Rpschultz13
Well-known member
What the he!! is that brown thing that says DALE on it where the 2k2 should be next to the 22u?
Diplomat - Matchless DC30's EF86 Channel
- Thread starter vigilante398
- Start date
What the he!! is that brown thing that says DALE on it where the 2k2 should be next to the 22u?
Hehe it is a 2k2 resistor, i ordered a Diplomat as a kit and looks like they made a mistake, a 2k2 resistor was missing (a 220k was extra). I only had this 2k2 dale resistor in my stock.
I already ordered the 390R resistor and a 350V capacitor to increase the B+, should be deliver next week.
Rpschultz13
Well-known member
Awesome. Lmk how it goes. That seems like something I'll do after I get mine built. Just waiting on the enclosure from Tayda...
I just tried the 390R resistor, the B+ was 376V, so if 560R is 257V and 390R is 376V... Seems like 470R will be close to 320V.
Just spend some time to check the B+ voltage, actually I had 257V instead of the expected 240V because I waited 2 to 3 min to do the measurement (the time for the valve's heater to kick in), but after waited 15 min the voltage dropped 15V. It need 30 minutes to be stable (15 to 30 min the voltage dropped 5V).
Now i have parallel 560R and 2k2 so a total of 450R it give 300V B+.
Now i have parallel 560R and 2k2 so a total of 450R it give 300V B+.
Rpschultz13
Well-known member
Just finished mine, it works! So how do I make the LED brighter, I put a yellow in and it’s kinda dull. Looks like it doesn’t have a traditional LEDR, but taps off the tube voltage. It may not be adjustable, although I could tap off 9v but would rather not.
vigilante398
Authorized Vendor
It has a 1k CLR off the 9V already, you can decrease the value of that resistor to increase the brightness of your LED.
bluedmc777
Well-known member
FWIW-I’ve actually been using some old tubes that I love that have become microphonic in these pedals and they sound absolutely fine, I’m referring to tubes that have started displaying mechanical noise in my combo amps. I’ve got an old 50s Sylvania long black plate as well as a Raytheon LBP that I had to pull out of the combo but sound great in the particle accelerator.
vigilante398
Authorized Vendor
Put a resistor (anywhere from 240kΩ to 1MΩ) in line with pin 3 of the volume pot.
So just pull pin 3 from pot and put resistor between it and PCB?
vigilante398
Authorized Vendor
Yup, exactly that.
vigilante398
Authorized Vendor
The higher the resistance you're putting in line, the lower the volume is going to be.
I added a 1M resistor and it didn't appear to lower the volume much at all.
It's probably because you have the volume at a low setting.
It is a logarithmic potentiometer so you may have only 10% output when you set it on 5.
Let say you are at 2,5 on the dial, you only have 5% output, you adjust the resistor... So now you have around 2,5% output at 2,5. It's not a big change.
The biggest effect will be at higher setting, like 6 to 10. Because there the output will go from 10 to 100%.
Tassieviking
Active member
I would increase the resistance of the 470k resistor (R21) that is on the left side of the 100uF capacitor.
I thought that the bright cap (C13 180pF just above R21) would cause the highs to bypass the volume pot, especially at low volumes.
The Bright cap would also bypass the added resistor on leg 3 of the pot, at least in the higher frequencies. (If I understand it correctly)
The 470k resistor is inline with the volume pot and reduces the output of the tone switch by about 1/3 already so making it 1M would lower the volume a little bit more.
I would try a 1M5 or 2M or thereabout if you need to lower it a lot.
Since I love modding pedals I would add a switch so I could select a high or low output setting if I did it.
EDIT: This explains it better then I do:
www.ampbooks.com
I thought that the bright cap (C13 180pF just above R21) would cause the highs to bypass the volume pot, especially at low volumes.
The Bright cap would also bypass the added resistor on leg 3 of the pot, at least in the higher frequencies. (If I understand it correctly)
The 470k resistor is inline with the volume pot and reduces the output of the tone switch by about 1/3 already so making it 1M would lower the volume a little bit more.
I would try a 1M5 or 2M or thereabout if you need to lower it a lot.
Since I love modding pedals I would add a switch so I could select a high or low output setting if I did it.
EDIT: This explains it better then I do:
Bright Boost Capacitor Calculator
Last edited:
I've just finished my build via Klaus at Das Muzikding, my version had a resistor deleleted from the board R21 maybe, to the left of 100uf cap.
Initial impression is that it sounds great, the rotary tone produces good thin to thick tones but it is very loud. I've tacked in a 22k resistor across lugs 1 and 3 and this has tamed the output to pedal levels. I'm tempted to put this on a toggle as I might add passive send /return loop to one of my amps to try it as a preamp.
Initial impression is that it sounds great, the rotary tone produces good thin to thick tones but it is very loud. I've tacked in a 22k resistor across lugs 1 and 3 and this has tamed the output to pedal levels. I'm tempted to put this on a toggle as I might add passive send /return loop to one of my amps to try it as a preamp.
Tassieviking
Active member
If you have a link where R21 470k resistor should be you have increased the output of the pedal by about 30%, R21 limits the output of the signal.
If you add a 22k resistor across leg 1-3 on the volume pot you have also changed the tone of the pedal a lot, you have lost a lot of the low end of the signal.
I think it would be a lot safer for the tube if you install R21 at 470k or even higher if you want to drop the output level, and then you could place a switch across R21 to increase the output level when the switch shorts out R21.
You can use this calculator to see what changing the volume pot to less then 22k will do to the signal, CG is the capacitor you select with the rotary switch (390pF - 47nF) and RV is the volume pot 1000k or 22k if you add the 22k resistor across it. The "Control % Resistance" is where the volume pot is set and I just leave it set at 100%, and "Output Impedance" is the impedance of the tube output but it is not crucial in this case so I would leave it alone as well in this case (unless you really want to work it out just for fun).
I could be wrong but that is what I think is happening in this case.
Cheers
Mick
PS....a picture of your pedal would be nice to see as well.
