Tube Chassis Layout

[JJH0906]

Good point about the power, I will see if there was a specification on the size/watts.

Wattage is not an issue because there is no dc current flowing through the pot, therefore zero watts dissipated. But voltage is an issue. A PEC pot would be a good choice for that pot.

Yeah, so these PEC pots A) look hard to find/purchase and B) run $25-40 ssoo.... Pass on the shift notch. Sorry Merlin!

[sluckey]

Good point about the power, I will see if there was a specification on the size/watts.

Wattage is not an issue because there is no dc current flowing through the pot, therefore zero watts dissipated. But voltage is an issue. A PEC pot would be a good choice for that pot.

Yeah, so these PEC pots A) look hard to find/purchase and B) run $25-40 ssoo.... Pass on the shift notch. Sorry Merlin!

Merlin told you how to deal with the voltage issue. Cost a $1 capacitor.

Comments about a PEC pot were based on the schematic you provided.

[JJH0906]

I did see the capacitor in the drawing, is that going to block out the 250 volts or so that is running through that circuit? Obviously the capacitor would have to be rated for that, just not quite sure how tiny capacitor is going to block that much voltage?

[pdf64]

Provided their voltage rating is sufficient, that’s what they do.

[JJH0906]

Very well! Sorry Merlin, I recant my earlier statement.

[JJH0906]

I may scrap it but the example he provides as far as the notch shift seemed like an advanced way of shaping the tone outside of the 3-bamd EQ.

Again, he may have specified a certain kind of pot but I'll have to read through again to find out.

Follow Merlin's advise (highlighted) and you don't have to use a robust pot...

Would you share where you got this information from? I have Merlin second edition and it does not look like what is shown here.

[sluckey]

That info came directly from Merlin Blencowe - Designing Valve Preamps for Guitar and Bass, page 249.

[JJH0906]

*shrugs*

This has been my source from Merlin, same book but a 2012 publication 2nd Edition.

[sluckey]

Yes, he wrote more than one book. I also have the book you just posted.

[JJH0906]

Well thanks for passing that along anyway, it was helpful and putting that circuit together with better components.