Headfirst MTL Lead gain and saturation potentiometers 220KLog

[hopkinWFG]

Yep - that's what I did on my 25 watt MCII build. I also went with parallel heater runs and I'm really happy with the noise level.

Thats what we call it parallel heaters having the center wire of the PT sec soldered to board where the other two wires supplying 6.3VAC to the heater filaments?

So am i guessing the center tap of the PT sec soldered a ground or supply voltage?

 

[riq]

Thats what we call it parallel heaters having the center wire of the PT sec soldered to board where the other two wires supplying 6.3VAC to the heater filaments?

Parallel was referring to the how the actual wires are routed to the heater filaments on the tube sockets. In most amp's you see them those wires twisted like the red & black wires here:

But certain amps like Soldano's they will run those wires parallel to each other through the sockets like:
.

The 6.3v center tap being connected to HTR pad on Burger's board has nothing to do with parallel - that just DC elevates the 6.3v AC supply. You could also twist the wires and still connect that center tap to HTR. That said this was my first amp build so burger might chime in and correct me.

Check out http://www.valvewizard.co.uk/heater.html for some more detail on this.

Other resources that I use a lot during my first build was:

Burgers documentation
Rest of the valvewizard site
https://robrobinette.com/Amp_Stuff.htmUncle Doug's YouTube channel - https://www.youtube.com/channel/UCuR4hQTXkG_KxozLxwPzEjQ

 

[hopkinWFG]

Parallel was referring to the how the actual wires are routed to the heater filaments on the tube sockets. In most amp's you see them those wires twisted like the red & black wires here:
View attachment 66402
But certain amps like Soldano's they will run those wires parallel to each other through the sockets like:
View attachment 66401.

The 6.3v center tap being connected to HTR pad on Burger's board has nothing to do with parallel - that just DC elevates the 6.3v AC supply. You could also twist the wires and still connect that center tap to HTR. That said this was my first amp build so burger might chime in and correct me.

Check out http://www.valvewizard.co.uk/heater.html for some more detail on this.

Other resources that I use a lot during my first build was:

Burgers documentation
Rest of the valvewizard site
https://robrobinette.com/Amp_Stuff.htmUncle Doug's YouTube channel - https://www.youtube.com/channel/UCuR4hQTXkG_KxozLxwPzEjQ

Thanks @riq

 

[burger]

Riq is spot on re the heaters.

5 pin DIN socket? I use these from my local electronics store
https://www.jaycar.com.au/5-pin-din-panel-socket/p/PS0348Note the dimensions.

You should be able to find the equivalent locally.

 

[hopkinWFG]

cool !!

 

[bwgintegra]

Here is a good read about heaters, the Headfirst board should have a divider built into it on the HT to provide around 50vdc to the heater center tap.

I prefer elevated heaters over DC heaters

http://www.valvewizard.co.uk/heater.html

 

[burger]

Here is a good read about heaters, the Headfirst board should have a divider built into it on the HT to provide around 50vdc to the heater center tap.

I prefer elevated heaters over DC heaters

http://www.valvewizard.co.uk/heater.html

All of my boards have this, tapped off the screen supply node.