The Amp Garage

if its in front of the PI,i would ground it at the tail of that.

Schematic is the metro amp zero loss,and it works as intended.
If it doesn't work it's either a faulty MOSFET,wrong component or bad execution.

In the old days of tube radios, they used an output transformer that allowed to connect the screen grid out of phase respect to the plate,turn ratios exactly the same of the current ratio between plate and screen,that way no hum.
Why nobody in the amp business never made it tells a lot.

Marshall and Fender used what was available and at reasonable cost,so just enough...
There are specific values of capacitance per milliamp of current,and all guitar amp are lower than that,even the stiffest.

there were some errors in the bias supplies,some typos,i should have an errata page somewhere.
The gyrator is ok,i would advise to just double check any circuit around with a good electronics book,99% of that is coming from a handful of well known bibles.

impedance is a function of tube type,plate and screen voltages,class of operation,type of configuration(pentode,triode,ultralinear).
Amps that use 3400 ohms primary with 2 EL34 at over 450V are all plain WRONG!

martin manning wrote: ↑Sun Dec 08, 2019 8:31 pm 4k:16, since pp transformer impedances are quoted plate-to-plate. A pp transformer is not made for single-ended use though.

there is a way,its called parafeed,then you could use anything even a toroidal.

i have seen someone,i don't remember where,wiring relay contacts on cathodes,the relays don't close until a predetermined bias voltage is reached,that seems to me a good solution.

its not bad,maybe the power tubes grid wires could be more direct,in general i find a bit odd making a point to point with 2 tag strips and there's nothing in between them except the 3 filter caps,i don't know if that's due to chassis dimensions,given the chance i would keep the preamp tubes closer ...

i would use a plastic flying fuse holder,direct to the psu

well,different people,different tastes. generally speaking an effects loop is needed whenever the preamp distorts so much that ruins the effected signal,such as reverb or delay. In amps like this or the 18w Marshall i would just derive the fx send from input 2 of the channel feeded by the guitar,and...

you know what,i've been told that it's overdrive in front of a BF Fender style...kind of a reverse ods

gutshot found online

There's a reason for a dedicated low impedance winding

i wonder if mr Dumble has ever followed these old rules,
i guess not.