Aion Plasma Colorsound Powerboost debug help!

[HamSandwich]

Hola - thanks for your help.

I'm attempting my second power boost, this time from Aion's Plasma project.

https://aionelectronics.com/wp-content/uploads/2015/05/aion-plasma-colorsound-overdriver-documentation.pdf

I attempted this pedal on perf in 2009 and it didn't work. Now, 9 years later, the second try still doesn't work 

I built it based on the Power Boost parts in the build doc. Things I changed:
- I'm using a MAX1044 based voltage doubler on perf, pins 1/8 connected, to get 18V.
- I left of D1 because it's present on the voltage doubler.
- I used a 10kA for the Gain pot rather than the 1kC (acceptable based on the build doc and the original pedal).
- I ran the the CLR directly from the power jack as to not draw the limited mA from the 1044 to power the LED. LED does work in this set up. So rather than the board LED switching, it goes power jack -> resistor -> LED on board -> Switch -> Ground
- Not really a mod, but C12 is an electro in the powerboost and the PCB doesn't have a polarity marked, so I put the negative side towards the volume control per some schematics of original units I've seen online.
- Also not a mod, but I'm using enclosed jacks, so the enclosure isn't grounded. I've grounded jacks, switch, PCB and power jack via wire. Don't think that's an issue, but thought I'd provide as much info as possible!

Voltages:
1Spot
9.45 V

Supply to board
18.04 V

Q1 2N5088
Q1
C 5.83
B 3.66
E 3.12

Q2 2N5088
C 9.99
B 5.83
E 5.18

Q3 2N5088
C 10.10
B 2.64
E 2.02

There is some issues with biasing the transistors. All three trimmers are basically turned all the way down. For Q1, I can't get it to go any lower than the 5.83V (build doc says 5V). Q1 and Q2 are almost all the way down, but have a little bit more travel on the trimmer before they bottom out.

It does pass sound, the EQ and the volume control work, but the gain control does nothing - no boost. With volume maxed, and the EQ set in the center, I get a slight volume drop. For testing, I've been plugging the pedal directly into my focusrite into my PC. I'd think if this thing was functioning, I'd be able to clip the input stage of the focusrite, but it isn't happening.

I have checked all resistor values using their color bands and all capacitor ratings. I have checked the pin out the transistors (they are also facing in the direction of the silkscreen). Working on getting a photo of the board up.

Any and all help is appreciated! Thanks.

Thanks,
Matt

[HamSandwich]

I just found my old DIYSB thread.. I had the same problem 

https://www.diystompboxes.com/smfforum/index.php?topic=80175.0

What are the chances?

[HamSandwich]

I have tried a batch of 2N5088's that I've had for a while and I'm having the same issue - if not worse. To get unity gain I have to have the volume full up. The Gain knob does very little right until it reaches fully on, then it gets a little sputtery, but there's no change in volume throughout the knob range. Still can't get Q1 collector below 5.8 and I can't really get Q2 or Q3 much above 10V.

Any ideas on what to do next?

[HamSandwich]

For posterity - intripped over on DIYSB went through the build doc and found there was a mistake. R6 should be *omitted* and not jump'd. Boosting my amp to the high heavens now.

[JC103]

This project is on the to do list (18v specs). The mistake was on your end or an error in the build doc?

[HamSandwich]

Mistake was on the build doc. Aion has since fixed the mistake.

[JC103]

Cool. Good to know. I guess no one ever builds the 18v lol.

[HamSandwich]

Cool. Good to know. I guess no one ever builds the 18v lol.

Guess not! The power boost version didn't work at 9V either. Sort of surprised the project was around for 3 years without anyone building it.