Build a QuadCaster or 5caster ?

[Perkla]

I have been doing some thinking, about building a tubedistorion pedal, i came across the valvecaster and thought about the idea to build 4 or 5 of them and just add them to my chain of pedals, but then i found a quadcaster, thats cool, 4 valvecasters in one box, but how about building a 5 caster, that means 5 tubes, anyone been thinking about it ?

I have some questions before i start this project...

1 Could 5 tubes make the pedal to "hot" and make it sound bad when maxing the gain knobs on all 5 tubes ?
2 What about using all 5 tubes on lets say 50%, would that give more gain that sounds good than maxing them all out ?
3 What voltage and Ah would be best for a quadcaster or a 5 tube version ?
4 Could this layout be used without any problems when building a quadcaster or a 5 caster by just adding a section in there to make it 5 ?
http://jrmcgrath.com/images/triple%20valvecaster.jpg

I have been thinking about this for some time now, and it would be super cool to build a high gain tube distortion, the valvecaster and the twin valvecaster is to lame for me, i play mostly hardrock and heavy stuff

[GibsonGM]

Hi Perkla.  Question: do you have a tube amp?  If you do, wouldn't even 2 extra input stages crank that thing ALL to hell??  I know it does for MY amp!   Makes my Fender sound like a Marshall all tricked out and ready for shredding...all that's needed to make it metal is to change the tone stack, which is really where a lot of the magic happens anyway.  Maybe MOST of it.

Can't see how chaining so many Valvies would make that any better at all.

BUT: if you want to make a PREAMP, and use it totally independently of your amp's existing pre - that's different.  VERY different.

In that case, maybe you want to check out the "GTFO" (search this forum), or something similar.  Just adding something like many valvecasters together isn't quite the same as a DESIGNED preamp like this!   The tone is shaped between stages for what it sounds like you want to have!  IF YOU DO THIS - PLEASE LEARN MORE ABOUT HIGH VOLTAGE SAFETY!!!!!  There, disclaimer - the 'really good stuff' generally contains voltages that CAN and WILL kill you if you don't learn what is or is not dangerous.

To your questions:  Yes, too many stages will just make a square wave, very much like a fuzz pedal.
-You normally DO attenuate the level between gain stages to make a device not overdrive too much at once, which sounds much better!  Having trim pots in place makes this easy for such a simple, and low-voltage, build.  This is also where you use caps and resistors in various ways to tailor the should to what you want, which is most important.
-If you are just putting valvecasters in series, then the voltage for the 1 is fine for all providing your PS can take it...higher voltage WILL give more headroom (allow more 'room' to swing to further avoid the fuzz clipping I mentioned).  That is a design consideration - I might try 18V, if I had something lying around to use....it's all about experimentation.  The tubes were meant to be operated a lot higher, anyway.  Be sure of parts ratings!

Yes, you can use that layout - BUT - you are missing out on some things by not looking to the schematic and working with it.  You don't need multiple output caps, for instance...or input caps, as long as you've got the couping covered appropriately.  Without some background in what's really happening, you can put that together, but it may not sound much like what you want...it CAN be tweaked for more gain....but my instinct here is that if you either got a preamp kit more to your tastes and put it together CAREFULLY (ALL safety rules must be followed if you go high voltage!!), or spent time learning more about tubes and how to design, you'd end up with a *real* preamp you will use for years and years.

Just gomming together stuff often leads to disappointment, and wasted time....I learned that the hard way, just went ahead and learned what I had to, and I bite the bullet and get the right power supplies for what I want to build. It is less frustrating that way!

[Perkla]

I am not interested in building a Preamp, i like stompboxes that runs on 9-18 volt DC, i built my first stompbox many years ago, i design and even etch my own circuitboards, i have never built any pedal using powertubes before so thats why i need to ask cus i dont know much about those things. I totaly suck on reading schematics to.. Wiring layout works best for me... i have two Laney IronHeart 120H heads running trough each 4x12 cab´s, last night i did a 30 minute project, building a A/B/Y pedal to be able to run those two amps at the same time... ALOT better sound now.





I have my fav pedal that i use at home for recording and with my band, its a Blackstar Metal, but i still like to build pedals and see what i can come up with.



The picture below is my own branded Distortion pedal, based of a Marshall Guvnor but with some mods to it..

[GibsonGM]

Nice looking boxes, man!    I think I see tubes in there, ha ha...can't believe you're not getting a total thrash sound when overdriving that...

Ok, if you want to go the route you're on, I'd say go ahead and build 'em up.  Maybe make the output caps smaller on each valvy....instead of 1u, maybe use 22n.  Make the last one 1u again.  You will not need an input cap between the 2-triode valvecaster and the next one you build!   Or the 1meg pulldown resistor.

I would take the volume pot between each stage, put in a 1K resistor, and add a 50k or 100k, 1/4 Watt trim pot in series with it wired just the way you see the volume set up.    This will let you adjust gain between stages until you like the sound.  You can bypass those trims with small caps, like 470p, if you think too much high gets cut along with level.   Use the actual volume pot on the last one, of course, with no 1K resistor.     If you do multiple stages and then go into an EQ, I think you can get a nice mid scoop. 

Or, go out on a limb and add a tone stack at the end, like from a Big Muff.  That is where you'll get the real metal crunch....There should be plenty of drive to overcome the insertion loss of a small tone stack like that.

There are a TON more tricks out there, but this will get you started with minimum need to go to the schematic...

[Perkla]

I am very picky when it comes to distortion for recording and playing live, VERY picky, my local music store has 200+ distortion pedals in stock, they have it all from like 20 bucks to 2000 bucks, i have tried it all, mostly in the pricerange of 65-300 bucks, it took me sevral weeks to try them all out at home with my own guitars and amps. None of them was in my taste, the best sounding one was a Boss Adaptive distortion and a Boss DS1X, but still not what i was looking for. A few weeks later my friend at the local music store called me just before they opened the store one day and said: Hey, wake up.. wake up.. get dressed and get your ass over here, i got someting u could be interested in, i said: What.. what what.. tell me.. he said: No.. just get here. And 20 minutes later i was looking at a Blackstar Metal pedal, 3 channel preamp pedal, clean, crunch and lead with a HUGE MASSIVE amount of gain. Its my fav pedal so far, and as close at possible to what i am looking for so i bought it right on the spot.

Anyway, whit this Valvecaster idea is just for fun, to see what type of sound i can get, and of course learn some new stuff. I build almost all my clones only from wiring diagrams, and all mods i make is right on the spot when looking at the wiring diagram and the circuitboard it self, i try different stuff, diodes, IC´s, pots etc etc.. even different brand and types of cap´s and resistors can make a different sound. I like different clipping sections in my distortionpedals, its cool.

I think u are right about your thoughts, but i still need a correct wiring diagram, or else i will not manage this,

This is some other pedals i have built...





I even modded my little Marshall MG15MSII Mini Stack.. with two extra clipping sections in the distortion section of the amp... cool stuff

[GibsonGM]

Here dude, this is a place to start, but it's schematic:  



This is 2 valve casters connected together.  Notice I changed the first one's "output cap", as it's now a coupling cap...don't need so much bass to come thru.   I also put in a couple of gain pots. You can use regular pots, and then put in 2 resistors if you like the sound.  Or, use trims.

Just expand this idea for as many valvecasters as you want!  The input and output parts stay the same. I omitted the tone control at the end here, too, for simplicity.  Not perfect, but a place to start - there are many places to shape tone in here!   You might need to change "R1 33K" to drop more...add a same value resistor to ground from there for 50% level cut, and so on, just a voltage divider.   C3 should also be smaller...22/47n.  Too much bass ruins the distortion...

[Perkla]

But i see 4 tubes in there.. i gotta need someone to transform that to a wiring diagram or something like that, cus i really cant read schematics, i was thinking of separate gain and volume and things like that for each tube, so i can blend and make my sound as neat as possible..

[GibsonGM]

Aww, but that's where the work of this hobby comes in, Perk!  I can't just DO it for you   That would take time outta what I'm doing (practicing new tunes for the band), and you wouldn't learn anything!

I can't say enough, knowing how to read a schematic is one of the major KEYS to being about to do things like this, in getting the sound you want.  What I'd tell you to do might get you close (those are just building blocks, in my schematic), but YOU have to tweak it to what you like!

Any reason you can't read the schematic?  Each tube pin has a number, and that pin leads to this resistor, etc etc.   I used to have to look down at one, then at the part in my hand, and cross it off, stare at it, get confused....but shortly, I picked it right up and breeze thru them, just like I know you can! 

The schematic shows 2 tubes (4 gain sections), and you can expand on that to whatever number you want by looking at how I connected the 2 valvecasters to 2 other ones, then you have the output cap & volume...

[Blitz Krieg]

a 'wiring diagram' would be more complicated, no?

[samhay]

I can't imagine that 5 valvecasters in series is going to sound significantly better than 2, or 3 or 4 in series, and the current draw is going to be fairly substantial.
As an alternative, how about 1 or 2 valvecasters (in series, perhaps switchable) with a solid state booster in front? In either case, I suggest you dust the breadboard off and see what works for you.

[mykaitch]

A while back I got an old Peavey Deuce combo.
I cut the top off with a saw and made it into a head unit - had to turn the transformers and valves over to the other side.
Looks good. Then I built a five valve pre-amp that replaced ALL the semiconductors. I built it in with a switch that flips between original and
all valve mode. Tend to use all valve - makes a huge diff to reverb. As to the orignal query, yeah, why 5?
Two ECC82 or sim gives you four stages. I needed five for preamp/tone control/reverb/ phase splitter.

[GibsonGM]

I can't imagine that 5 valvecasters in series is going to sound significantly better than 2, or 3 or 4 in series, and the current draw is going to be fairly substantial.
As an alternative, how about 1 or 2 valvecasters (in series, perhaps switchable) with a solid state booster in front? In either case, I suggest you dust the breadboard off and see what works for you.

+1  The end result would be a massively fuzzed out square wave, OR you'd attenuate and tone shape, getting a sound that you'd just be 'copying' into other stages not doing much, IMO.   8 to 10 stages aren't necessary to get a full metal tone, at ALL. 5 max, IMO. But hey, that's up to the experimenter, I suppose.   There are no rules...

[duck_arse]

hey gibson, don't forget to add some resistor from the third grid to ground, otherwise the wiring diagram won't come out straight.

[GibsonGM]

Good to point that out, Duck!  I did say:  " You might need to change "R1 33K" to drop more...add a same value resistor to ground from there for 50% level cut, and so on, just a voltage divider.   C3 should also be smaller...22/47n.  Too much bass ruins the distortion..."   Even 1M would be fine altho might keep the signal too hot. Or use a pot, doesn't matter.

But I wasn't clear that you really SHOULD have it.  There will be so much gain that you'll WANT to give some away!

I whipped that up in 10 seconds, not really with a wiring diagram in mind; can't do the lad's work for him entirely, lol...that's about as basic a set of stages as you can get.  What would really be needed are some dedicated tone-shaping networks....cut bass here, put it back there, drop mids....selectively boost highs, all that fun stuff.  For what he wants (real metal sound), even more would be required.  The tricks to that are kind of out there, like cutting highs right at the input and putting them back later via harmonic distortion, ugh - mind bending. 

But for experimenting and getting your foot in the door, the valvecaster idea would work, and will be safe at these lower voltages.  And you get the idea of what the stages are DOING if you mess around with them.  Nothing can beat some good reading about how to design with tubes, tho!

Put simply....only use an input and output cap at the beginning and end....change the 1u output caps on each stage to a lower value, like 22n, except at the end of course.  Use trimmers as gain controls so you can dial in the amount of clipping....try 12AX7s....I don't like the 'no cathode bypass' of this design, either, but it IS running about 200v shy of where it wants to be!