Roender's FC-100 prototype and builder's thread

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Hi Finished the small pcb s,, time to start on the big two and that means the case goodie :) regards john
 

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John, the 2 heatsinks that I am using as side-panel, have a size of 380 x 170mm. The ALU bottom-plate, on which I have screwed the 2 heatsinks,
has a size of 370 x 160mm and is 10mm thick.

This heatsink is never getting more than "hand-warm", regardless of how loud I play music.

Best regards - Rudi_Ratlos
 

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Andrew, I do not have an appropriate thermometer to measure the heatsinks's temperature.

"Hand-warm" means: I am always able to put my fingers on the heatsinks without saying: "Ouch" ("Autsch" - in German language).
Maybe about 50-60 degrees. I don't know.
I will know, after I have finished my "DS1820 - temperature-sensor" - little project.

Best regards - Rudi_Ratlos

P.S. The major indication for adequate heat-dissipation is: the NJL - transistors themselves do not get "hot"!
 
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@Rudi&Metal: If you would like to discuss Mihai's design, maybe you should consider doing it in RMI-FC100 thread. We are derailing this one into something I do not like too much, and would probably dislike even more if I was the designer of FC100. I have a great respect for Mihai's work, and would not want to end up building Symasym, FetZilla or lawn mower with FC100 boards from this thread. I don't know about the rest of the guys, but unless PCBs respect the original proven and tested design, I think I will pass for now.

Sorry if I am getting too sensitive about all this, I still think you guys are doing a great job ;)

QFT
 
I was playing with the LTP. I compared 2SK369BL and 2SK170BL

Idss of 2sk170BL 9,31mA/9,31mA other pair 9,34mA/9,34mA
Idss of 2sk369BL 9,40mA/9,43mA other pair 9,45mA/9,49mA

Result of Right channel about 30Wrms 6R resistive load.
Please do not take the high order harmonics into account since those are comming from my sinus generator.

THD1 LTP 2SK170BL:
View attachment 275684

THD1 LTP 2SK369BL:
View attachment 275685

Using 2SK369 in the LTP i can feel more air the vocals are much more defined i can hear the smallest breath.
Hmm... the 2sk369 has more Ciss but more Yfs, maybe the transconductance rules here
:confused:

Can you get and try LSK489?
 
Hello Telstar,

did you mean lsk389?
It would be nice to try but i plan to drop bf862 into the ltp and see how it works.
Cheers
:)

No I really mean 489, the new part that they were giving samples at Burning Amp. The distortion on the 389 was promising, and for power amp superlow noise is not 1st priority.
(edit: cant find correct part number)
 
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Yes, the thick line matches the "bar" in the diode and LED symbols and also matches the "flat", if there, of the LED.
My 3mm LEDs don't have a flat, nor do my rectangular LEDs have an identifying/orienting flat.

I can make rectangular LEDs from 3mm round and 5mm round, to enable thermal coupling in the three (3) locations where Roender designed in the tempco.
 
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