Tube boost + overdrive running off a 9 volt battery

[iccaros]

Sorry I must be stupid.. when you connect your voltmeter (your pannal VU )you plug one side into your i/o box and then have no cable, but the other probe is connected to the valve caster?
if so you not measuring volatge, as voltage can only be measured over a load. http://physics-tutor.site90.net/drupal/node/29, that would be measuring current, which If I remember my EE coursed from 20 years ago, a VU will read amp or milliamp in this configuration.


as for voltages, if these are read from pin to ground with tube in, well they are low for the plates.. I would expect 7 volts or so, are you running this through a voltage regulator, and why are you running it off a SAG power supply, the last thing we want in a starved plate design is low battery simulate, which is what your sag is doing. .That is cool on some old effects pedals, but kills head room on this pedal.

Lol, no, i doubt you're stupid.  I think i just described it wrong!  It sits in parallel between my I/O box and the breadboard, There are two wires into it (V+ and Ground) and two wires out of it to my breadboard (V+ and ground).  The purpose of the 'sag' knob is to dial my 18V adapter down to 12V (or 9V, etc), not to starve the Valvecaster.  It works perfectly on any other circuit, but the Valvecaster acts funny.

An interesting thing happened and I think (hope) it's the issue.  I was checking to make sure none of my components were touching each other and when I wiggled the input cap, i heard a scraping noise.... This breadboard has a metal plate on the bottom and is supposed to have a shield between it and the board, so I shouldn't have heard the scraping sound.  I think I have to rip it down and check my board... I'm thinking there may be something grounding out under there.  As soon as I get the time, I'll have to rebuild.  Thanks everyone for the comments and tips.

Beautiful pedal a few posts up too!  I love seeing other people's creations!

can you put of pictures of your Bread board.. maybe get another set of eyes on it.

[Renegadrian]

juan, nice works as always! Mind to share the mods you made to the original schem in the scond pedal!?

[CheopisIV]

I took some action shots of the breadboard few days back, just need to find time to put them on the pc.  I tore the board down last eve and the backing is intact so my grounding theory is out the window.  I had the VC apart so rebuilt it according to the pcb-less schematic, still does the same thing to my power supply, so there goes the too-many-wires theory too!  Another oddity though, this new build sounds fantastic, but my volume pot does nothing... I probably fried something while soldering.   I also took voltages and then tried a different brand tube, then got a bunch of different readings.   I'm thinking that maybe these tubes are just a bit far gone and that's the reason for the odd behaviour on the first build?  More dissection is needed!

[CheopisIV]

  ...if I were a bit smarter, I might have noticed the ground from the remaining Volume lug...  Also getting this off the breadboard and into an enclosure for kicks.  Pictures to come, but there wont be any fancy decals yet.  I want to work out all the bugs before I worry about pretty.

[iccaros]

...if I were a bit smarter, I might have noticed the ground from the remaining Volume lug...  Also getting this off the breadboard and into an enclosure for kicks.  Pictures to come, but there wont be any fancy decals yet.  I want to work out all the bugs before I worry about pretty.

Have you seen my videos? I am all good with function over form..

[juansolo]

juan, nice works as always! Mind to share the mods you made to the original schem in the scond pedal!?

There's still a little crackle when the gain pot is turned, not as bad as altering the tube bias on the original, but maybe another resistor to ground on the 2nd triode grid will make it better.  I might try it at the weekend. 

I don't think the 150n caps are a critical value, I had a few from a bulk buy, and wanted to use them up, had them 2 years and never used.  A 100n or 220n would probably work just as well.

I also tried a JJ ECC83 in this and it worked well, unlike when I've tried them in a regular valvy.  Not sure if its the 23V or the mods.  A 5963, 12BH7, and ECC83 all worked and all sounded good, all different in terms of gain and bass though.

[Death Super Mario]

I have problem. Tube socket holes are lower than tube pins.
I tried to cut lower the pins and I break tube .
I tried to filing another tube pins. Filing tangled pins. Filing  it slower is slow process and it can also tangle pins.
What to do ?

[merlinb]

I have problem. Tube socket holes are lower than tube pins.

You may have accidentally got solder inside the socket...

[Death Super Mario]

I have problem. Tube socket holes are lower than tube pins.

You may have accidentally got solder inside the socket...

No this is excluded. Tube socket holes are not long as the tube pins.

[merlinb]

No this is excluded. Tube socket holes are not long as the tube pins.

Then the socket is bad, replace the socket.

[Death Super Mario]

No this is excluded. Tube socket holes are not long as the tube pins.

Then the socket is bad, replace the socket.

In Estonia I have to be happy that I can buy right function tube and some socket.
In Estonia many things what is in other countries buyable is not on sale.

[merlinb]

In Estonia I have to be happy that I can buy right function tube and some socket.
In Estonia many things what is in other countries buyable is not on sale.

Then leave it alone. You already broke one valve, which probably cost more than another socket...

[Renegadrian]

juan, thx for posting the schem! 12BH7 you say, I got a couple and I like them!!!

[ThunderShowers]

I don't think the 150n caps are a critical value, I had a few from a bulk buy, and wanted to use them up, had them 2 years and never used.  A 100n or 220n would probably work just as well.

Hmmm, Those caps are pretty lowish, those alone should cut bass... Doth you have sound clips?

[iccaros]

juan, nice works as always! Mind to share the mods you made to the original schem in the scond pedal!?

There's still a little crackle when the gain pot is turned, not as bad as altering the tube bias on the original, but maybe another resistor to ground on the 2nd triode grid will make it better.  I might try it at the weekend. 

I don't think the 150n caps are a critical value, I had a few from a bulk buy, and wanted to use them up, had them 2 years and never used.  A 100n or 220n would probably work just as well.

I also tried a JJ ECC83 in this and it worked well, unlike when I've tried them in a regular valvy.  Not sure if its the 23V or the mods.  A 5963, 12BH7, and ECC83 all worked and all sounded good, all different in terms of gain and bass though.

try putting the pot behind the coupling cap.. This way current through the pot is not heard on the input of the next stage.

[zambo]

actualy if you put a cap between the pot and the grid it should cure the crackle. At voltages this low the grid starts conducting pretty easy and the cap should block it from the pot. You can use it to shape tone if you want as well. I would start with a bigger one though. .047uf should be fine i would bet.

[juansolo]

Will have to have a play at the w/e and see if we can eliminate the crackle.

Sadly I've got no way of making any clips

[Anon]

I don't get any hum, I have the 15v going through a capacitor/7812/capacitor setup, and it's really clean
Actually the output is powering all my pedals at 12v

I was wondering how you wired it. I had the 35V side going to the anodes and the 15V side going to the filament. I used a 7812 to convert the 15V to 12V. All I got was a loud hum with all the HP printer adapters. All of the grounds were connected properly. When I went back to the 15V radio shack adapter there is no hum

[iccaros]

I don't get any hum, I have the 15v going through a capacitor/7812/capacitor setup, and it's really clean
Actually the output is powering all my pedals at 12v

I was wondering how you wired it. I had the 35V side going to the anodes and the 15V side going to the filament. I used a 7812 to convert the 15V to 12V. All I got was a loud hum with all the HP printer adapters. All of the grounds were connected properly. When I went back to the 15V radio shack adapter there is no hum

that is filtering, I bet you money if you put the HP power supply to a o scope you would see a ac spike from the Switching power. Make sure your adapters say filtered and not switching..  Computers can having low frequency switching.. as they are no bothered by the noise at those frequencies. but audio equipment.. That is another story..

I have a 30v dc adapter from RS that is dead quite.  but hook up the HP printer one and I get noise..

[juansolo]

Well putting the cap after the pot failed completely.  It started to fart out when hitting the strings hard, so its gone back to before the pot.
I'll put up with the crackle.  I compared it to an original VC and its much less, so not an issue to me.

If I make another I'll have a little experiment, but for now it stays as is.  It sounds fantastic.