Bypasses volume loss?

[sengo]

Hey everyone,

    I was wondering if anyone had solutions to major volume loss in bypassed effects? I don't understand why this happens, all my effects have true bypass, but I am experiencing a huge volume loss when I bypass them. The biggest problem is with my wah pedal, which I enjoy using clean. Ive cleaned all the jacks with rubbing alcohol and that didn't help. I also tried taking the patch cables and holding the jacks together to see if maybe their length was causing the problem, but with just the cables I get full volume and tone. Can the problem be caused by the gauge of the signal carrying wires inside the effect? I would really like to know if anyone has had this problem or found a solution to it.

Thanks,

Nick

[PerroGrande]

Nick,

Some questions:

Do you notice "incremental" volume loss as you bypass more and more pedals?  In other words, if you've only got 1 or 2 bypassed, is your volume acceptable?

Have you tested each pedal individually to see if one of them is at fault?

Are you losing both volume and tone? 

The secret to solving any problem like this is to eliminate variables until you've isolated the most likely causes. 

[sengo]

Do you notice "incremental" volume loss as you bypass more and more pedals?  In other words, if you've only got 1 or 2 bypassed, is your volume acceptable?

I believe the volume loss is incremental, but the majority of it comes from my wah pedal. The volume is unacceptable no matter how many effects are in the chain however.

Have you tested each pedal individually to see if one of them is at fault?

Ive tested three pedals and they all have the same symptom.

Are you losing both volume and tone? 

I don't believe I am losing tone. I tried plugging straight into my amp and with the amp volume down it sounds less vibrant then with it turned up, so any tone loss seems to be purely from low volume.

[PerroGrande]

Well, putting aside the wah pedal for a second -- do your other pedals have a "level"  or "volume" control  -- i.e. one that controls the output volume of the pedal but doesn't effect the tone of the effect?

Where I'm going with this is:

If all of your pedals end up running with a slight gain, by the end of your pedal chain, you might have a noticeable gain relative to all the pedals bypassed.  Try adjusting each pedal's level or volume control so that the volume is the same bypassed and active (if this is possible).  Then re-check the volume level with all the pedals bypassed against the volume level when they are all "stomped".  If they are the same, then we can reasonably tackle the wah pedal issue as the sole cause.  If not, then we need to look elsewhere (*and* at the Wah).

Some Wah pedals have a fairly low input impedance (intentionally) and can suck tone (and volume) from certain types of pickups. 

[sengo]

My other pedals do have a volume control, however, I compared their bypassed volume to the volume of the guitar plugged directly into the amp with no effect pedal at all. Testing them this way has shown there is a definite volume drop from the bypassed pedal.

Thank you for your quick replies by the way

Nick

[sengo]

:bump:

[PerroGrande]

Well, it sounds like you've done a good job isolating the issue...

We're down to only a handful of possible culprits:

1) The bypass switch
2) Cold/Poor solder joints on switch or jacks
3) Cabling within the pedal
4) Cable running to/from/between the effects
5) Damage to cable insulation causing some loss  (I've seen this happen from melting the insulation accidentally during soldering, or pinching a cable in a metal enclosure).

I'd start with visual inspection, looking specifically for issues 2 and 5.

[sengo]

After checking out all the connections I remembered I had a small cap from input to ground in all my pedals to reduce radio interference, after removing it I got all my volume and tone back! Unfortunately I can't use my wah before my fuzz anymore, because that capacitor was really making the two behave together. I'm going to try a smaller capacitor and see if I can find some happy median between clean tone and a functioning fuzz/wah combination.

Nick 

[PerroGrande]

Nick,

Glad to hear you fixed your problem without another 6-layers of OSI-hell to go through.

Did you only have one cap total, or one per pedal?   If you had one per pedal, when you put it in bypass, all the capacitors are going to end up connected in parallel.  Capacitors in parallel add their value together.  So many small-ish caps became a larger one. 

Of course, the cap to ground is creating a low-pass filter.  The bigger the cap, the lower the 3dB frequency point of the filter and the more highs get attenuated.  If your effective capacitance is large enough, the cutoff starts to move low enough to impact "mids" -- where the guitar's fundamentals live.

You may be able to leave the cap on your wah-fuzz combo and leave it off the others and not have the attenuation issues.  Additionally, you could look for ways to improve the shielding of your pedals and possibly reduce the need for the caps at all.

Just out of curiosity -- what value caps were you using?

[slacker]

If you need caps to ground on the input of your pedals just move them so that they are only in the effected path and not the bypassed one. This can be on the circuit board or on the pin of the bypass switch that goes to the circuit board, that way your pedals will sound the same as they did before but you won't the volume loss problem when they're bypassed.

[sengo]

Did you only have one cap total, or one per pedal?

Yes I did.

Just out of curiosity -- what value caps were you using?

I never actually looked at them until now, I just grabbed them out of a pile. They are yellow monolithic caps with a 104K on them, I think that's .1uF. which I think is way too big for their purpose right?

I'm going to move them all to the bypass switch now, except the one on the wah. That one really improved the sound of the fuzz/wah combination. Unfortunately it ruins the clean tone when I try to use the wah directly with the amp. Do you think I should make it switchable so when I want to use the wah and the fuzz I can have it on, but when I want just the wah and the amp I can turn it off with the flip of the switch? I think that may be the only real way to get the best of both worlds?

Nick

[PerroGrande]

Yeah -- those caps are WAAAAAY too large for merely cleaning up RF. 

You cleaned up RF and, unfortunately, a decent amount of AF, too!