I added your name to the list. Perhaps the question in regard to 4-ohm speakers should be, how much power does it make sense to design for?I am interested in 1-2 pairs of boards for sure.
And I am interested in the 4OHM discussion as well
Cheers!
I have been thinking of this as a "small" amp. Sort-of like a sports car. You avoid some of the pitfalls of bigger heavier vehicles, precisely because it is small, so good performance does not cost much.
The most obvious answer to more power without changing the design much is to use the ALF16N/P devices, but it will no longer be low cost.
Yes the component selection is good start...
1. I see some other CFA-amp use 2-3watt feedback resistor
see NX-amp by Bonsai
now where I can find these dale resistor
so 0.5watt is minimum if we go for higher supply (this what I thought).
-snip
Regards
Hallo bli John, on F5 (i think it CFA too) use 4 x 3 watt resistor.
I think it depend on current passing through on the resistor not depend on voltage, hence it call CFA. CMIIW
PMI, any schematic ?
Didiet
Those are Jason's boards, so I would ask him, but if there was a problem, you would probably know it by now.
The magic blue smoke would be set free if there were an issue. The MOSFETs are really quite forgiving and rugged, given the dynamic nature of music I would not expect any issues with your set-up. For testing with full power sines use 8 ohm.
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It's not even breaking a sweat. This is a very impressive amp. I just built a speaker switch so I could do an easy blind test with my amps. I have to tell you, the peeceebee doesn't take a back seat to any of my amps. I am using a B1 mezemerize and an X-BoZoZ for volume controls. I have been amazed how close all the amps are when their volumes are equalized. To my surprise, the peeceebee has a bigger soundstage than my Honey Badger. It really is an amazing design.
Thanks for reporting. This gives me hope for my attempt to make a balanced version, my load is 8 OHM but each half will see half of it. I am using TO3 Exicons for that, very similar in specs with your K135/J50.
Cheers!
thread appear difficult to find
and I suspect its being caused by the title starting with the word Another
would like to try it like this(or 'another' suggestion)
Through-hole VSSA, a Build Thread by PMI
or maybe its just me needing glasses ???
VSSA Through-Hole PCB build thread
Most suitable to find
I agree with you, especially on the bolded comments.
I find the detail in the sound is one of the characteristics of this design that keeps me going back to it. I can play a piece I know well and almost always pick out something subtle that I hadn't noticed before. On good recordings you can hear the musician's technique, not just the fundamental sound of the instrument. Things like the bassists fretwork, the percussionist allowing the stick to 'ride' a cymbal and excellent definition in the bass drums.
As for soundstage, PeeCeeBee and its other VSSA based bretheren do an excellent job of fooling us into hearing a 3-D image of the performance, just as the artist and engineers intended. Many others seem to present the piece as being too flat or with too much separation. Not the PeeCeeBee, it gives a very natural presentation. Put yourself in your room's sweet spot and close your eyes; the experience becomes almost holographic.
Anyhow, I have gone on before about this design but went on about it some more simply because it is IMHO so good. More skeptics should put aside all the semantic banter about different topologies and control modes and just give it a try.
LC is correct, there is a special quality to the sound, I think the closest word is "transparency". A friend's wife said she could understand vocals on some difficult older music for the first time, just spending a few minutes listening.No signal details lost - you hear more.
It has been hiding in the PeeCeeBee thread. The first version was actually built in May.at first I thought how could I have missed this thread
until I noticed it was posted yesterday
Several people have been helping, and I intended to have this revision about the same time as the CM PSU board, but ran out of time. (And I also wanted to play with Lazy Cat's modules...
) I have posted pics before, test results, and info for people who built the last version (see reposted pics below). So have one or two other people.This revision diverged from the original PeeCeeBee topic too much to post the technical details there - however, my intent is to let anyone interested to etch the board from a pdf file, and build it with the simple components that Shaan proposed. I also needed a place to collect all the support documentation, and some of the component discussion, which was sort-of lost there.
"Another" in the thread name was a nod to the several other VSSA-inspired TH designs here.
If nobody objects, I think we can go with Lazy Cat's suggestion, after all, he is the proud father of VSSA...
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