Tube Driver & BK Butler ?

[David Schwab]

Augh, guys! Some of you would know tell me the voltage measured or + (pin 8) and - (pin 4) on the 4558?
In the schematic that I downloaded are indicated +12.5 and -13 Volts ...
Has anyone tried what happens with the 12AT7/ECC81 (like the original '80s) or 12AY7/6072A?
You hear a difference by replacing the 4558 with the TL072?

Thanks, Alex

I have a BlueTube, I can measure it for you. It should be similar to the TubeDriver. I still have the 4558 in it, so I can't answer that.

I use a 12AU7 in my BlueTube. That gives me less fuzz and more of a clean tube amp tone. I use it for bass. I can still get a lot of overdrive when I want.

[mozwell]

There are a lot of threads on freestompboxes about butler tube drivers.
One of the people there did his own design, based on the work of Butler & others
freestompboxes.org • Login

I have built one, as have many other people, & i must say i really like it. It is now my "go to" overdrive of choice....

Some butler schematics for those who are interested

[David Schwab]

There are a lot of threads on freestompboxes about butler tube drivers.
One of the people there did his own design, based on the work of Butler & others
freestompboxes.org • Login

I have built one, as have many other people, & i must say i really like it. It is now my "go to" overdrive of choice....

Some butler schematics for those who are interested

Great, the Blue Tube schematic! Many thanks!

I love the sound of mine, but there's an annoying hum when it's not bypassed. I don't know if it's because the transformer is so close to the tube, or from AC to the heaters... but I've been wanting to build a new version and try to make it quieter. It also needs an output buffer.

[mozwell]

When i first built the one from freestompboxes, it had a loud hum. I didnt follow the layout, so my fault. Playing around with the position of the heater wiring improved it greatly. I rebuilt it a few months ago, using the layout provided, & its as quiet as a mouse.
its all about keeping the heater wiring away from everything else. If the PT is close to the tube, that wont help. I used a 16VAC 1A plug pack (wall wart) to power mine

[David Schwab]

Well there's only so much you can do with a factory built Blue Tube or Tube Driver because everything is on a circuit board. The power transformer is in the box, and the box is pretty small.

I might try removing the transformer and moving it outside the box and see if that helps. Or maybe some shielding...

[mozwell]

Hi David
It may be the heater track layout. If you cut the heater tracks at the tube, and then run a twisted wire pair straight from the heater to the 12VAC secondary of the transformer (or where the 12VAC enters the board), you may be able to position the wiring to reduce the noise. Run the wires from the tube heater pins 4 & 5 directly out from the pins & away from pins 2 & 7, we can reduce any interference to the valve grids.
You could also make a small power supply for DC to supply the heater.
The main thing is reducing any voltage drop in the 0V tracks on the board, so heater current doesnt cause small voltage drops in the 0V tracks, which you would hear as noise / hum

[David Schwab]

Hi David
It may be the heater track layout. If you cut the heater tracks at the tube, and then run a twisted wire pair straight from the heater to the 12VAC secondary of the transformer (or where the 12VAC enters the board), you may be able to position the wiring to reduce the noise. Run the wires from the tube heater pins 4 & 5 directly out from the pins & away from pins 2 & 7, we can reduce any interference to the valve grids.

That's a good idea! I hadn't thought of that.

You could also make a small power supply for DC to supply the heater.

I thought about doing this.

I've also been wanting to make an output buffer. If I plug it into certain devices, I lose all the output.

All this makes me think of just building a clone with improvements.

[Walking Eagle]

David: Hi, You are very kind! In fact, I'd like to know what are the tensions on the 4558 at least as the TL072.
Why not try it on your Blue Tube the 12AY7?
To be sure that the hum is caused by the heaters, I'd suggest comparing the buzz with the 12AX7 and the 12AU7.
Since the 12AX7 has an amplification factor in tension decidedly higher than the AU (is more sensitive), if the hum is due to the AC (which is applied close to the pins of the grids) should hear more strongly when it is mounted the AX.
The shield seems to me a good idea does not do much weaving together the wires that carry the current to the heaters, you may instead use two shielded cables (coaxial).
Try it before building a bulky AC DC ... I have done so for the heaters of 6550C in a single ended amp like the ace of "picche" of my avatar (equipped with a 300B tube).
The 6550, as is normal in the power tube, has an amplification factor in tension rather low, so it is not very sensitive to the induced AC hum of the heater.
However, this AC is 1.6 A RMS, and then tends to disturb the other signal tubes of the circuit, if it is not the screen.
It seems to me an excellent idea of the output buffer. I wonder if it might fit the pattern of the Tube Screamer, without having to use another IC?

Mozwell: Thanks for the info! It 'a very interesting pattern, but there are some ambiguities that do not understand.
Only 12pF in the DRIVE control? Or wanted to write "120"?
Still, there is an inscription ".01" close to the tone stack that you do not understand what it refers. Maybe they forgot to mark a capacitor?
Also in the tone stack there are two words "220K" and "500K" in close vicinity to the same pot ... For the rest it seems to me a pattern that deserves to be studied, because if it sounds good as you say ... WOW!

[David Schwab]

David: Hi, You are very kind! In fact, I'd like to know what are the tensions on the 4558 at least as the TL072.
Why not try it on your Blue Tube the 12AY7?
To be sure that the hum is caused by the heaters, I'd suggest comparing the buzz with the 12AX7 and the 12AU7.
Since the 12AX7 has an amplification factor in tension decidedly higher than the AU (is more sensitive), if the hum is due to the AC (which is applied close to the pins of the grids) should hear more strongly when it is mounted the AX.

The reason I'm using a 12AU7 is that when the pedal was set to sound clean, the output level was too low. So when I turned the gain up to get the pedal to unity gain, it would be too distorted. With the 12AU7, I can crank the gain up and get a nice clean warm tone. And I can still get plenty of overdrive and distortion. With the 12AX7 is was too fuzzy. I mostly use this pedal with bass.

I still have the original tube. I'll give it a try and see if the hum is any different. It's not a very loud hum, but it's enough to be annoying.

I bought this Blue Tube new when they first came out. For a while I had a NOS Sylvania ECC83 in there. That had a different tone from the stock tube.

This is what it looks like on the inside:

[Walking Eagle]

It's very interesting what you say, and in fact is also intuitive. Certainly one of the original pedal is not advisable to make changes. You could build a clone and then modify it. It's just what I intend to do because it is a fascinating distortion (the "holy grail", according to some)... One thing I will try to do now is replace the anodic charge resistors 68K (if I remember correctly) with others of lower value, eg 47, 39, 33 ... up to 22Kohm with 12AX7 and then compare the sound with what you get from 12AU7 loaded with the original resistors. Another test that I will definitely be trying a pair of N-channel JFETs in place of the tube. I will try also to replace the 1N4148. Have you ever tried to boost the signal entering the Blue Tube with a booster? I also play bass, but I never use the distortion. What kind of music do you play?
From your picture it is seen that the transformer is actually very close to the circuit which processes the signal. I've recently built a solid state preamp for electric guitar in a container 22 x 25 x 5.5 cm which also contains the transformer, but I proceeded to shield the power of the preamplifier through cuttings of shaped copper connected to ground and the noise is KO.
That's why the first version of the Chandler Tube Driver had an external transformer housed in a special container.

[David Schwab]

Have you ever tried to boost the signal entering the Blue Tube with a booster? I also play bass, but I never use the distortion. What kind of music do you play?
From your picture it is seen that the transformer is actually very close to the circuit which processes the signal. I've recently built a solid state preamp for electric guitar in a container 22 x 25 x 5.5 cm which also contains the transformer, but I proceeded to shield the power of the preamplifier through cuttings of shaped copper connected to ground and the noise is KO.
That's why the first version of the Chandler Tube Driver had an external transformer housed in a special container.[ATTACH=CONFIG]17773[/ATTACH][ATTACH=CONFIG]17774[/ATTACH][ATTACH=CONFIG]17775[/ATTACH]

My signal path is an old MXR AC Limiter pedal, and then the Blue Tube, and then recently I added an MXR Phase 90. I have the Limiter set for pretty much unity gain. I have tried driving the Blue Tube, but then it gets fuzzy. Generally I don't use the Blue Tube for distortion. I have it set clean, with maybe a tiny bit of grit. I use it mostly to fatten up the tone. For some songs I might turn the drive up a little more for some over drive. If I want distortion, I have a Bass Brassmaster clone that I made.

The Blue Tube really has a nice bottom end. I had tried one of those new Hartke LH-1000 amps, and even though they have a similar preamp as the Blue Tube, it just didn't have the same low end fatness. So I leave the Blue Tube on most of the time. What the Blue Tube needed with the 12AX7 was a gain stage after the tube. The problem was that when the gain knob was set low to get a clean sound, the output was too quiet, even with the volume all the way up. It also needs the output buffered because the impedance is too high. If I plugged it into things like a mixer, the output was too low. This even happened with certain pedals. I would have to plug it into a buffered pedal first.

Here's a low light (i.e., crappy) cell phone photo of my rig from the last gig I played:



I play all kinds of music. Mostly alternative and progressive rock, but I was doing this gig with a classic rock cover band.

[mozwell]

Hi Guys
If you are building a clone, check out my previous link freestompboxes.org • Login
In various places through this thread, there are schematics & pictures of builds.
the guy that did this project, based it on the Butler, but made improvements on the original butler design

Many people there have built it, as have i, and it is indeed a really nice OD.
I havent used a Butler, so i cant compare, but people on FSB have commented how much they like this newer version over the Butler one.
There are also schematics there for butler units with "bias" control etc, well worth some time reading through the (now) long thread.
The guy sells a pcb for the project, and with his permission, i have put a vero board layout there as well.

If you leave the butler driver on all the time, but with not enough output level, instead of modifying the butler, just put a preamp pedal after the butler & leave it on all the time.....

[David Schwab]

Hi Guys
If you are building a clone, check out my previous link freestompboxes.org • Login
In various places through this thread, there are schematics & pictures of builds.
the guy that did this project, based it on the Butler, but made improvements on the original butler design

Many people there have built it, as have i, and it is indeed a really nice OD.
I havent used a Butler, so i cant compare, but people on FSB have commented how much they like this newer version over the Butler one.
There are also schematics there for butler units with "bias" control etc, well worth some time reading through the (now) long thread.
The guy sells a pcb for the project, and with his permission, i have put a vero board layout there as well.

Yes, thanks for the link.

I started going through the thread. The old posts are missing a lot of the images, like the schematics and stuff, but I have found them online, so I'm guessing they show up later. I haven't gotten that far into it yet.

If you leave the butler driver on all the time, but with not enough output level, instead of modifying the butler, just put a preamp pedal after the butler & leave it on all the time.....

My original plan was to build an output buffer with some gain to make up for the problem. But the pedal still sounds better for bass with the 12AU7 in it. I tried it out with the 12AX7 and a preamp after it to make up the gain. This way I can get some more signal into the tube, which gives a fatter tone but doesn't go fuzzy on me. The BlueTube was supposed to be a "tube enhancer" and not really an over drive per se.

But I think I'll build a clone and keep that on all the time, and then use the pedal for over drive.

[Walking Eagle]

Hi David. The pedal in the picture is equipped with 4558 or TL072?
I'm experiencing my own version of the Tube Driver and I have developed some new features, with which we have found that the benefits, including flexibility, improved compared to the traditional version.
The power supply takes particular care, so that my guitarist friend says it's quiet.
Right now, however, we performed all tests using the TL072. In the coming days we will receive the JRC4558 and are eager to repeat the tests.
Perhaps they will sound even better?

[David Schwab]

Hi David. The pedal in the picture is equipped with 4558 or TL072?
I'm experiencing my own version of the Tube Driver and I have developed some new features, with which we have found that the benefits, including flexibility, improved compared to the traditional version.
The power supply takes particular care, so that my guitarist friend says it's quiet.
Right now, however, we performed all tests using the TL072. In the coming days we will receive the JRC4558 and are eager to repeat the tests.
Perhaps they will sound even better?

It has a TL072. The TL072 is a J–FET input op amp. The JRC4558 has a bipolar front end. I find the TL0s tend to sound brighter.

Interestingly, I've been comparing the Tube Driver to the Blue Tube and the only difference is a 100K resistor after the second op amp to reduce the level to the tube on the Blue Tube.