Switchable Hi-Z input impedance, how ? - Page 15 - diyAudio
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Old 2nd June 2012, 07:56 AM   #141
tinitus is offline tinitus  Europe
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found RCA tone control manual
and a Crowhurst article
looks like even I can do that

btw, consider its a 2channel/stereo
using one channel for bass, and one channel for mid/top
enables the two channels to be configured differently
like using the trick with a small bypass cap on cathode resistor, to achieve a little more high frequency gain
and having seperate attenuator for each channel further enhances sound balance control
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Old 6th June 2012, 10:18 PM   #142
tinitus is offline tinitus  Europe
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trying to draw curcuit, with EQ

not sure why the cathodes are bootstrapped
but seen that elsewhere

hmm, maybe only output tube should be bootstrapped
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Old 7th June 2012, 11:53 AM   #143
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I find it exstremely funny to read a text bit like below
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Old 7th June 2012, 08:27 PM   #144
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Quote:
Originally Posted by tinitus View Post
not sure why the cathodes are bootstrapped
ah, ok
by bootstrapping, the input/gain tube would achieve a bit more gain
guitar amp builders say it gives more 'grunt'
well, no real need for that here

bootstrapping the cathode output tube gives higher impedance load
and that might be of advantage, considering the EQ curcuit
well, I dont know this, but it seems logical

hope its beginning to look better
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Old 8th June 2012, 08:11 AM   #145
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ahh, managed to make the desired drill/router bit for doing solder pads
have been on the to do list for some time

needs a bit 'refinement', but seems to work ok
means I can get on with the solid state output (BA-3)
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Old 8th June 2012, 09:45 AM   #146
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Quote:
Originally Posted by tinitus View Post
needs a bit 'refinement'........
works better, smoother and much faster now
I think it will be a good tool
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Old 8th June 2012, 10:24 AM   #147
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and this is the way I plan to use it

seems like I will have to do some cuts for soldering directly to the ground plane, or else it takes too much heat

hmm, solder pads appears to be a bit big for some smaller components like multiturn pots with smaller legs
might have to use bigger pots

or try to build a smaller tool
well, I might take the challenge
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Old 8th June 2012, 10:52 AM   #148
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Quote:
Originally Posted by tinitus View Post
hmm, solder pads appears to be a bit big for some smaller components like multiturn pots with smaller legs
its close, but looks like that will work too
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Old 8th June 2012, 12:14 PM   #149
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Why not just build it on plain matrix board?.
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Old 8th June 2012, 01:38 PM   #150
tinitus is offline tinitus  Europe
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Quote:
Originally Posted by Nigel Goodwin View Post
Why not just build it on plain matrix board?.
I dont have any
only ordinary boards
old pieces, bought long time ago
why waste them

anyway, you dont find it good to have a 'free' ground plane ?

but ofcourse you are right, matrix board would be easier
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