Help with onboard dlator for non HRM

[Tonegeek]

I am preparing to build an amp similar to #124 and want to incorporate a dlator. I have done this successfully with 2 other amps, but they were both HRM amps and had clean masters. This one won't have the clean master and I am concerned that the level will be too hot for the input of the dlator. actually, i am hoping to also eliminate the master and let the dlator return level be the global master. This is the case with my HRM amps and it works well. But having the clean master gives me more control over the level I hit the dlator with in clean mode.

I tried to simulate how this non HRM might work by turning the clean master to 100% on my HRM amp and it was a bit difficult to get the OD to sound decent because the volume ended up being set lower than I normally set it and the send and return pots of the dlator also had to be turned down which affected the tone as well. I would like to get suggestions from anyone who has already solved this problem. I can always add a clean master to this circuit, but I really would rather not. I also thought about adding a trim pot as a voltage divider on the clean side (a hidden master if you will) and just turning it down slightly to allow me to open up the dlator controls a bit more which I think would help the sound. But thats with the HRM, maybe the new amp won't need that.

[butwhatif]

I built one internal with trims for the send and return which i really never adjust once i found the spots. My $ .03 is that the normal master replete w/ the small byp cap is part of the sound, or can be depending on how hi u run it.

[Tonegeek]

My $ .03 is that the normal master replete w/ the small byp cap is part of the sound, or can be depending on how hi u run it.

I agree. Changing the load and gain structure can change the tone. I did a little testing and it seems that if I remove the master, then there is a good chance I will over drive not the follower, but the input to the recovery stage of the loop. Of course even with a master the same thing could happen if you turn the master all the way up and don't bring the loop send level way down (I am just going straight through the loop for now, no FX in it). What I might try is leaving the master in, putting the send on a trimmer and leaving the return on a pot on the back panel. Now the master becomes my send level and the return pot is there just to deal with situations where the FX are misbehaving. Normally you could set it and forget it. On my HRM I normally leave the loop controls at 12 oclock and it works with all volume levels.

Mainly I just want this to be uncomplicated with just enough controls to be manageable.

[butwhatif]

+1 on the uncomplicated bent, when i get to a gig i want to play, not adjust.
I also have 100K between send and return in the bare loop, it helps w/ the tone. Another item which can be adjusted to taste is the 250K/500pF grid return- this is a real tone modifier, and a smaller resistor w/ no cap may work better.

[Tonegeek]

+1 on the uncomplicated bent, when i get to a gig i want to play, not adjust.
I also have 100K between send and return in the bare loop, it helps w/ the tone. Another item which can be adjusted to taste is the 250K/500pF grid return- this is a real tone modifier, and a smaller resistor w/ no cap may work better.

I have played with that grid network in the past and used a 68k in place of the 220k, but went back to the 220k. There is a loss of high end in that area which you helped me diagnose in another thread.

The fact that you use trimmers gave me an idea about putting the dlator in the non hrm amp and still keeping it simple:
Add the dlator between the master and the PI, but use a trimmer for the send level. Heres the trick though- put the master on the back panel and label it "send". Then put the recovery level on the front panel and label it "Master", in place where the original master was. You still get the interaction of the original master on the tone, but the actual volume is controlled by the recovery level. I simulated this today and it works pretty well, you just have to get the trim send set correctly (seems to work best around 25% from off) so you don't crush the recovery input. When you have FX in the loop you can still control the level to them with the master turned "Send".

whit

[butwhatif]

That might work if u r satisfied with the tone at a low level-- from my experiments the return to pi needed to be up a bit for a full tone, seemed like it got thin at low trim settings-- i still use the master as 'master'