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Old 5th December 2005, 03:02 AM   #5021
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Join Date: Apr 2002
Location: Salt Lake City
Quote:
Are any boards still available?
John,
Email Mark. He ordered another 100 boards recently and I believe he mentioned that they are coming in this week.
LGreen, I shoulda kept my mouth shut about the 500th page! Everybody and his solder slinging grandmother jumped on it!
Except for you and your "inopportune moment".
Lyndon
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Old 5th December 2005, 07:26 AM   #5022
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Quote:
Originally posted by AndrewT
Hi UK buyers,
I am still finding trouble sourcing Polypropylenes for C105/6(22pF 0.4/0.6), C101(680pF 0.4/0.6), C104(100nF 0.3).

Rapid and RS don't supply to these pin pitch.

Digikey do C104 but want 25 extra for post and handling to UK.

I can solve 22pF & 680pF by using polystyrene.

I am thinking of using These for the 680 and 47 pf caps
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Old 6th December 2005, 02:36 AM   #5023
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More Boards Are On The Way!

There are 97 more boards on the way to me that I will have tommrrow. So anyone interested in some should contact me asap. These are .060 thick instead of the .090 of the last order. Hopefully this will help with the hole size problem a bit.
This will be the last large buy of KSA-50 boards by me.

Its time to move on to other projects and to take what little amount of spare time I have right now and get my KSA50's into their perspective chassis. Then its on to an ultimate version of the 12B4 line stage....

Anyone that ordered boards and have not yet received them will be receiving them very, very soon!!

Mark
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Old 8th December 2005, 02:33 PM   #5024
googler is offline googler  United States
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Troy,

Any news with the parts GB?

Thanks,
Brad
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Old 9th December 2005, 01:18 AM   #5025
lgreen is offline lgreen  United States
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Chumlies, how about a reply to my post #5016?

Quote:
Originally posted by lgreen

Hey, here is a question---

I'm using a 3-in-1 AC inlet/switch, you know the kind with the on/off switch built into the ac inlet so its all 1-piece. Now, sometimes when I turn the amp on, I hear a click come from the AC inlet and the power immediately turns off. This happens right away when you turn the amp on. My guess is that the AC cord is coming loose from the AC inlet, or the 3-in-1 is malfuntioning. I can't find anything wrong with the connections inside the amp. This all happens before the soft start has time to bypass the thermisters, it all happens immediately on flipping the on/off switch. Sometimes I get the same noise when I turn the amp off because my big thumb is blocked by the AC cord and its tough to make a decisive off-switch motion, so its off for a split second and then on again but no juice is coming into the amp.

I just turn it off adjust the power cord from the wall to inlet, and then turn it on again and it works, or if not, readjust and keep trying till it works. Weird. Anyone have this problem before or know what it is? Thinking a bridge could have been blown, I checked the DC rails with a scope, everything looks good and is at the proper voltage.

I have tried 2 power cords and it happens with both. A standard IEC cord, and a really massive PS Audio Lab cable that is so humungus that if you saw it you might suspect this type of problem.

Note- my soft start uses 3 ohm thermisters but shunts them using a 15A/220 V relay and 14 gauge wire 5 seconds after turn-on.
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Old 9th December 2005, 04:08 AM   #5026
zlast is offline zlast  United States
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Default KSA 50 questions

I have been reading the WIKI and KSA 50 thread and have a few questions about the Jans origonal KSA 50 pcb and output boards.

1) If the mainboard is assembled WITHOUT the protection circuit, then only P-OUTPUT, N-OUTPUT, -VCD and +VCD are connected to the output boards? Is this correct?

2) Several DIYers have finished the KSA 50, any comments on including or excluding the protection circuit ?

3) If you want to run the amp in high bias constanly, can you simply leave out R144 ?

4) For the DIYers that have built both an ALEPH and the KSA 50, or listened to both, which do you recommend?

Thanks !

Z
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Old 9th December 2005, 04:41 AM   #5027
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Quote:
1) If the mainboard is assembled WITHOUT the protection circuit, then only P-OUTPUT, N-OUTPUT, -VCD and +VCD are connected to the output boards? Is this correct?
I believe there is also a feedback connection to hook up .

Quote:
Several DIYers have finished the KSA 50, any comments on including or excluding the protection circuit ?
If your speakers have a very strange impedance curve you may want to include it... Other wise the original factory built KSA's didn't have any protection circuitry at all.



Quote:
If you want to run the amp in high bias constanly, can you simply leave out R144 ?
Someone else here might know for sure but the output devices can only take so much current before they will self destruct so its probably not a good idea to leave it out... Mine are biased at 400 mv per device measured across the emitter resistors. There is a BIAS CALCULATOR some place in the Builders WIKI that will help you calculate the proper bias level based on your rail voltage and number of output devices..


Quote:
For the DIYers that have built both an ALEPH and the KSA 50, or listened to both, which do you recommend?
It depends on what your having for dinner........ Both are like fine wines....... Both are excellent amplifiers......
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Old 9th December 2005, 04:44 AM   #5028
Luke is offline Luke  New Zealand
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Quote:
4) For the DIYers that have built both an ALEPH and the KSA 50, or listened to both, which do you recommend?
try them and see, I prefer alephs but both are good amps. Everyone has different systems, likes and dislikes so you will get diferent answers from everyone. No one is right or wrong, just opinions
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Old 9th December 2005, 05:37 AM   #5029
lgreen is offline lgreen  United States
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Default Re: KSA 50 questions

Well, so much for trying to get some answers!!!!


Ok, Zlast-

1) Wrong! You will need those, PLUS, (a) the feedback wire, (b) Q111 Base, (c) Q111 Emitter, (d) Q111 Collector. Note that Q111 should be placed on the hottest output heat sink for thermal tracking or compensation of some sort. This makes for a lot of wires, trust me, I know. I used 3-conductor shielded wires and had an extra braided shield to ground, so had even more wires running around. Someone (probably Jacco) said to make sure that the feeback wire was high quality-- silver/teflon or something if you care about that kind of thing.

2) I made it without protection and so far no explosions, and I play it very loud. But I've got some serious transistors and a big power supply.

3) Yes, I don't think anyone except me has actually put in a R144. R144 does nothing unless you also put in a switch, but the board is not properly drilled for such a switch. I had to hack the ((**&^^ out of the board to get my switch in there. Plus if you omit R144 and you want to turn down the bias you can just turn it down with R126 and a screwdriver.

4) Aleph X in progress; check back in about 6 months......................
EDIT- Oh wait, you said "Aleph" not A-X. I've got an Aleph 3, and to be honest-- I like the KSA a lot more. Its got more depth, its effortless compared the Aleph, which is saying a lot since the Aleph is a sweet amp. I swap them back and forth and always prefer the Krell unless the volume at which I am listening is very low. Both of these are little room heaters. My speakers dip to 4 ohms so the KSA's are a little better at providing current to this load. However I hate to not recommend the Aleph, with certain speakers they may be better-- just not mine. Also.....don't tell anyone but the Aleph has a tiny bit less hummmmmm than my krell.....but i'm working on that. sshhhh.....

my ksa is at www.parttimeprojects.com
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Old 9th December 2005, 07:33 AM   #5030
AndrewT is offline AndrewT  Scotland
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Hi Lgreen,
have you rechecked your grounding?
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