Thanks Jacco, got the same thing from Mouser. I have worked through the parts issues and everthing fits. Whether it works or not is another question. I have even received a large batch of 4 terminal caps.
Question- is it ok to extend the leads of the Sanken output transistors a small amount by soldering a very short wire onto each terminal and then onto the board?
Reason1- these are going on used (large) heatsinks and its either extend the leads a tiny amount or mount the transistors on top of a small screw hole.
Reason2- the L/R channel boards are quite compact and they do not space the transistors out as much as I would like, so the transistors will be pretty far off center on the heatsinks reducing efficiency. I would need to extend the leads as much as 6 cm from each side of the board to get them centered on the heatsinks. I assume this is too much of an extension?
So 1 cm extension avoids mounting on top of a hole and 6 cm extension centers them on the heatsinks.
Question- is it ok to extend the leads of the Sanken output transistors a small amount by soldering a very short wire onto each terminal and then onto the board?
Reason1- these are going on used (large) heatsinks and its either extend the leads a tiny amount or mount the transistors on top of a small screw hole.
Reason2- the L/R channel boards are quite compact and they do not space the transistors out as much as I would like, so the transistors will be pretty far off center on the heatsinks reducing efficiency. I would need to extend the leads as much as 6 cm from each side of the board to get them centered on the heatsinks. I assume this is too much of an extension?
So 1 cm extension avoids mounting on top of a hole and 6 cm extension centers them on the heatsinks.
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Answer : use extension boards (diy).
Reason 1 : You'll need something to mount/solder the base resistors on, they need to be acap to the base lead of the power devices.
Reason 2 : Why start with hardwiring if you have such pretty amp boards.
On the other hand, there's also the option to go for both stretch limo boards and hard (possibly even silverplated solid) wiring.
Attachments
almost there...
Almost there.
See I'm really not extending the leads that much.
Have to put the transistors in these spots
since the heatsink was previously drilled in a lot of places.
Anyone got some spare thermal pads to spare that can be cut to the big Sanken size?
(or know where to by a sheet?)
Almost there.
See I'm really not extending the leads that much.
Have to put the transistors in these spots
since the heatsink was previously drilled in a lot of places.
Anyone got some spare thermal pads to spare that can be cut to the big Sanken size?
(or know where to by a sheet?)
An externally hosted image should be here but it was not working when we last tested it.
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thermal conductive sheets
thermal conductive sheets
http://www.intermark-usa.com/products/Thermal/index.shtml#1
http://export.farnell.com/laird-technologies/k200-na-30x30/insulating-sheet/dp/1219148
thermal conductive sheets
http://www.intermark-usa.com/products/Thermal/index.shtml#1
http://export.farnell.com/laird-technologies/k200-na-30x30/insulating-sheet/dp/1219148
Hi Igreen, what's the dimemsion of your heatsink?
It seems like your almost done. Let us know the results.
Cheers,
Fred
Yep, after I obtain some thermal pads I can turn this thing on (thanks for the recent post on this). Oh wait, I've got to remove the broken tap from the other heatsink too.
FYI, heatsinks are approx 17.5" (44 cm) long by 8" tall (20cm) by 1.5" (3.8 cm) thick.
The heat dissipation requirements for my build are easier to meet; I will not be building this to 100WPC class A, as my tranformers are 16VAC and the emitter resistors are each 1.3 ohms.
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Power ON
Power up...(images can be made very big with proper mouse-over and clicking)
I had some problems at first but eventually got it going.
The offset control works as it should and the heat sinks get nice and toasty.
I am getting a small amout of transformer hum, I think from the variac? Each channel has 2x60,000 uf + 4x22,000 uf capacitance.
Power up...(images can be made very big with proper mouse-over and clicking)
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I had some problems at first but eventually got it going.
The offset control works as it should and the heat sinks get nice and toasty.
I am getting a small amout of transformer hum, I think from the variac? Each channel has 2x60,000 uf + 4x22,000 uf capacitance.
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Not yet...
Thanks. hard to believe it but I think you are right in that no one here has attempted this beast. I reread this entire thread and saw lots of positive posts but no builds, other than the orignal poster SSassen who has disappeared and anyhow stopped answering questions months ago.
I have not listened to it with a speaker yet. There is still much to do- check the other channel; install and wire up both power supplies with those unruly crimp connectors; install the final hardware with all the lockwashers and such; test the soft start and check all the DC voltages; clean the heatsinks; find a workaround for a tap that broke inside one heat sink; check grounding; complete back panel wiring; complete front panel LEDs and their wiring.
My intent is to report the results compared to a bunch of other diy amps in a separate "here it is" thread like people did in the old days when finishing a project. If everything still works it will be very soon. I will also post the parts list with prices and hyperlinks which I think is now pretty complete.
Wish me luck.
Thanks. hard to believe it but I think you are right in that no one here has attempted this beast. I reread this entire thread and saw lots of positive posts but no builds, other than the orignal poster SSassen who has disappeared and anyhow stopped answering questions months ago.
I have not listened to it with a speaker yet. There is still much to do- check the other channel; install and wire up both power supplies with those unruly crimp connectors; install the final hardware with all the lockwashers and such; test the soft start and check all the DC voltages; clean the heatsinks; find a workaround for a tap that broke inside one heat sink; check grounding; complete back panel wiring; complete front panel LEDs and their wiring.
My intent is to report the results compared to a bunch of other diy amps in a separate "here it is" thread like people did in the old days when finishing a project. If everything still works it will be very soon. I will also post the parts list with prices and hyperlinks which I think is now pretty complete.
Wish me luck.
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I am trying to order my transformers from www.shuro.de, but i get no reply from them at all. There transformers look sweet, and i want shielded ones. Not only for the looks
Any of you guys lucky to order something from them. Really want to move on with my project. I emailed them in english and German, so that could not be the problem. I used in my former project transformers from amplimo.
But i don't think they have shielded and casted ones, or do they?
There transformers look sweet, and i want shielded ones. Not only for the looks Any of you guys lucky to order something from them. Really want to move on with my project. I emailed them in english and German, so that could not be the problem. I used in my former project transformers from amplimo.
But i don't think they have shielded and casted ones, or do they?
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