Hello, I'm planning on building the Matsumin ValveCaster from either this vero layout: http://tagboardeffects.blogspot.com/2014/01/matsumin-valve-caster.html
...or this direct PTP layout:
http://s47.photobucket.com/user/krinor/media/Valvecasternylayoutmkabler.jpg.html
I've heard demos of the ValveCaster and they sound pretty dark (in a not good way). I was thinking of setting it up to run through the GuitarPCB.com Tone Tweq EQ board, or maybe a Rangemaster-like boost on veroboard. I was wondering how to modify the layout so that you can eliminate the tone pot. Actually, it might make sense to eliminate the tone and the volume, since the booster circuit or Tone Tweq can take care of the tone and volume. Any ideas?
Go to the layouts gallery link at the top of the page, and search for Valvecaster...Renegadrian has some vero's with no tone control (see his pages in the gallery). If the sound is too dark for your taste, consider using smaller input and output caps as well, and see what you think.
A lot of what the valvecaster does is linked to the amp. If you're using the pedal as a true overdrive to force the amp into its own preamp breakup, the result can be dark as the lower frequencies can be more effected than the highs. As a result, many leave the tone full up all the time. I've built both and haven't heard a difference in my normal setup however, if I use a bright tele, I need to tone down the treble and there appears to me to be a big difference between using the tone pot and changing the input cap.
Also watch out for online demos of the pedal. I can get really good sound out of my valvies but I can't record it well enough to reproduce the bass frequencies. Even if I could, I'm not sure my pc could play it back accurately. The end result is a pedal that appears to sound pretty poor
Quote from: rutabaga bob on December 22, 2016, 01:41:30 AM
Go to the layouts gallery link at the top of the page, and search for Valvecaster...Renegadrian has some vero's with no tone control (see his pages in the gallery). If the sound is too dark for your taste, consider using smaller input and output caps as well, and see what you think.
Thanks that's super helpful! I was able to find R's layouts and they look great. He/She has 12V as input. Would it be ok to run at 9V or would this require component subs?
@stallik, thanks for the tips!
Well, the filament of the tube runs on 12V, so you need to provide that to the heater...and since it's there, it just runs at 12V ;)
In short, no, 9V won't work...
I think this layout looks good:
http://www.aronnelson.com/gallery/main.php?g2_view=keyalbum.KeywordAlbum&g2_keyword=Valvecaster&g2_itemId=37363
(http://www.aronnelson.com/gallery/main.php?g2_view=keyalbum.KeywordAlbum&g2_keyword=Valvecaster&g2_itemId=37363)
If I want to skip the volume pot and run it right into a separate boost or eq circuit, would I just send C3 minus to the input of the next circuit?
Also, for those who have modded this circuit, is it better to stick the eq circuit after or before the Valvecaster?
Yes, but I would be sure about what the voltage level is with no volume control. You probably don't want to send more than a couple of volts to your next pedal...which is why I choose to leave volume controls in until I know for sure.
EQ is the same for most (all?) distortion circuits -- you try it before, try it after, see which sounds better to you 8) The ideal situation would be to have TWO EQ's, so you can do both at the same time!
I typically EQ after, it is just how I roll. If something is weird, such as too much shrill high content, I will go in and 'snub' it before a stage that accentuates it.
Well...the original Matsumoto schematic ran off 9 volts, but I wouldn't. I always put the idea to folks to use a 9au7 tube, allowing the heaters to run at the standard stompbox power, and use a voltage multiplier for the plate supply. My 2 cents worth, anyway...
Thanks for citing me, Larry! Now, cnspedalbuilder, do me and yourself a favour, ditch the valvy ckt as I did and use the valvemaster ckt - it is more true to real high voltage tube preamps and it reacts better to low voltage - yeah I always complained about the valvy being too dark, so I followed the valvemaster ckt and got better results...heck, they're so damn easy cks you can try both before you finalize the pedal!!! I like to put a resistor on first triode's pot, you know the pin going to ground - that way you don't kill the signal but you mantain some sound even with pot at 0.
If you want to try something more versatile, you may look at the alembic ckt (whick work sooooo good) and there's another tube ckt floating on the net which is similar, with a james tone stack instead of the regular TMB between the triodes (a la Ampeg). else you may want to look at Fender amps' preamp schems and replicate them (they do sound great even at low voltages) (alembic f2b is like the showman, then you may want to try princeton, or other preamps with just bass and middle, etc)
Quote from: Renegadrian on December 26, 2016, 05:30:09 PM
Thanks for citing me, Larry! Now, cnspedalbuilder, do me and yourself a favour, ditch the valvy ckt as I did and use the valvemaster ckt - it is more true to real high voltage tube preamps and it reacts better to low voltage - yeah I always complained about the valvy being too dark, so I followed the valvemaster ckt and got better results...heck, they're so damn easy cks you can try both before you finalize the pedal!!! I like to put a resistor on first triode's pot, you know the pin going to ground - that way you don't kill the signal but you mantain some sound even with pot at 0.
If you want to try something more versatile, you may look at the alembic ckt (whick work sooooo good) and there's another tube ckt floating on the net which is similar, with a james tone stack instead of the regular TMB between the triodes (a la Ampeg). else you may want to look at Fender amps' preamp schems and replicate them (they do sound great even at low voltages) (alembic f2b is like the showman, then you may want to try princeton, or other preamps with just bass and middle, etc)
@renegadarian, thank you I just pulled up your layout for the Valvemmaster. That does look like an easy layout. Is it a lot better than the Valvecaster (which I've already built)?
You'll have to forgive me but I'm not sure what you mean by "ckt".
You've got a ton of cool tube layouts. One that I noticed was the Vibracaster, which I assume does tube tremolo? Does that circuit do overdrive and tremolo, or do you sacrifice overdrive for the tremolo feature? Would you recommend using that instead of the Valvemaster? I'd love it if I could get tube overdrive and a switchable tremolo from a one-valve pedal!
ckt - circuit.
Quote from: cnspedalbuilder on December 28, 2016, 11:14:17 PM
@renegadarian, thank you I just pulled up your layout for the Valvemmaster. That does look like an easy layout. Is it a lot better than the Valvecaster (which I've already built)?
You'll have to forgive me but I'm not sure what you mean by "ckt".
You've got a ton of cool tube layouts. One that I noticed was the Vibracaster, which I assume does tube tremolo? Does that circuit do overdrive and tremolo, or do you sacrifice overdrive for the tremolo feature? Would you recommend using that instead of the Valvemaster? I'd love it if I could get tube overdrive and a switchable tremolo from a one-valve pedal!
yeah ckt is for circuit. the vibracaster is a valvecaster plus the tremolo part - the latter uses two transistors to do the job, when depth is at 0, you have a regular valvecaster. It's not a bad circuit per se, but I guess it would be even better to take the tremolo part of the vibracaster and add it to the valvemaster - you won't find a layout of it, but I guess it won't be so difficult to mod a vibracaster layout to valvemaster specs.
@Renegadrian: How would you alter the Valvemaster layout if you didn't want a tone pot? Or would you strongly advise against that idea?
The tone pot grounds the high frequencies. Just leave it out and the circuit works like the tone knob is at max
So, I looked at the Valvemaster. Looks like it uses fixed gain on each triode, and the "gain" knob is a volume control between triode 1 and triode 2. Certainly a viable option.
2 questions--Why the choice to go with much smaller resistors, and what are the caps between the cathode and ground for?
I finally built the valvemaster and have it in my former valvecaster enclosure. The pedal is much less noisy, which is good. Also, it can get LOUD. The only thing is that, even on max gain, it's not as distorted as I'd like it to get.
@Renegadarian (or others): Is there a simple mod to up the gain/tube distortion in this circuit?
Even if not, I can see using this as an "always on" pedal to get more preamp gain. I definitely recommend it.
Lower the supply voltage. But keep the heaters at 12V....
In a tube circuit, the power supply allows for 'headroom'...how far you can swing a signal without it distortion. The more headroom you have, the lower the distortion (in conjunction with a couple of other things...biasing and so on). Originally, this thing ran on 9V...put it back there, you'll have more drive due to lower headroom.
You can also try raising the plate resistors to 100k, 220k, allowing for more swing for a given input, altho admittedly we are WELL below anything we can really predict based on load lines. Might be interesting, tho!
Running a tube at 12V makes a good pedal but hey you can't have your cake and eat it too...you have to compromise somewhere...yeah it gives a good push but the gain will be limited...you may want to try higher voltages, a multiplier or a transformer...
I've always considered the valvecaster best when overdriving the input of a valve amp. Doing this can give you some serious tones and leaves you with amazing control over distortion via the guitar volume pot.
If you're not using a valve amp or would prefer to keep levels more normal - perhaps to better work with their pedals, you could try clipping diodes. I've done this on one of my valvecasters and organised them on a switch so that without the diodes, a resistor is in line with the signal. This is bypassed when the diodes come in so that the volume loss with the diodes is not noticeable.
I know it seems to defeat the whole idea of a valve pedal but it does sound nicely distorted.
Quote from: Renegadrian on March 07, 2017, 05:02:50 PM
Running a tube at 12V makes a good pedal but hey you can't have your cake and eat it too...you have to compromise somewhere...yeah it gives a good push but the gain will be limited...you may want to try higher voltages, a multiplier or a transformer...
GTFO ;)
At the risk of being booed out of the forum, I have yet another question. :-[
I've blown two LEDs that were on the switch for this circuit. I think maybe it's the 12V input. I have a 1.8k resistor for the LED which I thought would've been good enough. I'm not sure, maybe there was a short in both cases.
Any suggestions for resistor values for, say, a 3mm blue LED? I don't know the forward voltage or current otherwise I'd use a calculator. Values I popped in based on some google searches (3-4 volts, 25mA) gave pretty low resistor values (less than 1 k) so maybe that's not the problem?
The "pretty low" resistor value you get from these calculators is a minimum, below which your LED might be expected to fry. But that's not the same as saying you need this value of resistor for it to be visible. Far from it: you'll likely find such a value will zorch your retina and cause commercial aircraft to land in your back garden. Try a couple of (higher) values on a breadboard.
@bluebunny, true but in this case I don't mind blinding intensity because I'm putting the LED in the tube socket so that it will illuminate the tube. Also, it's a 3mm LED so the intensity isn't that bad. But for some reason I seem to have blown two so far. In both cases, the LEDs worked but then went out after a few days.
If a 1.8k resistor value isn't bad, then maybe it's a wiring issue?
That is VERY odd. It should be ok with 1.8K. Are you SURE the resistor is the correct value? Can the legs of the LED short out against anything?
Where's your 12V coming from? A regulated supply, or somewhere a little more rock'n'roll?
Quote from: bluebunny on March 08, 2017, 03:02:19 PM
Where's your 12V coming from? A regulated supply, or somewhere a little more rock'n'roll?
I'm thinking of a million AC/DC lines right now... :-X
It's coming from a regulated power supply.
Quote from: GibsonGM on March 08, 2017, 01:38:08 PM
That is VERY odd. It should be ok with 1.8K. Are you SURE the resistor is the correct value? Can the legs of the LED short out against anything?
That is my guess. I heat shrinked the last couple, but there were some exposed parts.
I'm using a 3pdt daughterboard and I wonder if another possibility is that the resistor isn't soldered in well. But I'm guessing if that happened then I would not get anything from the LED right?
Yeah, you really shouldn't....anything bypassing the resistor would be considered a short. I haven't heard of an LED failing when it's getting the correct voltage and current for its operation. Shorting has to be the simple solution!
Well everyone has been so helpful, I thought I should share the finished product. Not nearly as neat as anyone on this forum, but it's the neatest I've been able to do, so that's something. Thanks for all the tips. Let's hope it holds up for the gig tonight!
(http://i1378.photobucket.com/albums/ah90/Ch_Ra/valvemaster_glow_zpsfi4gbq6t.jpg)
(http://i1378.photobucket.com/albums/ah90/Ch_Ra/valvemaster_zpsj8esrctt.jpg)
(http://i1378.photobucket.com/albums/ah90/Ch_Ra/valvemaster_guts_zpsykuyabp0.jpg)
By the way, it sounds great when driven by another pedal like a Rat. I will likely just keep it last in my distortion chain so that it's either just pushing the tube amp alone, or it's adding a massive gain stage when stacked with a Klone, Rat, or Harmonic Percolator.
Very nice - and it has that blue glow mojo! 8)
That came out really nice! Enjoy it! Have a good gig.