$200 avc wiring diagram

discussion of magnetic volume control design for both line and speaker levels.

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noviygera
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Joined: Tue Apr 08, 2014 12:14 am

$200 avc wiring diagram

Post by noviygera »

Please help me out with wiring the $200 avc to the 24pos rotary switch. I got this set used and would love to build it.

See my diagram. Is this correct? How does the swtich get wired? What pins are what? Just an example of one cahnnel would greatly help. I read the wiring guide but I am asking about the actual switch in the photo.


From the FAQ guide:
>>Because the foil has a very high magnetic permeability it should not be placed as far as practical from the autoformers, preferably at least 1/2 inch.

Please read this sentence. Does this statement mean that the enclosure should be large?

Recommended large knob (2-3") for the control?

Thanks,
Herman
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dave slagle
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Post by dave slagle »

hey,

the wiring instructions are at the link below

http://www.intactaudio.com/AVC_wiring.html

as for the switch the wiper goes to the output RCA center pin and the taps get soldered in succession to the pins. Turn the knob all the way CCW and use a DVM to find which tap has continuity and solder the ground wire to that pin. Rotate switch 1 click clockwise and locate the tap with conductivity and that gets the -42dB tap. repeat around the wiper taps and then solder the signal in to all of the remaining taps so all of the pins are wired. This will prevent an open circuit situation if the switch is turned past full volume. Be sure to view the switch from the front when rotating it all the way counterclockwise to start otherwise your rotation will be backwards.

Remember that both the signal in and ground connections should be wired to the switch in addition to the RCA connectors. When signal is is routed to the wiper you get full volume and when ground is selected you get mute.

dave
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noviygera
Posts: 5
Joined: Tue Apr 08, 2014 12:14 am

Need a stepped switch

Post by noviygera »

Thanks Dave,

I was getting confused when tracking the switch contacts. Took it apart, no wonder!!! It's missing one wiper!

Can anyone sell a similar, inexpensive but useable switch?

Ebay sellers all from China -- long wait :(

Wiring like this?
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dave slagle
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Post by dave slagle »

yes that wiring diagram looks correct.

I don't have a quick source for that switch.

dave
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noviygera
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Joined: Tue Apr 08, 2014 12:14 am

Re: $200 avc wiring diagram

Post by noviygera »

Is it possible to have a balanced output with this avc? If so, how would I wire it?
merlin el mago
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Re: $200 avc wiring diagram

Post by merlin el mago »

Sure, buying other unit and connecting the cold as the hot signal.

Good lucky.
dave slagle
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Re: $200 avc wiring diagram

Post by dave slagle »

it is not possible to get a balanced output from a single ended circuit but two units per channel can attenuate a balanced to balanced line.


dave
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