GTFO - Full tube high-gain pedal (2x 12AX7)

[njkmonty]

ok, thanks

[njkmonty]

just wish to post that i have completed the latest version, and all working first time, i even made a temporary tone stack board to hear the difference.

one thing ive noticed it the output signal appears slightly below the bypass levels, (enough to notice),
also sounds a little gravely, Ive built a slo clone before so im familiar with the desired outcome. i will try and post my voltages etc soon.
have others found results similar to this?  ive got a few new and old stuck tubes to try, should this make a huge difference?

[gtudoran]

@njkmonty: hmm that is strange ... the only thing i had to modify on this pedal was the high volume output (the unity gain was at about 9-10 o'clock) - please be sure that you have the right values resistors at the volume/tone control section. The low volume output is with the tonestack or with the original tone control?

Some voltages would be nice, also this behavior could be because of a faulty section of one tube (highly improbable but...)

Regards,
Gabriel

[njkmonty]

ill get some voltages for you,
the volume etc occured with either tonestack

[gtudoran]

Or could be a faulty pot (volume pot) - you can change POT3 in the PDF schematic with a 1M fixed resistor and collect the output on the junction of the resistor and C6 - be careful can get very loud - if you have a blast of volume there, then your problem in the volume pot or the tone stage.

[njkmonty]

this is what i found..
if i connect amp at end of c6 (bypassing tonestack  i get equal volume to bypass, but its a bit gravely/gritty.
i connected my tbm tonestack to this point thinking it may be the onboard tone control, but the same thing, a drop in volume.

some voltages...
ic
1  6.5mv
2  5.3v
3  5.2v
4  11.14v
5  7.45v
6  5.3v
7  5.3v
8  11.14v


valve 1 ( next to distortion pot)
1  300v for 2 seconds then drops down to a steady 157v?
2  9mv
3  1.12v
4  ground
5  11.14v
6  215v
7  18mv
8  1.4v
9  5.7v 

valve 2 ( next to volume and tone  pot)
1  310v
2  11mv
3  3.49v
4  ground
5  11.14v
6  240v
7  11mv
8  1.7v
9  5.8v

voltages at junction of resistor 25 , c12 and R4   305v
voltages at junction of resistor 24 , c13 and R5   326v

[njkmonty]

anyone got some reference voltages?

[gtudoran]

Just ordered a batch of GTFO PCBs - the SMPS is not included on the board (came to a conclusion that is better to be on a separate PCB.
So if anyone is interested let me know.

[mikestorm]

Hi Guys

Where can i get a gtfo ready to solder pcb?

is a site in us where they sell?

best for all
Mikestorm

[Luke51411]

I'd be interested in a board. How much shipped to the US? Do you have an smps board as well?

[gtudoran]

Hi Guys

Where can i get a gtfo ready to solder pcb?

is a site in us where they sell?

best for all
Mikestorm

Mike i'm selling them (they will be ready in couple of weeks). I'm based in EU and as far as i know there is no site that is selling them, as the project was posted under GPL Licence Agreement.

Luke, yes all the necessarily PCBs will be available (PCB +SMPS)

Regards,
Gabriel

[mikestorm]

Thanks Gtdoran

I was in europa, well... iwas born in Italy, but now i'm moved to dominican republic. Buy from US and bring it to her is a little bit expencive but is possible. But bring it from EU with the stealer in the tax line will be tricky one.

Just to know, how much euro's will cost me the preamp pcb and the psu pcb?

Best for all
Mikestorm

[gtudoran]

@mikestorm or i can provide you the files and build your own PCB if this would be better for you.

[mikestorm]

Hi Gtdoran

I've sent you a private msg

Please let me know

Best for all
Mikestorm

[gtudoran]

@Mikestorm and Hilli - you got mail

Regards,
Gabriel

[Hilli]

Thank you VERY much !!!

Regards Hilli

[Hilli]

This is my latest version with Clean Vol Pot.

Regards, Hilli

https://dl.dropboxusercontent.com/u/44238774/Bilder/Verschiedenes/GTFO%20Redraw%20with%20Clean%20Vol%20Pot.jpg

[gtudoran]

Finally i can consider the GTFO project closed. No alterations will be made (by me at least) and no further development will be done (again by me).
The project is ready to be shared and i give you a small preview of this. It's using a 1590C type enclosure, tubes are hosted inside (first version / prototype had the tubes outside).
It's using a SMPS for the HV and it requires a single 12V DC @ 800mA PSU (center negative)
If you don't remember about this project (from the DIYSB forum), here it is how it sounds:

All the project details will be posted in a PDF document (as they were on the previous version) and also a preorder for PCBs can be made at the following address: http://oseq.org/pre-order/
Please be advise that for the project you will need both main board and SMPS board (if you are using another PSU for the HV then you will need only the main board).
Soon kits will be available that will include: PCBs / Pre-drilled enclosure / Jacks / Switch and parts.
As i said, this is the last form of the project and no further developments will be made.

[Hilli]

Great work! Thank you. 

[Hilli]

My first "Original" build in a BB box. Sounds awesome! But it's also nice to have a middle+bass pot. This one is finally for me and NOT for my friends!!!