorrect advice let alone talking about things that weren't even mentioned.

klasaine
October 19th, 2011, 11:30 AM
I've used a passive Goodrich 120 for 26 years both pre and post fx (comp on all the time) without any noticeable loss of tone or anything else negative. Studio and stage - zero issues.

*My 120 finally gave up the ghost. I too now use a 'thru-tone' modded active EB vpjr. (Awesome!)

RomanS
October 19th, 2011, 01:31 PM
The issue is the impedance imbalance results in a lowered taper pushing most of your volume throw to the last end of travel.

As I said, I use an active volume pedal (a George Dennis) myself - but I do also own a Boss FV500H (that's Boss passive high impedance vol. pedal, with a 250k pot, just like the Ernie Ball), and incidentially, I also own the Marshall ED-1 compressor (output impedance <1k - definitely low impdance!) that the original poster wants to use always-on in front of his volume pedal.

So, to gather some real-life data, I just hooked those up with my Tele and my VHT Special 6 amp - and can indeed confirm that change in taper!

If run:
-) guitar->FX pedal->high Z vol. pedal->amp - the volume pedal has a very smooth taper, going seamlessly from off to full on over the full travel of the pedal (the Boss vol. pedal has an extra pot for setting a minimum volume, I turned that down all the way, so that the pedal travel really starts with no volume at all; and I turned down the compression on the ED-1 all the way, so the effect would not influence the results).

If run:
-) guitar->high Z vol. pedal->FX pedal->amp - there is no change in tone, BUT: there's a VERY noticeable change in the volume pedal's action/taper - there is almost no increase in volume for the first 50% of the pedal travel, and then there is a very sudden increase on the last part - it reacts more like an on-off switch, rather than a swell pedal...

Unfortunately, I don't own a low impedance volume pedal for comparison purposes - but I can indeed confirm that a high Z type does change its taper (and quite a lot, more than I expected), if run following a low Z effects output - seems like both Boss and Ernie Ball do indeed know what they are talking about in their vol. pedal manuals/FAQs... :mrgreen:

Vizcaster
October 19th, 2011, 03:24 PM
If you ever plan on possibly using the same volume pedal as an expression pedal for some other effects box or amp, then consider the requirements for that controller. For instance the Fender Cyber Deluxe has a certain impedance it wants to see from the volume pedal when used as an expression pedal (to control the wah, Leslie speed, and oh, yeah, volume). So check the specs on the multi-effects device to see what kind of volume pedal it wants to see when using it as an expression pedal. Otherwise I would expect the 250K EB pedal to be more common and more readily available used.

Incidentally I have both the EB "Jr." and grownup pedals and the junior is way big enough for my hind paws; both operate very smoothly.

fly135
October 19th, 2011, 07:07 PM
The issue is the impedance imbalance results in a lowered taper pushing most of your volume throw to the last end of travel. It will work fine, but the OP wants to know which one will work best for him. Stop trolling the thread and going off tangent. The solution has been supplied to the OP's issue and you are in here stating incorrect advice let alone talking about things that weren't even mentioned.My advice is correct and you cannot demonstrate with paper and pencil your claims. It is not trolling to correct someone who said stated a claim that is incorrect.

I run a 250K EB pedal in a completely buffered circuit and have a fine sweep. Bottom line is that your claims are incorrect and cannot be substantiated by examining the circuit equations.

klasaine
October 19th, 2011, 09:37 PM
My advice is correct and you cannot demonstrate with paper and pencil your claims. It is not trolling to correct someone who said stated a claim that is incorrect.

I run a 250K EB pedal in a completely buffered circuit and have a fine sweep. Bottom line is that your claims are incorrect and cannot be substantiated by examining the circuit equations.

I agree.
This afternoon I had a quick session and I used my newly modded EB vpjr. in passive mode (thru-tone mod allows it to revert back to 'stock' if you don't use a 9v. pwr sply). Perfect opportunity to check out both my new vol. pdl. and hear if there's any difference where it's placed in a normal/standard guitar rig.
I placed it in between a Fulltone 'fat boost' II and an Xotic 'EP booster'. when 'ON' they are indeed buffered. I noticed absolutely zero difference in the taper/sweep and response of my EB ... yes, I tried it straight into the amp too. In 26 years I never noticed anything weird with my Goodrich 120 no matter where I ran it and I almost always have something buffered.
*The buffers in the fulltone and the xotic are excellent so ...

I don't know what the 'math' says. My ears say no difference.

tjalla
October 20th, 2011, 12:14 AM
Most interesting fly135, klasaine.

I have had to correct a friends board who was running his guitar direct to a boss vol pedal. It sounded terrible this way, grainy and splatty as if there was a dying battery somewhere in line or a bad cable. Put a buffered tuner first in the chain, volume pedal after, and that solved that.

So perhaps a low impedance vol pedal *must* see a buffered signal, but a 250k vol pedal can be place anywhere?

klasaine
October 20th, 2011, 12:26 AM
Yes, if you're using normal, non-active pkups you definitely can't go straight into a Boss FV-500 L.

fly135
October 20th, 2011, 10:56 AM
For guitar applications a low impedance volume pedal is never needed in front of an amp. And is only needed when placed before a low impedance input like many amp FX returns. Many amps have a fx loop intended for rack FX which work with higher level signals and can drive a lower impedance FX return. These loops are not suitable for many guitar pedals mainly because the signal is too hot.

In normal practice there will never be a pedal with a low impedance input in front of an amp. That's why the 250K pedal will always work. Which is contrary to some of the advice above.

Of course you can put a device with low impedance input if you want to do something specific and know what you are doing. Even a 250K volume pedal can suck tone on passive pups. So it's still better to have an active buffer before the 250K volume pedal.

I have my 250K EB volume pedal after several active pedals... Fish Chips EQ, Line 6 M5, and a Yamaha Magicstomp. My whole pedalboard is in an active circuit because it's in the loop of an RP1000. All of the above pedals are active and have a low impedance output. The sweep of the EB pedal is fine.

popthree
October 21st, 2011, 12:32 AM
I gotta go with what Romans and boss and eb are saying....I think that I'll be fine with the 25k in my setup ....I can always upgrade to the thru tone mod at a later time if I want to

stratohiker
February 10th, 2013, 01:23 PM
I'd like to resurrect the post for my own selfish purposes :wink:
I recently had my older Goodrich pedal "rebuilt" (new pot, string, etc). Sent it off to get it done. It's a 120 model and I'm pretty sure they used the 500k pot that appears to be the standard Goodrich replacement these days.
I've noticed that since I got it back and placed it back on my board (in the same place in line as always), that, the taper is such that the volume comes on very suddenly in the travel of the pedal.
I'm guessing that there is some difference in the pot on the rebuild to cause this, as it appears that this only happens when it's on my board. Seems to be ok by itself into my little PR amp at home.
Anyone have some input on this?

Thanks

fly135
February 10th, 2013, 01:29 PM
Do you have an ohm meter? You can check the pot by ohming out the input cable with nothing attached to the output. If a higher impedance pot was used and you are plugging onto a circuit that has a low impedance it can cause the sweep to change like you described. Since nothing else changed it does appear that the pot is different.