Sherwood Newcastle AM9080 owners... (1 Viewer)

[StevenK]

maybe i can get some input on this.
I just bought a cheap Sherwood receiver with Digi-Link III to trigger the amp (and it works ). I've hooked up an oscilloscope to the Digi-Link III output and saw a 5.5 Volt step, followed by a 12V spike. So the question now is how do I reproduce that pattern without the receiver, so I can trigger amp? Do you think there is any way to modify the standard 12-V trigger on most other receivers to do this pattern? I've tried to manually approximate this pattern via a crude breadboard circuit, but nothin'...I'm obviously missing something else. Any clues?

 

[Camp]

I can't help in this endeavor but I would like to know if it's possible. I'd love to buy a solution for this "problem".

 

[Gil D]

Steven,
Does it stay at 5.5volts or does the signal consist of single pulse? If it's a pulse, how long does the pulse occur and when the 12v spike occurs does it go from 5V to 12V and drop to zero at the end of the pulse.

 

[Ted Kim]

Another useful bit of info would be how a more typical 12V receiver output trace is on the scope. Then it would be easier to determine how to turn the 12 V signal trace into the Sherwood trace.

 

[Gil D]

Typically an amp trigger is just a DC voltage threshold(ie steady voltage above 5-12V). The Sherwood is apparently different and if there is a spike going twice the voltage when you turn off the receiver it may be driving a relay coil directly. But it sounded like a pulse from Steve's description...

 

[StevenK]

First off, please excuse the lack of proper electric/electronic related terms....i'm an aerospace engineer after all ...and to tell you the truth, I got a C on both my electronics class in undergraduate school There is a high probability I could just be reading the oscilloscope wrong.
anyways, the 5.5 V, looks like a step function--that is, baseline is at ~0.5 V, then "jumps" to 5.5V after pressing "standby" on the Sherwood receiver. This is immediately followed by as 12V "pulse" -- going to 17V, then back to 5.5V. I'd also like to mention that the Digi-Link III connection also does things such as controlling Sherwood transports and synchronizing Sherwood components, so maybe one of the 2 things happening has nothing to do with the amp trigger.
btw, i traced a "regular" 12V trigger and indeed it is just a 12V "pulse".
Thanks for all your input.
I have EE guru coming over tonight to drink beers and fiddle around with this stuff...might not be a good combination.

 

[Philip Hamm]

Ha ha ha!

 

[StevenK]

I'm confused....

are you mocking us poor people who can't afford the matching AVP9080?

or just me...the electronics buffoon?

 

[Philip Hamm]

I have EE guru coming over tonight to drink beers and fiddle around with this stuff...might not be a good combination.

 

[Brian Schucher]

That AVP9080 IS for poor people LOL. It can be had quite cheap and from what i read, its a STEAL!