Hi Melon Head,
I agree with your philosophy.
I would say science is not only in theory, but also is in proving it in practice by experiment or implementation.
We cannot calculate all details and speaker usually is big "x" rather known value.
Even voltage is not constant from the wall, it may fluctate +/-3V AC, what converts into 1-1.5V on power supply rails (or 4-6%) and changes not power output, but generated heat.
My idea was to be able roughly calculate limits of heatsinking I may require. Now I think I will need at least 150W/ch heat dissipation. Based on my previous experience I will go for bigger rather smaller PSU - 2x400W or 2x500W transformers. I have no doubt that I will need to "play" with adjustments, but that's beauty of DIY.
Anyway, thanks for your support.
BTW, are you familiar with Aleph X calculation spreadsheet (for single ended)
http://www.facstaff.bucknell.edu/esantane/movies/AXE-1-2.xls
Best regards,
feriandas
Mono-block approach sounds sophisticated, but it is not so much advanced as dual mono.
Pros:
- Shorter speaker wires
- Theoretically better heat dissipation
Cons:
- 30-40W mono-block, is not too much?
- Higher cost for 2 cases
- Almost double time to make 2 cases
- Heatsink configuration*
- Almost impossible to use DIYAUDIO shop boards
- Doesn’t make sense if I will not use high (3A) bias
*BA-2 it is convenient for placing 2 channels into 1 chassis. Output stage board with 3 pairs of transistor is 25 cm long (12”). It fits nicely on 40 cm heatsink (16”). 40 cm x 16 cm x 8 cm (16x6.5x3 inches) heatsinks on each side may ensure necessary heat dissipation, 4U thick alu front plate.
Having a mono-block I would need to increase number of transistor pairs to 4, split it to both sides of chassis 2/2. It will increase length of internal wires and will place some wires close to PSU parts. Also it means custom build power output boards.
Alternatively I may design a case with only one heatsink, but currently I have no ideas for visually attractive asymmetrical case.
Extra question:
What about speaker protection?
I'm not sure if this is the right thread for very basic questions about the BA-2 from someone who is new at diy and has little electronics understanding. If not, please redirect me to the right place. I'm interested in building a new amp to drive vintage electrostatics (acoustats 2+2's). Is the BA-2 (or F-4/5) suitable for this use? Also, I had not considered them before because of the relatively low watt output, but after going through this thread twice (but not fully understanding most of it) it seems with proper cooling you could configure the BA-2 (or F-4/5) to output 100-150 watts/channel? This would be ideal for my application if it can do this wattage and drive well the 4ohm (down to 2ohm in certain frequencies) acoustats. Thanks for any info and please forgive the ignorance.
Sounds like you need a Pumpkin and crippled F4's, maybe with a 6 deep output for low impedance drive, thats 24 FETs per mono amp.
Start here at post 2994 http://www.diyaudio.com/forums/pass-labs/97540-f4-power-amplifier-300.html#post2086609
Start here at post 2994 http://www.diyaudio.com/forums/pass-labs/97540-f4-power-amplifier-300.html#post2086609
Only a fool or a mechanic hits the road with no brakes.
Any plans for the quiescent bias level ?
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I need to check on how many we have shipped.
We just got more BA-GS front end boards for Burning amps! they will be in the US store in about a week,
Not a record because the F-5 is the most popular board by far. We just got some of the cviller cascode F-5 boards with 2 of each output MOSFET. Which will also be in the store in about a week..
Mark
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Was planning on a 6 deep output, 1.2A per device, 7.2A per bank, 14.4A total (mono), that should drive 2 Ohms quite happily, my speakers are 3 Ohm.
The output stage PSU will be 1KVA 2x18V transformer, 6x100,000uF Kendeil capacitors CRCC.
Two 400mm lengths of these heatsinks should do for a mono amp.
Heatsinks: 9000 Series - 9740HS
Thats a burning amp
I don't think this is a good analogy.
It appears you are accusing quite a few people of being fools, possibly Nelson included.
)
I've met a lot of mechanics that I would not let touch a toy car let alone a real one.
The problem with the analogy is, how do you know if you are mechanic or a fool?
Wouldn't anyone who could build an amp be a mechanic?
I know a lot of mechanics that could not fix a car let alone build one.
And if you are a fool then you are probably too foolish to admit/know you are a fool.
The problem with the analogy is, how do you know if you are mechanic or a fool?
Wouldn't anyone who could build an amp be a mechanic?
I know a lot of mechanics that could not fix a car let alone build one.
And if you are a fool then you are probably too foolish to admit/know you are a fool.
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I know difference between a fool and mechanic , just because I'm dumb enough ;
and I can guarantee that Jaccolina is dumb enough , too - to speak about real mechanic .
I have a friend who is maxilo-facial surgeon ; he's greening when I call him "techie"
terms "mechanic" and "craftsman" are becoming cheap ( long time ago ) because of ppl not worthy these titles , not because of rare good ones ,
rare mechanic doesn't need brakes for engine test .
rare mechanic doesn't need loudsp protect and anticlick for his hot boiling amps .
edit:
care ..... is in root of everything ;
http://www.diyaudio.rs/blog/6/entry...es-zen-and-the-art-of-motorcycle-maintenance/
and I can guarantee that Jaccolina is dumb enough , too - to speak about real mechanic .
I have a friend who is maxilo-facial surgeon ; he's greening when I call him "techie"
terms "mechanic" and "craftsman" are becoming cheap ( long time ago ) because of ppl not worthy these titles , not because of rare good ones ,
rare mechanic doesn't need brakes for engine test .
rare mechanic doesn't need loudsp protect and anticlick for his hot boiling amps .
edit:
care ..... is in root of everything ;
http://www.diyaudio.rs/blog/6/entry...es-zen-and-the-art-of-motorcycle-maintenance/
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