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VSSA Lateral MosFet Amplifier

Ex-Moderator R.I.P.
Joined 2005
getting harder to find now
but only change is reading 4,00V instead

Please also post new instructions.
As far as i know there was a bug in the printed instruction that came with the amp modules concerning adjustments.

Hi all VSSA GB members :wave:

By re-reading VSSA Installation manual I found one important thing to be corrected. ;)

In Step 2 of Calibration adjustments the correct text should be as follows:

"Our final target for V-meter 1 reading is 4,00 V and 0 mV for V-meter 2 reading. Turn on the power supply and observe both V-meters displayed values. Clockwise rotation of TR3 will increase V value of V-meter 1 and should have no effect on mV value of V-meter 2 readings. Rotate trimmer TR3 in a direction to reach our final target goal 4,00 V reading on V-meter 1 (meaning 4,00 V/22 Ohm = 182 mA output bias current + front end bias current)."

Please make a note and calibrate output bias according to upper correction. Thanks. :up:
 
Please also post new instructions.
As far as i know there was a bug in the printed instruction that came with the amp modules concerning adjustments.

In Step 2 of Calibration adjustments the correct text should be as follows:

"Our final target for V-meter 1 reading is 4,00 V and 0 mV for V-meter 2 reading. Turn on the power supply and observe both V-meters displayed values. Clockwise rotation of TR3 will increase V value of V-meter 1 and should have no effect on mV value of V-meter 2 readings. Rotate trimmer TR3 in a direction to reach our final target goal 4,00 V reading on V-meter 1 (meaning 4,00 V/22 Ohm = 182 mA output bias current + front end bias current)."

Please make a note and calibrate output bias according to upper correction. Thanks. :up:
 
Also the new Scan Speak subwoofer.

Scan Speak distortion is so low probably because of Symmetric Drive. If in and out movement of the cone is identical harmonic distortion is low. Also, if some kind of compensation ring is used on the pole piece to prevent permanent magnets's field to be modulated by the field created in the voice coil, additional reduction of harmonic distortion is achieved.

BTW, I can not wait to see the design for your new three way closed box. I believe that it can be great match for VSSA. I think that most people need something that is not too expensive but is good sounding.
 
Member
Joined 2011
Paid Member
Do not cheap! By another one, or maybe two!
UNIT-61E is a good choice also.


I've got only one DMM at hand. This one:

Sinometer AC/DC Auto/Manual Range Digital Multimeter, MS8268 - Amazon.com

Have anyone succeded biasing it with one instrument? Is it possbile? If I were to buy another one, all recommendations welcome. To cheap or not cheap is the question. This one is on my radar so far:

Amazon.com: Extech EX330 Autoranging Mini Multimeter with Built In Thermometer with Type K Remote Probe: Home Improvement
 
2200u/16v fits OK but for 1000u/50v I had to bend legs a little. 2200u/50v has proper distance 7.5mm. I can't find anywhere FG nichicons at reasonable prices.

Yep, those were the ones in question. The KA series have very similar specs to the FG, just higher heat tolerance. I'll probably get them and "make them fit" for the two who are 5mm spacing into 7.5mm holes.

-Melt