TECH21 Sansamp BassDriver DI (or something like that) *SCHEM*

[Shakal]

Does anyone has this schem or knows where to find it?

I'm searching like crazy the schem, layout, project, anything about this Bass Driver DI but I found nothing! Just the GT2...

I think it gonna be awesome for the bassist community to have this project...

A project of other pedal but this same kind of stompbox would be helpful too!

Thanks for reading! Seeya!

[Nikolay]

Another two tech21 schem
http://www.amtshop.com/index.php?productID=90

[Timebutt]

Great pedal: I own one and it's a very valuable tool for bass
I would be very interested in a schematic just to understand how the effect actually works, but the link provided takes me to a page with some very weird language on it

[markm]

Russian?

[Shakal]

Russian, greek or something...

The schem is way bigger than that!

Can someone help us find this rare schem?

This is a pic of someone's PCB of Bass Driver DI: Bass Driver DI PCB

I'm scared, aren't you? What is that black scary thing? OMG!

[Timebutt]

Guess there is a reason to buy instead of build this pedal
I think I'll open mine as well tomorrow or something, it's really got me wondering what great schematic must be getting all of this done

[Rodgre]

You could also pick up the Behringer clone of it for $40. I haven't tried it, but if you're not afraid of SMD components, you could mod it to your heart's content.

I have used the Sansamp Bass Driver for 10 years, and other than it being a bit hissy, I think it's a great sounding bass preamp/DI.

Roger

[jrc4558]

Yes, it is russian. Download the RAR archives, extract them and you will see the full schems with PIC switching omitted.

[Shakal]

Sorry, didn't see the RAR files.

Very complex huh... Do you know where is the schem for the PIC? I would like to see the digital switching system, I'm so interested in that!

[soulsonic]

The big black thing in the pic is a piece of foam that's stuck to the board to help hold it in place and keep if from shorting against things inside it's box.
You don't need to know the scheme for the original switching circuit - any logic circuit will do for getting the switching to happen. Personally, I'd rather have it use a system where each channel had it's own footswitch, so you wouldn't have to "scroll" through them with the single button that the original uses.

[MR COFFEE]

Constantin,

Thanks very much for the link. The tri-OD is especially interesting to check out.

Was there a link in there somewhere for the Sansamp Bass DI schematic also? I know absolutely NO Russian at all, so I am basically wandering around clicking links at more or less random trying to find things of interest.

I wish American schools did more to teach a broader variety of languages. I got a little French; Russian, Spanish, Japanese and Chinese would have been much more helpful

I have never actually heard the Sansamp DI, much less played through one, but new schematics are always food for thought.

[jrc4558]

MR COFFEE, thanks for thanks, but link was posted by Nikolay. I simply pointed out he RARs.
For whatever reason, and I notice it quite often with Russian websites dealing with musical electronics, a lot of stuff is published in *.rar format, so look out for those!
As far as the schematic - unfortunately, thats all these guys have hosted there. I can ask at the russian forums and see if anyone there has it.

[soulsonic]

.rar is the zip of the underground! All good hacker stuff is in .rar format.

[Shakal]

Man, I don't think .rar is underground, its a lot popular.

About the languages. INDEED! I wish I had some Russian class, I know a little bit of English and count 1-10 in German. Spanish I don't bother to learn cuz it's almost the same of Portuguese.

Constantine or Nikolay (or another one who understand Russian) can translate what is on Bottom Left of Tri-OD schem, please? I'm VEEERY interested in these switching systems. Actually, I'm on a project of one of these systems with some friends.

Well, let the big companies to clone it for us... I think its too complex for me right now... someday maybe.

Thanks!

[giego]

http://home.planetahost.ru/~firewood/teb21.pdf

[Kornell]

  Thanks giego.

Do you know if it's correct?

[George Giblet]

Thanks a heap for the schematic!  I knew it had a notch filter in there!

I've put together a little summary of the key circuit regions of all the Tech 21 units - see below.  The idea is to provide a way of seeing the differences and commonalities between the units.  From his you can see where each unit stands from the rest.

I've seen a rough frequency response curve for the bass unit and the voicing (notch) filter looks close.  The voicing filters for the guitar and bass are different but I think the bass schem is correct (or at least close to it).

The cab sim part of the circuits vary quite a bit but they seem to be in the same rough ball park.  There is the possibility that the cap values are off by one value due to measurement errors - luja pointed this out some time back on his traces.  Whether the different caps in the cab sim circuits is real or due to measurements is hard to resolve.  Despite this they should sound fairly close.

I"m not sure what to make of the tone control in the Bass Driver - see comment below.

----------------------------------------------------------------------------------------------------
* Stages (Bass/classic Mode)

                   Stage 1   Filter 1              Stage 2       Stage 3
GT2 (lujia/tonepad)   47n/22k    100k/2n2/10n/22n      22n/11k/22k   2u2/2k/23k
GT2 (Dark Angel)     10n/22k        "                  "                    "
Tri-AC               47n/22k    333k/2n2/10n/22n     ~10n/2k5          -
Tri-OD              22n/22k    333k/2n2/22n/22n      3n9/22k         2u2/Rv
Bass Driver DI         n/a           100k/22n              10n/Rv        -

Rv = variable resistance on pot

* Voicing Filter:

GT2          sw   ~22k/9n4/22n/6k2/65k load;  +more filtering
Tri-AC         notch   22k/10n/22n/6k2/40k load;   +more filtering
Tri-OD         notch   22k/4n7/22n/6k2/70k load
Bass Driver DI        notch   22k/22n/47n/6k2/no load


* Cab Sim LPF:
              Stage 1      Stage 2      Stage 3
GT2         28.9k/560p   2n2/1n      -
Tri-AC         22k/470p   2n2/1n      2n2/470p
Tri-OD         22k/820p   2n2/1n      -
Bass Driver DI        28.9k/470p       2n2/1n2      -

* Tone Control:

Same on all but the Tri-AC, which has a mid pot and different bass/treble.
The Bass Driver DI mentioned a different tone control but it's the same as the guitar units!
----------------------------------------------------------------------------------------------------

[George Giblet]

Looks like the Russian guys have done a through-hole layout:

http://www.hot.ee/wirelessmic/bassdriver.rar

[O]

Does anyone know if the layout is actually derived from the jpg, or from another schem?

[Shakal]

Hmmm thanks both of u!

What is that "BYPASS - two JFET switches (J112) controlled by discrete flip-flop".

I think something is missing... Don't you?