Help with a Canadian De-Mod

[theSeeker]

There is a wire clipped between terminals on the input where the coax is soldered in. I assume this was part of the Canadian mod and needs to be resoldered like the input above it?

Thanks, Jason

012a.jpg (104.32 KB) Viewed 237 times

[Dr.HIWATT]

it looks like the resistor has been cut out.

[theSeeker]

The 1M input resistor is there, behind the coax in the pic. Right below where the coax is soldered
you can see where the wire was clipped and bent down towards the blue coax on the right.
I assume it should look exactly the same as the bright channel on the right, and not be cut?

[mhuss]

To be more precise, it looks like the extra resistor normally soldered there as part of the C.M. has been cut out, and the coax soldered directly to the jack instead. In other words, that piece of resistor lead is not 'factory.'

See the first picture on this page: http://mhuss.com/Hiwatt/ca_mod.html

--mark

[theSeeker]

Mine is exactly as described by mikhailwatt, both w/o the 470k resistor and the opposite wiring on V2.

Re: DR504 Canadian Import Conversion
by mikhailwatt on Mon Aug 25, 2008 4:00 am

A high-res "before de-modding" pic: http://home.comcast.net/~going2spain/hi ... ainmod.jpg

A couple items of note:
- The added 470k resistor at the input jack was omitted from this specimen.
- The V2 cathodes appear to have been wired opposite from the mhuss 2-input schematic - the 1k cathode resistor + 47nF bypass cap is disconnected, and the other 1k is connected to pin 8.

I can't tell from his image, if the wire between terminals is cut.
Here I have pointed at the two terminals that the wire was soldered to. You can see where the wire was clipped on the left terminal, and from below, where it was bent away from the terminal.

012a.jpg (149.47 KB) Viewed 170 times

[mikhailwatt]

Both resistors remain on the input jacks . It's just the 470k in series with the coax that was omitted.

[mhuss]

That was clipped so the bottom jack (in the picture) does not short out the signal when the top jack is being used. If you're revising the amp to the original true two-channel form, that connection should be restored as well.

--mark

[theSeeker]

Thanks all, it is successfully de-modded! Gotta go play.