G'day Guys,
Something the thrify DIYer should know is the wonderful source of parts that are Onkyo/Integra AV receivers.
It is fairly well established that Onkyo/Integra home theatre recievers from the late 2000's and mid 2010's have a well known issue with their HDMI boards that causes them to fault and are expensive to fix.
At least in New Zealand, these end up on our local version of Ebay for cheap, often less than $20. I've been collecting these for a few years now as they are so common. I see several every month. I imagine in larger markets there would be even more.
The best thing about these is their power transformers and heatsinks.
They typically have both 120v/230v primaries and a whole host of secondaries usefull to the DIYer.
Depending on the model, they range from 300w to 900w.
The 600ish watt models typically have secondaries that look like this:
I especially like the 21-0-21v taps as these are quite usefull for chip amps etc, I imagine various lower power class A amps as well (which I haven't gotten around to yet)
The 300w models typically have secondaries like this:
Some of the higher power models have even higher voltage on the B+.
They also have good looking heatsinks:
This is the most typical kind found in the 300-600w models. Some are larger.
These weigh about 900g and measure:
289mm x 94mm x 50mm.
I estimate their dissipation at something like 0.5C/W
I imagine that 2 could be stacked on top of one another with some aluminium plate used as a heat spreader to make a larger heatsink appropriate for higher power designs. Something I intend to try in the future.
The largest heatsink I have found so far was from a TX-SR602 which was 130mm tall compared to the usual 94mm.
They also have some other good stuff on board.
All in all, if one can get them cheap they are very good value.
The power transformers alone are probably worth something like NZD200 for something with equivalent VA from Mouser/Farnel et al.
At least in New Zealand, heatsinks are hard to come by so these are an absolute gold mine.
Something the thrify DIYer should know is the wonderful source of parts that are Onkyo/Integra AV receivers.
It is fairly well established that Onkyo/Integra home theatre recievers from the late 2000's and mid 2010's have a well known issue with their HDMI boards that causes them to fault and are expensive to fix.
At least in New Zealand, these end up on our local version of Ebay for cheap, often less than $20. I've been collecting these for a few years now as they are so common. I see several every month. I imagine in larger markets there would be even more.
The best thing about these is their power transformers and heatsinks.
They typically have both 120v/230v primaries and a whole host of secondaries usefull to the DIYer.
Depending on the model, they range from 300w to 900w.
The 600ish watt models typically have secondaries that look like this:
I especially like the 21-0-21v taps as these are quite usefull for chip amps etc, I imagine various lower power class A amps as well (which I haven't gotten around to yet)
The 300w models typically have secondaries like this:
Some of the higher power models have even higher voltage on the B+.
They also have good looking heatsinks:
This is the most typical kind found in the 300-600w models. Some are larger.
These weigh about 900g and measure:
289mm x 94mm x 50mm.
I estimate their dissipation at something like 0.5C/W
I imagine that 2 could be stacked on top of one another with some aluminium plate used as a heat spreader to make a larger heatsink appropriate for higher power designs. Something I intend to try in the future.
The largest heatsink I have found so far was from a TX-SR602 which was 130mm tall compared to the usual 94mm.
They also have some other good stuff on board.
- Panasonic ALA2F24, 3A125V relays for the outputs
- Typically Nichicon LS or LQ series filter capacitors from 6200uF to 15000uF on the higher end models
- Toshiba 2SA1941/2SC5198 100W outputs on most models, Sometimes the 120w 2SA1942/2SC5242 on the higher power models.
- decent bridge rectifiers
- good heatsinks for rectifiers/regulators
- JRC 79xx/78xx regulators
- 2SA1930/2SC5171 driver transistors
All in all, if one can get them cheap they are very good value.
The power transformers alone are probably worth something like NZD200 for something with equivalent VA from Mouser/Farnel et al.
At least in New Zealand, heatsinks are hard to come by so these are an absolute gold mine.
Yep... I've never encountered an Onkyo that was operational, but they're doubtless a treasure trove of parts.
Agree with your findings. Shame the chassis are mostly junk, at least the front panels. I was lucky enough to pick up an immolated parasound HCA-1206, whose chassis is practically a modushop dissipante 4u, which now houses a wolverine
On 98% of defective ONKYO AVR's there is one single chip on the HDMI board that has been bonded at too low temperature, making the contacts fail after some time. In most cases, using a good flux and quite some concentrated heat, you can fix this. At least for a few years, until it fails again for the same cause. The component in question is not available any more, but there are quite some specialists which remove, clean and re-flow the chip in question. In this case they are really specialists, as this needs not only some special tools, but a steady hand and quite some patience. You got to exactly position about 200 solder balls on a fingernail.
These AVR's can be converted into nice 5-9 or even more channel amplifiers after removing the obsolete stuff, but you got to simulate some voltages to switch them on without the HDMI board directing it. You got to do a lot of reading on the schematics...
These AVR's can be converted into nice 5-9 or even more channel amplifiers after removing the obsolete stuff, but you got to simulate some voltages to switch them on without the HDMI board directing it. You got to do a lot of reading on the schematics...