OS,
I thought you had the boards at 100mm width. 75mm works for me, much better, won't be the problem I wrote to you about. Ya!
I thought you had the boards at 100mm width. 75mm works for me, much better, won't be the problem I wrote to you about. Ya!
On a NJW0302/0281 about 23mm (15/16") between where you
bend the leads to the top of the device.
13mm between holes and edge of board ... leaves 10mm of
OP extending beyond each board edge.
10 + 10 + 76.2 = 96.2mm ... you need 3-7/8" wide (tall) heatsink.
A 3 or 4 U heatsink/chassis ... will work.
With the ops/ips 90 degrees 177mm long OPS + 20+mm for the IPS.
A 200mm deep heatsink is minimum. The 250mm HS would be better ..
as it has a better C/watt rating.
One this big would be larger than BOTH HK990 HS's 😱 .
PS - Op hole is 5mm from top of the device 2X5=10 96.2 -10mm= 86.2mm
( parallel holes on the heatsink) .. roughly 3-1/2" apart ...
Edit - I would make the holes 88-90mm apart - the bends in the OP leads would add a
couple mm to the distance.
OS
bend the leads to the top of the device.
13mm between holes and edge of board ... leaves 10mm of
OP extending beyond each board edge.
10 + 10 + 76.2 = 96.2mm ... you need 3-7/8" wide (tall) heatsink.
A 3 or 4 U heatsink/chassis ... will work.
With the ops/ips 90 degrees 177mm long OPS + 20+mm for the IPS.
A 200mm deep heatsink is minimum. The 250mm HS would be better ..
as it has a better C/watt rating.
One this big would be larger than BOTH HK990 HS's 😱 .
PS - Op hole is 5mm from top of the device 2X5=10 96.2 -10mm= 86.2mm
( parallel holes on the heatsink) .. roughly 3-1/2" apart ...
Edit - I would make the holes 88-90mm apart - the bends in the OP leads would add a
couple mm to the distance.
OS
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What was described for a Borbely Class A amp was Neutrik SpeakON connectors for the output stage and XLR for the front end.
I will follow this method because most of the cost is in the power supplies when building various power amps.
The HK you showed looks like it has two fans opposing each other on the inside of the heat sinks.
Thanks Harry. I have used the Speakon connectors in PA applications but never an XLR for a power connector. That is fine as long as nobody ever plugged that power supply into a line level connection!
OS,
As a past vendor for Harmon/JBL there markup is 10X cost. So total cost to manufacture of $250.00 in the box.
As a past vendor for Harmon/JBL there markup is 10X cost. So total cost to manufacture of $250.00 in the box.
$200 - 250 is about enough for just the "slewmaster" PS.
2 X 51$ 400va toriods
2 X 26$ steel covers for these toroids .
8 X 6$ for caps
2 X 8$ for 35A bridges
20$ for assorted other parts
102+
52+
48+
20
-----
222 +
shipping and other b$...
250$ , most likely. Just the PS !
OS
Don't forget they purchase in bulk and a majority of it would be Asian sourced. They are tough on pricing, they would never pay those kinds of price. They'll beat you up over 25 cents! Some of their smaller speakers cost them $10.00 in the box and sell for over $100.00. Had plenty of fights with them, even slow on payments, had to hold their product until they paid their bills!
They will spend more on marketing than on the product itself. The things I made for them were for the Japanese market, extreme quality standards for those products.
Power supply ideas
I'll be hard wiring the cables into the power supply to eliminate connectors on that side. These cables with the Neutrik connectors on the other end will hopefully create a CRC power supply (R= resistance in the wire & connector), which is currently popular.
I am not an engineer so forgive me if I am wrong. I intend to experiment with large plastic caps (2.2 - 10uF) in parallel to the electrolytics on the PCB. This is not for filtering and in fact some engineers have shown that the 0.1uF cap in parallel can create resonances. Hopefully the plastic cap will "speed" the discharge into the output transistors....🙄
I'll be hard wiring the cables into the power supply to eliminate connectors on that side. These cables with the Neutrik connectors on the other end will hopefully create a CRC power supply (R= resistance in the wire & connector), which is currently popular.
I am not an engineer so forgive me if I am wrong. I intend to experiment with large plastic caps (2.2 - 10uF) in parallel to the electrolytics on the PCB. This is not for filtering and in fact some engineers have shown that the 0.1uF cap in parallel can create resonances. Hopefully the plastic cap will "speed" the discharge into the output transistors....🙄
UMS ...(not really criticizing it) , was intended for the "Pass" camp.
That layout really is not optimized for high power AB amps.
I did the best I could with the "Badger" , as UMS makes it REAL
hard to shorten/ minimize ground returns and signal paths.
In fact , this is why the "Badger" is a EF2 OPS.
Edit - you could redrill the DIYA heatsinks - they are quite adequate for
this project. As is their PS PCB /Chassis ...
OS
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OS How far away are you from the Protection circuits etc. I am not pushing, just wondering...You have a lot on your plate and it has been a great edumuncation just looking and kibitzing and seeing the amp design process in real time. THANKS
Last steps on this NAD-S vers.1.2.
It's time for cleaning and testing this ALONE.
I manage to power this with +/- 20v .
Ostripper what dummy can i put after this?
What about the feadback path in this first test?
Thanks.
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