Well with the O/S not on the PCB itself leaving it out is simple enough. Maybe on a next version there can be a more elegant way of doing it though.
About the DC-coupling of the feedback loop for purists preferring not to have capacitors in the signal path, there is provision for a jumper on the PCB, so briefly shorting it out is a breeze.
I've SPICE'd the circuit; in fact I've SPICE'd the KSA50, KSA100 Mk1 and some of its variants too to investigate the influence of different components and check how they compare to the math. I'm very busy lately but will try to experiment with DC servo's when I have the chance.
About the DC-coupling of the feedback loop for purists preferring not to have capacitors in the signal path, there is provision for a jumper on the PCB, so briefly shorting it out is a breeze.
I've SPICE'd the circuit; in fact I've SPICE'd the KSA50, KSA100 Mk1 and some of its variants too to investigate the influence of different components and check how they compare to the math. I'm very busy lately but will try to experiment with DC servo's when I have the chance.
heatsink
I might be able to keep a channel or two comfy with this ... no?http://cgi.ebay.com/ws/eBayISAPI.dl...MEWA:IT&viewitem=&item=290050516535&rd=1&rd=1
I might be able to keep a channel or two comfy with this ... no?http://cgi.ebay.com/ws/eBayISAPI.dl...MEWA:IT&viewitem=&item=290050516535&rd=1&rd=1
That BOM is a bit outdated and has a few errors on it as well. The FET's are listed incomplete and since I changed the PSU configuration the decoupling caps have increased and assigned different reference designators. The jumpers have also increased from 1 to 3. The updated version is at work unfortunately but I'll post it tomorrow.
The resistors and caps of the non-optional section is correct though, but I'd change R17 & R18 to 0.5W too to be on the safe side, and R38-R41 cannot do harm by going to 0.5W as well. The only one that's mandatory to be 0.5W are the 12k's since they dissipate over 120mW.
Since I've to place an order at Parts Connexion anyway, I'll see if I can add the order numbers and prices to the BOM of what would be a good balance. It will be a combination of PRP, Holco and Mills resistors, polystyrene and silver mica pF caps, BG Std for the 10uF 16V (they're cheap anyway) and Solen 1uF for the PSU decoupling.
The rest, preferably the Wima/Rifa MKP 100nF's and Panasonic FC electrolytics should be sourced elsewhere or otherwise use what you can find, just make sure they'll fit on the pads. For the semiconductors it's each man for himself.
It would be good also a few "pioneers" may experiment early on with the various type of FET's provided for to see if there's any clear winner. The IRFD types are easy to do so with since they fit into a DIP-4 socket, but the SOT-223 packages are for keeps once they're mounted unless you've skill and guts.
For the LTP transistors fast ones would be preferable if fast output transistors will be used, and that's why the original 2SA/2SC ones will do well or alternatively BC546/556 that may work possibly even better.
The resistors and caps of the non-optional section is correct though, but I'd change R17 & R18 to 0.5W too to be on the safe side, and R38-R41 cannot do harm by going to 0.5W as well. The only one that's mandatory to be 0.5W are the 12k's since they dissipate over 120mW.
Since I've to place an order at Parts Connexion anyway, I'll see if I can add the order numbers and prices to the BOM of what would be a good balance. It will be a combination of PRP, Holco and Mills resistors, polystyrene and silver mica pF caps, BG Std for the 10uF 16V (they're cheap anyway) and Solen 1uF for the PSU decoupling.
The rest, preferably the Wima/Rifa MKP 100nF's and Panasonic FC electrolytics should be sourced elsewhere or otherwise use what you can find, just make sure they'll fit on the pads. For the semiconductors it's each man for himself.
It would be good also a few "pioneers" may experiment early on with the various type of FET's provided for to see if there's any clear winner. The IRFD types are easy to do so with since they fit into a DIP-4 socket, but the SOT-223 packages are for keeps once they're mounted unless you've skill and guts.
For the LTP transistors fast ones would be preferable if fast output transistors will be used, and that's why the original 2SA/2SC ones will do well or alternatively BC546/556 that may work possibly even better.
HI
With out the BOM it would be difficult to look for the parts or order them.
Which schematic we use , or some information about the transistor , mosfet replacement .
I thought we have the BOM like at KSA-50 .
Mark you already built the amp for test , which schematic U used ?
I just want to order the resistors until the sale end at Partsconnexion .
I don't want GB on the parts , I have some Panasonic capacitors and transistors already .
Regards
With out the BOM it would be difficult to look for the parts or order them.
Which schematic we use , or some information about the transistor , mosfet replacement .
I thought we have the BOM like at KSA-50 .
Mark you already built the amp for test , which schematic U used ?
I just want to order the resistors until the sale end at Partsconnexion .
I don't want GB on the parts , I have some Panasonic capacitors and transistors already .
Regards
