Dumbleator Tone

[Structo]

I have come to the conclusion that my D'lator is killing the high end of the amp connected to it.

The other day I installed some passive jacks on an amp and this amp is pretty bright and chimey.
When going through the D'lator the top end is squashed.
Some of this may be due to the two 15' cables that I run to and from my pedal board, so there is 30' of cable there adding capacitance.

I don't really care for the tone of the bright caps engaged to add highs.

This loop has a true bypass switch on it so I can hear instantly the difference with or without the loop engaged and it is definitely brighter when it is bypassed.

Can any of you smart guys tell me what cap or caps to change the value of to allow more highs to come through?

Yesterday I reduced the .1uF cap on the output to .047uF and didn't really notice any difference.

I was thinking that possibly lowering the value of the 220K/ 500pf filter resistor to 200K or 150K?
That should allow more highs to pass right?
Or change the 500pf to 250pf?

Am I right in thinking that I should leave the cathode follower components alone and try to adjust the recovery side of the loop?
So that basically leaves the 220K/250pf and the .1uF to play with.
Would reducing the 47uF cathode cap change anything? I would think not but I am not sure how to go about this.

Thanks,
Tom

[dogears]

15 foot cables will kill highs. Maybe try low capacitance 10 footers....

What kind of 15 footers? This actually matters a lot.

Lava ELC is a nice clear cable that may help.

[markusw]

You might want to try to reduce the 220k of the 220k/250p combo to 10k. I prefer it with a 10k than with a 220k, FWIW.....

Peace,

Markus

[Structo]

The cables are good quality Gotham with gold plated Neutrik plugs.

I think I will try a smaller resistor on the R/C filter.
I have a resistor substitution box that will make choosing the value easier.
Forgot I even had that thing.

[butwhatif]

the 220k grid return kills the hi end, it can be changed to taste

[Structo]

Thanks!

I cut one of the cables in half so the cable capacitance is halved.
Don't really notice much of a difference.
I'll try lowering that resistor.
I can't remember on those RC pairs, if I lower the cap value does that increase or decrease the highs?


Do those of you that built the D'lator later on and played your amp without one, notice a difference in the top end after connecting the loop?
I like my loop a lot, just think it is dampening the top half too much.

I put a bypass switch on my loop so I can hear a real time difference between the loop and no loop.

[butwhatif]

the cap becomes a moot point as the resistance is decreased

[dogears]

Dumble used a bright cap on the master volumes of amps that were run with Dumbleators. Worked for him!

What size do you have?

[Structo]

47pf

But the thing is, I want to be able to use this loop with at least one other amp or possibly more.
I like the control it gives me as well as the superior way I can use my effects with it.

[ericlee]

Hi Structo,

I have three way toggle mini switch on master with 47 and 100pf caps. Middle position is off. Very helpful wiht a loop management, also great if I’m using 15’’ bass speakers.
Check out the layout
http://www.drika.biz/OTSIKA.JPG
Cheers

[markusw]

Do those of you that built the D'lator later on and played your amp without one, notice a difference in the top end after connecting the loop?

Definitely. I also have a bypass relay in my D'lator. However, completely disconnecting the D'lator is even more noticeable than just the bypass within the D'lator even without any cables in the send/return jacks of the D'lator.

But the thing is, I want to be able to use this loop with at least one other amp or possibly more.

Another thing you probably could try would be to decrease the D'lator's send pot's value from 250k to 25k. Should reduce/eliminate the low pass filtering effect of the "send cable". If my calculations are right the filter cutoff of a 470n/25k high pass should still be around 13 Hz. So reducing the pot to 25k shouldn't remove any bottom end....

What do you guys think?

[Max]

Dumble used a bright cap on the master volumes of amps that were run with Dumbleators.

As far as I know he did this only on some of these. As far as I know many if not most of the Dumble amps that are or have been used with a Dumblelator did not have this bright cap on the master volume.

BTW: I never had any "lost highs" problems when using a Dumble amp with a Dumblelator.

Cheers

Max

[dogears]

You are correct. I did not specify all amps. However, some of my favorite tones were of these bright cap mastered Dumbles.

I do agree about the Dumbleator not hurting the tone on a non bright cap Dumble. However, only when short cables are used!!

Dumble used a bright cap on the master volumes of amps that were run with Dumbleators.

As far as I know he did this only on some of these. As far as I know many if not most of the Dumble amps that are or have been used with a Dumblelator did not have this bright cap on the master volume.

BTW: I never had any "lost highs" problems when using a Dumble amp with a Dumblelator.

Cheers

Max

[Structo]

Thanks for the good discussion.

While I understand how a bright cap works and can see it used, I personally don't really like the tone of it in the D'lator.
When I use one or both on the loop, the frequencies that it adds or effects
are high such as a presence control adds.

I would rather just make the loop more transparent and not color the tone too much.
Maybe that is asking too much.
I'm going to try lowering the grid stopper value.

I've tried to scour the internet for info about the grid stopper and parallel cap network filter and I'm not finding what I want to know.
Perhaps I wasn't using the correct words for what I was searching for.
If I wanted less attenuation of the highs, would I go larger or smaller on the cap?
I'm thinking smaller but I guess I will just have to try it.

I suppose I should just fire the iron up and try some different values.
I was just hoping to understand it better.

[hitchcaster]

maybe you should try different bright caps in the dumbleator. if your using mica, go ceramic... maybe try lower values till you like what you hear