B+ and Zout questions?

[Satamax]

Hi everybody!

Huh, i've asked before, checked all the 5E3 schemos i could find but to no avail. What should be the B+ on a 5E3 and what should be the output impedence?


Thanks a lot.

Max.

[MWJB]

350v to 370v-ish with 5Y3 & stock cathode resistor.

8.5K primary into 8 ohms.

[Bruce / Mission Amps]

Pretty close.
But keep in mind the 5Y3 in question must be a real or (NOS) 5Y3GT as the Russian one is not a true 5Y3GT and the B+ will be a ferw tens of volts higher.

[Satamax]

Uk cool guys!

Thanks a lot for your replies! So the trany i have is too low on voltage! It's 280vac out, so i'm expecting (as per Duncan's PSUD2) 319Vdc at the first cap. Tho, with a GZ34, i get arount 350/360! which seems ballpark. What do you think?

Thanks a lot.

Max.

[MWJB]

Well, I'm a great believer in using what you have, as long as current ratings are up to the job (after all, if Fender had stock problems they used to fit the next best part rather than halt production). I would suggest that you might even end up 15-20v less that what you estimate, once you have the full tube compliment installed.

Even so, I'd give it a go, a lot of guys switch out to a 5V4 rectifier for a tighter response with a 5E3...you'l be able to use the GZ34 without having to worry about a larger cathode resistor and you get the benefit of slow warm up.

At the end of the day there is some leeway, depending on whether you want "period correct" voltage (you will still be a little shy of this), or actual "vintage" 5E3 voltage...then there's differences in wall AC, tube brands etc., filter cap arrangement...If you really don't like it, it doesn't take that long to change a power tranny. Bear in mind that it will be slightly down on power compared to a vintage 5E3, especially one fitted with a 5V4, which may have another 80 or so volts B+. But if it's just for recording/practice and you like the tone..it's your call.

If you absolutely must have "real 5E3" voltages, then Bruce will have the part.

[MKB]

Mine is a bit lowish, around 320V or so with a 5AR4, only get around 12W into a dummy load. But it sounds really good as it is, several guys are wanting to buy it. I'd say try it out to see how it does with the lower voltage tranny.

[Bruce / Mission Amps]

10-12 watts "clean" into a dummy load is all any 5E3 will do!

[Satamax]

350v to 370v-ish with 5Y3 & stock cathode resistor.

8.5K primary into 8 ohms.

Hi everybody!

Well, i've tested my tranies, 269Vac on the PT + 3 X25Vac??? Plus heaters 6.3 normally. No 5V for recto

And i have 6932 for 4 Ω I usualy use 5.33 in my actual favorite cab, so i'd have 9240, close enough then???