Matsumin Valve Caster tubes question

[timd]

Has anyone built the Matsumin Valve Caster? I have a 6V6 tube but the project calls for a 12AU7. Will this work?

[frequencycentral]

Everyone here built at least two of them:

http://www.diystompboxes.com/smfforum/index.php?topic=63479.0

Happy reading!

[seedlings]

Has anyone built the Matsumin Valve Caster? I have a 6V6 tube but the project calls for a 12AU7. Will this work?

6V6 is a power tube not a preamp tube.  I suppose, technically, with lots of fiddling with parts and researching datasheets you *might* be able to pull it off.  However, while you're researching, someone else just ordered a 12AU7 NOS tube and is jamming in their basement. 

CHAD

[artifus]

maybe just use a socket then you can try various toobs.

*edit* i mean, if it doesn't work it wont be a complete waste of time and resources - just set it aside until you do come across a suitable valve.

[seedlings]

The 6V6 is a pentode instead of a dual triode.  The original design has the first triode overdriving the second triode.  The 6V6 has one pentode, so it can't overdrive itself.  Not to mention it may not work well at 9V (although I have a 6V6 amp with the Variable Voltage Regulator circuit and the 6V6 does work as low as 37V, just not in this type of application).

I highly recommend picking up a different tube.

Have a read of this.  Whenever you read "EL34" substitute "6V6" as they are similar.
http://www.freewebs.com/valvewizard1/se.html

CHAD

[timd]

Thanks - time to order the right tube!

[Mustachio]

If you got a couple extra bucks try picking up a 12au7, and a 12ax7, and a 12bh7. Experiment with which ones you like best. Pretty much every tube is gonna have its own characteristics unique to itself.

And yeah like everyone else said , no go on the 6v6.

[timd]

Alright - I built the pedal and it sounds great - super warm and can get a little crunchy on the high gain.

He're my issue - the tube doesn't light up at all, but it works...I have response from all 3 pots, and the tube gets warm after a bit.

I have no prior experience with tubes - which is one of the reasons I wanted to do this one. I'm sure it's natural for tubes to get warm. Do they ever get too hot to touch?

The tube I'm using is an old used one I had laying around, and its probably from the 60's. I don't have a tester either. I thought (maybe naive) that if the tube doesn't light up, it doesn't work. This doesn't appear to be the case here though. Any info would be helpful.

BTW - yes I am ordering a new one or two - I was just curious about tubes.

[timd]

Also - I'm using a 9V wall wort for power, so it shouldn't be a low voltage thing like a dying battery.

[Bill Mountain]

Well...tubes aren't light bulbs so they don't actually light up.  Some manufacturers will put lights in or around them for show.  The heaters should glow but they are usually less bright at 9v and on my nos 12au7 you can barely see them.

[timd]

Hey thanks. I guess I was expecting a magical glow to accompany that magical sound!

[Jdansti]

I'm running my valvecaster on 12v and the tube barely glows. This is normal.  This tube gets warm, but not too hot to touch. Some people install them inside the enclosure with no problems.

If you want to make it look lit, place the "head" of an LED inside the the center hole of the tube socket from underneath. I used the bypass indicator LED on mine:



Also, you might want to try a 12v power supply. If you are using the 12AU7, with the heater voltage connected to pins 4 and 5, and no connection to pin 9, the two heaters are in series and are rated to run at 12v. Just don't run them any higher than 12v.