Ok, measured heatsinks temperature with industrial digital thermometer.
Top cover off.
Room temperature more or less 29 C.
In half an hour top of the heatsinks (closer to mosfets) 45 C.
In three hour it increase to 58 C and did not rise any further.
Didn't took any readings from mosfets.
Next step, drill holes on top cover and bottom cover and raise chassis feets a little bit.
Top cover off.
Room temperature more or less 29 C.
In half an hour top of the heatsinks (closer to mosfets) 45 C.
In three hour it increase to 58 C and did not rise any further.
Didn't took any readings from mosfets.
Next step, drill holes on top cover and bottom cover and raise chassis feets a little bit.
Drilled more or less 100 holes at the top, also apprx 30 at the bottom. Now its better.
But! Yes there is always a 'but'
After one or two hour, both speakers has very low level buzz. It's not hum. All drivers. I can hear it 20cm away from the speakers. Shorted inputs for a test, dead silent. Replaced pre power interconnect, no effect. It still create a buzz after 1-2 hour continuous playing. Input wires to pcb is twisted pair 26awg silver wire.
Also swapped transformer orange secondaries to bridge. This cured toroid periodic mechanical noise, thanks!
Now I have to find a cause of this audible buzz from the speakers.
But! Yes there is always a 'but'
After one or two hour, both speakers has very low level buzz. It's not hum. All drivers. I can hear it 20cm away from the speakers. Shorted inputs for a test, dead silent. Replaced pre power interconnect, no effect. It still create a buzz after 1-2 hour continuous playing. Input wires to pcb is twisted pair 26awg silver wire.
Also swapped transformer orange secondaries to bridge. This cured toroid periodic mechanical noise, thanks!
Now I have to find a cause of this audible buzz from the speakers.
Pass DIY Addict
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Your issue with buzz is likely grounding at this point. You might want to try a few things to connect PSU/signal ground the AC Mains ground. My a40 has a thermistor to connect these two points. If I put a diode, it buzzed. If I made a direct connection, it buzzed. With a thermistor, no buzz. My Aleph-X amps were the opposite - needed a direct connection to prevent the buzz...
F5 for LXMinis
kind of a side discussion but still relevant to "Which Pass amp?" and F5:
http://www.diyaudio.com/forums/multi-way/274047-playing-ob-speakers-4.html#post4426180
do you think this system stands a chance, and could a BA3 FE-style preamp be a backup in case this does not stack up to enough gain for those little tough-to-drives which SL engineered?
kind of a side discussion but still relevant to "Which Pass amp?" and F5:
http://www.diyaudio.com/forums/multi-way/274047-playing-ob-speakers-4.html#post4426180
do you think this system stands a chance, and could a BA3 FE-style preamp be a backup in case this does not stack up to enough gain for those little tough-to-drives which SL engineered?
I have a similar 8" Phillips fullrange driver, thinking of building a box for the pair...I understand yours is a 140ltr box, can you help me with the dimensions...the specs on the driver are very weird and many folks from other forums claim it will sound similar in most box sizes...
I discarded these big boxes because of the waf issues.
I'm digging for box sizes for hours but i couldnt find.
Instead I found these drawing. Shared by original philips fr cabinet owner. I wanted to try this one but I dont have patience and wife for that too..
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