The Tone pot in the OD, does this have a any effect on the OD in terms the actual overdrive, can the amps treble/bass controls do the tonal effect??
Can the active loop send level be fixed at a set level and the pot mounted on the circuit board as a set and forget,does it need to be adjusted often???
The pot used as the FX level, T said that it worked great as a MASTER VOL, I have had great success with the PPIMV and was going to use it in this build. Could this FX level replace the PPIMV as a master vol???
I have had a switch that in other build that allows FIX and CATHODE biasing will the FIX bias work with this PPIMV??
I have had a switch that in other build that allows FIX and CATHODE biasing will the FIX bias work with this PPIMV??yes
I have had a switch that in other build that allows FIX and CATHODE biasing will the FIX bias work with this PPIMV??
yes
Sluckey,
I am SO glad that you are around to help us out! I genuinely appreciate your seeing in our(my) blindspots and keeping us (me) on track! Thanks, my friend!
Your very generous with your help and time! So many of my builds would've remained problematic without your knowledge and generousity.
With respect, Tubenit
For fixed bias PPIMV do you not need the resistors & caps after the wipers going towards the 220k resistors w/ the neg bias voltage as in schematic below???QuoteI have had a switch that in other build that allows FIX and CATHODE biasing will the FIX bias work with this PPIMV??yes
*Need Sluckey's help on this "universal" PPIMV schematic if it can be done or not?Are you referring to the Mission Amps schematic you posted? If so, yes, that MV will work well with a fixed bias amp.
relays i have don't have the + marked on them,so i will assume that it can be wired any way and a diode won't be requiredYes, you can wire the coil either way.
Or, you can eliminate a couple caps and resistors by using the MV in the schematic Timbo posted in the first message in this thread.
Here's a pic of a board I recently built with 8x relays built right onto the board, along with the DC power supply/voltage regulator.Geezer, are you utilizing a special wiring scheme for the power supply to those relays?.....I think I see that one "blocking" diode appears to be serving 2 relay sockets...?
Well there's one difference. The bottom of the MV pots connect to ground for a cathode biased amp, but the bottom of the MV pots connects to bias for a fixed bias amp. Other than that difference, the circuits are the same.Does anyone have the two drawings of a PPIMV for comparrison: one for cathode bias and one for fixed bias to see & look at the differences and which can be printed out? TIA, Keo
Was there any reason for two caps coming off the pots as shown in the Mission Amps schematic for the fixed bias version?Yes. The caps isolate the MV from the bias circuit, preventing the MV from changing the bias to the output tubes. That would happen since Bruce's circuit connects the MV pots to ground, therefore the MV would provide a current path for the bias voltage which will create a voltage divider that changes the bias to the tubes. This problem does not exist if you connect the MV pots to the bias voltage rather than ground, eliminating the need for the extra isolation/blocking caps.
This would allow better "lower vol" clean-ish tones from a 50watt amp lets say.I don't have any hands on VVR experience, but getting a low volume clean tone from a big amp has never been a problem. Just turn the volume down. I believe VVR is all about getting a low volume "dirty" sound from a big amp.
(can you spot the GOOF)Do you mean you weren't trying to merge those 2 tubes together for a little transconductance mojo?? :think1:
i'm thinking that being able to dial it down to 0v may not be a good thingI agree.
Quite an ambitious project. And nicely done too.
So i disconnected the wire from pin7 V2 and i STILL are getting signal through
you are missing 2 caps in the PPIMV ckt. - in fixed bias mode - you'll upset power tube bias without them. please see attached schematic.The 2 caps you added will destroy the tube bias for fixed bias as well as cathode bias. Timbo's bias circuit works fine just as he has it drawn.
Quoteyou are missing 2 caps in the PPIMV ckt. - in fixed bias mode - you'll upset power tube bias without them. please see attached schematic.The 2 caps you added will destroy the tube bias for fixed bias as well as cathode bias. Timbo's bias circuit works fine just as he has it drawn.