Zobel network on Vox AC-10?

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EtherealWidow
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Zobel network on Vox AC-10?

Post by EtherealWidow »

So I'm planning on building some sort of AC-10 based amp. In looking at the schematic, I can't seem to understand why they would put the two 100R resistors on the '84 plates. The most logical thing I can imagine them accomplishing by this is a zobel network. Am I correct?

http://www.voxamps.com/downloads/circuits/ac10_2.jpg
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LeftyStrat
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Re: Zobel network on Vox AC-10?

Post by LeftyStrat »

It's never too late to have a happy childhood.
EtherealWidow
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Re: Zobel network on Vox AC-10?

Post by EtherealWidow »

Thanks for the reply man. Yeah, it seemed weird. At first glance I thought it was on the screens just like Structo did in that previous thread. I was just worried about reducing wattage. The plate resistors in addition to the sag resistor with the tube recto blew my mind. SO INEFFICIENT! I'm making this from an old Gulbransen organ that I put a thread up a couple months back on. I guess I'll see what I'm working with x former wise, but I have some changes to the design already in mind. Sometimes quirky is just too quirky.
Gaz
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Re: Zobel network on Vox AC-10?

Post by Gaz »

They are just plate stoppers. There presumably to prevent oscillations. Yeah, you can just move them to the screens instead ;)
EtherealWidow
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Re: Zobel network on Vox AC-10?

Post by EtherealWidow »

I was gonna put some on the screens for sure, I was just wondering if it was a high pass zobel to give it some extra chime or something. Seemed really weird. :lol:
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LeftyStrat
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Re: Zobel network on Vox AC-10?

Post by LeftyStrat »

I'm interest in what you end up with. One of our members here posted a link to a youtube video of him playing an AC10 Twin, and it sounds awesome. Lot's of chime and swirl.

I've been meaning to try to clone one.
It's never too late to have a happy childhood.
EtherealWidow
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Joined: Sun Jun 10, 2012 8:47 pm

Re: Zobel network on Vox AC-10?

Post by EtherealWidow »

I'm interested to see how it will sound as well! It's really going to be more AC-10 inspired than a clone. Far too many changes made.

-Doing away with tremolo channels.
-Doing away with ECF82 and replacing with 12AX7
-Gonna have to change the Ra and Rk on that first stage.
-DC CF with the unused triode after first stage.
-SS recto.
-Bigger sag resistor?
-Bypassing first filter cap.
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