kevin gilmore

krell ksa5 klone

621 posts in this topic

my guess is that the output transistors and the 2 ohm resistors are toast.

 

I replace the pot with fixe resistor to test, and everything run fine ;D

 

Put sine wave in the input and get an nice sine wave at the output !! Need just to wait to get the right pot...

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Inu, nice use of Teflon tubing to get all the small transistors exactly the same height.

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Very clean and it reminds me to get some tubing...  :)

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http://gilmore.chem.northwestern.edu/ksa5klone.jpg

 

the fat version of the pot fits perfectly.

 

I figure about 5 hours of build time total if I had all the parts

ready to go  without having to start and stop waiting for

multiple orders.

Edited by kevin gilmore

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Can someone PM me the gerbers?

 

Thanks!

 

Edit: I should ask, does anyone have a board?

Edited by holland

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Thank you for another great project.

 

Is there a preferred version of the LSK389? Trendsetter. com has both the B & the C variant in stock.

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Yeah, the B-job. It's better, you know that.

Hell, it will only cost you a buck more. What are you waiting for? Dew eet!

 

Or look at it this way - would you buy a crappy Escort when you got the dosh to throw down on a GT? I thought so.

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Doesn't really matter which version you pick but it's normally good to go for the lowest noise. 

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Yeah, the B-job. It's better, you know that.

Hell, it will only cost you a buck more. What are you waiting for? Dew eet!

 

Or look at it this way - would you buy a crappy Escort when you got the dosh to throw down on a GT? I thought so.

If the B-job makes the KSA5 Klone go better like the GT, then I am tempted to pay the extra few bucks. But I might come back and complain if my KSA5 ends up with the (reported) reliability of the GT ;D

 

Doesn't really matter which version you pick but it's normally good to go for the lowest noise. 

Excellent. Thanks.

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original power supply version of the krell ksa5 power supply

also suitable with lower voltages for the singlepower squarewave

the later version coming shortly

 

 

http://gilmore.chem.northwestern.edu/ksa5psorig.jpg

 

http://gilmore.chem.northwestern.edu/ksa5psorig.zip

 

 

and here is the alternate version of the krell ksa5 power supply

 

http://gilmore.chem.northwestern.edu/ksa5psg.jpg

 

http://gilmore.chem.northwestern.edu/ksa5psg.zip

Edited by kevin gilmore

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I love TO-3 packages. They look so cool and retro :)

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Only problem, finding some HV ones that are not for TV use and with horrible Cob....  :(

 

Edit.  And who ever thought it was a good idea to call the new ones TO-3P needs to be taken out back and shot. 

Edited by spritzer

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original power supply version of the krell ksa5 power supply

also suitable with lower voltages for the singlepower squarewave

the later version coming shortly

 

 

http://gilmore.chem.northwestern.edu/ksa5psorig.jpg

 

http://gilmore.chem.northwestern.edu/ksa5psorig.zip

 

 

and here is the alternate version of the krell ksa5 power supply

 

http://gilmore.chem.northwestern.edu/ksa5psg.jpg

 

http://gilmore.chem.northwestern.edu/ksa5psg.zip

 

Silkscreen on the original board = I think R4 is 562 not 750.

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Has someone finish and listening to his KSA-5 ?
I just finished mine, and I'm very disappointed :- 
Sound very "thin" and clip very quickly.... Not exactly what I was waiting for !

 

Edit : I use a Beyerdynamic T1, which is not very difficult to drive...

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don't know about T1, but sounds great on hd800 and lcd2.

this amp does not have as much voltage swing as you might

expect for something that runs on +/-21v.

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Mine actually run with +/-25V ! and I expect to rise to 28V...

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better change the opamp to something that can handle that like opa445.

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better change the opamp to something that can handle that like opa445.

 

I have a OPA445 8)

 

The headphone output from my old CD player is far better ! I hope that with burn in time he will get better...

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I suspect something is broken for it to sound this way. 

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Has someone finish and listening to his KSA-5 ?

I just finished mine, and I'm very disappointed :- 

Sound very "thin" and clip very quickly.... Not exactly what I was waiting for !

 

Edit : I use a Beyerdynamic T1, which is not very difficult to drive...

 

 My origional KSA5v with the blackgates has never shown any signs of clipping even when driving my k1000s at full volume( it drives them to a reasonable listening level at full volume ,but definetly could use more power then the krell can produce) but it is very clean sounding with no clipping at all. No way would I call the Krell thin sounding.

 I have found the T1 to sound best with tube amps,I have never tried the T1 with it. I do own A Blackdragon  recabled T5p I will have to give a listen with the Krell when I get a chance.

 I also find the T5p to be picky with some portable amps but sounds great directly out of My Dell laptop listening to CDs go figure.

Edited by bozebuttons

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I go to buy a function generator to see how and when he clip. Like this I can measure the output power too...

 

Any recommendation for the generator ?

 

The amp run since 5 hours and he is getting to sound better !

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