How to..

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karmakim
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Joined: Sat Jan 26, 2008 9:59 am

How to..

Post by karmakim »

How do I connect one triode stage to create a Non Inverting Recovery Stage??
Andy Le Blanc
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Re: How to..

Post by Andy Le Blanc »

What for?

there is the cathode follower, as a buffer, but the gain is not there.

There is also the grounded grid, Im sketchy on gain or whether it inverts,
Ive played with a GG as a reverb recovery but followed it up with an extra
gain stage as per an old magna/esty amp schematic, and was not worried
about signal inversion.
lazymaryamps
Wayne
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Re: How to..

Post by Wayne »

Grounded grid is an inverting amp, and it takes a helluva lot of power to drive one due to low input impedance.

W
Alexo
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Re: How to..

Post by Alexo »

karmakim wrote:How do I connect one triode stage to create a Non Inverting Recovery Stage??
Pretty sure it's impossible. If you're really desperate, you can use a transformer to flip the phase, but I would rather use a series connected low-mu twin triode, like a 12AU7 or something, but I assume you need to keep this to half a tube.
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collinsamps
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Re: How to..

Post by collinsamps »

Enquiring minds want to know :roll:

What are you building that phase inversion is an issue?
karmakim
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Re: How to..

Post by karmakim »

Im using negative feedback to EQ and want to put an extrastage next to it..
Last edited by karmakim on Thu Mar 26, 2009 10:02 am, edited 1 time in total.
karmakim
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Joined: Sat Jan 26, 2008 9:59 am

Re: How to..

Post by karmakim »

Im using negative feedback to EQ and want to put an extrastage next to it..
Last edited by karmakim on Thu Mar 26, 2009 10:03 am, edited 1 time in total.
karmakim
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Re: How to..

Post by karmakim »

..schema..
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Last edited by karmakim on Thu Mar 26, 2009 10:06 am, edited 1 time in total.
karmakim
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Re: How to..

Post by karmakim »

..and sorry about my bad english
ampdoc1
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Re: How to..

Post by ampdoc1 »

I could be wrong, but can't you invert the phase by "flipping" the OT secondary windings?

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VacuumVoodoo
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Re: How to..

Post by VacuumVoodoo »

ampdoc1 wrote:I could be wrong, but can't you invert the phase by "flipping" the OT secondary windings?

ampdoc1
Just as well as flipping OT primary.
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karmakim
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Re: How to..

Post by karmakim »

..Maybe Ill just do it like this and forget the extras :)
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Structo
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Re: How to..

Post by Structo »

Do you have this amp built?

I was wondering because the cathode bias resistor for the EL84's seems kind of low value?
Tom

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collinsamps
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Re: How to..

Post by collinsamps »

Can't stop scratching my head at this. What got you started down this path? Obviously only one phase for feedback will work (continue to be negative) regardless of where you switch(secondary or primary OT). Just curious what your goal with this circuit is. Has this been used somewhere before and I'm just now seeing it for the first time? Edu-ma-cate me.
karmakim
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Re: How to..

Post by karmakim »

yes. I have SE-version prototype ..and working but with no extra gain stage.

The cathode bias resistor is straight from the datasheet..

The feedback circuit is to manipulate the frequency response and amplitude of negative feedback. (More gain - more feedback at mud frequencys)

..I dont know if there is this kind of guitar amp circuits somewere.. This is more common circuit in recording channels.
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