Valve noobie asks for help / advice

[SY]

Haven't tried Capiaux yet, but I've had other Pinots from some of those vineyards. I'm probably the wrong one to ask- when I see alcohol levels like that in Pinot Noir, I tend to be a bit put off. California Pinot in general tends to be grown in areas where the soil has too much vigor and the climate is too warm. You end up with a big, powerful hot wine, which to me is not what Pinot Noir should be about. There are some few precious exceptions still coming out of Anderson Valley, Mendocino, and selected parts of the Central Coast.

Errr... ummm... OK, back on topic, the Maida I used was identical to the one I used for the screen supply for the Red Light District. I've put that schematic up a few times, so you should be able to find it with a quick search. If not, let me know and I'll repost this weekend when I'm back at my home computer.

Renron, you've got it.

[Renron]

Cbutterworth:
"I will be practising making dovetails by hand and building what I hope will be a gorgeous wood chassis with a polished aluminum top-plate.

sounds like a lot of work and frustration (for me) I'd love to see it's progress when you get started. Ought to be gorgeous!

Ron

[jayme]

Originally posted by Renron
Jayme, Sy, and Cbutterworth,
Thank you for your input, I'm trying to digest and understand your suggestions.

Back to basics; If the Aikido circuit splits the B+ voltage between the 1st and 2nd stage (the input and ouput) valves and the recommended B+ is 250V (from John Broskie's user guide) then won't each valve see 125V?
What am I missing???
specs for the valves are;
Typical characteristic:
Ua = 250 V
Rk = 800 Ù
Ia = 10,5 mA
S = 2,2 mA/V
Ri = 7,7 kÙ
ì = 17

4 valves total = ~42mA Right?

Thanks for the hand holding guys......

What I do not understand is the B+ voltage split thingee.

Ron

Well, the 250V is not "split" between the input and output stages. They both see 250V. The CURRENT is what is split between them.

[jayme]

Originally posted by cbutterworth
Sy,

Please could you detail your CRC Maida regulator supply? If you have read my previous posts, you'll know that I am having the dilemma of how to improve my PSU on my Aikido. I could easily settle for 350VDC for my 6SN7's.

Regards,
Charlie

Try Voltage Regulator Tubes in a Shunt Regulator mode! I took my CLCLC filter, and added a 500R resistor between the CLC and final LC. Then I added 2 0D3 voltage regulator tubes in series as a shunt to ground right after the resistor. (The 500R was calculated to give 20mA drop across the shunt regulator).

When I pull the gas regulator tubes, it reverts to a simple CLCLC with the equivalent of 500R extra resistance added to the final L DCR.

For 350V PSU, you could use an 0D3 and two 0C3, all in series.

And they glow oh soo cool...

[cbutterworth]

Jayme,

Hmmm.....I always thought that the circuit split the voltage between the plates of the tube, not the current, but when I look back at the schematic, I can never tell quite how this is done. My interpretation is that plate #1 sees 300V, cathode #1 sees 154V, plate #2 150V, cathode #2 4.5V. I always assumed that this meant that each side of the tube sees approximately half of the B+ voltage, which Broskie sets at 300V in his original design.

As for tube regulators, I have pondered over the idea of these, but have always been unsure on exactly how to use them in a PSU to give around 340V. Maybe I'll have to start digging around and see if they would work in my Aikido.

I have a basic web-page with some of my amps shown:

http://homepage.mac.com/butterworthfam/AudioDIY/

Charlie

[Renron]

Thanks Jayme,
Let me see if I got it right this time.

The B+ voltage is seen by each valve,
each valve shares 1/2 B+ at it's plateS,
that's where the noise cancellation takes place.

The current is shared by all valves.

Charlie,
After re-reading your 1st post several times I am begining to understand what you wrote, thank you.

Sy,
Thank you! Even thou you speak in riddles (to a neophite like me) I appreciate your time, experience, wisdom and input. I'll get it eventually. Don't give up on me. This is my first venture into electronics of any sort.

Ron

[Renron]

Yea, Charlie, good post!
It does not seem as clear as it could how each valve "shares" voltage and current.
Thanks,
Ron

[cbutterworth]

Ron,

You made me think for a second there! I am wondering if Broskie's table list current per plate and not for the entire tube. If this is the case, then I'll have to double my estimate of PSU current draw from around 18mA to 36mA! I'll go back and look at his original schematic and try to calculate current for his set-up and see if it comes out close to his table.

Charlie

[SY]

Originally posted by Renron
Yea, Charlie, good post!
It does not seem as clear as it could how each valve "shares" voltage and current.
Thanks,
Ron

Water. Think water. Suppose you have a big pipe with a constant water pressure of 100psi.

Now, take a thinner pipe and attach it to the end. The pressure at the input to that pipe is still 100psi. Measure the flow. Let's say it's 10 gallons per minute (gpm). So since the far end is open, pressure there by definition is zero psi.

OK, take an identical thin pipe and attach it to the big pipe just like its twin. Now you have two pipes whose pressure goes from 100psi at the entrance to zero psi at their exits. But the flow rate doubled!

One more thing to do: let's put the two thin pipes i nseries and attach one end to the big pipe. The pressure runs from 100 psi to zero psi again. But now, the pressure at the end of pipe one and the entrance to pipe two has to be 50psi since the pipes are identical.

Convert "flow" to "current" and "pressure drop" to voltage.

[EC8010]

Originally posted by Renron
I don't think I have ever read a post from SY that I have understood completely.

Yup, I'm lost on water analogies for explaining electricity. (But I have drawn circuit diagrams to understand plumbing.)