I don't use the loop brightcap. However, I did use it on this clip of Tag's ex-Dumble since the Dumble had no bright cap on the master. My cables were close to 200pf per side. The Dumble tone was dead (note to Max) unless I used the 'lator bright switch. Recovery side btw. The Send bright was way too bright.
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.
dogears wrote:I don't use the loop brightcap. However, I did use it on this clip of Tag's ex-Dumble since the Dumble had no bright cap on the master. My cables were close to 200pf per side. The Dumble tone was dead (note to Max) unless I used the 'lator bright switch. Recovery side btw. The Send bright was way too bright.
I agree, that original .001uF bright cap on the Send is way too much.
I had a look I have a 330pf on the send pot and a 270pf on the recovery.
Do you guys with the non HRM ODS amps find your tone stacks very responsive?
I play through a 2 x 12 with EVM 12L's.
I ended up lowering my slope resistor to 120K which helped just a little.
But I really don't hear as much change as I would like to hear with the TMB controls.
I would think that if I turned up the treble it would ice pick but it doesn't.
Which is strange because I played a guys Super Reverb a while back and his controls seemed to work good.
Of course those only have bass and treble.
I know the ODS tone stack is a bit different but it is mostly like a Fender.
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.
If you want less attenuation of the highs you needed to increase the cap. However, if you believe Spice simulations even increasing the cap to 2n has less influence than decreasing the 220k to 10k....
Hey Structo have you tried different tubes to see if makes any improvement. I know some 12ax7s can be darker than others, sounding like a loss of highend. Just a thought.
if u use the loop, and then bybass the loop and there's a vast difference, it makes for an even more convoluted tonequest. last thing i want is a loop that is not flat, and if you put a sq wave thru the loop as we know it, you'll see the rolloff. and if you investigate further you will find that the 220k return grid resistor is the major factor in this. i think 47k is in mine.
I tried my resistor substitution box yesterday and tried a few different values.
I was a bit surprised that the difference between the 220K and lower values wasn't more apparent.
I put a 100k in it for now but may go lower today after playing it.
It was getting late in the night so I didn't get to hear it at volume.
According to Spice simulations you can get the D'lator pretty flat if you also reduce the send pot to 25k. Even 300-400p of cable connected to the send jack should'nt cause any significant loss of highs if the D'lator itself is connected to the amp via short, low capacity cables.
Without removing the send pot you could try to add a 25k-30k resistor from the top of the send pot to its wiper. It will mess up with the taper but at least it would give you an idea what you get if you reduce the send pot to 25k.....
Cool, thanks for running that sim.
I have Spice LT but never really got into it enough to know how to run sims.
I will parallel a 10K with the 100k (for a total of 9.9K) today and see how that sounds.
Then try the added resistor to the Send pot to see how that sounds.
The cables from the loop to amp are 6 inch patch cables.
The cables to the pedal board are now 7.5 ft as I cut one of the cables in half so now I have 15 ft total to and from the board.
I ended up just installing a 10K resistor.
When I tried it, there is a bit more high end.
I haven't tried it at loud volume yet but the wife is going shopping later and I will give it a fair listen.
What was interesting is when I had the 100K in there, I clipped my resistor box across that and started with 1M then dialed downward.
The results were a bit more subtle than I expected.
I'll give this tweak a fair chance then decide if I need to change anything else.
you could also make sure your internal shielded wire in the dumbleator is good quality/ low pf... also, ive had instances where the insulation melted a bit and didn't cause a short, but was shorting SOME highs to ground... you really shouldn't have to mod this thing to get it to work right IMHO. good luck though
