Hafler DH-200/220 Mods

[jxdking]

Could anyone confirm whether the RCA jacks are insulated from the chassis on DH-200/220.

 

[ticknpop]

I think I have one open at work tomorrow. I’ll let you know

 

[ticknpop]

The 3 in the shop have new gold RCAs, They are insulated, but I didn’t build them and don’t see the connection.
The manual for the DH 200 and 220 shows the original jack grounded to the chassis.

 

[jxdking]

I compare the manual of dh200 with dh220’s. The input ground arrangement is quite different. In dh220, input grounds are shorted to chassis with a wire. Thus, the socket should be insulated one? Maybe it doesn’t matter.
In dh200, the input grounds seem to be terminated only at the amp boards. I guess only insulated ones should be used.

 

[Bob Cordell]

I think the general rule is that the internal circuits should be connected to chassis ground only at a single point. This would mean that the RCA input connectors should be insulated.

Cheers,

Bob

 

[rsavas]

On the dh-200, they use a 4.7-ohm resistor to connect one of the RCA jacks isolated shield to chassis, so that’s your single point connection.