Low wattage tube (1/8 watt) Amp

[iccaros]

Nah...keep the b+ at 30V, or 29 to be safe. The operating point should be with the plate around 20V, (2/3 of b+), which means .5mA thru the 22kohm plate resistor. Looking at hte graph, with 20volt on plates, 0.5mA current, u should have 1volt negative on grid, so a 2kohm cathode resistor should fit the bill.

When using a choke or transformer as a load, the plate voltage equals the b+ (minus the small drop over the OT) and the voltage will swing up and down around that voltage. So with b+ at 30volts on the output tube, u may see swings up to 60volts on the plate (if the idle current and load permits). So the voltage supply for output tube should be 15-20volts or so. But keep the preamp b+ as high as possible.

It seams that with the space charge grid, the voltage on the output tube seams to not exceed the plate of 28 volts I have now. I need to connect to the scope to see, but I do not see on the meter anything above the + charged grid. ?

[iccaros]

So this is with the 5watt transformer, at the end (last 2 min... skip a head) is the O scope reading from the OT to speaker.
so I am getting average 1volt over 8 ohm (.5 is what the scope is set on)
anyone see issues, this looks like way too much power for this tube, but its ratings are for 12.6 volts, not 28. 30 is the max plate voltage listed in the datasheet.

[iccaros]

Most Up to date build

with PDF here http://dl.dropbox.com/u/14312589/FireAntV1.pdf
Will post sound clips or video soon.
I have given up on this being clear, at least from the Les Paul. So with rolling down the volume its clean.. using my Valve caster with a 12AE7 in it, This gets good overdrive... even distortion.. My wife says its too loud, so It must be my playing. I am thinking of adding the valve caster in the front with a switch to put in it line or not.

[iccaros]

HELP!!!!!!!!!
I am having a small issue. I would like to add a stage in-front the current stage. One that could be used to really overdrive the design, but I keep getting squeals and blocking distortion. It could just use one triode from a tube and see, but I get a volume drop when I do this. These tubes do not have a lot of headroom. The first triode moves form millivolts to 100's millivolts and the second is outputting from 100's millivolts to 3 - 6 volts.
The power section is taking this and putting out between 8 - 16 volts.
All measured with my meter in AC. I tried biasing the first stage really cold, but it does not seam to care. I tried to put these in parallel, but nothing, get less output unless I place each preamp as their own input on the power side.
This does not get me anything.
If someone could give me ideals on the math. This amp really does not sound no matter what I do, it works or is way too distorted.

I can put my valve caster in front and get some good overdrive, but if I try to build this in, I get nothing. here is the video with the valve caster.

[iccaros]

Latest Video... Need to update amp schematic

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[iccaros]

[redelephant]

Fantastic! Great job.

[iccaros]

thanks