Ross Compressor, 50k or 100k Volume Pot???

[bigstomper]

So I'm working on building a Ross Compressor (tonepad board, all high quality parts for low noise, etc, etc).  I've seen some people use a 50k on the volume, where others opt for the 100k.  What is the difference between these two?  Do they sound different?  Different range of loudness?  Any help would be most appreciated.  Thanks all!

[jacobyjd]

So I'm working on building a Ross Compressor (tonepad board, all high quality parts for low noise, etc, etc).  I've seen some people use a 50k on the volume, where others opt for the 100k.  What is the difference between these two?  Do they sound different?  Different range of loudness?  Any help would be most appreciated.  Thanks all!

No difference that your ear can hear

[BAARON]

...although the output cap is small enough that you might find the 100k pot is a bit fuller sounding in the low end.  Subtly.  Of course, it'll also mean worse output impedance, so you might lose a little more high end.

[bigstomper]

Hmmm...maybe a 50K linear would be the best way to go.

[BAARON]

I actually find that I usually have to leave the volume on my Ross maxed most of the time anyway, in order to have unity gain in the chordal work.

[bigstomper]

Hmmmm....I owned a Keeley comp at one point (Ross clone with a couple mods I believe) and recall it having a bit more volume on tap than that.  Is the low volume output a common thing with the Ross type compressors???

[Scruffie]

Hmmmm....I owned a Keeley comp at one point (Ross clone with a couple mods I believe) and recall it having a bit more volume on tap than that.  Is the low volume output a common thing with the Ross type compressors???

Yeah I saw a proguitarshop demo of the pedal and it did have more volume on tap than unity, probably a simple mod anyway if it was a problem, but he did say in the chordal work, having not used it, I couldn't comment if it's quieter for chords and louder for single notes.

[jacobyjd]

If I max out the compression on mine (why would you?), the volume hits unity at max. Back off the compression a bit to get more volume. Then again, I used a 100k for my volume control, so I may be getting a hair more out of mine.

big, if you have one or the other lying around, just use what you've got--no need to make a special parts order. However, if you have both, and others have volume complaints, you may want to stick with the 100k. The differences, though, are almost not worth bringing up.

[BAARON]

It's true that with heavier compression, the output level is limited more.  I just find that it clamps down so much on the attack when you feed it with a loud signal (i.e., heavily strummed chords through moderately high output humbuckers, which occasionally happens) that you have to have the volume maxed out to get unity.  It's not as much of an issue with single coils.

[jacobyjd]

It's not as much of an issue with single coils.

Haha--that explains it  

[Mark Hammer]

It's true that with heavier compression, the output level is limited more.  I just find that it clamps down so much on the attack when you feed it with a loud signal (i.e., heavily strummed chords through moderately high output humbuckers, which occasionally happens) that you have to have the volume maxed out to get unity.  It's not as much of an issue with single coils.

The answer is simple, my friend: turn the compression down.  The circuit works by turning tings down, and then letting them creep back up when the coast is clear.  The degree to which the gain is reduced is proportional to the input signal.  So, if the input signal is hotter, then a lower compression setting will still achieve the same degree of gain-reduction as a weaker signal with the compression cranked.

[bigstomper]

Lots of good info here....thanks guys....I will be using single coils, or the occasional lower output PAF type humbucker with it, so output shouldn't be a problem hopefully.  I have both 50k and 100k lying around here so I may experiment with both and see if I can detect and difference.

[BAARON]

It's true that with heavier compression, the output level is limited more.  I just find that it clamps down so much on the attack when you feed it with a loud signal (i.e., heavily strummed chords through moderately high output humbuckers, which occasionally happens) that you have to have the volume maxed out to get unity.  It's not as much of an issue with single coils.

The answer is simple, my friend: turn the compression down.  The circuit works by turning tings down, and then letting them creep back up when the coast is clear.  The degree to which the gain is reduced is proportional to the input signal.  So, if the input signal is hotter, then a lower compression setting will still achieve the same degree of gain-reduction as a weaker signal with the compression cranked.

Normally I would indignantly say "I don't run my compression very high!" but after hearing how the Ross does its job, I suppose it doesn't matter how high the compression is set so much as it just matters that if you find a sweet spot for a quiet input signal, the sweet spot is going to be lower for a hotter signal.  I usually only run it with the compression knob around 30% anyway.

[Processaurus]

For a bit more volume, replace the 10K resistor in series with the volume pot with a piece of wire, or a low value resistor like 1K or 470Ω.  No idea why it is that high (the 10K), maybe they figured nobody would need full output, and that the volume knob would be less touchy with a more limited range.

50K will be lower output impedance, always a good thing.  With twice as much current flowing through the volume control, any noise picked up on the signals way to the amp or next pedal will be half of what it would be with 100K.

I've kind of found 50K pots to be a good starting point in transistor circuits for volume controls and the like, more often than not they seem to often be in the right spot in between too low messing with the output circuitry and too high making the signal weak to the next stage.

For opamps however, 10K volume controls are good, as their output impedance is always quite low, and the lower impedance (more current flowing through it) of the 10K pot helps send a stiffer signal to the next stage.

[sevenisthenumber]

Quick question.

I built the tonepad Ross and i noticed that when i increase sustain it gets louder? Seems to be opposite of what you guys have said? hmmmm?

[bigstomper]

Well I got my Ross Comp all built up and it sounds great.  However, like the poster above, I noticed when I turn the sustain up on mine the output gets louder.  Is this normal for the Ross?  However the controls function correctly in the regard that as you turn the sustain knob up it does add sustain.  Any info???

[jacobyjd]

Is this normal for the Ross?  

It's normal for any compressor

[petemoore]

  The thing is constantly turning the volume down at such speeds I couldn't replicate manually, it seems there's a drop in gain every time I hit a note [nice when it's working 'right], especially on hard hits and low notes, even strumming, any high input transients set off a gain dip/rise sequence.