Ok-there is little story about making thiny non-complicated sand preamp.......
Hehe-like always -there is no such thing like non-complicated.......especially when you know that power supply is vital part of this sort of audio device ; In this case - power supply is more complex then audio section . For further explanation , you can always look at Pass Labs site for BOZ (or - Bride of Zen - if you wish ) document in pdf format.
In any case-for making this preamp main responsible is my friend Oliver Isailovic from BG,who made just for me this wonderfull PCB; I'm too lazy and too PTP oriented to make my own this time.
He also made main changes from N. Pass's original schematic,mainly in supply section - dedicated gene for zener string ,and also dedicated mosfet regs for each channel.
Like you can see from photo of finished and populated PCB , I use some smaller caps for bypassing of input and output caps : 50nF PIO for input and 0,1µF "unknown tubular" for output cap. In time when case will be finnished I'll try even big MKP cans salvaged from ancient phone facilities.
Heatsinks on all transistors are almost unnecessary , but some small ones on 1K load resistors are more than welcome.That biggie heatsink for both signal mosfets is there solely from one reason - I like to keep them on same temperature.
Those funny looking diodes in Graetz are super duper speedy ones , in fact -duo diodes salvaged from tossed ATX supplys.
One more thing-due to Ugs of reg mosfets , one 10V zener in zener string must be replaced with 15V one , in case that you are picky about exact 60 Volts on top of Rload ..... ;)
Like always-more than gratitude to N. Pass (go to "links" page) not just for all his schematics - his cheerfull attitude is even more valuable , at least for me.
In case that you can't see some detail on schm or PCB , just save it wherever you want ,and open it with some picture wiever.......
Ideas for further tweaks - just for fun : tube rectifier , gas tube shunt reg , parafeed or even xformer output....
ps-except this PCB drawing ,I dont have any other.
anyway-I'll try to measure exact dimensions of PCB and to write it here
