Tube boost + overdrive running off a 9 volt battery

[trad3mark]

here's a pic of the board (top side)
http://i44.tinypic.com/2nsrgur.jpg

and the tube wire colours are:
1 grey
2 white
3 red
4 purple
5 orange
6 blue
7 yellow
8 green

any way i could check the pots/jacks with my multi?

[trad3mark]

built it anew with fresh new parts. Still no output, but here's some new voltage readings:

PINS:
1 6.08
2 -0.01
3 0
4 0
5 7.39
6 6.69
7 0 <----- DISASTER!?
8 0.42
9 3.58

sadface...

[frequencycentral]

Ok, you battery is now giving out 7.39 volts, I don't think that's enough to get the heater hot enough to start boiling off electrons. Consider using a fresh battery or better still a wallwart. Also, as I said earlier, your voltages will probably not match mine as you're using a ECC81, which will certainly give different voltage readings at the plates. As an example, running from a 12 volt supply a 6111 has a pin 1 voltage of 9 volts in this circuit. Compare this to the ~3 volts pin 1 voltage of a 12AU7.

[trad3mark]

well, the 9v thing aside, cos it's been done with 9v before, are there other things i could check which would be causing problems?

[frequencycentral]

well, the 9v thing aside, cos it's been done with 9v before, are there other things i could check which would be causing problems?

Ok, you battery is now giving out 7.39 volts, I don't think that's enough to get the heater hot enough to start boiling off electrons.

You haven't got 9 volts even, you've got 7.39 volts and counting. The first Valvecaster I made was battery only, it didn't take long for it to drain a battery low enough to be gatey and blarty. The tube you're using has a 12.6 volt heater requirement, it's getting 7.39 volts ATM. That's a problem you could solve before all others.

[Renegadrian]

Actually you shouldn't consider at all the use of a battery in a Valvy. If the tube is a 12AU7 and requires 12V, give it what it needs...Otherwise use 9V from a wall wart using a 9AU7.
Every other argue is useless if the circuit hasn't got the proper voltage (regulated and filtered).

[trad3mark]

ok so i found a wallwart that'll do 9v or 12v. which should i go for first?

[frequencycentral]

ok so i found a wallwart that'll do 9v or 12v. which should i go for first?

Go for the 12 volt choice. Best one for the heater. Make sure you hook it up with the correct polarity - test it with your DMM first.

[trad3mark]

HURRAY!!!!!! :D:D:D

Ok first off, COLOSSAL thanks to both Renegadarian and Frequency Central. I have to say thanks before i go into this at all.

I have boost/od.


Running it on 12V at the moment. The boost is great, and the od.... It's VERY subtle. But i like it. So now i'm just wondering though, to get a bit more out of it, what about some sort of a booster before hand? can, for example, a rangemaster vero/schematic be changed to run on the same 12V rail?

[frequencycentral]

Cool! 

Those tubes sure like wallwarts better than batteries! The OD is probably subtle as you subbed the 12AU7 for a 12AT7. Would you please take (and post) voltages again now that it's working - just curious as to what the plate voltages are with teh tube you used.

You have a broud choice of boosts to drive it harder, Adriano will be a long soon to say 'Tillman', I like an LPB, some folks even like my own very humble Pentaboost or 5840 Booster.

[trad3mark]

VRefs for yew! ~(i think the taper is backwards on either gain or tone, but this sounds right)

1. 9.62
2. -0.28
3. 0
4. 0
5. 12.12
6. 9.99
7. -0.13
8. 0
9. 6.03

As for boosters, i had an interesting idea....
the way i was going to do it was put in a second circuit that runs on a 9v battery with super low current draw. This way, you're basically getting 2 boosts/od's in one box. It'll be done in such a way that you could either have just the VC on, the VC and Boost on, or just the boost. There'll be a DC jack for the 12V, but because i dont have and Voltage Reg IC's, you'll need the battery for the boost. If you don't have a battery, the VC will still work off the plug, and if it's not plugged in, but there's a battery, you'll still be able to use the boost. Totally true bypass, 2 switches, 4 dials. DESPERATELY need opinion on this one.

[frequencycentral]

Interesting, those look just like a 6111 Subcaster set of voltages, thanks!

[Renegadrian]

Did someone already suggest a Tillman b4 the Valvy?! 

[trad3mark]

any ideas for a booster i can run off the 12V rail without one of those voltage regulator ic things to get 9v? like if i had a 9v booster, and put a big resistor from the 12v rail to the 9v circuit, could i do that? (sorry if it's an unclear explanation...)

[frequencycentral]

Most boosters (in fact most circuits) designed for 9 volts will work at 12 volts. I built a footswitchable LPB into my second Valvy, running at 12 volts. I like the sound of it a lot.

[trad3mark]

fantastic. that makes things so much easier! i just tried the VC with my Super Hard On before it. Sounds MUCH nicer. So i think i've parts for a Rangemaster. I assume i just build it the normal way, but run 12v into it?

[slacker]

Rangemaster + valvecaster is very nice 

[frequencycentral]

fantastic. that makes things so much easier! i just tried the VC with my Super Hard On before it. Sounds MUCH nicer. So i think i've parts for a Rangemaster. I assume i just build it the normal way, but run 12v into it?

Isn't the stock Rangemaster PNP and positive ground? That would be a problem running of the same supply as the Valvy. Though you could do the modified (and NPN, negative ground) Rangeblaster: http://fuzzcentral.ssguitar.com/rangemaster.php

[doitle]

I finally figured out how to simulate tubes in LTSpice. Thought I would simulate the Valvecaster. Does this look right? If so, look at that low frequency BUMP!

[trad3mark]

HUZZAH!! I now have it all going on breadboard!

FC, the rangemaster is PNP yeah, but i got a vero for the NPN one, so all is well. I tested a bunch of NPN's i had, which gave these results:
2N3904   Hfe=214; Too trebly, very flat sound
Bc107   Hfe=193; Rounder, More Fuzz/Distortion/Gain even at low levels
2n2222   Hfe=248; Similar to BC107, slightly more fuzz, less silicony
C2655Y   Hfe=181; high level Gain. Distortion at any levels of boost
C2878b   Hfe=226; Grainier, not very crisp/clean
C1815gr   Hfe=241; V.Low gain. Almost no od at max boost

With whatever i use though, the VC does give much better results, it kinda needs a boost like.

I think i'm going to go with either the 2N2222 or the BC107. That being said, the C2655Y would be just awesome in some sort of fuzz like a Rat or similar. Going to get breakfast, then i'll start on the final vero.