Finally got 1200AS2

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I had hard time finding 1200AS2 in the US so bought an assembled unit. I received 2x 1200AS2 modules in case with 8x Furutech FT-807, 4x Neutrik XLR, VanDen Hul CS-16 wiring and on/off switch. It is pretty but has problems: heat sinks have no conducting area attached to module plates, switch (speced as Shaffner EMI/RFI filter) was on/off toggle with 10amp fuse and 14/3 power cord, amps are thermal isolated in closed box and go into clipping when driven hard. These are 150watt amps with 6db headroom that is not much heat. The amps seem to be designed for European power and would benefit from higher voltage. I will replace 10 amp fuse with 20amp (maybe with 30amp Filtered Entry Module someday), make 12/3 power cord with high temp C-15 connector and run 20amp, install 2-Noctua-NF-A8-5V fans and wire to 5v auxiliary on boards and rewire power LED’s to clipping pins on boards. Final thought: these modules would benefit from direct mounting to heat sinks with pull through cooling, I am glad they did not include EMI filter as speced as I can use different value fuse, heat sinks that are not mated to base plate are useless.

Modules

Bottom

Side

Back
 
These modules pretty much depend on good air flow and low in case temperature. As you mentioned, some fan making the air inside circulate should help a lot to transfer heat to the case.
If you exchange the air, by flowing through holes in the case, you have to clean the amp up on a regular base, best done with compressed air. Only both, exchange plus fan combined, will give you a long therm reliable amp.

As far as I remember, the technical instructions talk about constant temperature of all components on the module, not only the heat sinks. To me it seemed hardly possible to meet these requiermeants in a closed case and without active venting.
Also the output with 115V AC seems a little diffilcult.
 
Last edited:
These modules pretty much depend on good air flow and low in case temperature. As you mentioned, some fan making the air inside circulate should help a lot to transfer heat to the case.
If you exchange the air, by flowing through holes in the case, you have to clean the amp up on a regular base, best done with compressed air. Only both, exchange plus fan combined, will give you a long therm reliable amp.

As far as I remember, the technical instructions talk about constant temperature of all components on the module, not only the heat sinks. To me it seemed hardly possible to meet these requiermeants in a closed case and without active venting.
Also the output with 115V AC seems a little diffilcult.


Thanks for the reply, I have ordered larger fans 2x Noctua NF-A20 5V and plan to mount frame on top blowing air down on boards. Yes I agree on voltage will try a 5000W step up transformer hope no problem with 60hz but I think this may be source of "buzzing" sound.
 
Was going to purchase step-up transformer, checked case ground and it is isolated from power input on boards. I think I could run 240V to board by mains input Pin 1 and 3 neutral and live because board just sees neutral as a reference should be good, 60hz may be a plus. Guess I could float the chassis ground just in case but seems the diode that need pull to ground need case ground. Any input is appreciated as I do not know if board functions different when live.
 
I had hard time finding 1200AS2 in the US so bought an assembled unit. I received 2x 1200AS2 modules in case with 8x Furutech FT-807, 4x Neutrik XLR, VanDen Hul CS-16 wiring and on/off switch. It is pretty but has problems: heat sinks have no conducting area attached to module plates, switch (speced as Shaffner EMI/RFI filter) was on/off toggle with 10amp fuse and 14/3 power cord, amps are thermal isolated in closed box and go into clipping when driven hard. These are 150watt amps with 6db headroom that is not much heat. The amps seem to be designed for European power and would benefit from higher voltage. I will replace 10 amp fuse with 20amp (maybe with 30amp Filtered Entry Module someday), make 12/3 power cord with high temp C-15 connector and run 20amp, install 2-Noctua-NF-A8-5V fans and wire to 5v auxiliary on boards and rewire power LED’s to clipping pins on boards. Final thought: these modules would benefit from direct mounting to heat sinks with pull through cooling, I am glad they did not include EMI filter as speced as I can use different value fuse, heat sinks that are not mated to base plate are useless.

Modules

Bottom

Side

Back

what are you talking about? are you saying that these are 150 Watt RMS amplifiers that B&O is selling as 600 watts into 8 ohms? have you done a measurement? do you have a picture of the screen on a scope that you used?? did you eyeball it? if you have evidence would you like to join me in a class action lawsuit against the company that is misrepresenting its product?
 
what are you talking about? are you saying that these are 150 Watt RMS amplifiers that B&O is selling as 600 watts into 8 ohms? have you done a measurement? do you have a picture of the screen on a scope that you used?? did you eyeball it? if you have evidence would you like to join me in a class action lawsuit against the company that is misrepresenting its product?

That is probably the case, not much different than Hypex does. However, I'd say it's more in the marketing of the "assembly companies". The companies out there that buy these prefab amp cards, and just add wires to a case for connections. Those "assembly" companies frequently grab the max output value on the line cards, and post that as the amplifier's power output, this isn't something that BO or Hypex controls.

While most of us are accustomed to the classic RMS, or Continuous ratings, you would need to dive into the spec sheets from Hypex and Icepower for the associated boards. Even then, a "continuous or RMS" rating is either not listed, or carries some sort of cooling waiver/requirement, that none of these "assembly" plant companies have implemented.

My whining aside, I'm actually quite curious as to how this amp turned out. Any updates Toodle?
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.