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

[J0K3RX]

Still waiting for caps  I guess no gut shots huh, anybody build one yet?

Good luck with that , I for the life of my can not find caps that have a small enough footprint that will accomodate the PCB , I also found that my eyesight isn"t good enough to properly solder components on this PCB ...... All those Verticle resistors and the traces so close to each other just made it too difficult of a PCB for me to work with ....... I ended up just redesigning the whole PCB to allow for bigger foorprint caps and for more space between the traces and to allow for the resistors to lay flat , and too alow for terminal blocks and pots closer to the edge of the board ......

Cheers

I found these, I believe they will work.. They look like they should fit the small board size? They have the 250v kit with 35 caps and the 650v kit also...
http://www.smallbearelec.com/Categories.bok?category=Capacitors%2C+Topmay+High+Voltage+Poly+Film

The rest like the electrolytics I will try to find at Digikey, shouldn't be hard to find.

Tired of waiting for Futurelec.com so I am doing a full re-order!

[J0K3RX]

Hey Jim, hope that i can do some pictures today - but the only unit that i have is the V1 (but that would not pe a problem i hope).

Regarding the small foot -print of the PCB - that was the whole thing about ths design to fit in a 1590BB type enclosure - ofcourse that you cand make it a little bigger as you have some space to spare inside the box .... speaking about seeing - last week i'be broke my glasses... $#@$@#$^%^ c'est la guerre

Best regards,
Gabriel Tudoran
Analog Sound

Still waiting for caps   I guess no gut shots huh, anybody build one yet?

Gabriel - no worries... I looked at some of your other pedals and noticed that you put a cab simulator in some of them.. This would probably be great running direct with either hardware or software cab sims.. Have you tried running direct yet?

[gtudoran]

Not yet but that would be a good ideea... the only drawback would be the level of signal that enter in the cabsim, but it's possible to attenuate it so that would not be a problem afterall.

Best regards,
Gabriel Tudoran
Analog Sound

[J0K3RX]

ok, I ordered all the caps today from Digikey, they should be here Tues or Wed of next week... I don't know why I didn't order form them to begin with, stupid move on my part! I would already be jammin with this thing Came to about $42.00 but I ordered enough to build 6 of them... I have all the other parts so as soon as these get here I will build it immediately!   

[J0K3RX]

Gabriel, is the schematic and layout on your very first post good? That is the board that I etched and half way populated... I would like to keep going with this one if it works. I have all the parts now.

edit: The pdf that I made the board from says last modified on 1/8/2012 by Gabi Tudoran

[gtudoran]

Hey Jim, yes, there schematic, layout and all the instructions are good to go, there other versions have smaller socket footprint and some parts are mounted on vertical. In the first PCB / Schamatic version you will have also a split in the HV branch made with 2 HV electrolityc caps and 2 resistors, if you don't have the space to mount the 4 parts, you can skip them without a problem (take a look on the schematic) and that is all . As a way to go, i recommand you to first buid the SMPS and see that everything goes smooth and clear .

Best regards,
Gabriel Tudoran
Analog Sound

Gabriel, is the schematic and layout on your very first post good? That is the board that I etched and half way populated... I would like to keep going with this one if it works. I have all the parts now.

edit: The pdf that I made the board from says last modified on 1/8/2012 by Gabi Tudoran

[J0K3RX]

Gabriel,

Ok, I have this thing all built using you latest instruction/pdf... I have a problem and this may sound stupid but can you help me with the off board wiring? I have all of the pots wired up and the IN and OUT and 12V but where do the negative/ground go? I tried attaching them to ground but it didn't work... I am not using a foot switch yet until I can actually get this to work then I will box it up and use a foot switch. Also is there supposed to be a jumper from pin 5 to pin 4 of the 555 chip?

Thanks,
Jim

[gtudoran]

Hey Jim, that is no problem. So we will take it from bottom.

First of all you have to be sure that the 3 jumpers are in place:

-the first one is under de 555IC
- the second one is from C1 to R25
- the third one is above the sockets and connects the V1 and V2 pin number 5 together (the heaters are there) - take care of the heaters pad you will also have to connect it to the 12V positive side.


After that:
- Input is from R2 and GND (any point from ground plane will do)
- Output is from R17 and R18 junction
- 12V input is on the positive side of the 470uF cap C9 on the layout

You will have to make the following checks before you put the tubes in the sockets:

- you have to have 12V @ pin 4 and 8 of the 555 timer
- you will have to have >90v at the positive side of C11 (4.7u) - is the HV out
- you will have to have almost the same voltage like above to the sockets V1 and V2 (pin 1 and pin 6 of the sockets) take your mesurment on the pin directly
- you will have to have 12V @ pin 5 of both sockets - there heaters voltage

After that, if everything is in place and good to go, disconect from the 12V supply, put the sockets in place, reconnect the 12V supply and you should see the heaters glowing. You should take the messurments again (the ones from above) - and @ point 3 from above you should have smaller voltage readings then the first ones. Only after that you should hear smth ... and btw keep the volume low and pay attention to your fingers - do not touch FET's metal tab.

Best regards,
Gabriel Tudoran
Analog Sound

Gabriel,

Ok, I have this thing all built using you latest instruction/pdf... I have a problem and this may sound stupid but can you help me with the off board wiring? I have all of the pots wired up and the IN and OUT and 12V but where do the negative/ground go? I tried attaching them to ground but it didn't work... I am not using a foot switch yet until I can actually get this to work then I will box it up and use a foot switch. Also is there supposed to be a jumper from pin 5 to pin 4 of the 555 chip?

Thanks,
Jim

[J0K3RX]

Hey Jim, that is no problem. So we will take it from bottom.

First of all you have to be sure that the 3 jumpers are in place:

-the first one is under de 555IC
- the second one is from C1 to R25
- the third one is above the sockets and connects the V1 and V2 pin number 5 together (the heaters are there) - take care of the heaters pad you will also have to connect it to the 12V positive side.


After that:
- Input is from R2 and GND (any point from ground plane will do)
- Output is from R17 and R18 junction
- 12V input is on the positive side of the 470uF cap C9 on the layout

You will have to make the following checks before you put the tubes in the sockets:

- you have to have 12V @ pin 4 and 8 of the 555 timer
- you will have to have >90v at the positive side of C11 (4.7u) - is the HV out
- you will have to have almost the same voltage like above to the sockets V1 and V2 (pin 1 and pin 6 of the sockets) take your mesurment on the pin directly
- you will have to have 12V @ pin 5 of both sockets - there heaters voltage

After that, if everything is in place and good to go, disconect from the 12V supply, put the sockets in place, reconnect the 12V supply and you should see the heaters glowing. You should take the messurments again (the ones from above) - and @ point 3 from above you should have smaller voltage readings then the first ones. Only after that you should hear smth ... and btw keep the volume low and pay attention to your fingers - do not touch FET's metal tab.

Best regards,
Gabriel Tudoran
Analog Sound

Gabriel,

Ok, I have this thing all built using you latest instruction/pdf... I have a problem and this may sound stupid but can you help me with the off board wiring? I have all of the pots wired up and the IN and OUT and 12V but where do the negative/ground go? I tried attaching them to ground but it didn't work... I am not using a foot switch yet until I can actually get this to work then I will box it up and use a foot switch. Also is there supposed to be a jumper from pin 5 to pin 4 of the 555 chip?

Thanks,
Jim

Oh cool!! I really appreciate your help Gabriel! I will try this tonight and see if I can get this up and running... I am dying to try this beast out! I read through it real quick and I noticed you have a jumper from C1 to R25? Is that right? Those two are nowhere near each other on the board I have?

Thanks Again!
Jim

[gtudoran]

Hey Jim,

Could you please send the exact board that you have - i did some changes some time ago and i might put some things out of order. If you send me the exact pdf that you have i can guid you from there without a problem (i would die to have the possibility to upload files on the forum - in this way you could have a nice history of the files)

Best regards,
Gabriel Tudoran
Analog Sound

Hey Jim, that is no problem. So we will take it from bottom.

First of all you have to be sure that the 3 jumpers are in place:

-the first one is under de 555IC
- the second one is from C1 to R25
- the third one is above the sockets and connects the V1 and V2 pin number 5 together (the heaters are there) - take care of the heaters pad you will also have to connect it to the 12V positive side.


After that:
- Input is from R2 and GND (any point from ground plane will do)
- Output is from R17 and R18 junction
- 12V input is on the positive side of the 470uF cap C9 on the layout

You will have to make the following checks before you put the tubes in the sockets:

- you have to have 12V @ pin 4 and 8 of the 555 timer
- you will have to have >90v at the positive side of C11 (4.7u) - is the HV out
- you will have to have almost the same voltage like above to the sockets V1 and V2 (pin 1 and pin 6 of the sockets) take your mesurment on the pin directly
- you will have to have 12V @ pin 5 of both sockets - there heaters voltage

After that, if everything is in place and good to go, disconect from the 12V supply, put the sockets in place, reconnect the 12V supply and you should see the heaters glowing. You should take the messurments again (the ones from above) - and @ point 3 from above you should have smaller voltage readings then the first ones. Only after that you should hear smth ... and btw keep the volume low and pay attention to your fingers - do not touch FET's metal tab.

Best regards,
Gabriel Tudoran
Analog Sound

Gabriel,

Ok, I have this thing all built using you latest instruction/pdf... I have a problem and this may sound stupid but can you help me with the off board wiring? I have all of the pots wired up and the IN and OUT and 12V but where do the negative/ground go? I tried attaching them to ground but it didn't work... I am not using a foot switch yet until I can actually get this to work then I will box it up and use a foot switch. Also is there supposed to be a jumper from pin 5 to pin 4 of the 555 chip?

Thanks,
Jim

Oh cool!! I really appreciate your help Gabriel! I will try this tonight and see if I can get this up and running... I am dying to try this beast out! I read through it real quick and I noticed you have a jumper from C1 to R25? Is that right? Those two are nowhere near each other on the board I have?

Thanks Again!
Jim

[J0K3RX]

Gabriel,

Here is the board that I am using...
http://dl.dropbox.com/u/11178619/GTFO.pdf

Thanks,
Jim

[gtudoran]

Hey Jim,

So you're using the last version of it excellent, in this case the only jummper is under the 555IC, all the voltage readings and all the check list remain the same. As i cand see in the layout (i've zoomit about 200%) there is a small gap between pin no. 4 of the 555IC and the pad, so again you should have 12V @ pin 4 and 8 of the 555 timer hope everything will go smooth from here.

Best regards,
Gabriel Tudoran
Analog Sound

Gabriel,

Here is the board that I am using...
http://dl.dropbox.com/u/11178619/GTFO.pdf

Thanks,
Jim

[J0K3RX]

Gabriel,

Ok so you are right, I do have 12v @ pins 4 and 8 of the 555 timer and I had around 150v coming from the HV cap C11 so I turned the little onboard pot down until it read 90v. I checked the board/trace side of the tube sockets like you instructed and  again you were right... So I guess I just run a 12v jumper wire to the middle trace that goes between both of the pin 5's for the heaters right?

~Jim

[J0K3RX]

Gabriel,

Ok, I got it up and working now Thanks to your help!! I am running it direct and it sounds wicked good!! When going direct it doesn't seem to have the intense gain like your videos but that is because it's the pedal all by itself... Just throw a tube screamer in front of it and there it is! The tone is amazing and with the tube screamer it flat out kix ass!!! The TS808 adds a little edge and bite and sounds perfect with the GTFO! I am using it with impulses of a 4x12 25 watt greenback celestion. One thing it does though and maybe you have some ideas but when I plug it into my USB recording interface it reboots my computer? As long as it's on when the computer boots up it's fine but if I power the pedal off and back on again it reboots my PC again...? Overall it sounds insanely good and no noise at all, super quiet!!!  

~Jim

EDIT: Ok, I forgot all about the little on-board voltage pot so I decided to tweak it a little bit so, I turned it all the way up! WHOOOOOOOOO......!!! SHAZAM!! Talk about high gain! Sheeeeit!

[Minion]

i also want to tell you that I built it also and it sounds pretty good but I redid the whole thing .......

because I only had larger sized caps I redesigned the PCB to accomidate bigger caps ......

I first populated the PSU and tested it but I couldn"t get it to work properly so , Instead of banging my head against a wall trying to figure it out , I redesigned the PCB again to accomidate a Linear PSU , I just happened to have a Powerpack that I built for a different project laying around that puts out 220v AC and 12v AC and I had another DC regulated 12v supply laying around to use for the heaters ......

I connected it up and got sound but it hummed badly so I switched to 12ac heaters and most all of the hum went away and it sounds pretty damn good for what little I have played with it .......

Since I have to use external PSU"s I have decided to use it instead as a seperate preamp chanell on one of my single channel diy guitar amps so i will have a 2 channel amp , I allready have a relay based channel switching design that i will use to switch channels ..... I have a single chanel amp I built a couple years ago that has a lot of space in the chassis for another chanell ........


Thanx

[J0K3RX]

Here's some gut shots...

http://dl.dropbox.com/u/11178619/DSCF0163-1.jpg

http://dl.dropbox.com/u/11178619/DSCF0160-1.jpg

[gtudoran]

Hey Jim,

You did a hell of a job there, very nice build. The HV should be >90V ) so yes you have to ajust the trimmer so at the output of the PSU you should have 240-260V ) that is why in the first place you could get as much gain as in my builds. Glad everything turned out ok.

@Minion - if you would like to use it as a channel amp, then you can use a clasical power supply without any problems.

Best regards,
Gabriel Tudoran
Analog Sound

Gabriel,

Ok, I got it up and working now Thanks to your help!! I am running it direct and it sounds wicked good!! When going direct it doesn't seem to have the intense gain like your videos but that is because it's the pedal all by itself... Just throw a tube screamer in front of it and there it is! The tone is amazing and with the tube screamer it flat out kix ass!!! The TS808 adds a little edge and bite and sounds perfect with the GTFO! I am using it with impulses of a 4x12 25 watt greenback celestion. One thing it does though and maybe you have some ideas but when I plug it into my USB recording interface it reboots my computer? As long as it's on when the computer boots up it's fine but if I power the pedal off and back on again it reboots my PC again...? Overall it sounds insanely good and no noise at all, super quiet!!!  

~Jim

EDIT: Ok, I forgot all about the little on-board voltage pot so I decided to tweak it a little bit so, I turned it all the way up! WHOOOOOOOOO......!!! SHAZAM!! Talk about high gain! Sheeeeit!

[J0K3RX]

Gabriel, I love this thing man!! Any new improvements?

I can't believe others are not building this thing..? Too easy to pass up!  BTW - I throw a TS808 in front of mine and record direct with software cab simulation.. sounds killer!!!

[gtudoran]

Thank you Jim, right now i'm working at a 2 channel version churunch lead... i will keep this topic updated. I hope you will have time to post some records.

Best regards,
Gabriel Tudoran
Analog Sound

Gabriel, I love this thing man!! Any new improvements?

I can't believe others are not building this thing..? Too easy to pass up!  BTW - I throw a TS808 in front of mine and record direct with software cab simulation.. sounds killer!!!

[J0K3RX]

Thank you Jim, right now i'm working at a 2 channel version churunch lead... i will keep this topic updated. I hope you will have time to post some records.

Best regards,
Gabriel Tudoran
Analog Sound

Gabriel, I love this thing man!! Any new improvements?

I can't believe others are not building this thing..? Too easy to pass up!  BTW - I throw a TS808 in front of mine and record direct with software cab simulation.. sounds killer!!!

Yeah, I will try to get some demos up real soon... just had 2 teeth pulled so I am kinda foggy right at the moment... You read my mind on the 2 channel thing! Are you just doing an extra 2nd gain and volume knob on a switch or...?