That looks good. I wonder if we may even need a small local heatsink on it? In which case, a little more spacing around it would be good.
Nice work Terry! You are way too fast. Good luck populating it.
I have to get me some of that Dollar Store iron on transfer backing paper...
Btw, do you have one of those micro drill presses or just a regular 1/2in chuck 8in workpiece drill press can be used to do the holes? I have the bits but keep thinking my regular press is too big and not precise enough.
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I use a Dremel drill press and Carbide bits. I buy extra bits in the 6mm, 8mm. 10mm and 1.25mm to have on hand. The bits last a while using the press. If you try to use this type of bit in a hand drill you will be lucky to drill 10 holes. In the Dremel press with the Dremel on high speed they last well and drill like butter.
I was about to buy that exact Dremel press. Thought I might ask before pulling the trigger. I guess I should try my big drill press and see how it works. If I bust a bit I will know it doesn't work.
Are these comparable or better than the KSA1381E/C3503E?
I noticed the KSA1220/C2690 have higher collector current and higher gain for the "Y" type.
Thanks...
XRK971,
I also use that dremel drill press. I tried my Bench Drill Press and it does NOT spin Fast enough to do those small bits justice. They just Break very easily. YMMV
I also use that dremel drill press. I tried my Bench Drill Press and it does NOT spin Fast enough to do those small bits justice. They just Break very easily. YMMV
You won't be sorry. I actually enjoy the hole drilling process now that I have the right equipment.
Zinyx:
That looks real nice. I wonder what Sonal's layout is going to look like? Nice work on getting down to 100mm x 60mm 🙂
Thanks!
X
You removed the rail filter caps. You don't need the 100n caps if the filters are gone. 2W emitter resistors might be a little light. Sonal used two 2w per output.
FH11 in 100mm x 59mm layout.
680uF is there for local decoupling. You can use smaller value, it depends upon how much space you have on layout you are designing and compromise you make for value of capacitors. Look at orignal AX14 pcb from Mr. Miles it has only 2.2uF capacitor.
680uF is there for local decoupling. You can use smaller value, it depends upon how much space you have on layout you are designing and compromise you make for value of capacitors. Look at orignal AX14 pcb from Mr. Miles it has only 2.2uF capacitor.
Attachments
the low current, low Cob, a1381/c3503 make good VAS and pre-driver transistors.
The high current, high Cob, a1220/c2690 make good driver transistors.
They are not interchangable. Their parameters are very different.
In practice, at 53v rails the 0.47R 1W x qnty 2 resistors I use don't even get warm so probably fine.
I wake up and still no one has completed and tested the FH11 yet? I was able to build a pair of VSSA's last night and tested one. The VSSA, although has the name "very simple" is not as simple as the FH9 🙂