Diplomat - Matchless DC30's EF86 Channel

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.
 
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.
Awesome. Lmk how it goes. That seems like something I'll do after I get mine built. Just waiting on the enclosure from Tayda...
 
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+.
 
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.
 
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.
It has a 1k CLR off the 9V already, you can decrease the value of that resistor to increase the brightness of your LED.

IMG_20240317_155906.jpg
 
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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.
 
Finally finished this build for someone. Sounds great and it stacks very well with overdrives. I am definitely going to build another for myself. I used a Tayda candy yellow enclosure and TAD EF86.
 

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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%.
 
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:
 
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