Hafler DH-220 AMP. Is it a kit?

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I just came across a Hafler DH-220 amplifier in a box that had never been opened. Yep, it's a brand new 30 year old amp. Anyway I know the DH-220 came both either assembled in the factory or as a kit to be assembled by the user.

This amp has all the electrical components soldered to the circuit board, however, all of the input, output, transformer and power wires and connectors are in plastic bags inside the amp. The box that it came in has "assembled" printed on the outside.

Does anyone know if this is a Hafler DH-220 Kit, or is this the way Hafler shipped all their amplifiers?

Thx,
Hal
 
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I just came across a Hafler DH-220 amplifier in a box that had never been opened. Yep, it's a brand new 30 year old amp. Anyway I know the DH-220 came both either assembled in the factory or as a kit to be assembled by the user.

This amp has all the electrical components soldered to the circuit board, however, all of the input, output, transformer and power wires and connectors are in plastic bags inside the amp. The box that it came in has "assembled" printed on the outside.

Does anyone know if this is a Hafler DH-220 Kit, or is this the way Hafler shipped all their amplifiers?

Thx,
Hal

Yes, this was Hafler's approach for Dynakit as well as Hafler, except for the Dyna FM-1 and FM-3 tuners.
 
"If they're carefully reformed, they may very well work out ok. "

Doubtful.

Try it with the 10,000 at 75V (after cooking them at 85°C for one hour), but just buy new ones for all the smaller caps (they're inexpensive).

Add 22µF at 100V to the main filter caps if they go 'squeeg' when the amp turns off.
 
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Is this worthless?

Even though I know more about electronics than the average consumer, I am not an electronic tech so I don't know how to test the electrolytic caps. ( I only know how to charge one and watch it discharge.)

Replacement caps at Mauser cost about $50 each so it seems to me that this amp at best could be sold for parts or at worse used as a boat anchor.

What is your opinion?
 
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Replacement caps at Mauser cost about $50 each so it seems to me that this amp at best could be sold for parts or at worse used as a boat anchor.

Give the old ones a try by reforming. Use a power supply set at the capacitor's rated voltage,
through a power resistor of a value that limits the current to 10 mA into a short, and of enough
power to absorb that short. Be careful around the caps until they seem ok.

If it's a 75V capacitor, use a 10k, 1W resistor. Charge the cap until the current is under 1 mA
(until the voltage drop across the resistor is less than 10V). Reforming may take an hour or two.
Once they seem ok, leave them burning in for several more hours.
 
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