Yeah I just know that to wire it how I want I just disconnect he ultralinear taps and power the screen grid with the screen voltage supply. Where is that

It's right there on the schematic you posted.

ak

 

Who is Pochie and what happened to Skylar?

 

Who is Pochie and what happened to Skylar?

ah screw sorry about that didnt realize i accidentally signed in with my other google account! Here I am! same person!

But I am kind of perplexed. The Plate wire of the output transformer is going to its proper pin( pin 3 plate) but the screen wire is going to pin 2 (heater)..

This seems incorrect to me. A novice friend of mine built this and there are mistakes in his wiring I have already corrected a few. I guess the question I should be asking is how to rewire this to pentode..

 

The pursuit of the generation of distorted sound by certain rock band types is rather amusing to me.
Obviously an ear that likes the sound of distorted music is totally unlike mine.
Perhaps that's why I never liked (hated actually) the sound of heavy metal.
But perhaps that music is not meant to be listened to when sober (or not high).

 

The pursuit of the generation of distorted sound by certain rock band types is rather amusing to me.
Obviously an ear that likes the sound of distorted music is totally unlike mine.
Perhaps that's why I never liked (hated actually) the sound of heavy metal.
But perhaps that music is not meant to be listened to when sober (or not high).

well I am going for a certain sound from 1970s and evh'y and this is a plexi/sunn copy so i cam converting the sunn part to plexi. sooooo... how do i change over to pentode

 

But can someone also explain to me why the leads are connected to the plate and heater

The screen wire coming off of off the output transformer is going to pin 2 which is the heater. Why is this? This is how it came to me.

 

Well, ill just leave the thread here. Here are my questions

With my ultralinear transformer, why is the Screen wire going to pin 2 (heater) yet the plate is going to the proper pin 3. How do i wire it properly.

How do I convert it to Pentode

I beleive that the reason for the very low plate voltage ever since i put the new transformer in could be due to the improper wiring. So some help please

 

Bump. I figured out the heater wire and stuff. That's all fixed. Still

How do I change Ultralinear to Pentode? Please do tell.

 

From what I've read you would need to connect a 470Ω to 1.2kΩ, 1W resistor from each screen grid to the plate voltage at point A.
Start with 1kΩ and see how that works.

 

So then as a blanket statement let me get this straight. I just remove the leads going to the screen, measure which point a,b,c,d is giving off about 350

From what I've read you would need to connect a 470Ω to 1.2kΩ, 1W resistor from each screen grid to the plate voltage at point A.
Start with 1kΩ and see how that works.[/QUOTE
I'll measure the current screen voltage and just try to match that with the resistor or what

 

From what I've read you would need to connect a 470Ω to 1.2kΩ, 1W resistor from each screen grid to the plate voltage at point A.
Start with 1kΩ and see how that works.

So I'll just measure the current screen voltage and try to match it or what. Or I just run that resistor between plate and screen?

 

1) Name the tubes you are using.
2) Look at post #12 where you were told to look up the tubes you are using.
3) Look up the tubes you are using.
4) add a resistor from your highest B+ voltage to the screen grid.
5) disconnect the wire from the output transformer to the screen grid.

 

1) Name the tubes you are using.
2) Look at post #12 where you were told to look up the tubes you are using.
3) Look up the tubes you are using.
4) add a resistor from your highest B+ voltage to the screen grid.
5) disconnect the wire from the output transformer to the screen grid.

Thanks! I am using el34's. So I just use the resistor to achieve the proper screen voltage?

 

So I'll just measure the current screen voltage and try to match it or what. Or I just run that resistor between plate and screen?

The current screen voltage is essentially equal to the plate voltage as it is connected through the transformer, which has a low resistance.
So just connect the screen grids with the resistors.
The resistors limit the screen current and operate the screens at a slightly lower voltage than the plate.

 

to achieve the proper screen voltage?

No,

The resistors limit the screen current

 

The current screen voltage is essentially equal to the plate voltage as it is connected through the transformer, which has a low resistance.
So just connect the screen grids with the resistors.
The resistors limit the screen current and operate the screens at a slightly lower voltage than the plate.

Okay so here's what I am going to do.
Disconnect the screen wires from the output transformer, run a wire from point A to the connection for the screen with the proper value of resistor in between to achieve proper screen current. Then bridge the two screens. Sound good?

No,

 

Then bridge the two screens. Sound good?

No. You need 2 resistors about 750 ohms each, but you better check the G2 watts to be sure you don't melt the tubes. Then check the watts on the resistors to be sure you don't smoke the resistors.

 

No. You need 2 resistors about 750 ohms each, but you better check the G2 watts to be sure you don't melt the tubes. Then check the watts on the resistors to be sure you don't smoke the resistors.

Thanks for the help. Do not bridge them. Run 2 individual wires with a 750 ohm resistor on each. Then check wattage on tube to assure it doesn't hurt it, and with the resistor same.

 

check wattage on tube

That's all part of the design process but you must check the power on G2 to avoid melting the grid right inside the tube.

 

That's all part of the design process but you must check the power on G2 to avoid melting the grid right inside the tube.

That is what I meant. Just make sure it is at least 70% of max