PeeCeeBee

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#2,001
triast said:
My Peeceebee, tested with 30vdc, It sound beautifully. Is it true that it don't need input capacitor? Thank you Shaan.
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Great job!

If your signal source has an output capacitor or has less than 10mV offset then there is no need for an input cap on the PeeCeeBee. It has unity gain at DC so any dc voltage at input will appear on the output in-amplified (so a few mV input offset won't cause problem). And if your source is single supply based then a capacitor must be installed (usually all single-supply preamps have caps at their outputs)

:up:

edit- I don't see any insulation between the VAS bjts and the heatsink. Are these electrically isolated?
 
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#2,003
shaan said:
Great job!

If your signal source has an output capacitor or has less than 10mV offset then there is no need for an input cap on the PeeCeeBee. It has unity gain at DC so any dc voltage at input will appear on the output in-amplified (so a few mV input offset won't cause problem). And if your source is single supply based then a capacitor must be installed (usually all single-supply preamps have caps at their outputs)

:up:

edit- I don't see any insulation between the VAS bjts and the heatsink. Are these electrically isolated?
Click to expand...

Thank you Shaan,

The VAS Bjts are Fairchild which have plastic isolated tab.
 
#2,006
Hi Thimios,

I'm glad you finally know what a well designed Lateral MOSFET amp can do. That is why I always wondered when I would hear guys saying that Laterals were weak in the bass.

I am tempted to build this one but I have 5 Peeceebees, two are completed in cabinets that I listen to often. My first Peeceebee is one using TO-3 laterals and it is hum free. The one built on PMI's boards does have a light hum. I always meant to get back in there and see if I could fix it by doing a little wiring adjustment but I have just been way too busy building other stuff and I have a dozen amps in cases so I don't really need it at all. I have been contemplating just pulling it out and installing one of Apex's little amps in there. It has a 600vA 25-0-25vac transformer with a Mr Evil cap multiplier and it seems a shame to have it powering a redundant amp.
 
#2,010
thimios said:
Hi Terry speaking for this Ver.2, i can't hear missing bass.
You must built this.The first PeeCeeBee absolutely silent:shhh:
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Though not at the top of the stack but it has less than 20mohm of output impedance and hence bass response is very good. The V2 was laid out primarily as a subwoofer amplifier and I am very happy to see that it's not lacking at its raison d'être. 😀

:cheers:
 
#2,012
V2 PeeCeeBee

Hi Shaan,
I built a V2 as well. I really like it. Very simple to build, low parts count & cost. I used KSC2690A for MJE340 and KSA1220A for MJE350 as these are what i had. Running it at +-56V. As Terry would say, "Sounds Lovely" 😀
 

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#2,015
new baby monster born !

*bc550c/560c swap to bc547c/557b, hard to find 560c here 🙁
*100pF swap to 220pF & 22pF swap to 33pF, use what i have in my drawer 🙂
*and also uses few of el cheapo 10% tolerance resistors


32vdc supply, 0.0-0.2mV DCO


salute for all who have contributed and develop this baby monster
 

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#2,018
guzz said:
...*bc550c/560c swap to bc547c/557b, hard to find 560c here 🙁
*100pF swap to 220pF & 22pF swap to 33pF, use what i have in my drawer 🙂
*and also uses few of el cheapo 10% tolerance resistors...

...baby monster
Click to expand...

Hello guzz.

I see that you have built 3886 based amps before. How does PeeCeeBee compare to them sound-wise? Better? Worse? Same?

Thanks.
shaan
 
#2,019
ermm... shaan sorry to say this (chipamp ers), this is my personal opinion, compare to my 3886... discrete much more better, specially in dynamics.. 🙂
it compared with my symasym, for this baby monster i have to build another decent supply for him 🙂
but even with just 3A transformator,4 x 3900uF and my old nokia phone as source... wow sound amazing, let see if i done with more decent supply and use cd player as source, power up as stereo... i believe 3886 will also lack behind 🙂
 
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