BK Butler - Tube Driver  [schematic]

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...

Re: BK Butler - Tube Driver

Postby Bernardduur » 28 May 2015, 19:07

Whaha, true!

BK Butler - Tube driver.JPG
You do not have the required permissions to view the files attached to this post.
'No more....... loud music.......'

For this message the author Bernardduur has received thanks:
Intripped (28 May 2015, 22:28)
Bernardduur
Transistor Tuner
 
Posts: 1139
Joined: 24 Aug 2007, 08:36
Location: Losser.........
Has thanked: 85 times
Have thanks: 475 times

Re: BK Butler - Tube Driver

Postby tictac » 29 May 2015, 03:24

Does anyone know about the "Bias Control" that's available as a new feature? According to Butler it controls the amount of current draw of the cathode.... You're supposed to be able to dial in the bias for different tube types....

Seems like it would be easy enough to implement... a pot between the cathode and V- perhaps? :hmmm:

TT
tictac
Breadboard Brother
 
Posts: 147
Joined: 27 Nov 2008, 08:30
Has thanked: 0 time
Have thanks: 9 times

Re: BK Butler - Tube Driver

Postby tictac » 29 May 2015, 03:40

:oops: sorry for not doing a search first.... yep, it's a pot, Bajaman already drew up a nice schematic...

Funny cause I'm tinkering with my Bajaman tube driver after reading this thread just didnt realise he made some updates to the circuit... :slap:

TT
tictac
Breadboard Brother
 
Posts: 147
Joined: 27 Nov 2008, 08:30
Has thanked: 0 time
Have thanks: 9 times

Re: BK Butler - Tube Driver

Postby teemuk » 29 May 2015, 17:07

tictac wrote:Does anyone know about the "Bias Control" that's available as a new feature?


In older TubeWorks units (e.g RT-902 Real Tube Rack) the "Bias" control was simply a potentiometer wired as variable cathode resistor.
teemuk
Breadboard Brother
 
Posts: 134
Joined: 17 Aug 2009, 20:54
Has thanked: 3 times
Have thanks: 50 times

Re: BK Butler - Tube Driver

Postby teemuk » 29 May 2015, 17:11

...oh, forgot to mention, quoted as being a feature that actually makes the distortion more tweakable and versatile.

Image
http://music-electronics-forum.com/atta ... e-rack.jpg
teemuk
Breadboard Brother
 
Posts: 134
Joined: 17 Aug 2009, 20:54
Has thanked: 3 times
Have thanks: 50 times

Re: BK Butler - Tube Driver

Postby whopperplate » 27 May 2018, 06:09

Thank you all for the wealth of info. I am working out the details for building one of these guys and I am I seeing correctly that only the hot is connected to the output jack, no ground? Is it connected via the input jack ground to chassis?

Another question, what would the effects be of increasing the drive and high pots from 500k to 1M? Some of the old pedals had this value and I am wondering about their tonal difference.

Thank you for the time!

Charlie
whopperplate
 
Posts: 18
Joined: 05 Jul 2008, 23:02
Has thanked: 0 time
Have thanks: 0 time

Re: BK Butler - Tube Driver

Postby Dirk_Hendrik » 27 May 2018, 07:43

Drive: Even more gain. About double of the max you had with a 500k pot. Tone: You'll change the frequency characteristic of the tone stack.
Sorry. Plain out of planes.

http://www.dirk-hendrik.com
User avatar
Dirk_Hendrik
Old Solderhand
 
Posts: 4165
Joined: 03 Jul 2007, 09:44
Location: Old Amsterdam
Has thanked: 250 times
Have thanks: 1004 times

Re: BK Butler - Tube Driver

Postby whopperplate » 27 May 2018, 12:21

Dirk_Hendrik wrote:Drive: Even more gain. About double of the max you had with a 500k pot. Tone: You'll change the frequency characteristic of the tone stack.


Awesome, that’s what I was assuming more or less, thank you!

Does it shift the frequency response up or down? I have never been educated on the math of what’s going on. I appreciate all the help, thank you so much.

Charlie
whopperplate
 
Posts: 18
Joined: 05 Jul 2008, 23:02
Has thanked: 0 time
Have thanks: 0 time

Re: BK Butler - Tube Driver

Postby whopperplate » 28 May 2018, 04:53

Still most curious about the grounding scheme
whopperplate
 
Posts: 18
Joined: 05 Jul 2008, 23:02
Has thanked: 0 time
Have thanks: 0 time

Re: BK Butler - Tube Driver

Postby whopperplate » 28 May 2018, 16:24

Also from looking at the PCB photos it seems the red LED is wired with the cLED to ground after , rather then between the R16 and the LED as written in the schematic. can anyone please also confirm this? Thank you

Charlie
whopperplate
 
Posts: 18
Joined: 05 Jul 2008, 23:02
Has thanked: 0 time
Have thanks: 0 time

Previous

Return to Vintage Stompbox Corner ( ... - 1975)

Who is online

Users browsing this forum: No registered users and 4 guests