I have to agree with not meddling with a functioning version of one of these, beyond replacing a few of the aging capacitors anyways.
They seem to be prone to corrosion between within the original solder joints, at least with the some four sets of boards that have passed through my current amp.
I now think of mine as more like a mousetrap and is not being used at the moment, as I do not want to jeopardize the new, matched set of outputs, which aren’t exactly a commonly available part these days.
They seem to be prone to corrosion between within the original solder joints, at least with the some four sets of boards that have passed through my current amp.
I now think of mine as more like a mousetrap and is not being used at the moment, as I do not want to jeopardize the new, matched set of outputs, which aren’t exactly a commonly available part these days.
Well, though I don't have it in possession, this seems to be a good working unit, tested by a known and trusted AK member. So probably I will not mess with it for now. I am interested in what CAN be tweaked and etc. on these units, so will go ahead and read up with all 145 pages of this thread, and take a peek inside. But will likely leave well enough alone for now. No need to fix what isn't broken.
Hafler 220 bias adjustment
I have 6 Hafler amps in my 7.1 chan home theater system that were built and modified by me between 1979 and 1982. One is a DH-200 that I did a full POOGE mod on. The rest are DH-220's with various adaptations of the POOGE mod. I'm in the process of stuffing 8 new "old stock" PC-19c boards with all new parts. I have one 220 that is completely stock, unmodified(yet). that I want to use as a test dummy. As I complete a board I want to install it in this unit to test it. The amp plays good and has low DC offset. However, when I try to check the bias according to the instructions in the manual, my DMM reads 0.000 ! I reverse the polarity of the leads(after shutting down the amp)and it's the same. I tried adjusting the pots and no change.
I've done this procedure to set the bias many times in the past. I run my POOGE modded DH-200 at 425mv. It runs hot but I've never had a failure. I can't figure out what's going on. I must be doing something wrong. I haven't tried another meter yet. I only have one DMM that reads accurate Milliamps. I'm beginning to wonder if the meter is at fault, although it works well on all other tests, ie
hms, AC and DC volts , millivolts to check DC-offset,etc. It's a Simpson mod 467 True RMS DMM that I've had for 20+ years.
Any suggestions?
I have 6 Hafler amps in my 7.1 chan home theater system that were built and modified by me between 1979 and 1982. One is a DH-200 that I did a full POOGE mod on. The rest are DH-220's with various adaptations of the POOGE mod. I'm in the process of stuffing 8 new "old stock" PC-19c boards with all new parts. I have one 220 that is completely stock, unmodified(yet). that I want to use as a test dummy. As I complete a board I want to install it in this unit to test it. The amp plays good and has low DC offset. However, when I try to check the bias according to the instructions in the manual, my DMM reads 0.000 ! I reverse the polarity of the leads(after shutting down the amp)and it's the same. I tried adjusting the pots and no change.
I've done this procedure to set the bias many times in the past. I run my POOGE modded DH-200 at 425mv. It runs hot but I've never had a failure. I can't figure out what's going on. I must be doing something wrong. I haven't tried another meter yet. I only have one DMM that reads accurate Milliamps. I'm beginning to wonder if the meter is at fault, although it works well on all other tests, ie
hms, AC and DC volts , millivolts to check DC-offset,etc. It's a Simpson mod 467 True RMS DMM that I've had for 20+ years. Any suggestions?
Power supply repair and/or improvements for the DH-220.
In this thread some are upgrading existing components, replacing the bridge rectifier and caps.
There are parts from ebay to accomplish this, like these.
HAFLER DH120, DH200 DH220 POWER SUPPLY UPGRADE | eBay
Others have suggested replacing the power supply with a board from ebay, like these.
High Quality Power Supply Rectifier Board 6 x 10000uF/100V for Power Amplifier | eBay
I typically would lean towards sticking with the original design and upgrading components. However at over 3 times the price for the upgrade components, the replacement seems to be an attractive option.
It would be nice to hear the pros and cons from the experts. Is there a performance difference between the two options.
Which one would you choose?
gabo
In this thread some are upgrading existing components, replacing the bridge rectifier and caps.
There are parts from ebay to accomplish this, like these.
HAFLER DH120, DH200 DH220 POWER SUPPLY UPGRADE | eBay
Others have suggested replacing the power supply with a board from ebay, like these.
High Quality Power Supply Rectifier Board 6 x 10000uF/100V for Power Amplifier | eBay
I typically would lean towards sticking with the original design and upgrading components. However at over 3 times the price for the upgrade components, the replacement seems to be an attractive option.
It would be nice to hear the pros and cons from the experts. Is there a performance difference between the two options.
Which one would you choose?
gabo
Hi Gabo,
none of the both. The first is too expensive. You can buy these capacitors, Rectifier and the CL60 for half the price at DIGIKEY and Mouser, just search for product name E36D for the capacitors, the rectifier is a standard 25/35 A /1000V bridge rectifier. The second one is to cheap, so you won't get happy with these capacitors. Maybe faked one.
I use in my DH-120 the E36D with 22000µF/63V, so in a DH-220/200 the 22000µF/100V (about 24US$ at DIGIKEY) will work fine. Check the measurements for the capacitors and choose the one that fits.
BR
Günni
none of the both. The first is too expensive. You can buy these capacitors, Rectifier and the CL60 for half the price at DIGIKEY and Mouser, just search for product name E36D for the capacitors, the rectifier is a standard 25/35 A /1000V bridge rectifier. The second one is to cheap, so you won't get happy with these capacitors. Maybe faked one.
I use in my DH-120 the E36D with 22000µF/63V, so in a DH-220/200 the 22000µF/100V (about 24US$ at DIGIKEY) will work fine. Check the measurements for the capacitors and choose the one that fits.
BR
Günni
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I have 6 Hafler amps in my 7.1 chan home theater system that were built and modified by me between 1979 and 1982. One is a DH-200 that I did a full POOGE mod on. The rest are DH-220's with various adaptations of the POOGE mod. I'm in the process of stuffing 8 new "old stock" PC-19c boards with all new parts. I have one 220 that is completely stock, unmodified(yet). that I want to use as a test dummy. As I complete a board I want to install it in this unit to test it. The amp plays good and has low DC offset. However, when I try to check the bias according to the instructions in the manual, my DMM reads 0.000 ! I reverse the polarity of the leads(after shutting down the amp)and it's the same. I tried adjusting the pots and no change.
I've done this procedure to set the bias many times in the past. I run my POOGE modded DH-200 at 425mv. It runs hot but I've never had a failure. I can't figure out what's going on. I must be doing something wrong. I haven't tried another meter yet. I only have one DMM that reads accurate Milliamps. I'm beginning to wonder if the meter is at fault, although it works well on all other tests, ie
Any suggestions?
Get a 1 ohm resistor. If you have OCD, measure it to get exact resistance. Take apart a blown fuse that fits in the fuse holder. Attach the ends of the fuseholder to the resistor, so it will fit in the fuse holder, then measure voltage drop across it to get idle current. Or you can attach clip leads to the resistor, and clip it across the fuse holder (after taking out fuse).
Steve
Many thanks for that! The 220 has caps that are 2" diameter, the height isn't really that important. But checking on the caps you recommended, the part number E36D800HPN223MC92M, is a 2" diameter by 3.625" tall, which is a bit shorter than the original caps. 22000uF 80 Volt. Which is perfect. The original caps are 10,000uF 75 volt.
So I ordered two of those at $20.19 each. I may just keep the original rectifier as it seems to test out ok.
Thanks, gabo
Hi gabo.
thanks for honest comment. I would still change the rectifier to a 35A or 50A version (higher surge current), since you have a higher inrush current, caused by the doubled capacity. I also would add the NTC as shown in the ebay offer to prevent damage from the power-on switch.
Gunni
thanks for honest comment. I would still change the rectifier to a 35A or 50A version (higher surge current), since you have a higher inrush current, caused by the doubled capacity. I also would add the NTC as shown in the ebay offer to prevent damage from the power-on switch.
Gunni
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Hi Gunni,
I have used the second one and have been satisfied with it. The capacitors are each 10,000 uF rated at 80V and 105 C. They are made by Nippon Chemi-Con. The workmanship looks fine and the rectifiers look good (not just a big bridge rectifier). I would not speculate that these capacitors are fake any more than I would speculate that anything else on eBay is fake.
Cheers,
Bob
Hi Bob,
for me the offer is a little suspect. Imagine for example
6 capacitors 10mF 100V 105°C (brand KINGBOX(??) or Ruby(??))
+4 Diodes incl heatsink
+ 1 pcb 2oz Cu ,2mm, 160mmx75mm
incl. shipment to Germany for less than $45. But btw, i started to buy my parts only from the trustworthy sources, like Digikey, Mouser, TME.
BR
Gunni
Thanks Bob and Gunni. Interesting discussion. I might buy one of the ebay supplies for another DIY project I'm putting together, just to see how well it's made and works.
However, for this DH-220, I think I will stick with the original design. The cost for the two caps, rectifier, and other parts from mouser is basically the same price. I like the idea of sticking to the original design.
I've seen a few of the exotic rebuilds for these amps. Very impressive. But I've been happy with the original performance of it for many years. Now that it has had a little hiccup, I think sticking to the original design with some quality components is the way I would like to go.
Thanks for the help and input.
gabo
However, for this DH-220, I think I will stick with the original design. The cost for the two caps, rectifier, and other parts from mouser is basically the same price. I like the idea of sticking to the original design.
I've seen a few of the exotic rebuilds for these amps. Very impressive. But I've been happy with the original performance of it for many years. Now that it has had a little hiccup, I think sticking to the original design with some quality components is the way I would like to go.
Thanks for the help and input.
gabo
Making progress on my amp. I have replaced the filter caps, the rectifier, and added a 6AWG copper bar to replace the strap between the filter caps.
Now looking at the boards and getting ready to replace the ecaps on those boards. I noticed a difference in value for cap c8. On my board it's a 220uF, 10v cap. But the schematic I have shows it to be a 470uF, 10v cap.
In checking a bit further, my board is a PC-19 board and the schematic I have is for a PC-19c board. I assume the PC-19c is the latest version.
Should I change my cap to a 470uF? I'm not sure what other parts or circuitry is different between the two versions, so I'm not sure I should change the value.
I looked at the new PC-1 boards on ebay from qua-co, expensive! My boards are in great shape, so I'll keep them until someone comes out with boards from Bob's DH-220C version
I also need to add a thermistor for soft start to the order. I think I've looked at an SL-32-10015. And a poly cap for the 2uF, 50v C1.
Thanks, gabo
Now looking at the boards and getting ready to replace the ecaps on those boards. I noticed a difference in value for cap c8. On my board it's a 220uF, 10v cap. But the schematic I have shows it to be a 470uF, 10v cap.
In checking a bit further, my board is a PC-19 board and the schematic I have is for a PC-19c board. I assume the PC-19c is the latest version.
Should I change my cap to a 470uF? I'm not sure what other parts or circuitry is different between the two versions, so I'm not sure I should change the value.
I looked at the new PC-1 boards on ebay from qua-co, expensive! My boards are in great shape, so I'll keep them until someone comes out with boards from Bob's DH-220C version
I also need to add a thermistor for soft start to the order. I think I've looked at an SL-32-10015. And a poly cap for the 2uF, 50v C1.
Thanks, gabo
I need the pcb dimensions, including the holes(exact sizes,locations) to be able to complete. If I was to get a loner to use as my reference, I'd only need it for a short while. Depending on the time frame, I could send your original back and make the new design or you can wait and I'd do up the design, return a set of new pcb's (appreciation) and the original back.
Probably be just as cheap to purchase a blank PC-19c board here from ebay:
NOS HAFLER PC-19C (PC-19) Bare/Blank Driver Board (DH500, DH-500, DH220, DH-220) | eBay
That's the exact same boards as mine, sans it's the latest revision. And since it's not populated, it would be easier for you to get all the dimensions.
Send me a PM with shipping info. I will buy you one and have it shipped to you in exchange for a future set of new 220C boards.
Thanks, gabo
NOS HAFLER PC-19C (PC-19) Bare/Blank Driver Board (DH500, DH-500, DH220, DH-220) | eBay
That's the exact same boards as mine, sans it's the latest revision. And since it's not populated, it would be easier for you to get all the dimensions.
Send me a PM with shipping info. I will buy you one and have it shipped to you in exchange for a future set of new 220C boards.
Thanks, gabo
The hafler boards are 4-5/8” X 4-3/8”
The mounting holes are 2-21/32” center to center and 4-3/32” center to center.
The holes are 13/16” from one end and 1-3/16” from the other, so not centered in that direction.
If you look at a picture of a board, the orientation will be clear.
I was sure I had already replied to this before, don’t know what happened there.
The mounting holes are 2-21/32” center to center and 4-3/32” center to center.
The holes are 13/16” from one end and 1-3/16” from the other, so not centered in that direction.
If you look at a picture of a board, the orientation will be clear.
I was sure I had already replied to this before, don’t know what happened there.
Got it now I will make a project folder and it will go there for another day.
The hafler boards(PC-19c) are 4-5/8”(4.625",117.475mm) X 4-3/8”(4.375",111.125mm)
The mounting holes are 2-21/32”(2.65625",67.46875mm) center to center and 4-3/32”(4.09375,103.98125mm) center to center.
The holes are 13/16”(0.8125",20.6375mm) from one end and 1-3/16”(1.1875",30.1625mm) from the other, so not centered in that direction.
Hole sizes?
can i assume that these numbers are by eye and using a ruler and not using calipers?
I think if we round to the closest 0.1mm we are fine.
Thanks
I will make a project folder and it will go there for another day.The hafler boards(PC-19c) are 4-5/8”(4.625",117.475mm) X 4-3/8”(4.375",111.125mm)
The mounting holes are 2-21/32”(2.65625",67.46875mm) center to center and 4-3/32”(4.09375,103.98125mm) center to center.
The holes are 13/16”(0.8125",20.6375mm) from one end and 1-3/16”(1.1875",30.1625mm) from the other, so not centered in that direction.
Hole sizes?
can i assume that these numbers are by eye and using a ruler and not using calipers?
I think if we round to the closest 0.1mm we are fine.
Thanks
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