Hafler DH-200...expierences, mods, repairs?

[Robie]

Congrats on your choice. Nice amp.

My wife found one for me at a garage sale about 10 years ago. $75 for the DH-200 and HK Citation 17 (pre) and they threw in some ratty 3-way homebuilt speakers I now use in my garage. I really liked the amp.

Unfortunately, after using it for a block party (not even driven hard) I hooked it back up to its "normal" system and it made a really bad noise and blew out some Infinity drivers at turn on.

Took it to a recommended "pro sound" facility that advertised Hafler repair and was quoted $450 for a repair. As I recall, it was the output transistors that were no longer available.

I passed on the repair and had them keep the unit in lieu of the diagnosis fee. I didn't feel too bad about my decision until about 6-8 months later when I discovered it was in the Stereophile top 100 products over the last 50 years of audio. I called the dealer but it was long gone. Not so sure about my decision now.

 

[sfox52]

I seem to recall that output transistors are available from the UK maker Exicon-There's a crossover chart for the Hitachi # to the matching one. All pairs would need to be replaced. I used some of those for an old B&K ST140 a few years back. I wish someone made boards for those!

 

[vinyldavid]

I discovered it was in the Stereophile top 100 products over the last 50 years of audio. I called the dealer but it was long gone. Not so sure about my decision now.

I just realized....

My system will have2 of the products mentioned on that list when the amp comes. I am also using the New Large Advents as my main speakers....

 

[HomerJSimpson]

I have two of these, love them:thmbsp:

I repaired one, got the replacement outputs off EBAY, work great.

I hope to mod them to MONO someday...

 

[himm37]

All the manuals are still maintained on line here:

http://www.hafler.com/home/

As far as bridging goes, it's all standard parts, and a switch so it can be used either way.

 

[HomerJSimpson]

All the manuals are still maintained on line here:

http://www.hafler.com/home/

As far as bridging goes, it's all standard parts, and a switch so it can be used either way.

Have you done this before?

If so, let me know I could use your help....:yes:

 

[philcib]

.anyone know how to troubleshoot these if it does not work upon arrival?

There's no turning back for you now. With all the stuff you have, you should
be looking for an oscilloscope, and should own a good multimeter at the very least. An oscillator with at least sine and square wave output will be needed as well. There's no sense in owning old stuff if you can't keep it working.
Good luck. Repairing stuff can be a lot of fun too.

 

[Blue Shadow]

Repairing stuff can be a lot of fun too.

The joy of a repaired unit is a lot of fun.

I haven't found that the repairing units is a lot of fun until the problem is identified and parts are acquired. Hunting for the problem is not as much fun, but I need to learn more about this important step.

 

[vinyldavid]

There's no turning back for you now. With all the stuff you have, you should
be looking for an oscilloscope, and should own a good multimeter at the very least. An oscillator with at least sine and square wave output will be needed as well. There's no sense in owning old stuff if you can't keep it working.
Good luck. Repairing stuff can be a lot of fun too.

An o'scope is high on my list....first one I see, I'll pick up if it's a reasonable price.

I have a nice Craftsman DMM from an AK'er.

 

[vinyldavid]

Finally getting this...sometime soon...before the end of the month, I hope.

According to the modder, "It's been modified with Audioquest internal interconnect, better caps (replaced and bypassed) and gold plated binding posts.."

So this should be interesting. it was built in 1980, and worked in 2002...and did not sound too bad, driving Audio Physic Avanti III's.

What should I expect to have to do right out of the box?

BTW, I have an oscope now....

 

[whoaru99]

Hopefully nothing.

How long has it been since it was last powered up?

One thing is for sure, don't connect any speakers until you've verified no excessive DC offset.

 

[vinyldavid]

Hopefully nothing.

How long has it been since it was last powered up?

One thing is for sure, don't connect any speakers until you've verified no excessive DC offset.

It's been powered up and doesn't smoke...it was last hooked up (as far as I know), in 2002...to compare to the Sound Devices 2X150VT for a review in Stereophile....(this amp has a bit of a history ), and it worked fine and sounded good then.

I'll put my DMM on it when I get it and see if the numbers are good...if they do, I'll throw it on my junk test speakers, and if it doesn't kill those, my Advents.

 

[whoaru99]

I don't know what the "rules" are, but 6 or 7 years is a fairly long time. I wouldn't be surprised to see recommendations to slowly bring up the line voltage with a variac.

 

[vinyldavid]

I don't know what the "rules" are, but 6 or 7 years is a fairly long time. I wouldn't be surprised to see recommendations to slowly bring up the line voltage with a variac.

Don't have a variac....and it's been plugged in and turned on within the past month. Nothing connected, though. IDK why...

 

[Spalls]

I hope that you enjoy this amp for a long time, David. I built mine in 1980 and it is still going strong. It even survived the bachelor party days from my late 20s

 

[vinyldavid]

I hope that you enjoy this amp for a long time, David. I built mine in 1980 and it is still going strong. It even survived the bachelor party days from my late 20s

I don't intend on selling it for a long while....or ever, for that matter....it's a gift from a good friend of mine...

 

[budgetaudio6]

you will like it when it comes around.

i found one a while back. it has a fairly smooth sound to it. and i did have it connected to one pair of RSa speaks. but i had to change out amps looking for better synergy in components. found it sounding better, over all, with te dh 200 connected to 16 ohm speakers. which are more sensitive than the RSa, but lack any real bass extension. but have excellent midrange. which the hafler compliments.

did the switcheroo from using te hafler with rsa, to using the amp section on my pioneer 1500td to power my RSa. then with a m 70 power amp on te other pair of RSa.

sorry for the ramble. im quite tired now. long day at work.