Well, I'm finally building my Express...

[PlinytheWelder]

I've got a problem... I've got 355V on the plates of the PI tube when the voltage chart says I should have 190, 5.25V on the cathodes and .1V on the grids.
Somethings not right there...

[PlinytheWelder]

Looks like R13 wound up as 470K instead of 470... I guess I'll change it out tomorrow, I'm done for today......

[PlinytheWelder]

Woo Hoo! It's very alive and VERY LOUD!

Stable, no hum, some hiss, but with all this gain.....

FUN!

[PlinytheWelder]

Some quick pics...
[img:900:596]http://verosurfcam.com/TW12.jpg[/img]
[img:900:615]http://verosurfcam.com/TW13.jpg[/img]

[PlinytheWelder]

Well, I got the VVR in and it works! It's certainly not a bedroom amp, but the VVR tames it down some....

[img750]http://verosurfcam.com/TW14.jpg[/img]

[img487]http://verosurfcam.com/TW15.jpg[/img]

Now on to the cabinet... I think I'll try a Woodcraft drawer to start...
It doesn't hum and it doesn't squeal and it sounds great!

[Structo]

Looks like R13 wound up as 470K instead of 470... I guess I'll change it out tomorrow, I'm done for today......

Classic mistake.

I've done it as well.

If I had a nickel for every time someone did that.......

[rawnster]

Looks like R13 wound up as 470K instead of 470... I guess I'll change it out tomorrow, I'm done for today......

Classic mistake.

I've done it as well.

If I had a nickel for every time someone did that.......

Me too.

[CircuitButcher]

Nice job Mr Pliny!


Was there any particular rationale for component selection - what type of diode are you using for rectification?

What method of implementation is your VVR?

Thanks in advance.

[PlinytheWelder]

Nice job Mr Pliny!


Was there any particular rationale for component selection - what type of diode are you using for rectification?

What method of implementation is your VVR?

Thanks in advance.

I use the Dale RN's because I'm familiar with them, they are low noise and I think that they sound good.

The diodes are Silicon Carbide Schottky, they have the lowest noise of any diodes available. They are just plain quiet.

The VVR is a Hall VVR3 and the whole amp is regulated.

It also has a LarMar PPIMV done with a dual PEC pot similar to the other pots in the amp.

[PlinytheWelder]

Here's my mess in more detail.....

[img2142]http://verosurfcam.com/TW21.jpg[/img]