How about 15€ a pair from your neighbors? 🙂
It was mentioned several times in other threads, but repeating it doesn’t hurt.
https://www.audiophonics.fr/en/comp...x10n20-transistor-mosfet-2sk1058-p-15183.html
Thanks.
Yes, this is a simple project.
Suitable for everyone.
I wonder if @ZoltanChivay built it ....
Maybe he did PCB
Until the beginning of January I am completely out of DIY
I tested the previous version - there was no ground for the input of one channel
Latest version - I corrected this error and everything should be OK
How much is gate bias voltage? I want to see if it works with two 1.2v NiMH batteries to bias the gate.
I’m using IRFP(9)240 in two amplifiers for daily use. With a VBE multiplier based on a BD139 bolted next to the output transistors, I’m getting a slightly negative temperature coefficient. So it can be done. I’m tempted to try this design with that mod… I love the simplicity!
I've been looking into batteries in series with a mosfet's gate for providing the necessary bias voltage(in a different design). While there is little to no information to be found of this being used for mosfets. There has been some discussion on using it to bias a tube's grid. One thing I picked up on is that rechargeable batteries may not be the best choice here. I've seen some subjective impressions that they colored the sound. The measurements shown here, https://www.mvaudiolabs.com/diy/modern-jfet-noise-measurements/#battery, may provide a quantifiable reason why. With the rechargeables showing not only higher noise but also random spikes within the audio band.
I had amplifier wth exactly same topology, build with IRFP(9)240 and with string of green LEDs fixed into heatsink holes for temp compensation. It worked in the bridged mode and was delivering more than 40W into 8 Ohm. In my setup it worked with Harbeth C7-ES3 speakers, and sounded way better than my Lyngdorf TDAI-2170.
I don't have that amp any more, so can't provide any details, but I remember that bias was quite high (amp was getting quite hot) and that distortion was surprisingly low. Less or around ~0.001% into 20 kHz (into 8 ohm, I believe). Amp was also fast, and very stable (heavy testing with square wave into capacitive load).