Behringer Vintage Tube Overdrive VT911 = B.K. Butler Tube Dr

[frank.clarke]

Correction. There is a 1k resistor from pin 5 (heater) to the 470k grid pullup resistor. So it isn't exactly the same, the 1k resistor is on the tube board (probably a sub for the 2.2k heater resistor, there are only 4 wires to the tube board). And my digital camera batteries are taking forever to charge.

http://www.muzique.com/schem/tubedrvr.gif
http://www.google.com/patents?id=9bEdAA ... dq=5022305

SMT, but the component values are on the silkscreen.

The reject bin tube barely amplified, I had to replace it.

Enough room inside for your lunch!

[bajaman]

I had a B K Butler 4 knob new tube driver in the repair shop last week - took some photos - watch out for a clone project coming to this forum soon
In the meantime - any pics of the Behringer copy
bajaman

[frank.clarke]

OK, pics tomorrow. Macro photography, main board 1"x4" in a big box.
This is the patent version, I think the production version was different. The VT999 has 4 knobs, plus a noise gate.
Anyway, $50 in stores.

I get 0.07V on pin 2 grid, second gain stage. The original tube, I could hear the guitar signal biasing something. So something is wrong somewhere, or it is my voltmeter.

[bajaman]

I purchased a Behringer VT911 and took it apart AND ..... I have to tell all here that this is not even remotely similar to the B K Butler Tube Driver.
First it runs off 9v dc , NOT 12vAC (which is converted to +12vDC and-12vDC in the B K Butler)
It has a crappy single knob tone control in place of B K Butlers HI and LO controls.
It has a Coolaudio brand chip - unsure what it is - looks like a quad opamp SMD device in place of the B K Butler TL072 or 4558 dual opamp.
AND ...................it sounds like a badly biased germanium Rangemaster - you know, that shitty gated distortion effect in comparison to the smoooooth sounding B K Butler Tube Driver.
No wonder Behringer discontinued it - does any one have a schematic for it????
My local Behringer tech friend does not have it - I am contemplating doing some mods to make it a useable unit - then again, maybe I will just put it on the local Trade Me site (NZ Ebay) and see if I can get some money back
Anyone with a schematic - factory or otherwise email me baja002@clear.net.nz - I will not say where I got it okay

Do yourselves a favour DO NOT BUY one of these - build the B K Butler Tube Driver in the DIY Projects section instead
cheers
bajaman

[frank.clarke]

The schematic appears to be the one in the patent/AMZ schematic. With a different heater resistor value. I didn't check every component against the schematic. The main fix is to throw the Behringer "tube" in the garbage and put in a real tube.

[bajaman]

The schematic appears to be the one in the patent/AMZ schematic. With a different heater resistor value. I didn't check every component against the schematic. The main fix is to throw the Behringer "tube" in the garbage and put in a real tube.

thanks Frank - I will have a look at it - the patent - I can not believe how awful this pedal sounds
By the way, the Behringer tube fitted in my unit is a Chinese type and it gave very high emission qualities and good matching on my tube tester.
maybe you had the EHX Russian crapper in yours???
cheers
bajaman

[frank.clarke]

I don't know what nationality it is, it has a mirror-image "13" on the base. It doesn't bias in the circuit, while the first Mesa AX7A that came to hand did.
So I blamed the original tube, perhaps unfairly.
It sounds like a good fuzzbox with a decent tube.
Direct to soundcard:
http://www.guitar-pedals-effects.com/ber.mp3

[Dirk_Hendrik]

Baja,

Could you make a quick verification to which extend the thing related to the japanes version of the TK999?

http://dirk-hendrik.com/images/tk999_schem.gif

[analogguru]

http://dirk-hendrik.com/images/tk999_schem.gif

Dirk thanks.... but .... yes.... ahhmm.... what I wanted to ask..... ahhmmmm .... how should I say it ? yes.... dirk... ahmmm....

Do you have as special reason why you draw the part around the treble control (R34 -R40) not like this:

http://analogguru.an.ohost.de/temp/Iban ... hema_c.gif



I mean this would more explain, how there could be easily installed a "Super-Bass-control" and/or change the center-frequency of the "Bass" or Lo-Mid-control....

analogguru

[Dirk_Hendrik]

uuh,

Nope Just never looked at it from this perspective. Makes a lot of sense.

Already glad to know I'm not the only one
http://www.dirk-hendrik.com/temp/Ibanez-tk999.jpg

[bajaman]

The Ibanez Tube King has many more components than the Behringer VT911 Tube Overdrive. I will attempt to trace the Behringer in the next few weeks - unless someone has the factory schem they could supply me first.
xmas cheers
bajaman

[bajaman]

I reverse engineered it - not sure about the initial power supply filtering, but the rest of it is fairly close to the BK Butler Tube Driver patent - my apologies to Jack Orman for appropriating and editing his schematic - i do not know what the SMD quad opamp is - but i replaced it with an SMD TL074 - a lot quieter in operation - i will post the mods I did to make this pedal useable, instead of the horrible badly biased rangemaster gated fuzz that it was
No wonder behringer have discontinued it - someone show Uli the real Tube Driver
cheers
bajaman

http://i197.photobucket.com/albums/aa21 ... ematic.png

[bajaman]

here is my modified version
cheers
bajaman

http://i197.photobucket.com/albums/aa21 ... bybaja.png

[analogguru]

If this is really as shown, this would be sick....
Butler is runnig the tube at +/-12V (= 24V), the VT911 as shown is would only be running at 9V.

analogguru

[Dirk_Hendrik]

If this is really as shown, this would be sick....
Butler is runnig the tube at +/-12V (= 24V), the VT911 as shown is would only be running at 9V.

analogguru

Which does work, proven by the Ibanez Tubeking.

Baja,

Thanks for the schematic. Great job in keeping perspecive of 'what's happening in effects country' a neet and tidy place! When I suggested the comparison with the Ibanez Tubeking I was mistaken with the bigger "vintage Tube Monster" with it's 3-band tone control.

[wildschwein]

Hi all, I'm new.

I just wanted to see if anyone here has any experience with the Bitmo 2BO mod for the Behringer VT911? I'm considering getting the kit, as I have the pedal (which as some of you note above sounds like a fuzz) but I have no idea of the mod kit's contents and want to get some idea of the parts and procedure.

[aot]

Hi All,

I realise it's been a long time since anyone posted, but in case anyone's interested: Today I had a go at Bajaman's mod: I used 1206 SMD resistors, 20k's instead of the 22k's, and I didn't change the opamp. The difference is remarkable, it's actually usable now. It now sounds like something verging on a mesa boogie rectifier, that brittle, almost white noise kind of distortion. Not exactly what I was looking for, but an improvement. With my valve amp cranked (ashdown fallen angel 40w mkI + weber mass) it sounds even better - less harsh. It's not quite overdrive, but more musical than fuzz.
I tried it with a 12V power supply as well, and it sounded a tiny bit better, so I'm thinking a 24V supply (providing the caps can take it - most likely not :S) might make a difference.

Cheers,

aot

[TechNAB76]

Hello Everyone. My name is Niels, I'm 34 years and I'm from the Netherlands.

First of all I would like to wish everyone a Happy New Year and all the best.

That being the short introduction, I've got a question regarding this MOD to the Vintage Tube Overdrive*. I've been reading this topic several times now and I'm greatfull for all the information and images... but does anyone of you might have a short list of which part (resistor - capacitor) needs to be replaced with what?

I've already seen the two schematics of Bajaman, but I'm having allot of difficulty trying to find out on the schematic which resistor is which on the print.

I hope someone can help my, cause my *V.T.O. sounds not really good I have to say.

I'm using a Fender Superchamp XD Full Tube Amp... set it to the clean level and then I've hooked up the Behringer *V.T.O. to it... even the Overdrive and Distortion effects on the amp sound better then the Behringer one. Though I would still like to use the *V.T.O. too.

Thank you all for your help and advice in advance.

Niels

[aot]

Hi Niels,

These are the changes that I made:

Change R9 to 10k
Remove R8
Change R17 to 22k
put a 100k resistor between pin 7 of the 12ax7 to the top of R17
change R16 to 100k
change R18 to 22k
10k after C12
change R14 to 1M

I used 1206 surface mount resistors to make the modifications.

Good luck!

Aaron

[Hwasser]

Wow, those resistors are really small! xD I bought the ones suggested here, they are little larger in than the original ones, but they fit. Having a hard time soldering them without them moving around (because of how light weight they are), how do u guys solve this without a third hand?

And öhm, I need a little help

Remove R8: am I going to connect it together with copper-wire here or am I supposed to leavy an open space where the resistor was?

put a 100k resistor between pin 7 of the 12ax7 to the top of R17: is pin 1 the one to the left when you see the tube from below?

10k after C12: exactly, what? between C12 and what? Am I supposed to drill a hole somewhere?

Sorry if my questions seems dumb, but I havent soldered something this advanced before