| go home |
note: there is a MC and a MM gain stage to the left and a dual mono RIAA to the right. There is not a seperate RIAA for the MC or MM.
In trying to replace the opamp caps /w ELNA Cerafines I tore up the board.
Back in went a new set of Panasonics and circa 1970 Vishay resistors,
and some new trace made of discarded leads.
I also had to fix the connection for the BG input caps.
I ran some copper lead from a Riken resistor thru the board up
and soldered to the clipped leads of the cap.
Pretty ugly, as usual, but effective ... as usual.
| RIAA opamp |
LM4562 /w heatsinks + Blackgate NX Hi-Q .1uF/50v on pin 4 & 8 Replaced ceramic caps /w same value silver mica Vishay's NOS ~1970 100ohm 1/2 watt resistors Panasonic/Matsushita 470uF/25v caps |
| Subsoniuc caps | removed |
| MM opamp |
OPA2228 /w Blackgate NX Hi-Q .1uF/50v on pin 4 & 8 Rubycon XYF 1000uF/35v |
| MC opamp | stock opamp /w Blackgate NX Hi-Q .1uF/50v on pin 4 & 8 |
| Output | Blackgate NX Hi-Q 47uF/6.3V + Obbligato .22uF/640v + Vishay-Roderstein .01uf /160v |
| MM input |
Blackgate NX Hi-Q 470uF/6.3V + .1uF/50v Blackgate NX 220uF/6.3v |
| bypassing, ground |
Blackgate NX Hi-Q .1uF/50v |
| Power supply | c9, 10, 11, 94, 95 : Rubycon YXF 100uF/25v c55, 2, 4 : Rubycon XYF 1000uF/35v c3, 4, 5, 6 : Rubycon YK 330uF/50v repaced (6) rectifiers with Schottky 11DQ10 |
Resource: http://www.vinylengine.com/phpBB2/viewtopic.php?t=9098&start=0
The 640P benefits in terms of presence using the CineMag CMOB-2S steel core 1:1 @ 600ohm output transformers
Hookup =
IN : Orange + / Yellow -
OUT : Orange + / Red -
The old school chassis for the CineMag transformers
RCA short plugs with 4.7k resistors
Resource
10.11.2009