Tube boost + overdrive running off a 9 volt battery

[Hemmel]

What happens to pin 9 in this circuit ? Is it simply not connected ?

[Henry89789]

Hemmel:

I don't know but your question just helped me notice that is not the schematic for the dual valvecaster with valvemaster circuit I am looking for. 

[Jdansti]

What happens to pin 9 in this circuit ? Is it simply not connected ?

No, it's not connected because the heaters are powered in series.  Substitute your 9V power for the 12V shown below.

[iccaros]

Hemmel:

I don't know but your question just helped me notice that is not the schematic for the dual valvecaster with valvemaster circuit I am looking for. 

for a dual caster as its called, just repeat the same pattern.

[jmwreck]

using the right layout, does it have enough current to power the heaters as well as the main circuit? coz based on this statement:

(Renegadrians Voltage Multiplier), you'll get approx 60v from a 9v supply, 80v from a 12v supply and around 120v from a 18v supply. This charge pumped voltage is very low current, which is why you have to run the heaters from the source supply as they are the high current draw bit.

heaters needs to have a different source.

**Sorry for this question, I haven't seen a clear finished product of a Valve pedal. Using a charge pump for the main circuit and a 12v regulated to the heaters. Does it mean that there are two DC jacks for the pedal and that it obviously share the same ground?

[Jdansti]

>using the right layout, does it have enough current to power the heaters as well as the main circuit? coz based on this statement:

I'm not familiar with this circuit, but it appears that the 9V supply branches off to the 6V regulator and to the charge pump as I indicated here (assume that the regulator is a 7806-the diodes shown in your layout may not be the same):



>**Sorry for this question, I haven't seen a clear finished product of a Valve pedal. Using a charge pump for the main circuit and a 12v regulated to the heaters. Does it mean that there are two DC jacks for the pedal and that it obviously share the same ground?

If you use the "Boob Board", you don't need the 12V supply. Your 9VDC supply is regulated to 6VDC and supplies the two heaters in parallel. As shown above and below on the right:



You only need one DC jack tied to the 9VDC point on the left side of the board. The 6VDC on the right side goes to the heater pins 4 and 5 as shown in my modification above.  Pin 9 goes to ground. All grounds should be tied together at one point.

If you decide to forgo the Boob Board, you still only need one DC jack. The 12V supply feeds the tube heaters in series and supplies the input to your charge pump. The output from the charge pump feeds the rest of the circuit as shown here:

[toplak666]

I searched this thread for the schematic for the "double valvecaster with the valvemaster circuit"   that you suggested. Is this the schematic (below) for that circuit? The schematic says 12AU7 and you suggested the 12AX7 double valvecaster w/ valvemaster circuit. Is it the same circuit with 12AX7 tubes instead of 12 AU7 tubes? Or is there a  different schematic for the 12AX7 circuit?   Thanks.

Ye, sorry bout that... I should have been more specific about what I ment by "double valvecaster with the valvemaster circuit". Yes, this is the right circuit! The schematic should be pretty much the same for 12AX7s... However, instead of 9 volts you'll need 12 volts for the heater pins and 18 volts or more for everything else. Maybe I'll draw you up a schematic later if I find the time.

[iccaros]

Ye, sorry bout that... I should have been more specific about what I ment by "double valvecaster with the valvemaster circuit". Yes, this is the right circuit! The schematic should be pretty much the same for 12AX7s... However, instead of 9 volts you'll need 12 volts for the heater pins and 18 volts or more for everything else. Maybe I'll draw you up a schematic later if I find the time.

I will finish up a drawing tonight, I am on travel for work so it my be a little latter. But its basic, if you have 9v and multiply that to 18 then you take the 9v and tap off to a regulator  getting 6v for the heaters, another tap goes to to the multiplier.   

[toplak666]

There ya' have it. Ain't she a beaut? With this design you should be able to get nice crunch tones from the first stage and great drive sounds from the second stage.

This should work with all 12A_7 tubes, but keep in mind that while other tubes should work with plate voltages above 9v, 12AX7s need at least 18v for the plates. They just don't sound right otherwise... I can't say for sure but I suspect 12AT7s would require 18v too.
The first volume pot is completely optional but I recommend leaving it in. You can get more sounds by fiddling with it while using both stages.
This is ment to be used with two true bypass circuits. One for the first stage and one for the second. Didn't bother putting those in the schematic because I figured if you can wire up this circuit you should be able to wire in a bypass...

You diystompboxes veterans are welcome to fix any mistakes in the schematic. I'm still pretty new to tube circuits...

[Henry89789]

Toplak666:

               Thanks for taking the time to draw up that schematic.  She is indeed "a beaut" and an important contribution to this thread. She also represents the highest level to which I expect to go in building pedals. I have gone through pages 80-140 of this thread and haven't found a schematic similar to yours other than the single circuit one I put up. The farthest I have gone so far is building a one tube pedal on the breadboard (w/o switch or bypass). When I first came on here about 2 years ago I didn't  even understand schematics. For me the great challenge is to follow the schematic, build that Dual Caster tube pedal and have it work perfectly the first time. So I apologize for being a nag about the schematic. I definitely expect to build it. I already have all the parts. 12 old RCA and Sylvania 12AU7 tubes (obtained used but tested for $3.00 each from a Hammond organ repairman); tube sockets; switches; box; caps; etc. It would be great though if someone could verify that schematic.

[iccaros]

that would work, you will find that 10uf on the cathodes have a lot of bass, you can try .1 uf and  for resistors 1.5K and for the first stage.  really if you can measure 1.5v across the first cathode resistor, will give good enough head room and stay linear, allowing better control for the following stages.

[jmwreck]

looking at the charge pump above, the layout on the right is coming from a 9v then connect to the 9v wire then to a 6v and 60v on the on the other end, it means that its a charge pump that can supply the heaters (6v) and to the main circuit (60v), does it have enough current?

[valve999]

change your coupling cap, use  smaller number, if your using .1 use a .01 or .022 ect.. you will roll off some more bass.

Thanks for answer, Iccaros - can I check what you mean by coupling cap - is that the last one before the output i.e. it couples to the next stage? I've built my pedal according to the Valvemaster circuit on p131 - so C3 = 1uf.
Many thanks!

There are several locations, you can change c3 but you may find a better sound by changing c2 to a .0022, or by changing the cathode bypass capasitors (the 10uf) to a 1 or .1. if you roll off bass early your not boosting frequencies in latter stages.

Thanks, Iccaros - I'll give that a go!

[Jdansti]

looking at the charge pump above, the layout on the right is coming from a 9v then connect to the 9v wire then to a 6v and 60v on the on the other end, it means that its a charge pump that can supply the heaters (6v) and to the main circuit (60v), does it have enough current?

The 6V is not coming off of the charge pump. It's coming off of the regulator labeled as Q1.

[toplak666]

Higher resolution version: http://i.imgur.com/Ag7Rckc.jpg

Thar she blows! This is pretty much what I made for my 12AX7 DoubleCaster except I don't have L2 and actually have two more 1000µF capacitors after L1. This shouldn't cost more than about 15-20$. Cost me a bit more since prices in Europe are higher, but that's still prety cheap for an incredibly clean power supply.
Ok, so the 600mA transformator should supply enough current for at least two tubes. After that we have your basic old bridge rectifier to convert AC to DC. After that we have two inductors. If you choose to include them, make them as big as you can fit in your enclosure. The reason I labled them as "Optional" is because in order to get a noticable effect from them they need to be relatively big, so they may not fit in everyone's enclosures.
Now for the filter capacitors... If you can eliminate all humm with fewer capacitors then HALLELUJAH! But this is what it took to completely eliminate humm for me and frankly capacitors are pretty cheap so why not add a few more while you're at it?
After that we have a 12V and 18V regulator and a few more capacitors.
Now if you already have a powerfull wall wart and want to use that then just connect it to the two regulators and ignore everything infront of that.

There you have it! Clean, powerfull and relatively cheap power supply! Feel free to fix any problems in the schematic! I'm sure there are many.

[johnravacio]

jokes apart, the persuader is just another story...playing with pure tube schematics is more difficult than just push a tube with a (mosfet in the persuader case) booster...yes you can do it, but then you got an hybrid circuit and the tube gets less involved in the outcoming tone, so less mandatory (at least in my eyes)
just look at the schematic, no cathode resistors or capacitors...I guess the tube used that way gives very little to the overall performance...but it's just my guess, driven by a dislike of hybrid circuits.

@Renegadrian.. I now understand why you dislike hybrid circuits. I just finished my SHO + Valvecaster today and it sounds like a Russian big muff if you crank everything up. I like the valvecaster alone but I guess there's no turning back since I'm done already. Plus I don't like the CRACKLE sound on both the valvecaster gain(using B500K) and the SHO gain(5K) when I turned those pass by 80% of their respective ranges.

Lesson of the story: Listen to suggestions  

Here are some pics:

[Spagooty]

This is very cool, I've wanted to do this for a long time but didn't know it was possible.  A good source for power supplies is thrift stores, you can usually find 9vDC with + and - centers and different mA's.  Thanks for a great site!

[jmwreck]

which one is good for this circuit?
I only have these options.








OR



here is my layout:

[Isak]

I've tested 3 types..
Electro harmonix
Stlvnia
And RCA
All sound good the RCA sounds best

[Burdin]

Hi,

i have one question, i'm new to this, so please  sorry my lame questions.
I decided to build valvecaster according to this scheme http://www.aronnelson.com/gallery/main.php/v/Renegadrian/Valvecaster+v0_5.jpg.html I used parts with same values.
Problem is that there's to much noise (hum) in the signal, doesn't matter if i play or not, there's lot of hum, but if I start to play, I can hear what I'm playing but it's in background.
I used valve 12AX7, because i have few of them at home, they sholud be ok, all parts are new except pots and I'm not sure if they're ok, but when I turn them around they're changing sound or volume can turn it off. I used power supply with 9DC and also 12DC, result was almost same. I read that it's better to use 12AU7, but and I said to myself that it shouldn't such a difference. Is it possible that AX makes such a noise and if I use AU it can work allright? Or ther's some other problem. Thanks for your answers.