A basic tube schematic question...

[GerryJ]

Hello, first post here- on learning curve, I have several old Traynor amps from ~ 1970 era, great machines, but as you know require periodic biasing, tube replacement, etc.
My questions are about correctly interpreting schematics. With a typical EL34/6CA7 amp like the Traynors, I see the B+ voltage coming off the output transformer (OT) delivering 537 volts to pin 3 the anode (plate).
Ques 1 : basic science question- I understand that the heater filament heats up the cathode enough that the cathode sends off electrons on their journey. But if the OT is supplying 537 volts to the anode/plate, isn't that in the form of current - ie, electrons? So how can the electrons coming from the cathode be attracted to the anode/plate, if it's teaming with electrons from the B+ voltage?
Ques 2- the power transformer (PT) supplies the output transformer (OT) which puts the very high voltage on the tubes?
Thanks in advance for helping me understand.

Traynor-BassmasterYBA1 & MKII-YBA1a-Schematics.pdf

[nworbetan]

1. High positive voltage comes from a lack of electrons, which are negatively charged.
2. Yes.

[Nixon101]

Just wanted to say I’m a huge traynor fan too. Let’s see what you got? Here’s mine. I could answer, but others will give you a much better explanation than I can.

[GerryJ]

High positive voltage comes from a lack of electrons, which are negatively charged.

Ok, now I see it - thanks!

https://electronics.stackexchange.com/q ... ransformer

[GerryJ]

Just wanted to say I’m a huge traynor fan too. Let’s see what you got? Here’s mine. I could answer, but others will give you a much better explanation than I can.

Hi! I've got a 1968 YBA-1 (my first real amp, I've had it since teenage years!) that's been modded with a master volume, and 3 others from the early 70s, all stock - a YBA-1, a YBA-1A Mk II, and a YBA-3 custom special. Incredible amps.
A different question, but since you're also a Traynor fan- what EL34/6CA7 have you found to be reliable? My amps have older ('NOS') Tesla El34s (pre- JJ), they seem to last quite awhile, outside of the occasional bad apple redplating or cracking it's ceramic base (quality control on non-US tubes is a fiasco). But I've noticed that the screen grid maximum voltage listed for the Teslas is 425 volts. YBA-1s are schematiced as giving 427 volts on the screens, but Mark IIs and YBA-3s put around 530 volts. So I was wondering if I need to step up to something like JJ KT77s, which are listed as allowing 600 volts on the screen grids? I don't play these amps at power tube distortion levels, as you know that would be insanely loud. Also, the specs on my '68 YBA-1 original tubes- RCA 6CA7s - list only 425 volts as max on the screens, lol- yet those tubes lasted fine for 8 years of HARD playing . I kind of think that in terms of current tube production, the Teslas (or later on, JJ EL34 or JJ 6CA7) will probably be sufficient...?

[Nixon101]

My ysr-1 still has the original philips branded mullards in it. Power tubes and pre amp tubes. They sound amazing and are still very closely matched. Never even thought about changing them other than wanting to try real beam tetrode 6ca7’s, like the old sylvania’s. The first yba-1a I got had sed winged c el34’s in it. After getting the bias under control, they are a little mismatched but still sound good. Never tried anything else as I’ve read the winged C’s were some of the most robust el34’s you could get as far as tolerating screen voltage. My second yba-1a has Japanese made el34’s. They are branded philips but say made in Japan and after some research, they are made by matsushita, who allegedly used the same tooling and materials as mullard did. This amp I just got not too long ago. I’ve been in it long enough just to figure out the bias was way too high, and one tube is really weak resulting in a big mismatch. Haven’t even put a 3 prong cord on it yet. I’ve heard other people say they like the genalex gold lion kt-77’s in the mkii’s. Your right, the screen voltage is a problem, especially with newer production tubes. Not sure what I’ll put in when I do have to replace them. I do want to try sylvania 6ca7’s but my wallet doesn’t. I’ve heard the EH 6ca7’s sound close to the sylvanias and people seem to like them, but then other poeple say they hate them and are horribly unreliable. Won’t know for sure unless I try them I guess.

[TUBEDUDE]

Bear in mind all tube production comes from three or four factories now. They are all Chinese, Russian, or Slovakian. Even though they are marketed under the brands appropriated from great tubes from the past,
(Genelex, Mullard, Tung Sol, etc.), they are new production and will likely not take the abuse some amps dish out that were designed with tubes from yesteryear.
That said, I have had good luck with the new Gold Lion KT series power tubes. I save my NOS power tubes for amps with harsh operating conditions.

[Stevem]

In reality current flows from negative to anything with a positive charge, the problem is this, when electronics where first being developed a wrong convention was put in place because it was thought way back then that current flows from positive to negative when it does not!

[thetragichero]

i had the same concerns as the original poster vis-a-vis running modern production el34-types in these traynor amps, especially the yba-1a. i'm sure they worked great with the xf2 mullards that came in mine but i converted to run 6550s so that i could be assured they'd run nicely. basically involved converting to adjustable fixed bias (if the particular model did not already have it) with enough range for the 6550s along with replacing the bias feed resistors with 150k. as i've aged i've shied away from running my equipment at the absolute bleeding end of safe and much prefer running things that will work reliably every time i flip them on

[martin manning]

Re "conventional" current vs. electron current, here's a brief summary: https://en.wikipedia.org/wiki/Electric_ ... onventions

[pdf64]

On the face of it, with their 300V g2 limit when not used in UL or triode mode, the KT77 doesn’t appear to be a great choice with amps with super high HT voltages.
https://frank.pocnet.net/sheets/086/k/KT77.pdf

[Stevem]

Well with the same needs for heater current as a 34,using kt88s other then draining your wallet deeper will last forever in these amps, and since you state that your not playing them loud enough to clip the output stage the overall sound of the amp(s) should be the same or better.