Yet another 12B4 line stage, or is the 12B4 better than the Grounded Grid..... - Page 52 - diyAudio
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Old 5th October 2006, 03:26 PM   #511
zobsky is offline zobsky  India
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Quote:
Originally posted by Wavebourn



Unlike Zeners they need a higher voltage to fire up, after that they drop voltage down to a regulated level. Slightly different resistors across them is the way to fire them up one by one and make resulting fire-up voltage less, if you connect them in series.


Could you post a rough schematic? I wasn't aware that VR tubes needed resistors across them. I do know that they need a resistor above them eg.
http://www.tpub.com/content/neets/14.../14178_150.htm


Thanks
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Old 5th October 2006, 03:33 PM   #512
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Quote:
Originally posted by zobsky



Could you post a rough schematic? I wasn't aware that VR tubes needed resistors across them. I do know that they need a resistor above them eg.
http://www.tpub.com/content/neets/14.../14178_150.htm


Thanks
Connect 2 gas tubes in series. Slowly rize voltage on them, of course through a current limiting resistor. Now connect pair of high ohm different bleeding resistors across them and compare. You may use a variac in the primary of your PT to check what voltage is needed to fire them up if you don't have a laboratory source of regulated voltage.
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Old 6th October 2006, 12:22 AM   #513
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Or just ask Zen Mod to do the quick calculations for you .

Mark
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Old 28th October 2006, 01:05 PM   #514
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Alright, I will ask Zen Mod or anybody who can simulate this:
I bought a transformer just for this project to run those OO3 gas regulation tubes. Do I need a choke or filter arrangement for this transformer to run those tubes correctly???

Transformer: www.edcorusa.com Model: XPWR106
115V 60Hz. 275-0-275
125mA 6.3V, 4A

Primary Voltage:
115VAC
Primary Frequency:
60Hz
First Secondary winding:
275-0-275VAC, 125mA
Second Secondary Winding:
6.3VAC, 4A

http://www.edcorusa.com/classx/power/xpwr/Xpwr106.htm
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Old 28th October 2006, 08:17 PM   #515
Zen Mod is offline Zen Mod  Serbia
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Quote:
Originally posted by LuckyLyndy
Alright, I will ask Zen Mod or anybody who can simulate this:
I bought a transformer just for this project to run those OO3 gas regulation tubes. Do I need a choke or filter arrangement for this transformer to run those tubes correctly???

Transformer: www.edcorusa.com Model: XPWR106
115V 60Hz. 275-0-275
125mA 6.3V, 4A

Primary Voltage:
115VAC
Primary Frequency:
60Hz
First Secondary winding:
275-0-275VAC, 125mA
Second Secondary Winding:
6.3VAC, 4A

http://www.edcorusa.com/classx/power/xpwr/Xpwr106.htm
you bought it before you know it's good or not?




which schematic?
like Mark's -with R on anode?


preliminary - that xformer is on the edge here..... if I presume that you want R loaded stage,with two OD stacked per channel.....
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Old 28th October 2006, 09:08 PM   #516
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Quote:
which schematic?

Same... identical as Mark's.

Mark... Mark my word on that!
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Old 28th October 2006, 10:09 PM   #517
Zen Mod is offline Zen Mod  Serbia
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Quote:
Originally posted by Mark A. Gulbrandsen



Same... identical as Mark's.

Mark... Mark my word on that!

in that case

xformer
then two schotkys (even from PC supply) as full wave rectifier ,common for both channels
then muuuucho of capacity
then same schmtc as for Mark's (one I drew it here..........http://www.diyaudio.com/forums/attac...amp=1147048038
mebbe just slightly smaller resistor in front of gass toobz,just because your (Lucky's ) voltages will be smaller than 400V before gas stabz

anyway-I can bet that xformer will be warmmmmmmmmmmmmm


Mark-did you tried your super reg variant?
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Old 29th October 2006, 03:02 AM   #518
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Quote:
Mark-did you tried your super reg variant?
Not yet... time factor, time is a 4 letter word. Working on KSA-100 and then this 12B4 line stage or he is going to come to hunt me down!

Mark
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Old 29th October 2006, 10:53 PM   #519
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I decided to put my 12B4A preamp in a different chassis-

Zen Mod, ugly enough for you?

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Old 29th October 2006, 10:55 PM   #520
Zen Mod is offline Zen Mod  Serbia
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Quote:
Originally posted by arnoldc
I decided to put my 12B4A preamp in a different chassis-

Zen Mod, ugly enough for you?


ugly!
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