yes. It's what the temperature de-rated SOAR shows as well.
That is where my formula came from after analysing many output stages at many temperatures.
Some time later R,Cordell joined the Forum and posted his guidance in one of his interviews. It turned out that his guidance althogh using apparently quite different parameters arrived at the same conclusion.
Maximum output power is determined by the output device power dissipation capability.
As an aside, if you run the output stage cooler you can get more output power from the same devices because you have used up less of the SOA.
And similarly if you run from lower supply rails you can get a bit more power due to using less of the secondary breakdown area (this does not apply to most mosFETs).
The corollary is that higher temperature and higher supply voltage results in a higher design factor and thus lower power.
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Hi Mile,
I will try that. I have seen a few circuits where they use the diode and a trim pot in series. Any good in leaving the diode in circuit?
Do you have some suggestions for the overcompensation issue? Also, is there a way to raise the gain?
Thanks, Terry
Add 2k2 in series with 36k (R2) to rise the gain... bias and gain must be set before proper compensation.
Another PCB layout for mosfet relay protect ,not tested yet
Regards,Alex
Hello Alex,
Good job, as usual!
Please share to us Sprint-Layout files, are more usefull than JPG or PDF.
Just build another i got this same problem after i changed the puff capaicator
Can anybody tell what is wrong AX-14 trobleshooting? And yes the transistor 2s5200/A1943 are getting very fast hot
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Hi Mile,
I pulled the 2k2 and now it will trip the speaker instantly with +1.5vdc from PGND to speaker in/out. However, it takes at least -6vdc to cause it to trip.
i will etch board today.i think this is for us1070. anyway anything worry about this amp please tell me.thanks.
Sorry, I quoted the wrong post.
I have built two AX14's. One with TO-3 and one with TO-3p. Both worked first time.
Use this circuit with TO92 triac instead transistors for DC detect.
Attachments
I must say very innovative and unique build. BTW what was the problem earlier and how did u solve it?
reg
Prasi
I build 1 with bakelite pcb and 1 with fr4 pcb as shown in the image
The new build fault of bulb lighting up was a mistake i put ttc5200 in the tta1943 slot i changed it started to work.
The old bakelite i build earlier was i put a lower value that is 20pf puff instead of 33pf capacitor which started heating the output transistor c5200/a1943 very fast after some time it gave speaker output of 14vdc look llke some small transistor got damaged. I fixed it by building again.
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BD139 vbe multiplier should be mounted on same heatsink along with 2SC5200/2SA1943. Add zobel network at output as suggested by miles.
My concern is amp module directly mounted over EI transformer.
Regards,
Sonal Kunal
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Hi C08bm,
I think Mr. Miles suggested to reduce 470uF to 100uF for faster response. also only one 1n4007.
reg
prasi
