Tube boost + overdrive running off a 9 volt battery

[XI93909834]

this is my third edition

[alambike]

Hello,


I made the Valvecaster and I did not listen the "drive" or the "crunch" sound in this effect. Is there any modification that I could make to addition a little bit of distortion in the sound ?


I found some videos about the Persuader that it used a MOSFET to this finality. The schematic for the Persuader is in the MOD's website, but it is not much useful.

[sgmb]

I've got another thread going but maybe I'll get more responses here. Since I have the other thread, I'll provide the jist of what's going on.

Original Thread: http://www.diystompboxes.com/smfforum/index.php?topic=108569.0

What I Have: Valvecaster as a preamp, 10-watt TDA2030 power amp, 5" Celeston neodymium driver (pulled from a Trace Elliot cabinet)

The Problem(s):
1) I have to turn the volume and gain all the way up in order to get loud.
2) My biggest problem is the lack of crunchy goodness I'm hearing in all the YouTube videos (http://www.youtube.com/watch?v=3cMqYlhSQ8c)

This is very interesting to me because it is almost the same setup that I built in my old radio on page 171. I used a TDA 2003 and my speaker is a 5X7 eliptical rola but really it all sounds the same.
  I had to put a trimpot between the valvecaster and the TDA2003 to bring the level way down. It seems I had the opposite problem.

[sgmb]

I have started building a new pedal.
    Although I've built 3 valvecasters in the past, this is will be the first one I've put in a pedal... the others have been preamps in diy amplifiers.
    I am combining a Beavis Audio Trotsky drive with a valvecaster in one pedal. I think the brightness of the trotsky will balance the darkness of the Valvecaster quite well. I'll put the trotsky first and do an interstage gain on the valvy.
    I am hoping someone could give me some suggestions as to how I might arrange the power supply.   Ideally, I'll have 9v to the trotsky... 12v to the heaters and 24v or more to the valvy circuit.
    I'm yet to plan the best way to do this from a single wallwart.
    Does anyone know if the Trotsky will run on 12v?... not that it matters too much... a 12v to 9v regulator wouldn't be hard.

    Cheers guys.

[Caferacernoc]

Yes. Just run the Trotsky on 12 volts. No problem.

[sgmb]

Oh cool, thanks.... In that case I may as well just run the whole thing at 12v. I haven't tried higher voltages yet but I've been pretty happy with 12v so far
  Cheers

[ayayay!]

Thought I would post my mods for giggles.  These are for the original Dano/Matsumin Valve Caster.

-Get rid of the tone stack.  You'll find you can get the dry and wet signals to match pretty much by changing caps. 
-Brighten it up by controlling the bass.  The second cap (between stages) can be a .033 or .022.  This will cut out a lot of fizzle and make it far less dark. 
-Change the gain pot to a 100kC.  Optional: 10K resistor between the pot and ground.  This smooths out the gain a lot and makes the potentiometer usable.

And finally, after these tweaks, you can use a 12AX7 with it!  Really.  I tried Sovteks, Chinese, GT's and Mesa Boogies.  I had surprisingly good overdrive results with everything but the GT's.  Those were a joke.  Run it at 12 Volts though.  It tends to sag a little at 9 or 10 volts with a 12AX7.

I didn't experience the sag when using 12AU7's at 9.6V and it sounded very good.  So either way you should be able to make something work. 

Cheers!

[ayayay!]

Thought I would post my mods for giggles.  These are for the original Dano/Matsumin Valve Caster.

-Get rid of the tone stack.  You'll find you can get the dry and wet signals to match pretty much by changing caps.  
-Brighten it up by controlling the bass.  The second cap (between stages) can be a .033 or .022.  This will cut out a lot of fizzle and make it far less dark.  
-Change the gain pot to a 100kC.  Optional: 10K resistor between the pot and ground. This smooths out the gain a lot and makes the potentiometer usable.

And finally, after these tweaks, you can use a 12AX7 with it!  Really.  I tried Sovteks, Chinese, GT's and Mesa Boogies.  I had surprisingly good overdrive results with everything but the GT's.  Those were a joke.  Run it at 12 Volts though.  It tends to sag a little at 9 or 10 volts with a 12AX7.

I didn't experience the sag when using 12AU7's at 9.6V and it sounded very good.  So either way you should be able to make something work.  

Cheers!

Got rid of the 10K after the gain pot.  Added a 150pF on the output to tame the fizzle and brightness.  This thing sounds great and matches my bypassed tone closely enough to be very usable.  I settled on the .033 between stages.  You can run it at 9V just fine if your power supply has enough current.  I'm using a 1A.  I think you need at least 400mA for it to truly work well. 

[Mindaugas]

Hello everyone. I'm new here and also new at electronics.  So what I got, I have 24V adapter from drill, and two tubes 6N2P-EV. I'm thinking of building two tube valvecaster, tubes will be heated through LM317 at 6,3V and anode will be fed with 24V. Do I need to change resistors or any capacitors in the valvecaster schematic in order to run it at 24V? Any suggestions how to improve this without going to high voltages? Thank you and sorry for my bad English 

[id3m]

Hello guys been reading this thread for a while now, trying to construct a dual valvey (going to try the new schematic from Trippy).

I'm searching for help in prototyping a line tube preamp for my POD XT for in between the POD and interface to fatten and smooth up the tone.
I just can't understand how to match impedances and gain levels for those... I don't even need any amplification gain in there, but something more like cathode follower, I can go on even decreasing gain, my pod puts a lot of volume out.

The big idea is to build a small circut which can be then fitted inside the pod itself

Please help me guys.

I will later post my idea how the schematic should look like (need to draw it first)

Cheers,
Max.

[id3m]

Hello guys been reading this thread for a while now, trying to construct a dual valvey (going to try the new schematic from Trippy).

I'm searching for help in prototyping a line tube preamp for my POD XT for in between the POD and interface to fatten and smooth up the tone.
I just can't understand how to match impedances and gain levels for those... I don't even need any amplification gain in there, but something more like cathode follower, I can go on even decreasing gain, my pod puts a lot of volume out.

The big idea is to build a small circut which can be then fitted inside the pod itself

Please help me guys.

I will later post my idea how the schematic should look like (need to draw it first)

Cheers,
Max.

Here's a schematic I've thought of: https://www.dropbox.com/s/1bcp5prpzanljyg/New%20Doc_1.jpg?dl=0
The first half is a clean (?) valvey with fixed bias, worked in my test.
The second half is a cathode follower. I just copied its schematic from P1 extreme.

Tell me please - will this work? Any ideas on this scheme?

[alambike]

How could I know if the circuit is in series or parallel.

I connect the out of SHO to the in of the Valvecaster and it worked very well, but after 20min the pedal stopped suddenly.

I noticed that the tone control (of the valvecaster) was not working. I changed the electrolytic capacitor (of the valvecaster board - 1uF) and the pedal came back to live again. Well, only for more 20 min and then stopped again.

Why this capacitor is breaking ? and it  is working only for a few minutes ?

[id3m]

Check the cap voltage, has to be written on it. Sometimes electrolytic aluminum caps are only 10-16v, which is not enough. Try tantalum electrolytic.

[Palealien]

Hey all,

I'm half way through building my first valvy, there are just have a few things I feel like I should double check before I can continue with the build, and would definitely appreciate a little assistance.

So in this diagram...

http://img155.imageshack.us/img155/3599/valvecasterv05qs5.jpg

...C3 is labeled as being 1uF, but I've noticed there are other diagrams in this thread which have C3 as being 1nF.

Are both diagrams correct? I've bought a 1uF for this build, so I'm hoping I have the right thing.

And speaking of C3, from my understanding of the diagram, the negative is connected to the tone pot, while the positive goes to track 6 of the board. Am I right on this?

One last thing. The pots in the diagram are shown from the bottom, right? So if the lugs on the pots were numbered form left to right the order would be 3, 2, 1. Is this correct or am I reading this all wrong.

I imagine it's clear to most reading this, that I'm pretty new to this electronics thing, I've learned heaps, but clearly have a long way to go, and would really appreciate any assistance anyone can offer.

Cheers.

Andy

[duck_arse]

the circuit diagram will reveal all. that's why we like to see them.



your 1uF appears on the original, so it should be ok. if you follow its connections, one end goes to ground via the 100k vol pot, the other end goes to +9V via the 100k resistor. on end will be more positive than the other, it should be easy to work out which.

for the tone control wiring, C4 is in series with the tone pot, so it doesn't matter if it is at the signal end or the earth end of the pot. when confronted by a layout diagram with pots not marked cw/c (or w)/ccw, look for the volume pot. ground will always be on (or via a small value resistor, to it) the counterclockwise lug. you can then work backwards as to the 1-2-3-edness of the lug numbering convention used.

or look the circuit, work it out from the source, and apply it to your parts yourself, cuts out the middleman. same goes for values on layouts.

have you been to geofex to read "the secret life of pots"? there is much in there to answer some of your future questions.

[Palealien]

Hey thanks Duck Arse, you've helped me out a few times now.

The secret life of pots looks like a great resource, I'll definitely be reading it when I have some time, later today.

Do you have suggestions for any other reading I should be doing, as someone who's new to this pedal building caper?

[duck_arse]

read everything at both geofex and amz, they'll tell you plenty you'll need and want. they show how to design the stuff that beavis puts together. and over at ampage you can see just how many pedals mark hammer can do mods on. you can use the search button ^, there have been a couple of threads on reading resources.

[wizdum]

Teej,

Do you have any info in that Power supply?

[alambike]

Hello,

Is there any valvecaster layout with 4 knobs or an additional switch SPDT ?

Thank you.

[vigilante397]

Hello,

Is there any valvecaster layout with 4 knobs or an additional switch SPDT ?

Thank you.

Probably. What do you want said 4th knob or SPDT to accomplish?