Moskido - Hybrid Aikido/MOSFET amplifier

[albertli]

Tubee,
Can you tell me more about 'snubber' or draw a simple schma if possible. I'm a newbie and don't know much about that.
Thanks
Albert

[jueic]

Originally posted by albertli
jueic,
Happy to know that you have finished yours and happy with it. Could you post some pics.
Albert

Hi, Albertli

See the attached pic.

[jueic]

Hi, Albertli

The attachment didn't go thru, possible file size too big...I shall take a smaller pic ..... my apologies.

JueiC

[jueic]

My Moskido..

The heatsink is bit too small..otherwise this is a good amp

JueiC

[albertli]

jueic,
This is nice.
How many pair of mosfet you have on?
2 pairs on each side?
Albert

[tubee]

Originally posted by albertli
Tubee,
Can you tell me more about 'snubber' or draw a simple schma if possible. I'm a newbie and don't know much about that.
Thanks
Albert

Read on it : http://www.diyaudio.com/forums/showthread.php?s=&threadid=58461&perpage=25&pagenu mber=2
http://www.diyaudio.com/forums/showthread.php?threadid=3894&highlight=rectifier

I added a 2.2K resistor over each powerrail(pos and neg each channel)
Added a 1ohm with 100N MKT cap in series over each powerrail, this dampens HF from diode.

Alternatively use Hexfreds, i suspect they don't need a snubber anymore.

[jueic]

Originally posted by albertli
jueic,
This is nice.
How many pair of mosfet you have on?
2 pairs on each side?
Albert

Hi, Albertli

I only have 1 pair each side due to my earlier mistake of choosing small heatsinks.

Your one have huge heatsinks, that is the proper way to run MOSFETs.

I also found only the matched pair should be used.. mainly because of thermal balance is extremely important in MOSFET outputs.

JueiC

[albertli]

Tubee,
Thanks for the reply, but that 2 sites cannot be reached
Albert

[albertli]

Jueic,
I'm going to run 2 pairs each channel with the old Hitachi 2SK134 and 2SJ49. I have them sitting on the box for over 20 years. See how they would work for me.
Albert

[tubee]

Originally posted by albertli
Tubee,
Thanks for the reply, but that 2 sites cannot be reached
Albert

Maybe it works now better:
http://www.diyaudio.com/forums/showt...888#post655888

The 2nd link was for a CDP's and contained non-working url's.


Btw i added a 0.12ohm resistor after the hexfreds, i will remove them soon because bass has become more muddy and less controlled
(the amp has a slightly higher internal resistance, also becaus i use only two fets/channel) I also swapped the standard diodebridge for hexfreds, maybe the hexfreds result in a somewhat higher resistance too?

The powerfets give for me the most natural sound in mids and treble compared to bipolar transistor, but bass is outperformed bythe latter imo. Or put 8 fets or more parallel