cap polarity.... another mosfet amp

[Nico Ras]

I appreciate everyone's response. I am looking to try a simple amp that I could learn from and troubleshoot. I see in your list of amps you have built a 100 watt mosfet similar to the postings I previously posted. It uses 2sk1058/2js162 mosfets though....would this be a good one to try? Does it work well?

I appreciate everyone's response. I am looking to try a simple amp that I could learn from and troubleshoot. I see in your list of amps you have built a 100 watt mosfet similar to the postings I previously posted. It uses 2sk1058/2js162 mosfets though....would this be a good one to try? Does it work well?

Hi rtill.

The amp that you found in your first post is almost identical and probably a bad component copy between an amp I did in the late 80's or early 90's and the one you found in the first site. This amp was designed to use lateral MOSFETS 2SK1058/2SJ162 and to replace the LFETS for V/HEXfets is catastrofic. Besides there pin configurations being different.

Since I am in the process upgrading my web site there aren't anything available on it so I will e-mail you the full documentaion with PCB layouts that many DIYs have built without problems and I don't think anyone wants to see the same circuits here again.

Kind regards

Nico

 

[rtill]

I would like to know for informational purposes....if I were to add an extra set of mosfets to this amp, would this give me more wattage? and would I have to increase amperage to get more watts?

I am just trying figure out why some 100 watt mosfet power amps only have one pair and some have 2 pair of transistors. Or does adding the extra set just dissapate less heat so the transistors are less likely to overheat?

 

[ostripper]

if I were to add an extra set of mosfets to this amp, would this give me more wattage? and would I have to increase amperage to get more watts?

That depends on the load (speaker) , 2 pair would be best
for a 4R sub , you would need more current and that
is where the extra pair comes in (read the safe operating area
plot on device paper) At 4 ohm you would develop almost
twice the wattage (200W) with the same rails (+-50V).
OS

 

[Nico Ras]

I would like to know for informational purposes....if I were to add an extra set of mosfets to this amp, would this give me more wattage? and would I have to increase amperage to get more watts?

I am just trying figure out why some 100 watt mosfet power amps only have one pair and some have 2 pair of transistors. Or does adding the extra set just dissapate less heat so the transistors are less likely to overheat?

Hi rtill, that is my amp. Okay I should not bitch, I placed it in the public domain so it becomes anyone's amp.

It is good for about 120 watt into 8 Ohm using +-55VDC. You can double up on the 2SK1058/2SJ162 and also get higher Vce transistors by changing MPSA06/52 for MPSA42/92 and BD140/139 for MJE340/350.

The bias is set to about 230 - 270mV as shown with the two diades

You can run this amp from about +-66VDC and get 232 watt from an 8 Ohm load and if your heat sinks are good and power supply
does not sag, probably around 300 watt into 4 Ohm, but for safety sake I will run four output pairs per channel. This is a nice general purpose performer and sound pretty neutral to anything thrown at it.

Kind regards

Nico

 

[Nico Ras]

Hi rtill, that is my amp. Okay I should not bitch, I placed it in the public domain so it becomes anyone's amp.

It is good for about 120 watt into 8 Ohm using +-55VDC. You can double up on the 2SK1058/2SJ162 and also get higher Vce transistors by changing MPSA06/52 for MPSA42/92 and BD140/139 for MJE340/350.

The bias is set to about 230 - 270mV as shown with the two diades

You can run this amp from about +-66VDC and get 232 watt from an 8 Ohm load and if your heat sinks are good and power supply
does not sag, probably around 300 watt into 4 Ohm, but for safety sake I will run four output pairs per channel. This is a nice general purpose performer and sound pretty neutral to anything thrown at it.

Kind regards

Nico

Correction MPSA56 for MPSA92, MPSA06 for MPSA42 and BD139 for MJE350 and BD 140 for MJE340. For the long tail pair you can consider 2SA970