KSA100 PCB try
Hello everyone,
I tried to read as much page as i can but there are many posts to read, i keep gooing to read them as i find time.
I really planned to construct a Krell ksa amplifier most probably it would be KSA50 but i draw an pcb in a way that i can avert it to the KSA100 or KSA50, as you know both amplifier very similar in schematic.
I want some advise from you about pcb that im drawing and about power supply , What voltage exactly i must supply to KSA50 and KSA100 ? and most importantly how much farad the capacitors must be ( im planing to use 4pcs 22000uf 63v for ksa50) ? in some try i saw tha caps was used as over 150 000uf , is it necessary for ksa50 ?
Thanks inadavnce
Hello everyone,
I tried to read as much page as i can but there are many posts to read, i keep gooing to read them as i find time.
I really planned to construct a Krell ksa amplifier most probably it would be KSA50 but i draw an pcb in a way that i can avert it to the KSA100 or KSA50, as you know both amplifier very similar in schematic.
I want some advise from you about pcb that im drawing and about power supply , What voltage exactly i must supply to KSA50 and KSA100 ? and most importantly how much farad the capacitors must be ( im planing to use 4pcs 22000uf 63v for ksa50) ? in some try i saw tha caps was used as over 150 000uf , is it necessary for ksa50 ?
Thanks inadavnce
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Then i need to use 8pcs 22000uf 63v , or as you said 4pcs 44000uf.
Do i must to make an CRC power supply for instance 88000uf - 0.01 ohm-88000uf , or what do you suggest, what must be resistor's value?
Thanks.
the KSA50 and KSA100 are hardly equivalent.
The KSA100 has most parts doubled compared to the KSA50.
Double the transformer VA, double the heatsinking, double the output devices, double the quiescent power, double the output power.
KSA50 runs on +-39Vdc requiring 50V capacitors
KSA100 runs on +-52Vdc requiring 63V capacitors.
Thanks AndrewT ,
I didnt say they are equivalent , i just draw a pcb competible with KSA100 and KSA50 , when you put the all parts according to the pcb it will be KSA100 , if remove some of them and make some parts changed in the input stage's supply it will be KSA50.
Still im improving the pcb, i dont know the copper plate can stand the 4A under 52v, i will test it by printing a test board otherwise i need to ticker the line.
I still waiting for the KSA advise
Thank to all of you.
You did not say they are equivalent.
You only said you want to swap between the two as if they were equivalent.
🙂 I just wanted to say that i drew a pcb board for Krell KSA50 and 100 , if you use my board you can construct either KSA50 or KSA100 on.
If you have any other advise please feel free to say,because i dont want to say i wish i would did this thing after finishing my KSA.
Thanks AndrewT
Hello everyone
I am just about finish my KSA50/100 test board one or two parts are missing, as i drew the pcb changable from 50 to 100 , i assambled it as ksa100 but i have a small transformer rated +/-52v 500va ,before buying new transformer i will test the board with that 500va transformers just to be sure the board is fine.
I think i will change this board to ksa50 to be able to compare both KSA and i will construct which one i like.
From now on i need a good power supply as i mentioned before i use 8x 22000uf Nippon Chemicon KMH capacitors, i want to use upc1237 protect in the power supply if you dont offer me better than that, i used that small protector in my F5 amp's supply and it was pretty good to protect spekars.
Im waiting for your reply.
Thanks
I am just about finish my KSA50/100 test board one or two parts are missing, as i drew the pcb changable from 50 to 100 , i assambled it as ksa100 but i have a small transformer rated +/-52v 500va ,before buying new transformer i will test the board with that 500va transformers just to be sure the board is fine.
I think i will change this board to ksa50 to be able to compare both KSA and i will construct which one i like.
From now on i need a good power supply as i mentioned before i use 8x 22000uf Nippon Chemicon KMH capacitors, i want to use upc1237 protect in the power supply if you dont offer me better than that, i used that small protector in my F5 amp's supply and it was pretty good to protect spekars.
Im waiting for your reply.
Thanks
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@huseying: I am not sure what you are asking us.
As for speaker protection: no, I am not using anything at all, but it is advised.
As for speaker protection: no, I am not using anything at all, but it is advised.
Im asking for speaker and over current protection, as i mentioned befor upc1237 do both job but i read some disadvantage about it, some said it detects only the positive rail or something like that.
Anyway Thank you henryv.
Best regards
I,ve built 6 Krell mono blocks and never used any protection at all.
That being said, if you feel unsure of your build then protection will give you piece of mind.
I just don't like what the signal passes through on its way to the speaker.
If you sit with your build on the bench and do all the stress testing beforehand and get a good feel of what's going on you can get away without it.
Regards
David
That being said, if you feel unsure of your build then protection will give you piece of mind.
I just don't like what the signal passes through on its way to the speaker.
If you sit with your build on the bench and do all the stress testing beforehand and get a good feel of what's going on you can get away without it.
Regards
David
Thanks AVWERK for your reply
In my leisure time i draw a pcb board for power sup. , i was thinking about this design for a while , it looks good and i think it works if the space is matter. It contains two upc1237 protect for each channel, when you think about upc's price , simplicity , there is nothing wrong to embede it in your amp, i think.
Still i havent got the chance to test the Krell board , after all test as KSA50 and 100 probably i encolsure it as Class AB amplifier because i have a good looking case but not big enough to run amplifier in Class A even in KSA50 mode of course if i wont get time to construct new amp case.
if any advice you wanna say pleas let it go.
Thanks
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It is not shown on the picture but there is a flat surface about in the center vertically and for 2/3 of the lenght. I can use a piece of corner aluminum. There is a cavity at one end where a directionnal coupler used to be inserted.
True I cannot connect a corner piece all along this heatsink.
I may use it instead for the CSX1 Amp then. I have only two fet to connect to the heatsink and I can insert the Jensen transformer in the cavity and shield it correctly from the power transformer using Mu-Metal.
I have other heatsinks.
Nice thing about these heatsinks though is that I have a very tough mating power supply, open framec chassis where the heatsink's mechanical mounting bolts match the supply bottom frame. I can have a very sturdy casing, missing only a nice front, rear and top (from Front Panel Express, to have a very nice looking amplifier. I may give it a try and see what are the transistors temperature. It may not be optimal, but it may be doable.
True I cannot connect a corner piece all along this heatsink.
I may use it instead for the CSX1 Amp then. I have only two fet to connect to the heatsink and I can insert the Jensen transformer in the cavity and shield it correctly from the power transformer using Mu-Metal.
I have other heatsinks.
Nice thing about these heatsinks though is that I have a very tough mating power supply, open framec chassis where the heatsink's mechanical mounting bolts match the supply bottom frame. I can have a very sturdy casing, missing only a nice front, rear and top (from Front Panel Express, to have a very nice looking amplifier. I may give it a try and see what are the transistors temperature. It may not be optimal, but it may be doable.
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