Santiago Alvarez (electronics engineer, JVM, YJM, AFD...)

[santiall]

Wrong forum.

I hope they don't ban me... It won't happen again, playing is overrated, let's buy more gear!
actually, does anybody here actually play guitar?

 

[Szlast]

there are few arguments to make them different. The phase splitter needs to drive 4 tubes instead of two, the output impdance of two tubes is ~half (you approx. double the transconductance), the output transformer, most likely, has lower resistance. Then the output votlage, for the same impedance is 1.4 times so you would need to compensate with the feedback. etc. On top of that, many 50W marshall power amps run at a relatively low voltage (the voltage that was in the datasheet btw) so the tubes are not even operating in the same point.

so yeah, there are a few arguments that points to potential differences. That doesn't mean that you couldn't design a 50W that is indistinguisable from a 100W, I guess Hi-Fi guys do this (or try to) all the time, but for a guitar amp one may want those two to be different.

I mean tonally if 100W sounds "better" than 50W? I know that there are guys that hear type of tolex of the head but realistic hearable difference:) 100W now is not needed as it was in old days where there was no stage sound systems.

Also have a quiz for you all. I recently wound my first output transformer in the most simple 3 sectional way on old EI102 core from I guess not top quality steel. I recorded two samples on my DIY 50W JCM800 one with bought transformer from top quality company in Poland, transformer is 5 sectional EI96 with top quality steel and second with this my. Can you guess which is which and why?

Samples where recorded as follows: Amp -> DIY reactive load from Marshall forum -> Tonex one -> DAW -> IR "LT TV MIX 7 500N" from Leon Todd free pack. Amp settings and guitar the same.

Output transformer test – Google Drive

drive.google.com

 

[santiall]

I mean tonally if 100W sounds "better" than 50W? I know that there are guys that hear type of tolex of the head but realistic hearable difference:) 100W now is not needed as it was in old days where there was no stage sound systems.

Also have a quiz for you all. I recently wound my first output transformer in the most simple 3 sectional way on old EI102 core from I guess not top quality steel. I recorded two samples on my DIY 50W JCM800 one with bought transformer from top quality company in Poland, transformer is 5 sectional EI96 with top quality steel and second with this my. Can you guess which is which and why?

Samples where recorded as follows: Amp -> DIY reactive load from Marshall forum -> Tonex one -> DAW -> IR "LT TV MIX 7 500N" from Leon Todd free pack. Amp settings and guitar the same.

Output transformer test – Google Drive

drive.google.com

they are pretty similar but I wonder if the turns ratio is the same?. Anyway, I'd flip the coin and say that the frist one, with the 1 is the EI96

 

[Szlast]

they are pretty similar but I wonder if the turns ratio is the same?. Anyway, I'd flip the coin and say that the frist one, with the 1 is the EI96

My transformer I wound has 4k primary impedance and bought one is Marshall replacement 3.4k. Black 1 and Rock 2 is EI96:) I hear only difference in lower frequencies, where bought one sounds thinner. This test shows how little OT has influence, or my recording skills are weak, which could be true:)

 

[santiall]

My transformer I wound has 4k primary impedance and bought one is Marshall replacement 3.4k. Black 1 and Rock 2 is EI96:) I hear only difference in lower frequencies, where bought one sounds thinner. This test shows how little OT has influence, or my recording skills are weak, which could be true:)

Ah, I was assuming that the xxx_1 and xxx_2 were the same transfomer in different playing styles... the one I guessed as EI96 has more bass, or the bass is more distorted depending how you look at it but if the impedance ratio isn't the same you can't 100% blame the interleaving or the size.
Anyway, yes, as you said, you really need a poorly wound transformer to hear significant differences.