Hafler DH200, DH220 restoration questions

I have a idea...

Start a thread in the diy forum and ask how many folks have in their lifetime seen a bad diode, resistor, transistor, cap, trim pot

Then explain how these parts don't go bad unless.....xxxxx....and that they should be good for 70-250ish years. I am curious as to the feedback you get.
Then I am the luckiest guy on earth. I have only had a bad inrush limiter go bad in a half century.
 
When using the quaco kit, the wiring "route" is a must because the way the new boards get wired to the chassis is different and the old wiring wont reach, gets bypassed etc. Plus....the old wiring is very stiff, hard to work with. The wire that comes in the kit is soft and flexible. The stiff wire can lead to side loading the components that it is soldered to. Aaaaand, it is a heavier gauge and in theory, better. I upgraded the chassis wiring more out of necesity from the kit than because i can hear the new wiring.
So the Quaco kit was made by a Hafler employee. He modified the Hafler circuitry. I suspect that made the amp perform actually worse than before. I certainly think that is the case with the Musical Concepts mods that are out for the XL amps. I am not convinced that a big part isn’t psychacoustucs. Just my opinion.
 
Look if you have the pot set to 20ohm resistance then it is irrelevant if it is 1/4 turn or 40 turn. 20ohm is 20ohm. If you are replacing because it makes you happy then great. As far as sound quality? I think it is psycho-acoustics.
Try to find the exact 20ohm spot on a old jumpy 1000ohm 3/4 turn pot. Then do the same with a new smooth 20 turn 1000ohm pot.

Sound quality? Who said anything about sound quality?
 
So the Quaco kit was made by a Hafler employee. He modified the Hafler circuitry. I suspect that made the amp perform actually worse than before. I certainly think that is the case with the Musical Concepts mods that are out for the XL amps. I am not convinced that a big part isn’t psychacoustucs. Just my opinion.

Ed, the guy that makes the quaco kits is 100% transperant with his kit. The specs and waveforms are there for the world to see. As such you don't need to "suspect" anything. Take a look-see for yourself on his eBay listing. If you see anything about it that is a step back from stock, please share. I want to know about it.
 
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