Slewmaster - CFA vs. VFA "Rumble"

[vargasmongo3435]

the Greenamp is the last circuit that Ostriper have the schematic the layout is 100% my own design and I don't think there is one thread dedicated for my layout nobody discuss about it

 

[Krisfr]

I am just looking for the post that shows the layout of the ops section of the green amp that you did. If there is one, Thanks

 

[vargasmongo3435]

Greenamp PCB V1.2 on PCBWay

I forgot this is also on PCBWay if you have an account there here is the link

"I'm not getting sponsor by them just in case "


Audio amplifier IPS driver board The Greenamp V1.2 final design by Pete "Ostripper" - Share Project - PCBWay

 

[edub2020]

hi Thimios is 125mm x 300mm I just posted here just in case I might lose the file or anything can happen, I spend many hours on this and here is a best save place if I need it is here on diyaudio.com

hello friend, would you have the gerber of this board with 5 pairs? can I use NJW21193 / NJW21194 transistors IN THE PLACE OF MJL / IRFP?
ola amigo, teria o gerber dessa placa com 5 pares? eu posso usar os transistores NJW21193/NJW21194 NO LUGAR DO MJL/IRFP?

 

[vargasmongo3435]

hi this is the original files that provide JKuteman and yes you can use those power transistors

 

[vargasmongo3435]

and this is the V2 gerbers

 

[edub2020]

Muito obrigado 👏👏

 

[vargasmongo3435]

you are welcome don't forget to translate to English any words bro also read a few previews post back

 

[still4given]

hello friend, would you have the gerber of this board with 5 pairs? can I use NJW21193 / NJW21194 transistors IN THE PLACE OF MJL / IRFP?
ola amigo, teria o gerber dessa placa com 5 pares? eu posso usar os transistores NJW21193/NJW21194 NO LUGAR DO MJL/IRFP?

I would not use those power transistors. If you search back through the thread you will see where I tried to use MJL21193/21194 resistors. For some reason the slower transistors don't play nice in this EF3 circuit.

 

[vargasmongo3435]

they are slow devices Terry? I didn't know that ok ok edu on must of my build I use this one https://www.onsemi.com/pub/Collateral/MJL3281A-D.PDF


just in case I'm gonna save this Sprint file here

 

[edub2020]

I would not use those power transistors. If you search back through the thread you will see where I tried to use MJL21193/21194 resistors. For some reason the slower transistors don't play nice in this EF3 circuit.

I will test, because I have several pairs here. What problems did you have?

 

[jkuetemann]

If memory serves it was issues with square wave testing at higher frequencies that caused failures due to shoot-through. I suspect the MJL2119x series would be fine with actual audio signals. Those devices are used in plenty of commercial and other DIY designs.

 

[thimios]

Don't use those in Slewmaster if you don't like magic smoke.

 

[jwilhelm]

Bob Cordell suggests that there isn't enough current flowing through the drivers to be able to completely switch old slower output devices off properly in this amp, causing shoot through and self destruction.

 

[thimios]

If memory serves well Ostriber didn't recommended fast drivers together with slow output.
Me personal sniffed the magic smoke as attempted to use mj21194-95 when this amplifier was under prototyping test.

 

[still4given]

I will test, because I have several pairs here. What problems did you have?

I am just trying to save you trouble. I tried several things to try and make them work. All ended in burned devices. You are welcome to travel down the same rabbit hole if you like or save yourself the trouble and use devices that are proven.

Blessings, Terry

 

[edub2020]

what would you recommend me to buy irfp240 / 9240 or mjl4281a / 4302?

 

[still4given]

If you are planning to use it as designed I would get MJL4302/4281. If you want to use the vertical MOSFET you need to follow Valery's schematic which changes it to EF2. Personally I prefer the BJT. Trouble free and proven.

 

[edub2020]

Ok

 

[edub2020]

I will use the irfp even because I can't find the bjt here, what are the modifications to use the irfps?