make one F6 with SS , and another one with plain vanilla
then call them as you want
sort of following on from that and relating to what Antoinel said in post 2927...I was just thinking(v. dangerous for me) that if Papa has all the SS stock then there is little point in him designing for us(diyers) because we can't build such designs without the devices(unobtanium).......
so what is Papa going to do with all that stock!!:
a) build like J2(not for diy) and keep some back for failure replacement(what failure!)....
b) release some, or design for those lucky enough to have a stash.
c) scrap the stock
d) find drop in replacement
I was just thinking, that's all
Papa? 🙂
seems like a very good investment to me, considering the going rate on other highly acclaimed parts. ZM is always trying to get us to see that Nelson uses whatever part he has and makes it sound like he wants it too. The F6 is a very valuable deisgn, for one reason, IMO. It allows the builder to tweak and listen to harmonic structure easily. If yo u do this while measuring, you can get a feel for what you like and possible ways of achieving it. Being noobs, we need hand holding, being the master, i could give him some random $2 part, and h would fashion it into a sweet sounding amp. The ACA comes to mind. If you look closely there, you have a pretty good idea of another popular Pass amp. Nelson has bread crumbs everywhere. Just got to follow thm and do the work. Thats wher i fail every time😀
I love it. The discovery is the most interesting part. Failure second. Then I guess listening.
Has anyone built an F6 with "standard" MOSFETs? What is needed for temperature stability? Will source degeneration be enough or will active thermistor control of the bias be needed?
make one F6 with SS , and another one with plain vanilla
then call them as you want
Is the extra 5 watt gain in the F6 due to the transformer in the circuit or the quasi push-pull output stage?
Another question- Can SemiSouth 085 be used?
Another question- Can SemiSouth 085 be used?
Extra 5 by comparison to ?
And no to 085 thats a depletion mode normally on part amigo
And no to 085 thats a depletion mode normally on part amigo
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I should explain myself. Most FW amps are low watts 5w-15w, but some are 25w. The F6 is 30w. The PS voltage is 23-24v on most FW amps. The F6 is also 23v. So, is there some effeciency gained somewhere in the F6?
From 6Moons article. "You've seen this supply many times and here it is again. It's got 18-volt secondaries that you can get from Antek or Plitron."
"As a push-pull Class A amplifier we traditionally expect it to operate in Class A to peaks of twice the value of the bias current. With degeneration a circuit designed to operate at 30Wrms into 8Ω in Class A would by definition leave Class A at 60-watt peaks. "
From 6Moons article. "You've seen this supply many times and here it is again. It's got 18-volt secondaries that you can get from Antek or Plitron."
"As a push-pull Class A amplifier we traditionally expect it to operate in Class A to peaks of twice the value of the bias current. With degeneration a circuit designed to operate at 30Wrms into 8Ω in Class A would by definition leave Class A at 60-watt peaks. "
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Here is my P2P F6. Not exactly totally safe construction.
I biased at what I think if 1.5A.
Measuring V across resistors in standard Pass supply.
1.5 x .(4x.47R) in power supply = .176
No big sound evaluation yet, just one mono CHR-70 running no baffle.
I have ordered The Cree SIC Mosfets, and will modify this to use them adding more LED's.
I biased at what I think if 1.5A.
Measuring V across resistors in standard Pass supply.
1.5 x .(4x.47R) in power supply = .176
No big sound evaluation yet, just one mono CHR-70 running no baffle.
I have ordered The Cree SIC Mosfets, and will modify this to use them adding more LED's.
Attachments
When no degen., the mosfets square law allows one half to run more than twice the bias before the other half cuts off. This for class A power.
There is more power into 8 ohms because less voltage losses due to no degen..
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Seaside walker ?😀
Knowing the coast you live in i can appreciate that.😎
Zen contemplative country....it just misses a cement pilar for ZM to sit on top when he visits......heheheheh
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My wife is of that opinion too; except her motive is cleaning rather than grieving. But my Threshold S/150 will be buried by my side or I'll will it to diyAudio's future museum of Pass Antiquities.
Unfortunately, diy F6 is unfinished business. I have a stash of 4 R100As and that is no consolation; R100A appear to be obsoleteium . DIY F6 has no spare parts;and there is not a clear solution for its new output stage.