The Amp Garage

fred.violleau wrote: ↑Mon Dec 02, 2024 4:16 pm And this is a recording through my phone, so it sounds as good as what a phone can capture...

https://youtu.be/cRVCCyMxx_U?feature=shared

great sounds!

PT should alyaws be mounted at maximum possible distance from the inputs.. so at the far corner.

noise is related with grounding, lead dress and mechanical layout (positioning of transformers) nothing to do with cathode resistor.

i see very thick traces...finally very nice

there is a big diference in bass quality in various OT's.. it is function of lamination quality (permeability) and number of the turns.. i like more inductance (nuber of the turns) because lower register is stronger in comparison with lower inductance where is muddy,

In my last build, power transformer is almost touching output tube (very small chassis for the purpose0 .. there is no any humm or problems.

Matthews Guitars, start to build something, and on 10th build you will start to understand something... with 0 experience what are you showing here all is truth , and ofcourse it is difficult to hold some point and to discuss with other people.

1000th repair and still asking basic questions on the forum

this is to tame high frequencies in high gain with 100-200pF value of capacitance in coax cable.. not technical method, nor smart idea, better to use some ceramic 100-200pF 1kV if needed

EL34 is not good candidate for AB2 class.. more are transmitter tubes for that.. grid g1 must be sturdy and dissipate some power (1-2W). Check 2E22 datasheet you can find some nice data there.. G1 on out. tube is pulling from 10-50 mA from the driver tube in AB2 usually - so driver tube must deliver...

nowadays, and I think many components and devices could easily be SMT rather than through-hole, still allowing to shrink the size of boards and builds in general. This is not a option in high voltage circuits..and many more reasons..many manufacturers made this mistake.. Also tube amps still are ke...

Wait, dont be so fast - Bm is NOT the max value from the datasheet of the laminations - and why is not?

Think about what is going on during rectification, and why for the transformer working for DC rectification you must use lower value

power transformer is easy - there is transformer formula

U=4.44*Bm*f*Afe*N

Bm- max magnetic flux (how much it should be - lets hear experts - this is key factor)
Afe- area of middle column in E lam in m^2
f- frequency- Hz
N- number of turns

those resistors in marshall are carbon film..

just winding 1kV 30W - nominal (42Wmax) Single ended output transformer for HiFi use..
and strong transmitter triodes.