F4 Beast Builders

Output stage assembled and tested. Everything works perfectly.
Next up will be to solder it all up on protoboard and play some music through it.

Congratulations 2PicoD :cheers:
 

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Joined 2004
Paid Member
You guys are making me crazy :)

Now I want to make one. I was all set on the BA 2015 single ended version but this has more appeal if we can dial in the second harmonic.

I just need to get the new mono bloc chassis finished.
 

Attachments

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Where are the measurements?
Hahahahaha

You want measurements? I give you measurements:

The columns are Capacitance, Vds

IXFN44N80Q3_Crss_500kHz_Vin1V_100R_3:
matrix(
[2639.643, 0.100],
[2092.511, 1.741],
[1660.747, 4.010],
[1452.482, 5.639],
[1261.769, 6.273],
[832.730, 6.587],
[465.920, 6.884],
[152.764, 7.323],
[78.104, 7.801],
[58.946, 10.738],
[48.607, 13.373],
[45.566, 16.416],
[38.661, 21.603],
[33.452, 25.637],
[30.854, 31.297])$

IXFN44N80Q3_Ciss_100kHz_Vin500mV_100R:
matrix(
[30660.732, 0.100],
[28124.641, 1.907],
[25384.206, 3.827],
[21513.361, 6.430],
[18652.306, 8.868],
[18676.345, 11.821],
[18326.933, 13.792],
[17984.509, 16.979],
[18344.200, 20.814],
[17984.509, 23.962],
[18344.200, 27.260],
[18344.200, 31.301])$

IXFN44N80Q3_Coss_100kHz_Vin500mV_100R:
matrix(
[34911.407, 0.620],
[22577.794, 2.503],
[17806.444, 4.150],
[13775.596, 6.011],
[10298.261, 6.429],
[8063.850, 6.572],
[4484.476, 6.769],
[2402.339, 7.037],
[1911.000, 8.833],
[1507.201, 12.013],
[1283.067, 15.274],
[1107.870, 19.707],
[993.041, 23.905],
[879.751, 29.626],
[865.696, 31.295])$
 
You want measurements? I give you measurements:

The columns are Capacitance, Vds

IXFN44N80Q3_Crss_500kHz_Vin1V_100R_3:
matrix(
[2639.643, 0.100],
[2092.511, 1.741],
[1660.747, 4.010],
[1452.482, 5.639],
[1261.769, 6.273],
[832.730, 6.587],
[465.920, 6.884],
[152.764, 7.323],
[78.104, 7.801],
[58.946, 10.738],
[48.607, 13.373],
[45.566, 16.416],
[38.661, 21.603],
[33.452, 25.637],
[30.854, 31.297])$

IXFN44N80Q3_Ciss_100kHz_Vin500mV_100R:
matrix(
[30660.732, 0.100],
[28124.641, 1.907],
[25384.206, 3.827],
[21513.361, 6.430],
[18652.306, 8.868],
[18676.345, 11.821],
[18326.933, 13.792],
[17984.509, 16.979],
[18344.200, 20.814],
[17984.509, 23.962],
[18344.200, 27.260],
[18344.200, 31.301])$

IXFN44N80Q3_Coss_100kHz_Vin500mV_100R:
matrix(
[34911.407, 0.620],
[22577.794, 2.503],
[17806.444, 4.150],
[13775.596, 6.011],
[10298.261, 6.429],
[8063.850, 6.572],
[4484.476, 6.769],
[2402.339, 7.037],
[1911.000, 8.833],
[1507.201, 12.013],
[1283.067, 15.274],
[1107.870, 19.707],
[993.041, 23.905],
[879.751, 29.626],
[865.696, 31.295])$


Wait a second, I'll just punch those numbers into the brain.

Yep, that looks good.
 
Congratulations generg!
There are quite a few of us that are following this thread with interest but are sitting on the fence until one of you guys manages to tame these hockey pucks. So for my understanding of this amp you are using high transconductance devices IXFN48N60P and IXTN40P50P as you mention in post#270 and the circuit is as in post #254?
The reason you are transcoding the buffer fet pair is to be able to drive M1 and M5 which in turn will be the driver for the high input capacitance of the hockey pucks?
Then to prevent thermal runaway you use the TL431 which we see bolted in the middle of the two hockey pucks? Then you have R17 sense as the positive feed back?

If I have understood this correctly you have made a wonderful sounding amp with about just over 2 Amp bias and 0 mV offset what is the frequency response like can you post pictures of what say a 50KHz square wave looks like please. Again many thanks for sharing your efforts and patience.
I'm also looking forward to see what 2 picodumbs has accomplished keep it coming!
 
Member
Joined 2009
Paid Member
THX formantjim for the comment!

The taming is as Picodumbs said no more the problem, more the adjustement of distortion and a reliable comparison to another very good amp.
You know selfmade amps switched on blow away every amp of this world......one day, until you get sober......:--))


Congratulations generg!
There are quite a few of us that are following this thread with interest but are sitting on the fence until one of you guys manages to tame these hockey pucks. So for my understanding of this amp you are using high transconductance devices IXFN48N60P and IXTN40P50P as you mention in post#270 and the circuit is as in post #254?
The reason you are transcoding the buffer fet pair is to be able to drive M1 and M5 which in turn will be the driver for the high input capacitance of the hockey pucks?
Then to prevent thermal runaway you use the TL431 which we see bolted in the middle of the two hockey pucks? Then you have R17 sense as the positive feed back?

If I have understood this correctly you have made a wonderful sounding amp with about just over 2 Amp bias and 0 mV offset what is the frequency response like can you post pictures of what say a 50KHz square wave looks like please. Again many thanks for sharing your efforts and patience.
I'm also looking forward to see what 2 picodumbs has accomplished keep it coming!