Hi Gm.
Thnaks.
Yes V4 has rounded clip edges (soft-ish clipping).
There was oscillation with zobel removed, oscillation with input RF shunt removed, VAS current instability, asymmetrical clipping, high noise, less than 30V/uS slew rate unacceptably high LF distortion and loose bass. But this is V4's story from 2016, when it was lying on bed being assembled, tortured, overloaded, dissected and reassembled over and over.
Eventually it found the way it sings best with the least effort.
Now we have no oscillation when both zobel and input RF shunt removed, rock-solid VAS bias, symmetrical clipping, ultra low noise, 100V/uS slew rate, ultra low LF distortion and bass as tight as we can imagine (You will be surprised how good a basic LatFet amp's bass can be!). V4 retains the superb tonal quality of the previous PeeCeeBee versions and delivers the ever so sparkling highs with grace.
Thnaks.
Yes V4 has rounded clip edges (soft-ish clipping).
There was oscillation with zobel removed, oscillation with input RF shunt removed, VAS current instability, asymmetrical clipping, high noise, less than 30V/uS slew rate unacceptably high LF distortion and loose bass. But this is V4's story from 2016, when it was lying on bed being assembled, tortured, overloaded, dissected and reassembled over and over.
Eventually it found the way it sings best with the least effort.
Now we have no oscillation when both zobel and input RF shunt removed, rock-solid VAS bias, symmetrical clipping, ultra low noise, 100V/uS slew rate, ultra low LF distortion and bass as tight as we can imagine (You will be surprised how good a basic LatFet amp's bass can be!). V4 retains the superb tonal quality of the previous PeeCeeBee versions and delivers the ever so sparkling highs with grace.
Hi Gm.
Thnaks.
Yes V4 has rounded clip edges (soft-ish clipping).
There was oscillation with zobel removed, oscillation with input RF shunt removed, VAS current instability, asymmetrical clipping, high noise, less than 30V/uS slew rate unacceptably high LF distortion and loose bass. But this is V4's story from 2016, when it was lying on bed being assembled, tortured, overloaded, dissected and reassembled over and over.
Eventually it found the way it sings best with the least effort.
Now we have no oscillation when both zobel and input RF shunt removed, rock-solid VAS bias, symmetrical clipping, ultra low noise, 100V/uS slew rate, ultra low LF distortion and bass as tight as we can imagine (You will be surprised how good a basic LatFet amp's bass can be!). V4 retains the superb tonal quality of the previous PeeCeeBee versions and delivers the ever so sparkling highs with grace.
20K Clipping shots of V4.
2x gain NE5532 preamp used between signal source and amp. No capacitor between amplifier and preamplifier. Load resistance 8 ohm. Zobel disconnected.
Pic 1 - Unclipped output
Pic 2 - Zoomed
Pic 3 - Clipped output
Pic 4 - Zoomed
How soft is that? 😉
2x gain NE5532 preamp used between signal source and amp. No capacitor between amplifier and preamplifier. Load resistance 8 ohm. Zobel disconnected.
Pic 1 - Unclipped output
Pic 2 - Zoomed
Pic 3 - Clipped output
Pic 4 - Zoomed
How soft is that? 😉
Attachments
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How soft is that? 😉
Could you increase the input signal a little bit to show heavy clipping? And also the input wave form on channel 2.
Is your power supply stabilized?
Thx, Toni
Looks very good so far - very good overload behavior. Zoom further in and check top and bottom edges for oscillations during recovery from overload.
May be difficult to tune your scope to get those readings. 😉
BR, Toni
Hi Toni.
Thanks for the tip.
I did notice that and thought there was something fishy going on. So I zoomed and checked both edges (with averaging on and off) and there is no oscillation, but forgot to take some photos. Will upload close-shots of the edges later.
🙂
Thanks for the tip.
I did notice that and thought there was something fishy going on. So I zoomed and checked both edges (with averaging on and off) and there is no oscillation, but forgot to take some photos. Will upload close-shots of the edges later.
🙂
Though I'm a noob and do not understand those curves and all. But I've built a couple of v3 with help of Shaan... and it's awesome.
For me only 'hearing is beleaveing' no big words, big brands, big names or critical technical terms doesn't make any sense.
I do not know if you have already built one of the any version or not but it worth to give it a try.
V3 layout and schematic has already been published so try this out and I can guarantee you won't regret. It can even outperform a lots of well regarded diy or professional amp.
Cheers!
BTW Shaan count me for your V4 board also.[emoji4]
Sent from my GT-N7100 using Tapatalk
thekingstallion,
Seen in light that Lazy Cat has his own VSSA-CFA design principles and diy amp kits your post is great good humor reading, you probably didn't know that before recommend Lazy Cat to build shaan amp 😛.
Seen in light that Lazy Cat has his own VSSA-CFA design principles and diy amp kits your post is great good humor reading, you probably didn't know that before recommend Lazy Cat to build shaan amp 😛.
Hi Shaan,
Great progress with the next generation PEECEEBEE. Count me in for V4 too!..
reg
Prasi
To LC,
We all know about the great design promulgated by you and everyone is (should be) eternally thankful to you (sincerely).
reg
Prasi
Great progress with the next generation PEECEEBEE. Count me in for V4 too!..
reg
Prasi
To LC,
We all know about the great design promulgated by you and everyone is (should be) eternally thankful to you (sincerely).
reg
Prasi
Ohhh. I really didn't know. It seems that he was ridiculing and I thought he should try this before passing any comments. Please accept my sincere apology.
But on the contrary he also shouldn't have behaved like this. It's really necessary to respect others to get the same. And I think we are here to learn things and expected to be pointed out to the right direction if we make any mistakes instead of being ridiculed.
Sent from my GT-N7100 using Tapatalk
Thank you Prasi. I'm sincere too, nothing bad on my mind. Congratulations to Shaan for this new exploring in CFA design. 🙂
All comes with some price. This design looks like to have a good clipping behavior.
Any amplifier which is driven to clipping leaves the audiophile zone regardless of the clipping figure. With a lower power amplifier it is very likely that you drive it earlier to this limit especially with lower efficiency speakers. A good overload characteristic doesn't better your hearing experience - only saves your treble speakers.
Hey everybody.
I have been "busy" auditioning the "old" V3 in various friends' places for the last couple of weeks, comparing it in some fine setups by the side of some fine amplifiers. Last week had two consecutive listenings into Usher V-601 bookshelfs with the amp driven directly from Emotiva Stealth DC-1 DAC's analog output. Source was a plethora of songs in various formats played in foobar2000. Yesterday the listening was into Usher V-602 floorstanders. Source was a Denon CDP playing SACDs and amp driven by a Cayin tube preamp (forgot the model no.)
It has been fun. V3's vocal and highs production quality, imaging, 3D presentation, transparency, focus on every single note of the different instruments and overall sonic synergy with the rest of the system had the standstill effect, that I am now quite used to see in almost every audition, again. The question that arose at the end of both sessions was this- "Is the amp really THAT cheap???". Of course it is!!!
The neutral attitude of V3 toward music was praised, and it was considered in both cases a "revealing" amplifier that retained the integrity of the source material and had no bias towards sounding either "bright" or "dark".
----------------
Right now I am trying to get some more auditions into some very different speakers from other manufacturers and let the adventure continue. Stay tuned. 😉
I have been "busy" auditioning the "old" V3 in various friends' places for the last couple of weeks, comparing it in some fine setups by the side of some fine amplifiers. Last week had two consecutive listenings into Usher V-601 bookshelfs with the amp driven directly from Emotiva Stealth DC-1 DAC's analog output. Source was a plethora of songs in various formats played in foobar2000. Yesterday the listening was into Usher V-602 floorstanders. Source was a Denon CDP playing SACDs and amp driven by a Cayin tube preamp (forgot the model no.)
It has been fun. V3's vocal and highs production quality, imaging, 3D presentation, transparency, focus on every single note of the different instruments and overall sonic synergy with the rest of the system had the standstill effect, that I am now quite used to see in almost every audition, again. The question that arose at the end of both sessions was this- "Is the amp really THAT cheap???".
Of course it is!!!The neutral attitude of V3 toward music was praised, and it was considered in both cases a "revealing" amplifier that retained the integrity of the source material and had no bias towards sounding either "bright" or "dark".
----------------
Right now I am trying to get some more auditions into some very different speakers from other manufacturers and let the adventure continue. Stay tuned. 😉