Quote from: J M Fahey on April 24, 2012, 11:34:26 PM
Not that I know of.
And I have searched, that and many other things.
I laugh when people say "you can find *anything* on the Net"
Yea, sure !!!  Keep searching !!!
You'll find (maybe) *some* of what anybody posted ... and what never was, never was.
You'll find lots of stuff on classic 40 years old tube amps, little on modern tube ones, almost nothing on SS ones.
Closest solution would be getting some classic discrete 100W into 4 ohms power amp kit and mod it slightly to add the mixed mode feedback.
You'd save 90 or 95% of the work.
Good luck.

Yes i spent a lot of time searching for something close .. and i found on eproject with PCB and Layout of a 100W RMS power amp.. but .. i don't know if it will work 
maybe i'll sepend more time learning how to add the mixed feedback..

Hello again .. 8|
Does anybody know any project to make a power amp close to the Randall RG100 with PCB and Layout?
i mean that uses Transistors intead of IC...

Quote from: Loudthud on April 04, 2012, 08:27:01 PM

Quote from: allan_belt on April 04, 2012, 12:15:14 AM

Quote from: allan_belt on April 04, 2012, 12:15:14 AM
2. tested the sound out of the preamp section into another guitar amp and the sound is great!!! punchy and Heavy  :dbtu: but when i connected to the power amp section presented here the sound is weak and too trebly for my taste, is it normal??

I would look for a bad component or wiring error. Try feeding another preamp into the power amp. Or just feed your guitar straight into the power amp.

Yes you are right i had a mismatched component  now the power amp sounds great and powerful ... thanks for your help.. i `ll post the amp when i put it in a Dynacord Chasis i have empty.. and maybe some demos too... 

Quote from: Loudthud on April 04, 2012, 08:27:01 PM

Quote from: allan_belt on April 04, 2012, 12:15:14 AM
1. Couldnt find the 2n5484 Jfet so i replaced them with 2n5457 i wonder if both have the same gain???

Those FETs are pretty close. The transconductance of the 2N5457 is spec'd at 1000 to 5000 uMho. The 2N5484 is spec'd at 3000 to 6000 uMho so on average, it's a little higher but it depends on the exact part you are using.

Thanx a lot for your support. i recently found the 2n5484 Jfets and the sound is improved now very tight and gainier than 2n5457.
Just one more question...the power suply needs 25-0-25 volts 3 or 4 A ... my question is       :is necesary to use 1/2w watt resistors at least? or is ti ok with 1/4 watt? i mean in the preamp section.. Thanks in advance..

Hello from Peru and congrats for the Randall Hybrid .. recently finished this project only have two issues:
1. Couldnt find the 2n5484 Jfet so i replaced them with 2n5457 i wonder if both have the same gain???
2. tested the sound out of the preamp section into another guitar amp and the sound is great!!! punchy and Heavy  :dbtu: but when i connected to the power amp section presented here the sound is weak and too trebly for my taste, is it normal??

on my experience with power amps the transistor ones are most pleasing sounding for guitar, and adds a little distortion to the signal when driving hard.. anybody know a 100 watts transistor power amp project with pcb and layout?? please let me know...
thanks for the project and please post some advances or maybe an audio demo..  :tu:
Allan Belt.