Full tube 3 channels guitar preamp

DarkRain · Post by **DarkRain** » 13 May 2014, 07:21

Hey guys, this is my latest build. A 3 channel guitar preamp. Main features:

- 3 switchable channels (it can be done MIDI compatible);
- switchable cab-simulator
- Separate EQ and Gain/Volume controls for Clean / Crunch-Lead
- uC switching system

Soon sound samples.

Best regards,
Gabriel Tudoran
Analog Sound

DrNomis · Post by **DrNomis** » 13 May 2014, 08:05

Looks really cool, I'm interested in building something like that so I can use it with my Behringer K3000FX Keyboard/PA Amp, would also be handy in a recording studio situation......

J0K3RX · Post by **J0K3RX** » 22 May 2014, 23:56

That's it?

You're gonna leave us all standin around with our pants around our ankles, a boner and not give us a happy ending??

rcustoms · Post by **rcustoms** » 23 May 2014, 04:29

J0K3RX wrote:That's it? You're gonna leave us all standin around with our pants around our ankles, a boner and not give us a happy ending??

JAJAJA
i agree with you

DarkRain · Post by **DarkRain** » 23 May 2014, 04:43

J0K3RX when did i do that?! I will post the schematic ASAP as i've made some mods that will have to be updated on schematic.

Best regards,
Gabriel Tudoran
Analog Sound

DarkRain · Post by **DarkRain** » 23 May 2014, 07:47

Ok, as i promised, here are:

- preamp schematic
- hv psu schematic
- pcb transfer for both of them
- topsilk for both of them

Any question will be answered

Best regards,
Gabriel Tudoran
Analog Sound

PS: the PSU requires a Xformer with this data: primary 120 or 220v, secondary: 6.3v @ 1.2A and 190-0-190 @ 20mA
PPS: the switching mode is one of your choice (you can use relays or you can use switches), the lead channel use all triodes form the top

DrNomis · Post by **DrNomis** » 23 May 2014, 08:19

Cheers for that DarkRain......

J0K3RX · Post by **J0K3RX** » 24 May 2014, 03:10

Looks interesting.. I really like the backlit blue LED face plate and knobs! Would like to see the MIDI and cab simulation. Hope to hear some samples and see some guts...

DarkRain · Post by **DarkRain** » 24 May 2014, 05:09

Sloppy sample:

Some guts pictures i will post them today.

Best regards,
Gabriel Tudoran
Analog Sound

J0K3RX wrote:Looks interesting.. I really like the backlit blue LED face plate and knobs! Would like to see the MIDI and cab simulation. Hope to hear some samples and see some guts...

DarkRain · Post by **DarkRain** » 24 May 2014, 14:07

And some guts pictures.

Best regards,
Gabriel Tudoran
Analog Sound

: IMG_2074.JPG (93.61 KiB) Viewed 2416 times

: IMG_2073.JPG (97.17 KiB) Viewed 2416 times

: IMG_2071.JPG (97.29 KiB) Viewed 2416 times

tictac · Post by **tictac** » 24 May 2014, 23:37

Nice work there...

I'm looking for a toroidal power transformer to build a guitar preamp and was wondering if you could tell us the make and model of the power transformer you used in your build...

Thanks,

TT

DarkRain · Post by **DarkRain** » 25 May 2014, 06:00

Hey TT,

It's a custom made toroidal. I's made in Romania and the price was about... 35-40$ The specs are 220v primary, 3.15-0-3.15v @1.2A and 190-0-190 @ 20mA
I can help you build one here but ... i guess is too much hassle to send it to you.

Best regards,
Gabriel Tudoran
Analog Sound

PS: i don't think that you will find a toroidal transformer that will suits your needs ready available .

tictac wrote:Nice work there...

I'm looking for a toroidal power transformer to build a guitar preamp and was wondering if you could tell us the make and model of the power transformer you used in your build...

Thanks,

TT

DrNomis · Post by **DrNomis** » 26 May 2014, 01:59

I wonder if it's possible to build this into a 1U or 2U 19 inch rackmount case......

J0K3RX · Post by **J0K3RX** » 26 May 2014, 03:17

DrNomis wrote:I wonder if it's possible to build this into a 1U or 2U 19 inch rackmount case......

I don't see why not... make a new layout with a tube daughter board and mount at right angle so the tubes are horizontal inside the case. Not uncommon..

I am trying to figure out what other tube preamp this is a spin off of? Looks like a combination of a few?

DarkRain · Post by **DarkRain** » 26 May 2014, 04:51

@DrNomis: Yes it it possible. In fact i had that thought ... but i choose this type of enclosure (is more like a desktop preamp).

@J0K3RX: In fact is a combination of only... 1 preamp, and we are talking about Diezel, but skiped some parts, lef aside a channel... modified some values, changed switching points ... and this is it.

Best regards,
Gabriel Tudoran
Analog Sound

J0K3RX · Post by **J0K3RX** » 26 May 2014, 23:17

DarkRain wrote:@DrNomis: Yes it it possible. In fact i had that thought ... but i choose this type of enclosure (is more like a desktop preamp).

@J0K3RX: In fact is a combination of only... 1 preamp, and we are talking about Diezel, but skiped some parts, lef aside a channel... modified some values, changed switching points ... and this is it.

Best regards,
Gabriel Tudoran
Analog Sound

If you have an enclosure that has the head room then why not keep'em standin up...

Diezel you say... What model? hmmm?

Looks like you stated with a Diezel and ended up with a GT1-Tuberan original

DrNomis · Post by **DrNomis** » 27 May 2014, 04:56

I'm seeing a bit of a Marshall/Fender influence in the component values in the preamp and tonestack circuits, I need to sort out my PC's sound so I can check out that soundcloud link so I can get a bit of an idea of what the preamp sounds like, but deffinitely a cool looking project, I like the Blue Led back-lighting, certainly gives it that High-Endy look.....

I'm rapidly becoming a fan of your work, DarkRain......

DarkRain · Post by **DarkRain** » 29 May 2014, 06:14

The tonstacks were tweaked according to taste. And yes... some known preamp models were used but none of them was copied

.

Thank you DrNormis for your kind words. Now i'm working on a full tube pedal (similar with GTFO but with some tweaks and options). SMPS based, 2xECC83 (12AX7).

A small preview of the SW project.

Best regards,
Gabriel Tudoran
Analog Sound

DrNomis · Post by **DrNomis** » 29 May 2014, 07:33

DarkRain wrote:The tonstacks were tweaked according to taste. And yes... some known preamp models were used but none of them was copied .

Thank you DrNormis for your kind words. Now i'm working on a full tube pedal (similar with GTFO but with some tweaks and options). SMPS based, 2xECC83 (12AX7).

A small preview of the SW project.

Render1_1.JPG

Render1_2.JPG
Best regards,
Gabriel Tudoran
Analog Sound

looking cool so far, can't wait to check out the project......

tictac · Post by **tictac** » 29 May 2014, 16:02

I found a toroidal PT that will work for a tube preamp; Antek: AS-1T175 it will put out around 250VDC rectified and is rated at 100VA

There is also a 300V version; they changed part numbers from "AN" to "AS" which may be why it's been hard to find...

TT