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Projects => Build Reports => Topic started by: Guitarmageddon on March 15, 2015, 05:07:15 AM

Title: Tube Driver
Post by: Guitarmageddon on March 15, 2015, 05:07:15 AM
My build of the THcustom Tube Driver.
.
Sounds nice, I've kinda missed the boat on these valve designs I'm seeing around.  I've had people asking "why don't you build something with a tube in it?" for so long. Never thought it worth the trouble at low voltage. The charge pump in this one puts out 70v from a 9v supply, or 100v from my 12v one. It's a really fun project and Thomas is a nice guy to deal with.

(http://i190.photobucket.com/albums/z30/codtone/1Caution_zpswd3bqjnn.jpg)

(http://i190.photobucket.com/albums/z30/codtone/Guts_zpsd4bv0rca.jpg)

Spent about a week debugging it because I stupidly soldered the tube socket to the wrong side of the board.  ::) Thanks for you help Thomas.

(http://i190.photobucket.com/albums/z30/codtone/IMG_4264_zpskfkaww2f.jpg)

I've run through a bunch of them, and some were definitely nicer than others, but find a 12AX7 to be too much gain for my taste, got a 12AU7 in there at the moment which I like much more, but getting some 12AT7. I think they will strike a nice middle ground. Decay can be a bit fizzy, I'm hoping tweaking the bias will fix that. Added a 100pf cap to ground to shave off a little brightness too.

(http://i190.photobucket.com/albums/z30/codtone/Lights2_zpstise6bc1.jpg)
Title: Re: Tube Driver
Post by: AntKnee on March 15, 2015, 05:24:39 AM
I am digging this build! The swiss cheese-style venting is cool!
Title: Re: Tube Driver
Post by: alanp on March 15, 2015, 05:47:19 AM
Sorry, dude, but I had a good laugh at first. "Hahaha, a blue LED where it can't be seen, just to light up the valve!" (Toobs are what you get inside bicycle tyres.)

Then I noticed the vent holes.

Bloody nice build.
Title: Re: Tube Driver
Post by: juansolo on March 15, 2015, 08:23:51 AM
Doesn't really get better than the 12AU7 in that. The 12AX7 isn't really being pushed hard enough by the pump running from a 9v source, from a 12v it's better but that's a valve that likes it's voltage. The 12AU7 in comparison is surprisingly sweet even a low voltage. Tis a nice thing. Try an RCA 12AU7A cleartop if you can find one. Thinking about it, a 12BH7 sounds lovely... Bit pricey mind and not really worth the difference from a RCA.
Title: Re: Tube Driver
Post by: Willybomb on March 15, 2015, 11:12:44 AM
Looks like I'm going to have to build a valve pedal one of these days...  I love my Blackstar, wonder if something running off 9v gets close.
Title: Re: Tube Driver
Post by: sirbergersworth on March 15, 2015, 01:20:21 PM
very cool build

I have some 60's 12BH7's from an old hammond organ. I would definitly trade you one or some for this pedal. lmao. seriously, I would trade one or some for something.
Title: Re: Tube Driver
Post by: lincolnic on March 16, 2015, 04:42:41 AM
Those shotgun-scatter vent holes are so awesome.
Title: Re: Tube Driver
Post by: TGP39 on March 16, 2015, 07:32:37 AM
Quote from: juansolo on March 15, 2015, 08:23:51 AM
Doesn't really get better than the 12AU7 in that. The 12AX7 isn't really being pushed hard enough by the pump running from a 9v source, from a 12v it's better but that's a valve that likes it's voltage. The 12AU7 in comparison is surprisingly sweet even a low voltage. Tis a nice thing. Try an RCA 12AU7A cleartop if you can find one. Thinking about it, a 12BH7 sounds lovely... Bit pricey mind and not really worth the difference from a RCA.

I think Merlin Blancowe agrees with you John.....

http://www.valvewizard.co.uk/Triodes_at_low_voltages_Blencowe.pdf

Steve.
Title: Re: Tube Driver
Post by: Leevibe on March 16, 2015, 01:20:46 PM
Quote from: alanp on March 15, 2015, 05:47:19 AM
Sorry, dude, but I had a good laugh at first. "Hahaha, a blue LED where it can't be seen, just to light up the valve!" (Toobs are what you get inside bicycle tyres.)

Then I noticed the vent holes.

Bloody nice build.

Haha! My thoughts too. Except I call them tubes. :)
Title: Re: Tube Driver
Post by: jimilee on March 16, 2015, 01:31:37 PM
Are the board and the stomp in danger of getting a little hot?
Title: Re: Tube Driver
Post by: Thomas_H on March 16, 2015, 08:04:59 PM
Very cool build!

Great you got it going. First buildof the inside driver with Tube LED :)
Title: Re: Tube Driver
Post by: Guitarmageddon on March 16, 2015, 08:29:53 PM
Thanks for the comments guys!
Tubes/Valves  ;D I'm Australian so I grew up calling them Valves, but affected "Tubes" having been pulled up on it so many times on US dominated forums. :P
Quote from: jimilee on March 16, 2015, 01:31:37 PM
Are the board and the stomp in danger of getting a little hot?
The ...erm... "miniature dual triode device" doesn't generate much heat, just glows gently and gets mildly warm.
The regulator on the other hand gets hot enough to burn! I'm going to bolt it to the side of the enclosure, but, no, I'm not concerned about heat build up inside. 8)
Title: Tube Driver
Post by: sirbergersworth on March 17, 2015, 09:54:03 PM
A few 12BH7 I found in an old organ.
They are about 5.8 mm tall. That measurement is taken of glass only. no pins.
(http://tapatalk.imageshack.com/v2/15/03/17/a898c49e1683db4ece1e5b5f76542a31.jpg)(http://tapatalk.imageshack.com/v2/15/03/17/b4af40826521d091118ff094819c9b47.jpg)


Sent from my iPad using Tapatalk
Title: Tube Driver
Post by: sirbergersworth on April 18, 2015, 05:54:16 PM
Did you try the 12BH7 yet? Interested in your results.