SLO preamp and SE 6V6 - enough drive?

[TDS]

Would there be enough drive to go direct to the grid of a SE class A 6V6 from the two master outs. I would need about 13 volt of drive before clipping the 6V6. The preamp would run at normal SLO B+ and the SE 6V6 would have a separate 250 volt B+ supply.

[defaced]

I can measure my overdrive circuit tonight. There are a couple of people doing low powered SLOs. This is one I know of, though it's not done with a SE 6V6. 5 watt SLO : DIY Fever – Building my own guitars, amps and pedals

[TDS]

If you could let me know the levels at the output of the masters in both modes it would be very helpful. I have built two SLO type amps before, so I'm not new to the structure, this amp is to be a low power (compact) bedroom practise combo for my son away at college.

[defaced]

I built the Avenger, which is just the lead channel of the SLO, so that's the best data I can give you. Using a guitar with EMGs at 18v, so a very hot signal, and pulling the phase inverter, the output with the master volume maxed was at about 5.5v AC with all controls at noon and about 7.5v AC with all controls maxed. Measurements were taken between the master volume wiper and ground. Assuming you're using the loop, the return stage *might* get you there. If you're not using the loop, it looks like you need another stage to overdrive the 6V6.

[TDS]

I with the master volume maxed was at about 5.5v AC with all controls at noon and about 7.5v AC with all controls maxed. Measurements were taken between the master volume wiper and ground.

Thanks very much! Is this level peak, or RMS?

If RMS it may be a bit low for a 6V6, but an EL84 with its higher gain, in the same configuration would only need about 7 volts to clipping.

Any comments anyone?

[defaced]

RMS

[diagrammatiks]

how could it not be?

you can drive a 6v6 into overload with one half of a 12ax7.

The full 5 stage slo would probably explode the 6v6 unless you cut a bit of signal before and after the tone stack.

[defaced]

No point in cutting signal before the tone stack. The original amp doesn't and neither do any of the other high gain designs. After the tone stack, this is how Bancika from DIY Fever (link above) did it:

Hi mate. I don’t have the schematic but there’s not much to it: I used bias circuit from AX84.com push-pull amps (they are all the same). PI is long tail but I wanted to reduce the output to suit smaller power tubes. Plate resistors are split into two in roughly 2:1 ratio (68K+33K and 56K+28K) with smaller resistor facing the plate and coupling cap is connected between them. That should reduce the output by 1/3. Similar could be achieved by swapping the tube to 12AY7, 12AT7 or even 12AU7.
I believe that grid reference resistors on EL91 are 220K but not 100% sure. I’ll need to draw the schem once, there were quite a few questions like these
Let me know if you need anything else.
Cheers,
Bane

[diagrammatiks]

actually it does a little but that's just quibbling over details.

i'd just be concerned whether a quad of 6l6s could take more current then a se 6l6.