Tonegeek wrote:Mat,
I had a similar issue with my onboard d'lator. Got hum at certain settings. I moved wires around too and it seemed like it made a difference, but not really. I ended up adding a 100k resistor ahead of the .047 coupler to the d'lator. Don't know why this works, but since the noise was the worst when my clean master was off, I was thinking that somehow the cathode follower does not like seeing ground on its input which is what happens when the clean master is all the way down. I think a 10k resistor would work just as well, long as there is some resistance there. Give it a try.
The thing in my case is that when the clean master is at zero there is no noise. Well actually now that I've been running the amp bit louder the noise is there but it is considerably lower level. But as soon as I open the clean master pot only a bit, it will give nasty noise, which does not get louder if cranking the pot but the character of the noise changes a bit brighter.
I will try a 10k in front of the coupling cap and see if that makes a difference. I havent moved the wires yet (just ended my summer holiday ) but will do that also ASAP.
Tonegeek wrote:Mat,
I had a similar issue with my onboard d'lator. Got hum at certain settings. I moved wires around too and it seemed like it made a difference, but not really. I ended up adding a 100k resistor ahead of the .047 coupler to the d'lator. Don't know why this works, but since the noise was the worst when my clean master was off, I was thinking that somehow the cathode follower does not like seeing ground on its input which is what happens when the clean master is all the way down. I think a 10k resistor would work just as well, long as there is some resistance there. Give it a try.
Tonegeek, BIG thanks The 10k did it ! Yeah! I still might reroute the OT secondaries...
mat wrote:
Tonegeek, BIG thanks The 10k did it ! Yeah! I still might reroute the OT secondaries...
I am beginning to see why some recommend not putting the d'ator onboard. Seems there are lots of little issues with it being internal. Glad you got the noise out! Wish someone could tell me why this works...
mat wrote:
Tonegeek, BIG thanks The 10k did it ! Yeah! I still might reroute the OT secondaries...
I am beginning to see why some recommend not putting the d'ator onboard. Seems there are lots of little issues with it being internal. Glad you got the noise out! Wish someone could tell me why this works...
whit
I would also like to know what is hapening in there. The clean master at zero or at full -> non noise
mat wrote:
Tonegeek, BIG thanks The 10k did it ! Yeah! I still might reroute the OT secondaries...
I am beginning to see why some recommend not putting the d'ator onboard. Seems there are lots of little issues with it being internal. Glad you got the noise out! Wish someone could tell me why this works...
whit
Beats me - I've done several with internal loops and have never needed to do this. It's good to know in case this bites a future build. Just out of curiousity are you using tooth washers when you mount the MV pot? (Is the pot case grounded to the chassis)
mat wrote:
Tonegeek, BIG thanks The 10k did it ! Yeah! I still might reroute the OT secondaries...
I am beginning to see why some recommend not putting the d'ator onboard. Seems there are lots of little issues with it being internal. Glad you got the noise out! Wish someone could tell me why this works...
whit
Beats me - I've done several with internal loops and have never needed to do this. It's good to know in case this bites a future build. Just out of curiousity are you using tooth washers when you mount the MV pot? (Is the pot case grounded to the chassis)
No tooth washer but the pot case contacts the chassis.
Not really unless you've roughed up the backside and really torqued on the nut - you need the teeth to imprint into the chassis and the pot or you could do what you see in some real Dumble's (and many old tube amps), solder right to the pot case.
heisthl wrote:Not really unless you've roughed up the backside and really torqued on the nut - you need the teeth to imprint into the chassis and the pot or you could do what you see in some real Dumble's (and many old tube amps), solder right to the pot case.
Sorry for my noobiness but what would it matter if the pot case touches to the chassis or not? I'm running the ground lug of the pot to the ground bus that contacts the chassis only at near of the input jack. Just trying to learn
It can be a source of noise that you don't find with normal methods. A potentiometer is a big open area to collect surrounding noise unless it is sheilded. When you use a star washer it gets grounded and the case acts like a sheild. The "chopstick" method won't find it, but if you carefully touch each pot case with your ungrounded finger you will hear noise unless the case is grounded (a muted version of touching the tip of a plugged in patch cord). Durning normal operation the knob insulates the pot from your fingers so you wouldn't catch it there either. I just worked on a friends D'lite and the preamp volume pot did this before I added a star washer.
) but will do that also ASAP.
The 10k did it ! Yeah! 
