Many years ago I bought a XL280 $100 as-is from a major audio store. Had a dead channel, brought it back to the store with the 'as-is' receipt asking their repair department to repair it and I'll pay for the said repair, since it was an as-is sale. The repair tech took the old one and brought me a new boxed 280, "Here you go" Thant unit ran many, many bridged hours pushing Klipsch W-bin. Thanks for the trip down memory lane.
To avoid damaging your Ampmeter, you could replace the fuse with an 1 ohm resistor and measure the voltage drop which should be 275mV for the expected 275mA.
Trevor.. really enjoyed your presentation on this amp. Great methodology. Would love to see a video describing setup of oscilloscope and signal gen for the final tests. I am ready to put a scope on my bench. Thank you.
Great video by the way, have one of these on the bench in front of me. DC on the right output, so far output transistors all okay so must be a biasing issue. I think I will put some sleeving on the cutouts to save the next person in here getting a shock. Quite scary to think these were built up as kits with exposed mains. I wonder how many people gave themselves a shock when setting up at the end of construction!! Also in Europe there are tag strips on either side of the transformer for the voltage taps which also have mains on them and are also bare. Good idea from Golkun about the resistor, I will use that when adjusting the bias later
The Hafler 220 Kit came with the 2 main left and right circuit boards pre-assembled and tested. The power supply and all other connections had to be assembled according to the kit instructions.
I fixed one of these awhile back. Someone had modded it heavily and it was unstable and heated the room. I put it back stock style, and it was fine from there forward.
Hi Trevor, just so you know for future reference if you work on one of these. The thermal switches on the heatsinks carry mains voltage on un insulated terminals
Yes, I saw that, not sure if I mentioned it in the video. Huge safety issue if you ignore where the mains wiring goes and don't take steps to protect yourself.
I build one myself ( kit).........and sold it years later. never a problem , just i didn't like the sound so much , a little to kind and laks expression.....but every one has his own taste. Maybe with more lively speakers like some JBl or Klipsch.......and maybe i should have kept it.....
I bought it in Paris.....less than 500 euro's.....At that time must have been something equivalent to + 500$ US ! I played it with an APT Hollman preamplifier... Have a nice day ; i like your approach of restoring these old beauties.@@TrevorsBench
Please, I would like to ask a question: would it be worth repairing a Hafler DH200 and pairing it with an AMC CTV 1030 preamplifier with a pair of Dynaudio 52 speakers and an Arcam cd73 CD player? thank you
I have a Hafler DH200 amplifier and a while back the sound from the left channel started to go down until I had no sound output from that channel. The preamp and speakers are in good working order does anyone have any ideas as to what the problem might be? Thank you
Hi Rob. It would need to go on a bench to find out where the signal is being stopped. Could be one of a long list of things like bad connections, open capacitor, failed transistor, cracked solder joints so it would be impossible to diagnose here in CZcams comments section.
Many years ago I bought a XL280 $100 as-is from a major audio store. Had a dead channel, brought it back to the store with the 'as-is' receipt asking their repair department to repair it and I'll pay for the said repair, since it was an as-is sale. The repair tech took the old one and brought me a new boxed 280, "Here you go"
Thant unit ran many, many bridged hours pushing Klipsch W-bin.
Thanks for the trip down memory lane.
To avoid damaging your Ampmeter, you could replace the fuse with an 1 ohm resistor and measure the voltage drop which should be 275mV for the expected 275mA.
Great tip, thanks for sharing that
Great work & troubleshooting on this powerhouse, been many years since I've seen one of these in action.
Thanks
Trevor.. really enjoyed your presentation on this amp. Great methodology. Would love to see a video describing setup of oscilloscope and signal gen for the final tests. I am ready to put a scope on my bench. Thank you.
i got this from work for free and im in love with this amp. its what got me into hi fi
it's that good ?
Great video by the way, have one of these on the bench in front of me. DC on the right output, so far output transistors all okay so must be a biasing issue. I think I will put some sleeving on the cutouts to save the next person in here getting a shock. Quite scary to think these were built up as kits with exposed mains. I wonder how many people gave themselves a shock when setting up at the end of construction!! Also in Europe there are tag strips on either side of the transformer for the voltage taps which also have mains on them and are also bare. Good idea from Golkun about the resistor, I will use that when adjusting the bias later
Yep, lol, them transistor packages can bite. I had one on a t.v. let me know it REALLY didn't like to be touched.
The Hafler 220 Kit came with the 2 main left and right circuit boards pre-assembled and tested. The power supply and all other connections had to be assembled according to the kit instructions.
I fixed one of these awhile back. Someone had modded it heavily and it was unstable and heated the room. I put it back stock style, and it was fine from there forward.
I suspect a lot of people don't know or want to do the idle current adjustments because it involves an ammeter and takes a few moments of their time.
Hi Trevor, just so you know for future reference if you work on one of these. The thermal switches on the heatsinks carry mains voltage on un insulated terminals
Yes, I saw that, not sure if I mentioned it in the video. Huge safety issue if you ignore where the mains wiring goes and don't take steps to protect yourself.
All of the boards were factory assembled all you had to do was put the chassis together and wire it. Ive fixed several of these .
I build one myself ( kit).........and sold it years later. never a problem , just i didn't like the sound so much , a little to kind and laks expression.....but every one has his own taste. Maybe with more lively speakers like some JBl or Klipsch.......and maybe i should have kept it.....
Nice! May I ask? What did the kit cost you, I'm really curious.
I bought it in Paris.....less than 500 euro's.....At that time must have been something equivalent to + 500$ US ! I played it with an APT Hollman preamplifier...
Have a nice day ; i like your approach of restoring these old beauties.@@TrevorsBench
great video. 👍
Thanks for watching. Stay tuned, more to come
Great video
Thank you!
Please, I would like to ask a question: would it be worth repairing a Hafler DH200 and pairing it with an AMC CTV 1030 preamplifier with a pair of Dynaudio 52 speakers and an Arcam cd73 CD player? thank you
It's normal for those to run borderline hot at idle even when properly adjusted.
I have a Hafler DH200 amplifier and a while back the sound from the left channel started to go down until I had no sound output from that channel.
The preamp and speakers are in good working order does anyone have any ideas as to what the problem might be?
Thank you
Hi Rob. It would need to go on a bench to find out where the signal is being stopped. Could be one of a long list of things like bad connections, open capacitor, failed transistor, cracked solder joints so it would be impossible to diagnose here in CZcams comments section.
Trevor can you work on a Hafler D110 Preamp
I can but I'm not taking any shipped in work until I'm caught up on my backlog
That’s normal for those DC pots