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
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
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
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
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
I believe there is also a feedback connection to hook up .
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.
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..
It depends on what your having for dinner........ Both are like fine wines....... Both are excellent amplifiers......
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
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
Re: KSA 50 questions
I'm still in the process of getting the KSA50 together.
But i've constructed Aleph amplifiers and heard both the real A and K things on the same and different loudspeaker systems.
It's a system approach, it depends on your loudspeakers and your preferences.
In the stone age i've heard the Japanese Kodo drums through the Infinity IRS and Martin Logan Statement 1, all Krell, completely out of this world.
On Quad ESL63's my preference goes to Pass amplifiers.
I do not wish to combine them with dynamic subwoofers, maybe if i have the chance of obtaining a second set of ESLs one day the KSA50s might be great to drive those.
But if you are talking dynamic, i've heard the KSA50 on Duntech loudspeakers.
And the description of Krells is right, it really slamms in your face.
Now, i am sort of an oddball(as if no one noticed)
I enjoy both hitting my Van and driving my neighbor up the wall with 100s of watts of Metal, Swiss Yello, and Art of Noise, showing off my tattoos and piercings.
On the other hand i like to play sophisticated private school nerd, and enjoy ballet, opera and jazz music.
I am guessing the Al styled KSA50s will be both better in the bang as well as the delicacy in producing voices than the Dan's.
When they are finished the KSA50s will be tagteaming with multiway dynamic loudspeakers for whenever i'm in the mood of some high quality wall shaking.
zlast said:
I'm still in the process of getting the KSA50 together.
But i've constructed Aleph amplifiers and heard both the real A and K things on the same and different loudspeaker systems.
It's a system approach, it depends on your loudspeakers and your preferences.
In the stone age i've heard the Japanese Kodo drums through the Infinity IRS and Martin Logan Statement 1, all Krell, completely out of this world.
On Quad ESL63's my preference goes to Pass amplifiers.
I do not wish to combine them with dynamic subwoofers, maybe if i have the chance of obtaining a second set of ESLs one day the KSA50s might be great to drive those.
But if you are talking dynamic, i've heard the KSA50 on Duntech loudspeakers.
And the description of Krells is right, it really slamms in your face.
Now, i am sort of an oddball(as if no one noticed)
I enjoy both hitting my Van and driving my neighbor up the wall with 100s of watts of Metal, Swiss Yello, and Art of Noise, showing off my tattoos and piercings.
On the other hand i like to play sophisticated private school nerd, and enjoy ballet, opera and jazz music.
I am guessing the Al styled KSA50s will be both better in the bang as well as the delicacy in producing voices than the Dan's.
When they are finished the KSA50s will be tagteaming with multiway dynamic loudspeakers for whenever i'm in the mood of some high quality wall shaking.
googler said:
Sorry for the delay. Bad weather here has changed my schedule dramatically.
Anyway. The GB parts list did not account for the differences between the boards.
I have stepped back and done a full evaluation of both boards and am now making two kits. Each kit will contain EVERYTHING on the PCB except the output transistors.
That includes the protection circuit(Jan), the driver boards(Al), output boards(both) and any component that solders on the PCB's. EDIT: Again except the output transistors!!
I am looking for the following as of now:
Bias switch (Jan's)
Jap transistors (Jan's)
Man I should have just taken the money and ran.
rabstg said:
Sorry for the delay. Bad weather here has changed my schedule dramatically.
Anyway. The GB parts list did not account for the differences between the boards.
I have stepped back and done a full evaluation of both boards and am now making two kits. Each kit will contain EVERYTHING on the PCB except the output transistors.
That includes the protection circuit(Jan), the driver boards(Al), output boards(both) and any component that solders on the PCB's. EDIT: Again except the output transistors!!
I am looking for the following as of now:
Bias switch (Jan's)
Jap transistors (Jan's)
Man I should have just taken the money and ran.
Troy Does it mean you will offer Jan/Al kits separately? Cause I have 6 of each. Does it mean you will ask us to specify how many of each?
googler said:Thanks for the update!
What are the transistors you are looking for on Jan's boards? I have some free time, and can surf online catalogs
Attached is the BOM version I have @ work..
It is 2 pages. On Jan's(first sheet) sheet the red rows are the semi's that are not avilable from Mouser. I think I checked Digi-Key too but can not verify that here @ work.