Stolen Trademark Amplifier from Jim's Audio on EBAY

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Depends on which zobel you are talking about. The RC at the output of the amp must be physically at the output of the amp - the original KSA 100 had them mounted on the speakers terminals - I know because I have one. Some system scan also benefit from a similar RC network at the speaker input terminals of 0.01 to 0.1 uf / 10 ohm 2watt, but this is not across the woofer terminals - across the woofer you may have an impedance compensation RC network of 10 to 40 uf and 5 to 10 Ohms - this performs a different function.
 
100 degrees is 37.77 C so it's definitely cool enough.
Have you checked the output on a scope to see if you have oscillations?
Tick is right about the Zobel being inside the amp
Did this to all of mine regardless.
You never know what load you might have.
Cheap insurance.

Regard
David
 
Depends on which zobel you are talking about. The RC at the output of the amp must be physically at the output of the amp - the original KSA 100 had them mounted on the speakers terminals - I know because I have one. Some system scan also benefit from a similar RC network at the speaker input terminals of 0.01 to 0.1 uf / 10 ohm 2watt, but this is not across the woofer terminals - across the woofer you may have an impedance compensation RC network of 10 to 40 uf and 5 to 10 Ohms - this performs a different function.
Thank you ticknpop. I believe what Partexpress.com tried to explain that high frequencies causes a rise in impedance or variable impedance in the woofer or away from their normal impedance--2, 4 or 8ohms driver impedance. OK, I will follow the original and Kaplaars's built by putting 0.1uF and 5.6ohm, in series, at the amp's speaker's terminals. But I would imagine that who designed my Carol and Altec Lansing Model 8s speakers took care of possible manipulation of the woofer's impedance by high frequencies in their crossovers, no?
 
Oscillations

100 degrees is 37.77 C so it's definitely cool enough.
Have you checked the output on a scope to see if you have oscillations?
Tick is right about the Zobel being inside the amp
Did this to all of mine regardless.
You never know what load you might have.
Cheap insurance.

Regard
David
No oscillations. Clean as a whistle. Will check again tomorrow though. The sounds are so clean. I play my music from a Marantz CD-67--which has a great DAC but only 16bit, but most music stops there--directly to a tree of dale resistors attenuator. I have a equalizer but adds a rush and noise to the sounds. The more I burn in, the bass appears. But the funnny thing, the left channel runs cooler ( 94F) than the right channel (120F) at the output T03s and 84F and 93F MJE15032/33s--between left and right channel. I matched the emitter channel within each channel, but not against each channel set. So the difference between the strings of each channel causes the current of each channel causes the difference in temperatures. Cool huh? The voltages at each channel's snubbers (R-50.11v and L-48.98v.. One volt difference couldn't cause the difference in temperature? Oh. This isn't a big deal, just an observation. Thanks for yours, David
 
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Wattage

No oscillations. Clean as a whistle. Will check again tomorrow though. The sounds are so clean. I play my music from a Marantz CD-67--which has a great DAC but only 16bit, but most music stops there--directly to a tree of dale resistors attenuator. I have a equalizer but adds a rush and noise to the sounds. The more I burn in, the bass appears. But the funnny thing, the left channel runs cooler ( 94F) than the right channel (120F) at the output T03s and 84F and 93F MJE15032/33s--between left and right channel. I matched the emitter channel within each channel, but not against each channel set. So the difference between the strings of each channel could cause a difference in each channel could cause the differences in temperatures? Cool huh? The voltages at each channel's snubbers (R-50.11v and L-48.98v.. One volt difference couldn't cause the difference in temperature? Oh. This isn't a big deal, just an observation. So. Now I have .360 at across each emitter resistor. Ohm's Law says .360/1ohm= 0.36 Ie. Can anyone tell me what kind of wattage I have going to the speaker. Thanks for yours, David
 
Test signals for Oscillation

100 degrees is 37.77 C so it's definitely cool enough.
Have you checked the output on a scope to see if you have oscillations?
Tick is right about the Zobel being inside the amp
Did this to all of mine regardless.
You never know what load you might have.
Cheap insurance.

Regard
David
Here are various test signals at speaker terminals. Oscillation check. Looks clean to me.
 

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Have received the Krell Clone KSA100 II PCB´s from Jims Audio. To everyone that are a little uncertain about the quality of these boards. The missing connection pointed out by Kaplaars is now in place. So are the faulty silk screen print of the two resistors. These boards are top quality with thick gold plated through holes. To me it seems that these are even surpassing the originals. Looking forward to get them powered up.
 
Spurlite, Here is a couple pictures of the very first answer board for the original group buy. Indeed, it makes a great headphone amp in and of itself. Square wave response was also perfect. What devices did you use as the Constant current sources? I am just curious as original board was set up for your choice of two different types of devices. Both of which I tested with great results...

Mark G.
 

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OK, I have been warned . We have to see how high a bias I will get before burning my hands. Otherwise I have to expand the cooling surface quite a bit. Just wanted to avoid the fans. Have to get the output turn on delay and DC protect in place before powering up. The current inrush limiting is in a separate enclosure. Crossing fingers !!
 
You are substituting the constant current diode with the three pin (TO-92 package)LM334, so the 23 Ohm resistor goes into the holes of the constant current diode. If you have the 33 Ohm resistor, just solder a 75 Ohm resistor in parallel with it and you are pretty close to 23 Ohm.
 
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