Korg Poly800/EX800 Users

Has anyone made a before/after recording of this mod? I would love to improve the 
characteristics of my poly's...


--- In korgpolyex@yahoogroups.com, "plutoniq9" <Plutonique9@...> wrote:
>
> The final audio stage of the Poly 800 goes through a NJM4558 OpAmp.
> The slew rate for this OpAmp is a little to slow to achieve a 20hz-
> 20khz Bandwidth reproduction, and normally when these are used for 
> audio, compensation capacitors ar used to make up for it's lack of high 
> end. The Final Opamp stage doesn't use these caps though, so it's safe 
> to say that the high end freq. responce of the audio outs are capped.
> 
> Well, no point in adding the compensation caps, may as well remove the 
> OpAmp and replace it with a socketed higher performance audio opamp 
> that doesn't need 'em, one also that has a higher Signal to Noise 
> ratio. So, Dis is how;
> 
> What you'll need;
> 
> -Solderin' Iron (30 watt or so)
> -Solder, Desoldering Braid
> -8 Pin IC Socket
> -NE5532 Dual Opamp (Pin 4 Pin replacement of the 4558)
> 
> Ok;
> 
> First you need to locate "IC2" on the KLM-598 Circuit Board (This is on 
> the top half of the Poly 800 synth). Unscrew the KLM-598 board from the 
> Poly 800 casing and remove the ribbon cables from the sockets on the 
> board(This will allow you to completley remove the circuit board out of 
> the synth to work on). Using the delsolder Braid, desolder all the  8 
> Pins of IC2 (NJM4558) and remove part from the board.
> 
> Next, Solder in an 8 Pin IC Socket where you removed "IC2", make sure 
> the IC socket is facing the right direction (matching up with the 
> drawing on the circuit board). Now, carefull insert you NE5532 Opamp 
> into the IC socket (The dot representing Pin 1 of the NE5532 should be 
> inserted into the socket so that it is on the side of the IC socket 
> with the Dip in it).
> 
> Now screw the KLM-598 board back into the Poly 800 casing, reconnect 
> all the ribbon cables, screw your synth back together....and your done!
> 
> Hope it sounds all the more sweeter. If ya find you prefered the ol' 
> noisy low-bandwidth NJM4558, hey it's easy to remove the NE5532 and 
> stick the old one back in there, no harm a done :)
> 
> Seeya
> 
> P9
>