When you say you have 90v, is that your supply voltage or is that the plate (anode) voltage?
For example, on the schematic I posted, the supply voltage is 240v and the plate voltage (measured to ground) is 105v. Technically, the anode voltage is measured from plate to cathode but schematics typically show voltages measured to ground.
If your maximum supply voltage is 90v, it might offer a tiny bit of improvement but not much. I would just leave the stock resistor values alone.
I agree that if you were going build something from scratch that there are better tubes to use than the 6AK5.
Yes, I could potentially be used to put before a qsc amplifier that I use to drive a couple of subwoofers in my home cinema, but I often use them for music as well.
I was curious about the effect a buffer could have on subs.
The kits are cheap only then you need a lot of other money for container, power supply, everything.
in the end the total is not pennies.
ok. I'll see if it's worth it. tube 01 is very cheap, already finished, and it was more convenient to try to modify it with little expense.
thanks for all the information, now I look at them.
I was curious about the effect a buffer could have on subs.
The kits are cheap only then you need a lot of other money for container, power supply, everything.
in the end the total is not pennies.
ok. I'll see if it's worth it. tube 01 is very cheap, already finished, and it was more convenient to try to modify it with little expense.
thanks for all the information, now I look at them.
My mods for my fx-01 its
.- input cap 2.2uf wima
.-output cap 3.3uf wima
.-resistor grid 470kohm
.-resistor load 56kohm
.-anode resistor 15kohm
.-cathode resistor 500ohm pararel with ( 470nf +500ohm in series)
.- heater filament use tiny adjust buck converter each valve
.- rewinding toroid step up converter from -+30vdc to -+50vdc
.- input cap 2.2uf wima
.-output cap 3.3uf wima
.-resistor grid 470kohm
.-resistor load 56kohm
.-anode resistor 15kohm
.-cathode resistor 500ohm pararel with ( 470nf +500ohm in series)
.- heater filament use tiny adjust buck converter each valve
.- rewinding toroid step up converter from -+30vdc to -+50vdc
I have one that's similar with a headphone jack and line level out I bought several years ago. The GE tubes definitely made a big difference. This one I have has a SS single ended class A output stage. It sound pretty good.
I use it with an amp I built that uses two sweep tubes.
I use it with an amp I built that uses two sweep tubes.
