yes i scale it bigger than the original size
i love the original size very compact
but i'm much comfortable building it bigger as of now
for safety,no shorted or open traces
I prepared all of my old PCBs for diy:
1 single side pcb
2 available parts, no smt parts
3 line no tiny that 1mm
And still be problems 🙂
😀no problem
but the thing is
you been doing this stuff for almost 30 yrs..
that means i was only 4 yrs old
you already doing this stuff
ha ha ha😀
by the way how old are you now miles
i'm trying to find easy way of etching pcb
but as of now i'm still using the hard way,no software no computerized i just print the design and........then its all in my hands,
i hope i can do like the others doing it,even the tinniest lines i wish i can do that
but by the way i trully give my deepest gratitude to you
apex,
thank you very much
for sharing all this stuff
but as of now i'm still using the hard way,no software no computerized i just print the design and........then its all in my hands,
i hope i can do like the others doing it,even the tinniest lines i wish i can do that
but by the way i trully give my deepest gratitude to you
apex,
thank you very much
for sharing all this stuff
![Triac%20DC%20Protect[1].jpg](/community/data/attachments/162/162603-790f010679fda55fe2622e2c9562fc0e.jpg?hash=eQ8BBnn9pV)
Triac connect output amplifier to ground if there is +/-35V DC offset, rail fuses blow and protect speakers of DC. If amplifier have not rail fuses then must put fuse on amplifier output before triac, and if there is main fuse for transformer it blow anyway. Peavey models 850, 1.3k and 2000 use DC protect with triac and have only main fuse, but there bridge recifer blow with fuse most the time.
I think that I builded better stuff when I was younger 🙂😀no problem
but the thing is
you been doing this stuff for almost 30 yrs..
that means i was only 4 yrs old
you already doing this stuff
ha ha ha😀
by the way how old are you now miles
By "blameless circuit" i mean a discrete op-amp based on Douglas Self amplifier ( Distortion In Power Amplifiers, without last output transistors, only one stage EF biased into class A). But now I am not aware of "preamplifier". I'm focused on output stage that starts from Q1 and Q2.
You can see in my another thread mosfet output stage for hibryd amplifier, but can be drive with SS also if preamp can deliver about 100Vpp.
http://www.diyaudio.com/forums/solid-state/164659-tube-mosfet-100w-hybrid-amplifier.html
Regards
But now I am not aware of "preamplifier". I'm focused on output stage that starts from Q1 and Q2.[/QUOTE]
In that stage U have current feedback.
In that stage U have current feedback.
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you are recommending that we short the output devices to ground and then wait for the fuses to blow.
What if the excess DC at the output was not due to an output device failure?
Shorting the supply rails to ground eventually blows the rails fuses and causes no other damage.
I recomended protect with relay, but triac DC protect for speakers is better than nothing. DC offset over than +/-35v will demage speakers no metter if output devices is failure or not. This triac protect connect after you sure there is not DC on amplifier output, and then you can connect speakers. At the end Quad405 have this kind of protect.
Regards
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Agreed.
Agreed.
But you seem to be overlooking the significant point that locating the protection triac across the speaker terminals rather than from Supply to Ground is virtually guaranteed to damage the amplifier, particularly if the fault is with the Source equipment and not the Power Amp.
Agreed, but many diyers not used any protect,triac protect is simple to use, and in that case is better change output devices than speakers.
Regards