Clean Bleed Volume Increase Mystery

bingefeller

Here is what I mean when I say clean bleed.  In this video I am plugging straight into a clean channel, the signal is guitar - Koko Boost - Boss SD-1 Waza - Amp.

So, I start off by playing the Boss SD-1 on and at the 23 second mark I turn on the Koko Boost and you can hear the overall volume increase, instead of the SD-1 getting more compressed.  This is happening because some of the clean signal is leaking through and the overdrive is just sitting on top of the clean.  Again notice the volume jump when I turn on the Koko at 33 seconds.

I then plug in the Suhr Riot and turn the Koko on and off and you don't get the clean bleed thing happening, the Suhr Riot just gets more compressed and the Koko introduces more midrange. 

The clean bleed thing doesn't just happen with the SD-1, it also happens with the Shiba Drive, Rockett Holdsworth Boost, TC Electronic Dark Matter.  Boutique or cheap pedals, happens with loads of them.

So, does anyone know why his happens and what type of OD pedals does it not happen with? 

Just a note - if I boost an overdrive channel of my amp I don't notice the clean bleed volume increase as much, it just really happens on the clean channel. 

It's nothing to do with the amp either as this has happened on both valve and solid state amps I've had in the past.

Also, it's nothing to do with the Koko that's doing the boosting - if I was to boost the SD-1 with a Micro Amp, Boss DS-1, Boss OD-1X, Suhr Riot etc the same thing would happen.

ICBM

I expect it will happen with all 'overdrive' type pedals (Tube Screamer family, of which the SD-1 is) which use the clipping diodes in the IC feedback loop, and not with 'distortion' type pedals which use the clipping diodes to ground (which I think the Riot is, since it's based on one of the Marshall pedals, I forget which).

The reason is that when they're in the feedback loop, the diodes pull down the *gain* to unity, not the final level - technically (as @ecc83 will remind me!) they are not 'clipping', they're limiting. So a volume boost in front will pass through a TS-type overdrive as a volume boost as well as an increase in distortion. But a volume boost in front of a distortion-type pedal will simply add more dirt without increasing the level because the clipping is a hard ceiling level.

So the type of 'overdrive' pedals you want are the ones which are actually 'distortion-type' pedals, eg the DOD 250, Rat, Marshall Guv'nor/Drivemaster, Fulltone OCD etc and any pedal derived from them.

NB, this is an educated guess and not complete certainty! I don't use clean boosts, and if I run one dirt pedal in front of another I would actually *want* it to do that, if I'd set the first pedal louder on purpose...

professorben

Vid appears to be a pic?

bingefeller

ICBM said:

I expect it will happen with all 'overdrive' type pedals (Tube Screamer family, of which the SD-1 is) which use the clipping diodes in the IC feedback loop, and not with 'distortion' type pedals which use the clipping diodes to ground (which I think the Riot is, since it's based on one of the Marshall pedals, I forget which).

The reason is that when they're in the feedback loop, the diodes pull down the *gain* to unity, not the final level - technically (as @ecc83 will remind me!) they are not 'clipping', they're limiting. So a volume boost in front will pass through a TS-type overdrive as a volume boost as well as an increase in distortion. But a volume boost in front of a distortion-type pedal will simply add more dirt without increasing the level because the clipping is a hard ceiling level.

So the type of 'overdrive' pedals you want are the ones which are actually 'distortion-type' pedals, eg the DOD 250, Rat, Marshall Guv'nor/Drivemaster, Fulltone OCD etc and any pedal derived from them.

NB, this is an educated guess and not complete certainty! I don't use clean boosts, and if I run one dirt pedal in front of another I would actually *want* it to do that, if I'd set the first pedal louder on purpose...

Ahh, ICBM, I knew you'd know the answer.

So I want an overdrivey sounding distortion pedal really?

professorben said:

Vid appears to be a pic?

damn, how did that happen?!  Fixed now. 

professorben

@bingefeller hmm I think @ICBM has once again nailed it. 
Sounds to me like you are using two pedals I'd use singly or as boosts. 
Ie; SD-1w ( which I used to own) boosting into another drive, in my case amp drive. 
OR Suhr Koko into another pedal, the very nature of the pedals seems to make them ideal boosters, however I've not really noticed the clean element of the sd-1w, but then I NEVER used it solely into a clean amp, oddly it was the one combination I didn't try. 
The DM I use to boost mids into a Blues Driver, which then goes into a edge of breakup clean, so it's compressing a few times over, and the Blues Driver doesn't ( to my ears) have any 'clean' mixed in. 

professorben

@bingefeller I've got an OCD clone going spare if you wanna try it out? 

bingefeller

professorben said:

@bingefeller hmm I think @ICBM has once again nailed it. 
Sounds to me like you are using two pedals I'd use singly or as boosts. 
Ie; SD-1w ( which I used to own) boosting into another drive, in my case amp drive. 
OR Suhr Koko into another pedal, the very nature of the pedals seems to make them ideal boosters, however I've not really noticed the clean element of the sd-1w, but then I NEVER used it solely into a clean amp, oddly it was the one combination I didn't try. 
The DM I use to boost mids into a Blues Driver, which then goes into a edge of breakup clean, so it's compressing a few times over, and the Blues Driver doesn't ( to my ears) have any 'clean' mixed in. 

I use to own a Blues Driver a few years ago, but can't remember if I experienced the clean bleed problem with it.  I normally would use these pedals as boosters, but just wanted to demonstrate the clean bleed thing. 

Interestingly I recall John Suhr posting on TGP saying the Shiba Drive doesn't have any clean bleed, which I disagree with, but he probably uses the term "clean bleed" for something else. 

professorben said:

@bingefeller I've got an OCD clone going spare if you wanna try it out? 

It's OK, thanks for the offer.  I'm just going to stick with the Riot and Koko boost combo for the time being.  I have a lot of pedals I want to get rid of pretty soon so I can buy some more.....

ICBM

bingefeller said:

Ahh, ICBM, I knew you'd know the answer.

Not know! Guessing based on the circuit .

bingefeller said:

So I want an overdrivey sounding distortion pedal really?

Yes, I think so.

bingefeller said:

I use to own a Blues Driver a few years ago, but can't remember if I experienced the clean bleed problem with it.

If I'm right, then the Blues Driver won't do it - that's a 'distortion-type' circuit.

bingefeller

@ICBM the Rockett Pedals Chicken Soup, based on the Nobels ODR, doesn't have the clean bleed problem if that confirms your circuit theory any.  I have no idea what circuit that pedal uses.

Here's a thread on TGP about the same issue I have.

http://www.thegearpage.net/board/index.php?threads/rockett-pedals-clean-bleed-does-the-blue-note-have-it-too.1216781/

ICBM

bingefeller said:

@ICBM the Rockett Pedals Chicken Soup, based on the Nobels ODR, doesn't have the clean bleed problem if that confirms your circuit theory any.  I have no idea what circuit that pedal uses.

Maybe . It's actually got both circuit elements - but the clipping diodes will override the feedback-loop ones because they still give a hard ceiling to the signal.

JDE

No knowledge to add, I just wanted to say thanks for this thread and the info. Clean bleed is something that has severely pissed me off for quite some time and it's nice to finally have a bit more understanding on the topic. I've tried reading about it for a while and all I ever got was discussion on what I would call "bypass bleed" or, to use a more disgusting word bandied about on forums, "leakage." This is people complaining of the tone of the pedal having some audible effect on the bypassed tone, which for dirt pedals has only ever been an issue for me with regards to the SD1 - which, I spose, leaks both ways. Vom. 

Dave_Mc

Yeah pretty much what ICBM said, I suspect.

I didn't actually notice it that badly in your video (though I am just using laptop speakers), but then again I use two feedback-clippers as boosts in my rig (timmy and sd1 or ts clone) and I don't really mind it there either.

professorben

Dave_Mc said:

Yeah pretty much what ICBM said, I suspect.

I didn't actually notice it that badly in your video (though I am just using laptop speakers), but then again I use two feedback-clippers as boosts in my rig (timmy and sd1 or ts clone) and I don't really mind it there either.

Are you running those into a valve amp? Just wondering if that might be one contributing factor? Would a SS amp be less forgiving of a 'clean bleed' than a valve amp with similar sounding base tones? 

bingefeller

professorben said:

Dave_Mc said:

Yeah pretty much what ICBM said, I suspect.

I didn't actually notice it that badly in your video (though I am just using laptop speakers), but then again I use two feedback-clippers as boosts in my rig (timmy and sd1 or ts clone) and I don't really mind it there either.

Are you running those into a valve amp? Just wondering if that might be one contributing factor? Would a SS amp be less forgiving of a 'clean bleed' than a valve amp with similar sounding base tones? 

Personally I've found no difference between the two.  

professorben

bingefeller said:

professorben said:

Dave_Mc said:

Yeah pretty much what ICBM said, I suspect.

I didn't actually notice it that badly in your video (though I am just using laptop speakers), but then again I use two feedback-clippers as boosts in my rig (timmy and sd1 or ts clone) and I don't really mind it there either.

Are you running those into a valve amp? Just wondering if that might be one contributing factor? Would a SS amp be less forgiving of a 'clean bleed' than a valve amp with similar sounding base tones? 

Personally I've found no difference between the two.  

Fair enough, I've used SS, modelling and finally Valve but never had one whilst I had the other to compare. 

Dave_Mc

professorben said:

Dave_Mc said:

Yeah pretty much what ICBM said, I suspect.

I didn't actually notice it that badly in your video (though I am just using laptop speakers), but then again I use two feedback-clippers as boosts in my rig (timmy and sd1 or ts clone) and I don't really mind it there either.

Are you running those into a valve amp? Just wondering if that might be one contributing factor? Would a SS amp be less forgiving of a 'clean bleed' than a valve amp with similar sounding base tones? 

Yes, and I have no idea, I haven't tried them into an SS amp.

JDE

It does it regardless of amp - SS or valve. I've ran an SS/valve stereo setup for years and it makes no odds. It's the pedal. Obviously it's less noticeable if the amp is dirty (if you're boosting a cranked JCM800 with a TS or SD1 then you probably won't notice it so much of course), but it's still apparent. 

bingefeller

JDE said:

It does it regardless of amp - SS or valve. I've ran an SS/valve stereo setup for years and it makes no odds. It's the pedal. Obviously it's less noticeable if the amp is dirty (if you're boosting a cranked JCM800 with a TS or SD1 then you probably won't notice it so much of course), but it's still apparent. 

apart from those pedals listed, have you found any other OD pedals that don't have the clean bleed problem?