SlewMaster Builds

Bellow 3 IPS boards --> files for thermotransfer, the 4th one Ill check after my holidays.
There is still some work left on all of them but they are safe to solder anyway.
IMPORTANT --> tube IPS is causing full DC at the output of the amp before cathodes are heated up so it can be used only with DC protection circuit (it needs approx 5-8s before NFB starts to correct DC).

The CFP-Mad, was tested on +/-45V psu so far.
Ready to populate. I changed the layout slightly to better match up with the Slewmaster.
 
Tery, couldn´t be problem here? Pins from transistors which are between resistor can easily damage resistors coating....
 

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The CFP Madness is singing but it has a little oscillation. No oscillation without a load.

I'm open for suggestions.

One note, the schematic calls for KSA1142 and I used 2SA1362.

Thanks, Terry
 

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Hi Valery,

Thanks, I will try that first thing tomorrow.

Hi borys,

I had your ops playing with the Krypton C for several hours. It was running on 60v rails and not breaking a sweat. I will try some other IPS tomorrow. I like it. The best thing is that it will fit in a 2U case.

I have the Cliffjumper ready to test too. I'll let you know how that goes in the morning. I wanted to test the VSHA too but I'm out of tube sockets.

Blessings, Terry
 
Thanks a lot !!
It really help me a lot in development, I have only basic equipment and poor head so any help is really needed.

The Cliffjumper --> the LTP's at the front are very low biased (approx 1mA total 2x0,5mA), use standard small diode with forward voltage drop around 1,8V.
There is plan B for that IPS too but not tested yet (pic bellow)

Regards
 

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Thanks a lot !!
It really help me a lot in development, I have only basic equipment and poor head so any help is really needed.

The Cliffjumper --> the LTP's at the front are very low biased (approx 1mA total 2x0,5mA), use standard small diode with forward voltage drop around 1,8V.
There is plan B for that IPS too but not tested yet (pic bellow)

Regards

The Cliffjumper is singing. Sounds fine. Square waves look a little rounded. I used 2u2 for the input cap cause I didn't have 3u3. I thought this might be the reason so I bypassed it. When taking readings after this the square waves looked the same but after a few seconds the driver on the - side shorted again and burned the resistors again and of course blew the fuse. Strange stuff.
 

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With 10p the oscillation is back just like before.

EDIT;

Let me get back to you. I want to try it with a bona-fide Slewmaster OPS and see if I see the same thing.

One more question. I didn't use KSA1142. Is there something different about those? I used 2AS1362.
 
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Looks like a thumb drive next to the Slewmaster.

It sounds really good and the amp is dead quiet.

There are some funny nodes on the verticals but the tops stay pretty straight. This is with the 10p cap installed.

I also have a 2u2 input cap rather than the 3u3 called for. I'm not sure if that matters.

Blessings, Terry
 

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I was looking at your slew setup to moderate my next "move".

I think I can get the "hulk" (below) to be "drop-in" compatible with the
original 5P slewmaster.

Just a little longer (247mm = 9.75").

Why the hulk ?

MT-200 = 5- pair , thermals spread out better for 2Kw of devices.
With 3 pair of whatever , still ... better thermals. (pretty universal)
300W - 500W !! (<800/4R) - your choice.

Since I am totally redesigning it .... should I make it VFET compatible ?
The thermals would be better here ... plus I could add the zener Vgs
protection ??

I'll move this discussion over to the main thread later.

OS
 

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I was looking at your slew setup to moderate my next "move".

I think I can get the "hulk" (below) to be "drop-in" compatible with the
original 5P slewmaster.

Just a little longer (247mm = 9.75").

Why the hulk ?

MT-200 = 5- pair , thermals spread out better for 2Kw of devices.
With 3 pair of whatever , still ... better thermals. (pretty universal)
300W - 500W !! (<800/4R) - your choice.

Since I am totally redesigning it .... should I make it VFET compatible ?
The thermals would be better here ... plus I could add the zener Vgs
protection ??

I'll move this discussion over to the main thread later.

OS
VFet compatible sounds like a good idea.