Conspiracy to Commit Electronics- Particle Accelerator and Diplomat

[Synchrony Pedalworks]

Wow! These are surprising pedals. Both add a nice boost, warmth and compression to the tone. The PA has more ability to sculpt the toan, but seems to have less gain. The Diplomat adds a nice boost that is perfect for driving the amp to breakup. Of the two, I may prefer the Diplomat. The color of the toan is slightly different than my Fender amp and compliments it nicely. Enjoy!

 

[Mentaltossflycoon]

Delicious and dangerous.

 

[giovanni]

The graphics are super classy. I love them!

 

[jessenator]

 

[Feral Feline]

WOW!

Looks like you struck paydirt!
Thar's tube-gold'n', them thar pedals.
Things really panned out for these two builds!


Ahhh the ecstacy you must be feeling...

 

[steviejr92]

Wow beautiful on both accounts man!

Perfectly executed!

 

[DailyDovetails]

Good looking builds! The particle accelerator is the one tube based build I have on my to do list. I have a Telefunken 12AT7 I have had forever I want to put in it.

 

[Rpschultz13]

So the tone switch on the Diplomat, are there frequency values that can be calculated? Is it like a notch filter? Boost?

 

[chris.knudson]

Wow! These are surprising pedals. Both add a nice boost, warmth and compression to the tone. The PA has more ability to sculpt the toan, but seems to have less gain. The Diplomat adds a nice boost that is perfect for driving the amp to breakup. Of the two, I may prefer the Diplomat. The color of the toan is slightly different than my Fender amp and compliments it nicely. Enjoy!

View attachment 63417View attachment 63419
View attachment 63420

That's beautiful -- inside and out.

 

[Synchrony Pedalworks]

So the tone switch on the Diplomat, are there frequency values that can be calculated? Is it like a notch filter? Boost?

Good question. Let’s include @vigilante398. He is the genius behind these circuit boards.

 

[vigilante398]

So the tone switch on the Diplomat, are there frequency values that can be calculated? Is it like a notch filter? Boost?

Good question. Let’s include @vigilante398. He is the genius behind these circuit boards.

It switches the coupling capacitor from the tube's plate, which controls the cutoff frequency of the gainstage. You can check out how coupling capacitor values affect response here:

Coupling Capacitor Calculator

 

[Rpschultz13]

It switches the coupling capacitor from the tube's plate, which controls the cutoff frequency of the gainstage. You can check out how coupling capacitor values affect response here:

Coupling Capacitor Calculator

So it's a High Pass Filter? A 1st order HPF I think. f = 1/(2 Pi R C). I calculate a frequency range of 7 - 870 Hz using the 470k fixed resistor after the tone selector.

 

[vigilante398]

So it's a High Pass Filter? A 1st order HPF I think. f = 1/(2 Pi R C). I calculate a frequency range of 7 - 870 Hz using the 470k fixed resistor after the tone selector.

Edit: I apologize, I initially misunderstood your question. That is incorrect.

 

[Rpschultz13]

I've done a little filter design. This scheme varies the capacitance via the rotary selector (390p - 47n) with a fixed resistor (470k). But most of the time it's the opposite with a fixed capacitor and a variable resistor (pot). I realize this is just a copied circuit so it probably wasn't thought about. But a pot instead of an 8 position selector might be better.

Quick math. You could get something very similar with a fixed 22n cap, 1M pot and an in-series 10k resistor. 7 - 723 Hz.
Now, if it was me, 7 Hz is unusable. I'd move that low range up some. Changing the pot to 100k instead of 1M would make the range 65-723 Hz which is fine for guitar. Might have to tweak some values for bass.

The other thing I'll add is usually HPF pots are anti-log (C). Although in the simulations I've done I often settle on linear B style.

 

[vigilante398]

I've done a little filter design. This scheme varies the capacitance via the rotary selector (390p - 47n) with a fixed resistor (470k). But most of the time it's the opposite with a fixed capacitor and a variable resistor (pot). I realize this is just a copied circuit so it probably wasn't thought about. But a pot instead of an 8 position selector might be better.

Quick math. You could get something very similar with a fixed 22n cap, 1M pot and an in-series 10k resistor. 7 - 723 Hz.
Now, if it was me, 7 Hz is unusable. I'd move that low range up some. Changing the pot to 100k instead of 1M would make the range 65-723 Hz which is fine for guitar. Might have to tweak some values for bass.

The other thing I'll add is usually HPF pots are anti-log (C). Although in the simulations I've done I often settle on linear B style.

Looks like I may have misinterpreted your question. In order for it to be a basic high pass filter, the R component would have to be going to ground, which it is not. The 470k resistor is part of a voltage divider with the volume pot to reduce the overall output of the circuit.

The filtering occurs by nature of the function of the coupling capacitor within the tube circuit. If you click on the link I posted above and punch in some values, this is what the frequency response looks like with the 390pF capacitor:

 

[Rpschultz13]

Ah, I understand. Thanks!

 

[Rpschultz13]

So it seems to me (I could be wrong) that the resistance to ground after the tone selector is some combination of the two 470k resistors and the 1M pot. So that resistance to ground will change (and thus the cutoff frequency) depending on the output volume. That resistance to ground will be somewhere between 470k (pot at 0%) -790k (pot at 100%).

 

[Creach]

I almost finished my Diplomat (kit from Das Musikding) i just need to add the font.

For now i just bench test it to make sure it is working good, B+ is 257V, plate voltage is 71V and cathode 1,4V.

If i understand correctly it is possible to increase the B+, i can see the HV board (sold separately) have a trimmer to set the voltage.
Is change the resistor 5 and 6 the correct way to increase B+? If yes any tips to go from 257V to 320V?

 

[vigilante398]

I almost finished my Diplomat (kit from Das Musikding) i just need to add the font.

For now i just bench test it to make sure it is working good, B+ is 257V, plate voltage is 71V and cathode 1,4V.

If i understand correctly it is possible to increase the B+, i can see the HV board (sold separately) have a trimmer to set the voltage.
Is change the resistor 5 and 6 the correct way to increase B+? If yes any tips to go from 257V to 320V?


View attachment 69220


View attachment 69218View attachment 69219

I would recommend that you start a new thread with your build and questions or post in the main Diplomat thread rather than posting on someone else's build report.

 

[Creach]

Thanks, I did not realise that it was a built report (I am new to this forum), yes sure I will post it to the main Diplomat thread.