12au7 guitar tubes bk butler tube driver

#12au7 guitar tubes bk butler tube driver mod#
#12au7 guitar tubes bk butler tube driver driver#
#12au7 guitar tubes bk butler tube driver mods#

Pots are clean(not scratchy) Cord is undamaged. The prior owner had made some marks around the top knobs and by the back bias knob(see photos, the- bias + markings are in ink, I tried wiping it off with a little lighter fluid but it didn't come off so it may be permanent ink) The marks that were around a few of the knobs are light and I think I mostly got them off but a hint may remain) From a non-smoker. I bought this last summer locally on a whim(I mostly just make noise on a guitar) I don't know what the installed tube is. Pedal works with no issues and sounds great. more that allows you to set the bias for the tube.

#12au7 guitar tubes bk butler tube driver driver#

Vintage Original 5 Knob Tube Driver Real Overdrive BK Butler Guitar Effects Pedal Distortion There are 9 photos of the item below.

#12au7 guitar tubes bk butler tube driver mods#

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 backĪnyone with a schematic - factory or otherwise email me - I will not say where I got it okayĭo yourselves a favour DO NOT BUY one of these - build the B K Butler Tube Driver instead No wonder Behringer discontinued it - does any one have a schematic for it? 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.

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.ĪND. It has a crappy single knob tone control in place of B K Butlers HI and LO controls. I have to tell all here that this is not even remotely similar to the B K Butler Tube Driver.įirst it runs off 9v dc, NOT 12vAC (which is converted to +12vDC and-12vDC in the B K Butler) I purchased a Behringer VT911 (reputedly similar to the B K Butler Tube Driver), took it apart AND.

#12au7 guitar tubes bk butler tube driver mod#

Tube Driver Bottom PCB layer parts placement and bias mod How does it sound? I did not care for it - but then I have been spoilt by a real tube overdrive ( 250v dc plate load feed as opposed to this 12v beastie) I think you may be able to improve it's sound by using a higher spec op amp such as the excellent Burr Brown OPA2134 and by using better quality metalised polyester or polystyrene film capacitors - who knows?Īnyway - big drum roll. Good luck if you want to build it - it uses a double sided circuit board. It uses a TL072 op amp and 47k plate load resistors and many other subtle changed components - more later. I have not redrawn the schematic yet - it should be up in the next few days - it is not the same as ANY of the many schems floating around on the net by the way.

The additional bias control pot is mounted above the input socket on the rear panel - I preferred it without the additional bias resistance and capacitance - but others may find this B K Butler mod useful. There is no mojo components in here - just cheap mylar greencaps and standard metal film resistors - so It won't sound very good - tell David Gilmour and see if he cares - he has two of these exact same pedals in his Pete Cornish pedalboard The earth pin on the input socket is connected by a parallel connected 100 ohm resistor and a cheap 100n mylar capacitor to the chassis near the front of the case. The input and output sockets are isolated from the chassis by plastic insulating spacers. You will need a suitable 12vAC power pack for this pedal - the original has a small toroidal mains transformer fitted internally near the front of the case.

This was traced from a recent B K Butler pedal and has the bias pot modification which alters the voltage on the cathodes of the 12AX7 tube.