I ran across a huge Hafler 500 (watt) amplifier at the thrift.

Guys wants $50.00 for it. Just looking at it, I doubt it works. Weighs about 50 lbs. No rack handles, no serious cosmetic issues either. Possibly has been sitting in someone's garage for a couple of years. At very least it needs professional attention by someone like EW. I don't have a thing to hook it up to, so the best I can do would be to sell it for parts.

Question: Is it worth it? Someone out there want me to score it for you?

I ran across a huge Hafler 500 (watt) amplifier at the thrift.

Guys wants $50.00 for it. Just looking at it, I doubt it works. Weighs about 50 lbs. No rack handles, no serious cosmetic issues either. Possibly has been sitting in someone's garage for a couple of years. At very least it needs professional attention by someone like EW. I don't have a thing to hook it up to, so the best I can do would be to sell it for parts.

Question: Is it worth it? Someone out there want me to score it for you?

I'll take it... PM sent

...

I realize this thing is valuable, it's just that the condition is so iffy (and it is so heavy) that I can't justify flipping it on ebay. (which I would in a heartbeat if I thought it was in good working condition and I had some gear to run it with..)

A mint one goes for about $400-$500. Perhaps worth $150 as a parts unit.

Long story short, I'm not qualified or inclined to work on this unit, but I know there is somebody out there (in AK land) who can bring it back to life and give it the attention it needs to be whole again.

There are some mighty nice folks on this forum who have done me favors in the past, and I feel that part of our AK Karma is looking out for each other.

Homer, FYI the front cover plate was off this unit when I found it (it's there, just not connected). No sign of the screws or the rack handles. It looks intact and clean internally, but no gurantee that it will light up. Like I said, this is a project, the first stop will be the work bench.

For $50, I'll be happy to make a project out of it... Thanks for the Karma.

An easy Amp to work on, With serious power when brought to factory specs. I used one for a year, Before getting it's big brother, The even more crazy XL600. Also easily modded. Hafler always underrated there amps, According to the guys at Musical Concepts. Re-doing just the front end of this amp, Is a huge improvment. Also adding binding posts, Better RCA's, And a cord are a must!. As a long time Hafler user, Fix it, And use it. Then get some HPM 100's, (A great match, BTW), And piss of the neighbors! Here's a look at mods done on a XL600 (Same chassis as a DH500).

Sweet!!!

An easy Amp to work on, With serious power when brought to factory specs. I used one for a year, Before getting it's big brother, The even more crazy XL600. Also easily modded. Hafler always underrated there amps, According to the guys at Musical Concepts. Re-doing just the front end of this amp, Is a huge improvment. Also adding binding posts, Better RCA's, And a cord are a must!. As a long time Hafler user, Fix it, And use it. Then get some HPM 100's, (A great match, BTW), And piss of the neighbors! Here's a look at mods done on a XL600 (Same chassis as a DH500).

...but that's the full blown Musical Concepts mod set, isn't it? The toroidals, the 4 caps instead of 2 and the front end boards....Over a Grand worth of upgrades IIRC....

So, the question becomes, how would you compare it's sound against other amps, mid-fi and hi-fi?....:scratch2:

Always wanted one of those.

...I've got one coming too....:thmbsp:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=150200962809&ssPageName=STRK:MEWN:IT&ih=005

I'm out, it was gone today.:tears:

...but that's the full blown Musical Concepts mod set, isn't it? The toroidals, the 4 caps instead of 2 and the front end boards....Over a Grand worth of upgrades IIRC....

So, the question becomes, how would you compare it's sound against other amps, mid-fi and hi-fi?....:scratch2:

Well over a grand, I actually got the Amp from CL, Was being sold "As is". When I powered it up, There was a very loud hum in the amp. Stored it for awhile, Then started shopping for a modern up to date amp. With a budget of $1500, Choices were limited. I wanted power output in the range of 250-300wpc. I was making due with a Hafler DH220 115wpc, And a PRO2400 120wpc. The DH500 had been sold. I checked some repair shops around, Thinking just bring the XL600 back to specs. A Bryson dealer told me about Musical Concepts, And gave them a call. With my budget I got there platinum upgrade, And pretty much rebuilt the whole thing. Never have compared it with another amp, Other than a Carver TFM55 (380wpc I think) with my speakers, But MC says it compares favorably with a Bryson SST4, Conrad Johnson PREMIER-350 (350wpc). Those Amps were over $2800, So for a $1400 investment, It worked out ok. In the last year it has performed well, After much abuse, The fan has been changed, But thats it. Heres some spec sheet info that comes back with the amp;

Measurements were made at 120V AC line voltage with both channels driven.
This amplifier does not invert polarity.
AC line current draw
Plugged in: 0.02A
At idle: 1.65A
Input impedance @ 1kHz: 80k ohms.
Output impedance at 50Hz: 0.12 ohms.
Gain (8-ohm load): 54.8X, 34.8dB.
Output noise, 8-ohm load, 1k-ohm input termination, Lch/Rch:
Wideband: 0.295mV, -79.6dBW / 0.465mV, -75.7dBW
A weighted: 0.112mV, -88.0dBW / 0.177mV, -84.0dBW
Distortion < 0.007% from 20Hz to 20kHz at 120 watts, IM or THD
Slew Rate >60 volts per microsecond
Greater than 120 volts per microsecond, bridged
Power
Bandwidth <1 Hz to over 100 kHz
Damping Factor Over 500 at 20 Hz, ref. 8 ohms
Input Sensitivity
1 Volt in = 100 Watts at 8 ohms
1.5 Volts in = 250 watts into 8 ohms
2.8 Volts in = 800W into 8 Ohms Bridged

AC Power Consumption & Heat Load
1. Idle Current 186W
2. Stereo 8 Ohms (250W ea.) 1200W
3. Stereo 4 Ohms (400W ea.) 1920W
4. Bridged 8 Ohms (800W) 1944W
5. Max. Wattage 1944W
6. Max. Heat Dissipation 1144W / 3904 Btu/Hr

Power output with 1kHz test signal

8-ohm load at 1% THD: 400W
8-ohm load at 10% THD: 500W
4-ohm load at 1% THD: 640W
4-ohm load at 10% THD: 800W

As you can see, They do a lot of Post mod tests, So you get what you pay for.

...I've got one coming too....:thmbsp:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=150200962809&ssPageName=STRK:MEWN:IT&ih=005

Great bidding! Let us know what you think.

Sorry man, I know you wanted it bad...

I should have bought it yesterday, given the size of that transformer, even if it was completely trashed, it would still have made an excellent doorstop or boat anchor.

On a positive note, the guy at the thrift said that he still hasn't unpacked all the stuff from the guy who donated the Haffler... he's going to get into it tomorrow, so I'll call him back to see if there are any more gems.

...Sorry to hear that yours got away. I would have been tempted to take it off your hands when you got it fixed. Oh well. As for Musical Concepts, I have a DH-220 with one of the early board upgrades, and I'm thinking about trying to score another to match the set....:D

Homer you ever listen to that 2nd DH-200 I picked up for you?:music:

I'm not sure, but I think the guy who bought it may be an ebay flipper. Keep an eye out for it.

General advise, if it looks decent and sells for chump change don't think too hard just buy it. I never saw the need for the Mods. Stock the thing has a huge power transformer and very big cappies. I own one and love it, gets the best out of my AR 10 Pi speakers. I have removed the relay for better sound but the speakers are fused.

General advise, if it looks decent and sells for chump change don't think too hard just buy it. I never saw the need for the Mods. Stock the thing has a huge power transformer and very big cappies. I own one and love it, gets the best out of my AR 10 Pi speakers. I have removed the relay for better sound but the speakers are fused.

This is true but I can confirm that there is significantly more performance you can wring out of the Hafler gear. I'm on my 4th generation of Musical Concepts driver boards and John Hillig seems to find ways to get them just a bit better than before. The original boards improved things greatly but the last set of boards I just installed this November into a DH/P500 appear to be the best yet.

Understand, though, that the boards themselves aren't the only thing that's done. Installation of the driver boards has you reworking the grounding scheme and adding some other components to make sure the amp remains stable at all loads - I'm driving a set of Quad ESL63s with the only I redid but are fused at 100wpc.

These same boards also work in a DH200/220 series amp with the same results - just less output power.

Cheers,

David

Sorry man, I know you wanted it bad...

I should have bought it yesterday, given the size of that transformer, even if it was completely trashed, it would still have made an excellent doorstop or boat anchor.

On a positive note, the guy at the thrift said that he still hasn't unpacked all the stuff from the guy who donated the Haffler... he's going to get into it tomorrow, so I'll call him back to see if there are any more gems.

Please let me know what you find...

How hard is the power cord upgrade? I picked up a XL-280 at a local yard sale, nice amp, it does run a tad hot.

What's a Hafler D-500 go for usually? I've got one I should either rebuild or sell. The front-end kit for $329 (http://www.musicaldesign.com/mc_amp_mods.htm ) looks kinda interesting -- but I don't have much need for all the muscle... so maybe someone else oughta have the fun.

The amp arrived today in good shape, and powers up and I hear the protection relay click. However, DC offset in the Left channel is ~100 mV, and ~500mV on the Right. Suggestions on where to start?....:sigh:

What's a Hafler D-500 go for usually? I've got one I should either rebuild or sell. The front-end kit for $329 (http://www.musicaldesign.com/mc_amp_mods.htm ) looks kinda interesting -- but I don't have much need for all the muscle... so maybe someone else oughta have the fun.

Those are the ones I mentioned earlier in the thread.

IIRC, D500s tend to go for $400 or so on the auction site. XL600s tend to run around $500 or so depending on cosmetics. You can find them in thrashed condition for less, of course. I picked up my P500 for about $200 on the local craigslist. The big issue is the shipping cost and packaging on these due to weight.

For Analog Addict, that offset should be adjusted out on the driver boards. Note that there are some caps and resistors that tend to go on the original boards and should be swapped. Do a search across AK to find more discussions on them. Also, hit DIYAudio.com as there have been extensive discussions on this same problem there.

Cheers,

David

I did risk my mini-me 77's on this, and it seems to put out reasonable sound, even as is. I'll do the search and see what comes up...:thmbsp:

And the one I got cost the fellow $35 in shipping USPS priority from TN to NC...:scratch2:

Grab it!

These amps are generally bomb-proof in my experience. I have two of them that have served me well.

Most "common" (pardon the pun) problem with them when they fail in my encounters has been an open input ground return resistor. Cheap enough to fix.