Internal Dumbleator Question

[Structo]

Say if a fellow wanted to build a Dumbleator loop into his ODS style amp, then use the output pot of the loop as a master volume instead of the regular 1M master volume pot.
How would you configure that?

Would you place a fixed resistor in the place of the 1M Master?

If so, what value, like a 500K or 220K?

[erwin_ve]

Say if a fellow wanted to build a Dumbleator loop into his ODS style amp, then use the output pot of the loop as a master volume instead of the regular 1M master volume pot.
How would you configure that?

Would you place a fixed resistor in the place of the 1M Master?

If so, what value, like a 500K or 220K?

Instead of the master I used a fixed voltage divider; 680K-330K.
And the output pot of the loop on the frontpanel.

[Structo]

So like this?

Did that give enough gain without overdriving the next stage?

[heisthl]

My Fav values for MV sub are 270k/100k to ground for cleaner amps and 270k/220k when you want a dirtier amp - The concept of return as a master works really well.

[markusw]

Do you guys include a bright cap with the fixed voltage divider ?

Peace,

Markus

[heisthl]

Tried a few values, settled on 30p, actually like it better without any.

[Structo]

Thanks Henry, I was hoping you would pop in.

Could a person put a trimmer for the master then dial in the sweetness?
Or is that too much current?

[markusw]

Tried a few values, settled on 30p, actually like it better without any.

Cool! Thanks!

[heisthl]

Thanks Henry, I was hoping you would pop in.

Could a person put a trimmer for the master then dial in the sweetness?
Or is that too much current?

Trimmers work just fine... more junk to mess with

[erwin_ve]

So like this?

Did that give enough gain without overdriving the next stage?

Yes like that. It's supposed to simulate at 30% taper pot half way up.

[butwhatif]

I like the straightforward concept of the classic master as we know it. I have a trimmer in the send and return, but have set the sweet spot for each, and pretty much leave them alone. As long as normal play mast volume is between 3-6, I'm happy. I like the thru sound of the loop with nothing plugged into it.

[Luthierwnc]

I'm going to take this slightly off topic but one school is that you need an outboard D'lator with medium capacitance (around 25 puffs per foot) send and return cables to take some of the highs off. Those units (if stock) have whopping bright caps.

If you are building one on-board, do your reduce or delete the bright caps according to how much capacitance you expect to lose in the cable runs? In the end, I'd just hardwire them by ear but I'd be interested in knowing if anyone has put more study into this,

Thanks, Skip

[martin manning]

My D'lator is built to the schematic with the 0.001 bright on the drive and 270p on the recover out, and I'm using 3' cables to connect it to a low-plate classic. For a SC guitar the drive bright is way too much, but the rec out bright sounds very good. An acoustic-electric (Taylor w/ Expression system) likes exactly the opposite- drive bright on, rec out off, and in general this is a really great sounding acoustic rig.

[Structo]

Yeah, I don't really use the bright switches on the D'lator.

I have tried them of course and I agree with Martin that the .001 is mucho bright!

I wonder why he chose such a large bright cap.
I think I changed mine to 500pf.