Thanks to all for the extensive work on this great little circuit!
Yesterday I breadboarded the stock Valvecaster from Dano Beavis' schematic, and it sounds pretty damn good.
If you have a minute, read my progress in the search for the ultimate low gainer.
Previously I was using a Paul C. Tim for my low gain needs, but I run a 50w Plexi set to absolute clean, but loud. Zero breakup from the amp, so I felt that the Tim, while brilliant when combined with a bit of amp dirt, was not the pedal for me. So I got a vintage Marshall Bluesbreaker pedal. Again, great pedal particularly with mid scooped amps like a Fender Twin, but the Plexi has it's share of mids in its' natural tone, and the Bluesbreaker pedal/Plexi amp combo is a little too boxy in the mids for me.
I ran the Valvecaster on the breadboard through my Plexi and it's very good. I was lucky enough to receive 4 vintage 1950's 12AU7's out of an old Baldwin organ, courtesy of one of the wonderful BYOC forum members. However, as noted, being that the circuit is optimised for single coils, with my humbucking guitars there was just WAY too much bass, bordering into soft farty fuzz territory in the low end. Not good. I wound all the bass out of the amp, and got a great rocking Malcom Young sound.
I have been comparing the JuanSolo/Cleggy Boobtube schematic against Rick Holt's Valvemaster schematic, and I believe Rick's mods could be quite an improvement on the intial Matsumin design.
Having the gain pot after the first Valve stage (here in Australia we call 'tubes' "Valves") seems to make sense to me in that it allows the circuit to ramp up it's total gain level before bringing it down, as opposed to bleeding signal to ground from the get go.
Today I will make some modifications to the Valvecaster circuit on the breadboard, and aim to do the following:
1) Work out if dropping the input cap OR the coupling cap (both 47n in the initial schemo) to a lower value is better for removing unwanted low end frequencies. I'm imagining that I'll be putting that component on a switch to work for SC's/HB's as the need arises. The JuanSolo/Cleggy circuit uses a 10n for HB guitars, so I'll try that.
2) I want to hit the circuit with various voltages. Right now it's pulling 9v straight out of a 1-Spot. I use a Cioks AC10 for my main board, and I believe I have a 9v, 12v and 18v tap free on the powersupply.
Before I get into this, I see on the JuanSolo/Cleggy schematic that there is 12v going to Pin 5 of the valve, while 23v goes to Pins 1 and 6 of the valve. I have read the thread pretty extensively, so may have missed the answer if it already exists, but what are the sonic benfits of sending different voltages to different Pins of the valve? (I have done a lot of DIY pedals with transistors, FETS, opamps etc..., this is my first valve circuit). Question - Can I just try different voltages to the whole circuit, eg: 9v, 12v, 15v, 18v, 24v? Or can only one part of the valve only be fed with 9v, while other parts of the valve can take higher voltages?
I have a great hammertone Pedalenclosures enclosure to use for this project. I plan to have the valve up back in some kind of protective rail, and to rock the sh*t out of this thing. If it works well, then I hope this does my low to medium gain tones for me. My medium to high gainer is a Kingsley Minstrel, and man that pedal is off the hook. So, another valve pedal to pair with it seems like the go.
Thanks for reading, any answers to my question would be great, and I will post pics once I'm done.