Hafler DH-220

skrol · April 2011

I have the opportunity to pick up a Hafler DH-220 locally. The seller is not the original owner but believes that it was factory assembled and not a kit. From what I read on-line this seems to be a very capable amp with a warm sound. I would plan to run this off my Denon DRA-835R pre-outs to drive my RTA-11TLs (possibly some LSi 7 or 9 in the future).

Is there anything I should be concerned about with this amp? Things to look for?

The seller is selling it for a friend and does not have it hooked up presently but invited me to bring speakers and a source to audition. Kind of a pain. From the photos, it looks like it was gently cared for.

Thanks
Stan

jinjuku · April 2011

The Hafler DH-220 is a stalwart. Hands down a great amp.

What is the price?

You will want a music source (phone with earphone out) and proper 1/8" stereo to RCA adapter and stereo RCA cable. A Speaker and a multi meter.

You will put the Multimeter to the DC setting (like a 20volt selection) and fire up the amp. Put the MM leads on the Speaker binding posts and see what the DC offset is.

If that is fine time to put a speaker on it and play something from the phone. The only way you will know if the amp is still within it's published spec's is to get it on a scope.

Keep in mind Hafler is out of business.

skrol · April 2011

I was just going to ask about checking the DC offset. I have a nice Fluke 178, a Sansa Fuze, cable and a small pair of Athena speakers that I'll take along.

The price is under $200 and he says make an offer.

It looks like there is good community support for refurbishing these amps if it needs. Apparently the MOSFETS are harder to find now.

jinjuku · April 2011

skrol wrote: »

I was just going to ask about checking the DC offset. I have a nice Fluke 178, a Sansa Fuze, cable and a small pair of Athena speakers that I'll take along.

The price is under $200 and he says make an offer.

It looks like there is good community support for refurbishing these amps if it needs. Apparently the MOSFETS are harder to find now.

I absolutely liked Hafler in the day but I have a personal preference to not purchase product of defunct companies. It is getting harder to source spares.

You could get that amp for $150-170 easy.

Get a 1Khz .mp3 on the Sansa and if the meter can read AC voltage to the ten's you can see what the output is on the speaker terminals and see if each channel is at the same voltage. If you can't get the voltage to 2.83 with both channels driven the same gain then there is a problem.

Fongolio · April 2011

I owned one a couple of years ago. I found it at a garage sale and "stole" it for $50. Worked great. Very warm sound and built like a tank. If memory serves me correct, something like 115 very conservatively rated watts per channel @ 8 ohms. Other than what is mentioned above the only thing I'd be thinking about is maybe doing a re-cap in the not to distant future. That amp will be getting on in age. There are still part galore on ebay and I think there is even a hafler owners group.

skrol · April 2011

How would the DH-220 compare to an Adcom GFA-545?

FTGV · April 2011

Fongolio wrote: »

...the only thing I'd be thinking about is maybe doing a re-cap in the not to distant future. That amp will be getting on in age.

Good point and while your at it I'd replace the bridge rectifier and IIRC there is an electrolytic cap in the feedback loop that you might want to replace as well.

jinjuku · April 2011

skrol wrote: »

How would the DH-220 compare to an Adcom GFA-545?

I personally liked the DH-220 over the 555.

skrol · April 2011

I checked out the DH-220. It looks like brand new. I did the DC offset check. One channel was 2.3mV, the other was 30mV

which is high but may be easily adjusted. I played music through the first channel and it sounded very decent. The other side had a hum and no music:frown:.

It might be a nice project but I am not into it at this time so I passed.

The guy also has a Acurus 100X3 that he is selling. I gave it a try and it seems in perfect working condition. I am thinking about this one now.
Stan

jinjuku · April 2011

skrol wrote: »

I checked out the DH-220. It looks like brand new. I did the DC offset check. One channel was 2.3mV, the other was 30mV which is high but may be easily adjusted. I played music through the first channel and it sounded very decent. The other side had a hum and no music:frown:.

It might be a nice project but I am not into it at this time so I passed.

The guy also has a Acurus 100X3 that he is selling. I gave it a try and it seems in perfect working condition. I am thinking about this one now.
Stan

30mV is a problem. How much is he asking for the Acurus?

FTGV · April 2011

jinjuku wrote: »

30mV is a problem.

Not necessarily in an otherwise working amp it depends on the the design.Some amplifiers can have offset's in the 50- 100mv range(ie older Bryston,certain Pass models and Gainclones).However the disparity in relation to the other channel with only 2.3mv and the lack of output and hum obviously indicate a fault.

skrol · April 2011

They are asking $285. Apparently, there is an A100X3 and 100X3. Anyone know anything about the Acurus 100X3?

Just found the specs on the Klipsch site. Apparently the A100X3 has better low impedance drive capability (150W into 3 channels @ 4 ohms) vs the 100X3 (125 into 3 channels @ 4 ohms).

Fongolio · April 2011

$285 is even kind of high for a pristine fully working DH-220 in my opinion. One side not working should be at least half that price. The output transistors are the hard part to find on that amp so if one or more are gone it could get pricey.

jinjuku · April 2011

Fongolio wrote: »

$285 is even kind of high for a pristine fully working DH-220 in my opinion. One side not working should be at least half that price. The output transistors are the hard part to find on that amp so if one or more are gone it could get pricey.

I think the $285 is for the Acurus.

jinjuku · April 2011

FTGV wrote: »

Not necessarily in an otherwise working amp it depends on the the design.Some amplifiers can have offset's in the 50- 100mv range(ie older Bryston,certain Pass models and Gainclones).However the disparity in relation to the other channel with only 2.3mv and the lack of output and hum obviously indicate a fault.

I wasn't saying 30mV is a problem on any amp. It is a problem on the Hafler.

FTGV · April 2011

jinjuku wrote: »

I wasn't saying 30mV is a problem on any amp. It is a problem on the Hafler.

OK ,it wasn't clear if your statement was in general or specific.

The DH220 does have an adjustment to null offset but the 30 mv is likely another symptom of the issue in that channel.

skrol · April 2011

The 30mV offset on the Hafler could probably be adjusted out. The bigger problem is that one channel does not work. It just hums.

Any opinions on the Acurus 100X3?

megasat16 · April 2011

Look for Acurus A200x3 which is 200w@8 ohms and 275-300W@4 ohms, I think.

It's a much better amp than A100x3 and they pop up for about 400. You got a lot more power for not a lot more coins.

skrol · April 2011

This one isn't even the A100x3. It is less capable driving 4 ohm.

megasat16 · April 2011

I wasn't aware of the regular 100x3 version. I think they are all A version. But if it's less than capable to the A100x3, I wouldn't bother for it.

skrol · April 2011

A100X3 = 3 channels driven 100W @ 8 ohms, 150W @ 4 ohms
100X3 = 3 channels driven 100W @ 8 ohms, 125W @ 4 ohms

Hafler DH-220

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