Stormrider

Where was I? Right, back to the workshop and cue the music.

Sorry in advance for my photos. They get the job done, but some of them look pretty bad now. I'd retake them but the amp has long since been returned to it's owner.

Once both channels were running happily with their new parts on the benchtop power supply I turned my limited attention to the chassis. The phenolic insulators sandwiching the RCA jacks in place were starting to crumble so, some shiny new jacks were fitted courtesy of ApexJr.com for 99 cents. The input wiring was done with 22AWG shielded wire.



The pro Hafler models like the P125 and the P230 have a solid aluminum bracket for the ground connections between the main power supply caps. The DH200 and DH220 models only got some tinned wire which isn't very convenient or nice looking. I fashioned up a new bracket with some scrap...

Doctor, Doctor

David Hafler (RIP) must have sold tons of these amps... There are always a wide selection of different models on ebay, but the DH200 and DH220 seem to be the most common. I have three of my own (2 P230's and a P125) that I cycle in and out of use. I've repaired and rebuilt several for other people, and yet I keep running into more of them. The most recent being Brokencrank's DH200, which I have documented below for reference, and to have a place to put my notes. I don't claim any of the info below to be gospel, just my experience. I also don't claim this to be a step by step guide to resuscitate your old Hafler. A basic understanding of electronics and amplifiers will be required. Know what you're doing before you do it, and you will make less mistakes. If you have questions, ask!*

Note: All of the component reference numbers (ie. R3, C14, Q10, etc...) I mention will be based on the schematics available in the manuals at Hafler.com. Because...