My 12AX7 zero negative feedback preamp, with measurement - diyAudio
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Old 22nd January 2008, 01:15 PM   #1
alexw88 is offline alexw88  Hong Kong
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Default My 12ax7 zero negative feedback preamp, with measurement

All of my previous projects are Opamp based pre and power amps. Now I have tried tubes and I really love it! I am a tube newbie so I hope I can learn more.....

My 12AX7 zero negative feedback pre-amp : http://www.shine7.com/audio/12ax7_pre.htm

Here are some photos and measurements from the above page :

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Old 22nd January 2008, 01:21 PM   #2
SY is offline SY  United States
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Very nice construction, and the distortion spectrum looks excellent. What is the output level where it was taken?

I like those prototype boards and terminals. Where did you get them?
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Old 22nd January 2008, 01:24 PM   #3
alexw88 is offline alexw88  Hong Kong
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Thanks, the output is at 1V p-p.

I have got the prototype board and the terminals at a local DIY components shop in Hong Kong.
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Old 22nd January 2008, 01:36 PM   #4
dhaen is offline dhaen  Europe
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I agree: nice construction. Also good philosophy IMO
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Old 22nd January 2008, 02:32 PM   #5
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Bravo! Very nice indeed!

I envy your skill!

GD
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Old 22nd January 2008, 03:17 PM   #6
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love your site!

Bob
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Old 22nd January 2008, 03:18 PM   #7
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That's freaking gorgeous !
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Old 22nd January 2008, 05:50 PM   #8
daanve is offline daanve  Netherlands
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SY,

if you ever make it to HongKong you have to visit the store where I saw those solder stands.
Bush Electronic Supply, in an alley behind a pretty big street in Hong Kong central or the Centre.
You enter the alley, then walk up some steps and you enter the shop. Amazing, the contrast.

http://hktubeaudio.homestead.com/files/Central_tube.htm


Daan
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Old 22nd January 2008, 06:11 PM   #9
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Very nice looking job, Alex!

(I need to get myself some of those prototype boards too!)

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Old 22nd January 2008, 06:37 PM   #10
SY is offline SY  United States
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Daan, I still have to get back to Holland before I can start thinking about travel for pleasure!
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