Dirtbaby blend question

[Boba7]

Hi everyone

I've been using a Dirtbaby for years now, and Im wondering about something. The blend pot won't go to 100% dry or 100% wet, it's always a mix (with really low level of wet signal when fully CCW, but still you can hear it a bit, and same thing for full CW)

Would it help to add an output buffer to the dry path and the wet path?
Im thinking simple BJT buffers after C4 and C38, so right before the blend pot.

What to you guys think?

[mjg]

Not sure that the buffers would help, but worth a try.

I think the reason you are going to get some signal is that the blend pot is 10k, so at most you are adding a 10k resistor in the signal path.

First thing that popped into my head, If you really want to kill the signal from one or the other, maybe expose T1 which will let you completely turn down the wet, and do a similar pot to ground for the dry signal, which would let you completely turn down the dry...and sum those together with an op amp.  It means you have an extra control to fiddle with, but it would definitely let you control the mix all the way to silence from either side.

[Boba7]

Not sure that the buffers would help, but worth a try.

I think the reason you are going to get some signal is that the blend pot is 10k, so at most you are adding a 10k resistor in the signal path.

First thing that popped into my head, If you really want to kill the signal from one or the other, maybe expose T1 which will let you completely turn down the wet, and do a similar pot to ground for the dry signal, which would let you completely turn down the dry...and sum those together with an op amp.  It means you have an extra control to fiddle with, but it would definitely let you control the mix all the way to silence from either side.

Thank you for your answer!

What surprises me is that the Deluxe Memory Man actually goes to 100% dry or wet. At least in my memories of it. I remember that I could get a pure vibrato sound.
I've thought about external pots for dry and wet levels but honestly it's just too many pots! I like the simplicity of a blend pot.

Also, I've seen 10k used as a blend pot, but only with properly buffered outputs before the pot. That's why I'm asking the question!

Maybe I should just try a 50k blend pot in my Dirtbaby, and that'd be enough...

[zombie_rock123]

To get fully wet or dry I think you'd need to offboard the blend pot and convert it to be something similar to the Pork Barrel blend with the middle lug connected to ground or VB. I think it was mentioned in one of the development threads about blend circuits best working this way (?) as it'll shunt all of the signal you don't want somewhere, rather than being passive.

I wouldn't have a suggestion as to the accompanying resistor values best suited. Nor do I really have any idea what I'm talking about but as the saying goes, the best way to get the right answer is to post the wrong one 

[madbean]

What surprises me is that the Deluxe Memory Man actually goes to 100% dry or wet.

Funny enough, this seems to be due to the large electrolytic caps used in the DMM on the dry/wet outputs. I remember posting this finding here a long long time ago (after I had tried 1uF film caps in the Dirtbag project) and never quite knowing exactly why (maybe due to the cap's reactance/ESR, or something else).

You could try swapping C4 for 47uF and C38 for 22uF like the DMM and see if you get more range on the blend pot (with the negative side going toward the pot in each case).

[Boba7]

To get fully wet or dry I think you'd need to offboard the blend pot and convert it to be something similar to the Pork Barrel blend with the middle lug connected to ground or VB. I think it was mentioned in one of the development threads about blend circuits best working this way (?) as it'll shunt all of the signal you don't want somewhere, rather than being passive.

I wouldn't have a suggestion as to the accompanying resistor values best suited. Nor do I really have any idea what I'm talking about but as the saying goes, the best way to get the right answer is to post the wrong one 

Thanks! Yes I thought about doing that, a properly done mix section, but I like the idea of having the real DMM output section...

[Boba7]

What surprises me is that the Deluxe Memory Man actually goes to 100% dry or wet.

Funny enough, this seems to be due to the large electrolytic caps used in the DMM on the dry/wet outputs. I remember posting this finding here a long long time ago (after I had tried 1uF film caps in the Dirtbag project) and never quite knowing exactly why (maybe due to the cap's reactance/ESR, or something else).

You could try swapping C4 for 47uF and C38 for 22uF like the DMM and see if you get more range on the blend pot (with the negative side going toward the pot in each case).

Wow, really... I dont know much but I would never have imagined it would have an impact! I'll definitely try it out soon, and I'll report here
Thanks a lot!

[Boba7]

And yeah, it does make a difference! Thanks a lot!