The Amp Garage

What attracts you to this amp?

Stevem wrote: ↑Mon Apr 01, 2024 3:41 pm What is up with that rectifier tube used in that schematic?

It's Weber's WZ34, a solid state plugin replacement for a GZ34.

It's been linked to DPS (double post syndrome).

V5A grid needs a resistor to ground.

Voltages will be high until you plug in the power tubes.

dpb703 wrote: ↑Mon Mar 25, 2024 3:31 am In terms of posting the entire schematic, I’ve gotta check whether there’s a copyright mark on it.

Never mind. I've seen it. I suggest you just build it according to Weber's plan.

pjd3 wrote: ↑Sun Mar 24, 2024 1:28 pm Can a similar thing be some with the 6.3vac filament circuit?

Use a thermistor in series with the primary winding to prevent high inrush current at turn-on.

Then there has to be a reason for the the 2 40uf caps in series, why else would the designer opt for 2 in series over just one 20uf cap? It's common practice to put two filter caps in series in order to have a higher voltage rating. This entire filter section is just stupid. Looks like a Weber draw...

I just think about the millions of top name amps that never fused the filaments. And I also remember the first new car I bought in the '60s... lap seat belts were optional, and you had to pay extra!

It's not for the actual heater currents. It's in case the CT is grounded and one heater wire breaks or otherwise gets shorted to the chassis or signal ground. I've been doing this stuff since '65 and have never witnessed such a failure. Have you? This just sounds like one of those new age theoretic...

A hard CT requires two fuses, one on each end. That's twice you've said that recently. I think two fuses is redundant. The same filament current flows from top end of the filament winding through the filaments and back into the bottom end of the winding. No current flows into the center tap. It onl...

It's redundant. Use one or the other. I prefer the resistors. Why do you prefer the resistors? I like the pretty colors. But there's also a technical advantage. It's not uncommon for an output tube such as a 6L6 to have an arc between pins 3 and 2. This arc is usually a result of playing loudly and...

martin manning wrote: ↑Sat Mar 23, 2024 2:08 pm If it's -100F outside, I'm not going ;^)

That's my point. -100° is definitely more cold than -10°.

It's redundant. Use one or the other. I prefer the resistors.

-100V is definitely more than -10V. Which will push more current through a resistor? Which would cause more pain if accidentally touched?