But it not the CFP that gives this design it "sound" , its the bootstrap.
The CFP is capable of greater slew , but the IPS has limited bandwidth. makes no sense from many points.
Perhaps if he combined a fast CFA with the CFP OP , that would make for a certain goal (Fast - faster).
CFP has higher current gain and can get closer to the rails. but what is losing 1.4V-2V versus unconditional stability.
CFP could be tamed at the source by just decoupling the drivers (R/C on the rails). same as I do with the EF3 pre-drivers.
I'm kind of amazed that these little tweaks were not implemented long ago. Especially as our semi's have gotten faster.
If the design "philosophy" is to cut corners and make a circuit device dependent , it is "folly".
All I'm saying is that as an introduction project , He should of went the way of - https://www.ampslab.com , his projects I built even before
I knew of DIYA back in the 20'th century. ROCK solid. The P3a mentions that for optimal operation , buy the PCB ??
It seems "AMPSLAB" has gone fully commercial now , but when he DID post projects and schematics , they were very device independent.
he said to buy his boards for a more professional look once you experienced the rock solid project. His kits were very similar to his free
projects. Ampslab did have a proper decoupled CFP design where he explained the "touchy" nested loop in detail.
I'm sure Rod is a good guy and he explains alot , but to fudge on a design for "noobies" detracts from from the good.
The CFP is capable of greater slew , but the IPS has limited bandwidth. makes no sense from many points.
Perhaps if he combined a fast CFA with the CFP OP , that would make for a certain goal (Fast - faster).
CFP has higher current gain and can get closer to the rails. but what is losing 1.4V-2V versus unconditional stability.
CFP could be tamed at the source by just decoupling the drivers (R/C on the rails). same as I do with the EF3 pre-drivers.
I'm kind of amazed that these little tweaks were not implemented long ago. Especially as our semi's have gotten faster.
If the design "philosophy" is to cut corners and make a circuit device dependent , it is "folly".
All I'm saying is that as an introduction project , He should of went the way of - https://www.ampslab.com , his projects I built even before
I knew of DIYA back in the 20'th century. ROCK solid. The P3a mentions that for optimal operation , buy the PCB ??
It seems "AMPSLAB" has gone fully commercial now , but when he DID post projects and schematics , they were very device independent.
he said to buy his boards for a more professional look once you experienced the rock solid project. His kits were very similar to his free
projects. Ampslab did have a proper decoupled CFP design where he explained the "touchy" nested loop in detail.
I'm sure Rod is a good guy and he explains alot , but to fudge on a design for "noobies" detracts from from the good.
Actually try the P3A with 22R base stoppers on the output devices and at least 47R emitter degeneration at the LTP . You would at least have a true
test of what this type of design "could" sound like ... it CAN be done. I used CFP in one of my VAS's (super-pair) it would be rock solid with some LTP's ,
others it would get "squirrely". The super -pair (CFP) would complicate the bode response , as it was a very HF nested loop. Newer/faster semi's especially.