Comparing Tube Driver schematics and about DC powering

[shredgd]

Hi,
I'm planning to build a Chandler Tube Driver and I found three schematics. I found one at General Guitar Gadgets (http://www.generalguitargadgets.com/v2/diagrams/tube_driver_sc.gif), one from John Greene at http://amps.zugster.net/articles/tube-pedals/BKButlerTubeDriver.gif  and one at http://members.chello.at/anubics/html/schematics/Chandler_TubeDriver.gif .
The only difference between the first two is the value of two caps in the tone stack (0.47u each in the GGG schematic, 0.047u each in John Greene's), which may be a typing error in one of the two (in any case, which value is correct?). I suppose John Greene's schematic is the one used by the majority of the ones who have already built this pedal.
On the contrary, the third schematic (which is very new) contains various differences with the first two, even if the basic layout is the same. It says to be traced from a tube driver of which the original serial number and PCB number are given. As it also differs from the other two in the power supply section, I'm wondering if the noise issues I read about in a previous thread (http://www.diystompboxes.com/sboxforum/viewtopic.php?t=12005&highlight=chandler) may be due to some "lacks" in the older schematics.
Basically I'm asking you which of the schematic I'd better follow.

My second question is about the possibility of DC powering, which I read in the thread I mentioned above.
I read I would need 30v DC and a voltage divider to feed the IC with, but I didn't understand well how much voltage I would need to feed the heaters with. In any case, are these mods the only ones I would need? Would it work?

Thank you very much in advance,

Giulio

[george]

Both schematics take a 12V AC power supply.

They have a rectifier section that gives the 30VDC required for the valve cathode and anode; the heaters just run off the 12VAC.

So all you need is a step-down transformer to bring the mains voltage down to 12VAC: for safety and convenience I would use a 12VAC wallwart adapter so you don't expose yourself to dangerous high voltages.

HTH

[Peter Snowberg]

The remote wall-wart also has the advantage of keeping the step-down hum out of your audio.

-Peter

[Arno van der Heijden]

I was asking myself the same questions and I did some investigations and collected images from Ebay auctions.
As I understand it, there are at least two versions of the Tube Driver made by Chandler (like it says on the housing). One of them says 'B.K. Butler' on the housing, the other doesn't (like the one at Anubics). They both have yellow knobs. I don't how much these versions are different circuitwise, but judging from the size of the filter caps there are at least some small differences.
There is also a reissue version was made by 'Tube Works'.

I don't know to which version the GGG and JG schematic belongs, but if I had to take a guess, again judging by the size of the filter caps, I would say it's the reissue version.

[shredgd]

The remote wall-wart also has the advantage of keeping the step-down hum out of your audio.

So are you saying the noise problems I read about will then disappear or will simply be lower?

They have a rectifier section that gives the 30VDC required for the valve cathode and anode; the heaters just run off the 12VAC.

So if I decide to use 30v DC to power up the circuit, I will simply use the voltage divider needed for the op-amp to run the heaters?

[george]

yeah I guess that should work ... if you mean feed the +15V to the heaters ... a 12V AC waveform has a peak voltage of +/-16V so I don't think feeding +15V DC to the heaters should be a problem in terms of exceeding peak voltages or whatever.

anyone who is a bit more expert than myself care to comment?

[puretube]

feeding 15V DC to the heaters shortens the tube`s live a couple of years.

that divider to get 15 out of 30V on the other hand, should be able to do this capable of 150mA! (i.e.: use 5W resistors...)

[Peter Snowberg]

If you have 15 volts available, consider using an 7812 or 78M12 regulator to make a real 12 volt supply. The tube will be much happier. Just remember to mount the 7812 to the case or to a small heat sink.

I don't know about the noise from that product (I've only serviced one and it was years ago), but if you can keep transformers away from audio, you have the best bet for keeping hum out.

Take care,
-Peter

[Arno van der Heijden]

Does anybody have more information about the different versions?

[shredgd]

What about the 9v DC 3-knob Tube Driver (suggested to be run at 12v, though) schematic at http://www.muzique.com/schem/tubedrvr.gif , instead? The schematic says numerous people have built it, is anyone nearby...? How does that sound?
Also, what about running the 4-knob circuit at 12v DC (by connecting the V- points to ground)? This way I wouldn't need any particular power supply (except a good wall wart). Would it work?
Thank you.

Giulio

[tarzanalog]

What about the 9v DC 3-knob Tube Driver (suggested to be run at 12v, though) schematic at http://www.muzique.com/schem/tubedrvr.gif , instead? The schematic says numerous people have built it, is anyone nearby...? How does that sound?
Also, what about running the 4-knob circuit at 12v DC (by connecting the V- points to ground)? This way I wouldn't need any particular power supply (except a good wall wart). Would it work?
Thank you.

Giulio

Sorry to be resurrecting such an old post, but I just picked up a 3-knob 9VDC Tube Works Tube Driver and I'm really curious if I can just plug in a 12VDC power supply and go!

Can the pedal take it? Would it if I modded the schematic a little? Just trying to get the voltage up to the heaters... but would that be too much for the filaments using the current (pun intended) schematic?

Thanks,
T

[A.S.P.]

the answer is in the link in the reply before yours...

[finkfloyd]

Hello, I too would like to experiment with building one of these , but before I do, I know these suffered from a design fault (noise problems), Heres an interview with BK Butler here explaining the fault in the circuit, related to the EQ, http://mywebpages.comcast.net/jroscoe/bkbutler.html

Which diagram is the new corrected version?

Actually the Chandler thing was a relatively minor incident in the overall history of my business activities.  There's not enough room here to elaborate much, but the truth of the matter is that somehow Chandler decided at one point that they had been the designer of the product, came up with the TD trademark and that I was infringing on their IP.  They obviously had somebody attempt to copy the electronics and the physical design of my TD, then produced and sold them.  I don't know how many unauthorized units are out there.  The mistakes inside are essentially within the EQ area and it would take too long to describe them.  Also there is a basic ground loop mistake as well.  The overall sound of the C copy is somewhat muted and not as clear on the upper harmonics, etc.  Eric Johnson never used one of these copies as far as I know.  All his pedals are ones I personally made