#1 Quad 405-2 circuit query
Posted: Sat Jun 19, 2021 7:01 pm
Hello
I have been working through my Quad 405-2, following Nick DeSmiths notes, with some of Keith Snooks DCD mod 3 changes (I'm not inverting anything as my pre amp is already inverting) - adding the Tr1a/b change and new Tr2/3 transistors (there was no Tr4). The board is M12565 iss.7, the same as Keith Snook is modifying on his site.
Snook states 'with Tr2 changed to 2SC2547E and R23 removed and Tr4 replaced with ZTX753 ** and C11 replaced with a link there should be no need for C7 // R14 and C7 can be replaced with a wire link'. I'm a bit wary of this change (C7 with a link wire) as C7 is actually a resistor not a 330nf capacitor, a 3R3k resistor, R17 and 'C'7 are both 3r3k resistors. Looking at other photos this is true for all 405-2 boards. For the intended circuit I remove both resistors and replace one with a wire link, C7. Can anyone confirm this would be correct?, it would be a pain to blow anything up at this stage
Cheers
I have been working through my Quad 405-2, following Nick DeSmiths notes, with some of Keith Snooks DCD mod 3 changes (I'm not inverting anything as my pre amp is already inverting) - adding the Tr1a/b change and new Tr2/3 transistors (there was no Tr4). The board is M12565 iss.7, the same as Keith Snook is modifying on his site.
Snook states 'with Tr2 changed to 2SC2547E and R23 removed and Tr4 replaced with ZTX753 ** and C11 replaced with a link there should be no need for C7 // R14 and C7 can be replaced with a wire link'. I'm a bit wary of this change (C7 with a link wire) as C7 is actually a resistor not a 330nf capacitor, a 3R3k resistor, R17 and 'C'7 are both 3r3k resistors. Looking at other photos this is true for all 405-2 boards. For the intended circuit I remove both resistors and replace one with a wire link, C7. Can anyone confirm this would be correct?, it would be a pain to blow anything up at this stage
Cheers