A question for fellow Hafler owners.
I'm modifying my Hafler 9130 amplifier, and have been comparing the schematics between it and the Pro1200. They both appear to be identical except (except for one resistor, R21) and the separate circuit that looks like the power supply to drive the front end.
I'm no expert on circuit design, can anyone suggest the difference between these two circuits, I assume the 9130 version is simply a "better" design and the Pro1200 version simplified to lower costs?
-Bryan
see attached
I'm modifying my Hafler 9130 amplifier, and have been comparing the schematics between it and the Pro1200. They both appear to be identical except (except for one resistor, R21) and the separate circuit that looks like the power supply to drive the front end.
I'm no expert on circuit design, can anyone suggest the difference between these two circuits, I assume the 9130 version is simply a "better" design and the Pro1200 version simplified to lower costs?
-Bryan
see attached
Attachments
The other change is the VAS bias resistor R16(R44). It was raised from 27 ohm to 33 ohm, perhaps to lower heat dissipation in the associated transistor string, to perhaps lower service repairs...have not cranked any numbers on that change...
O.K....just cruising by, looking into another matter and noticed this thread, 14 years later...HTH.
David
O.K....just cruising by, looking into another matter and noticed this thread, 14 years later...HTH.
David