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January 26, 2020, 04:52:55 AM

Author Topic: Soul Sister Question  (Read 2392 times)

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Offline xcortes

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Soul Sister Question
« on: February 25, 2014, 11:20:16 AM »
The 5670 version of the SS shows the tube at 150V plate, 9.5mA and 3.2V bias (332 ohm cathode resistor). All is good 'til I take a look at the 5670 charts that show that at 150V and 9.mA the bias is more like 1.8. What am I'm missing?
Thanks
Xavier Cortes

Offline Doc B.

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Re: Soul Sister Question
« Reply #1 on: February 25, 2014, 11:49:09 AM »
Man, that is going waaaay back. I can't begin to remember where the numbers came from. Truth be told I can't even remember what tubes I ran in mine. It's imaginable that there is an error in the plate current figure on the schemo. I can take a look after we get the archive back up.
Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.

Offline xcortes

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Re: Soul Sister Question
« Reply #2 on: February 25, 2014, 12:21:17 PM »
I know it's old. I was just studying it. No worries.

Saludos
Xavier Cortes

Offline Mike F1

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Re: Soul Sister Question
« Reply #3 on: February 26, 2014, 02:19:31 PM »
I made this preamp: http://bottlehead.com/smf/index.php/topic,2477.msg19877.html#msg19877

I wired it as shown on the schematic then later I installed LED (HLMP6000) on the cathodes but didn't change the CCS.
I'd give the nod to the LED's. To my ears it sounds very delightful!

YMMV

Mike
« Last Edit: February 26, 2014, 03:02:30 PM by Mike F1 »

Offline Doc B.

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Re: Soul Sister Question
« Reply #4 on: February 26, 2014, 02:36:18 PM »
Just want to point out that the current iteration of this concept can be seen in the Mainline.
Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.