So the Yamaha PM2000 is one of the only non-consumer products to use The Hitachi Corp HA1457 Chip. It was a very HiFi chip in it's day. It uses a dual rail +- 24VDC power scheme and it is clean reliable and has headroom for days. The down side is the rather cool but rare SIP package. So a replacement that plugs right in ain't out there. But time marches on. The TI OPA604 chip uses the same power scheme and has much better noise and linearity specs. So it is really a toss up. But I think to my ears the OPA604 is worth the time to replace. Yes I had to design my own PCB to make this work.
Card to convert the SIP to DIP for the HA1457 swap. It was really easy and straight ahead. I had some help from Chris Mitchell with the R&D he is the one that determined the need for the caps to ground on the power inputs to avoid parasitic oscillation and did some really scientific analysis between the two chips. Check his saga at:
Below is a brief picture gallery of the individual post fader outs of each channel and the transformer buffer interface that ties them to the system.
(click on each photo to expand)
(click on each photo to expand)
So this is the front plane DB9 location. The large olive green box in the lower right of the pic is the master fader housing. The switch is the CUE button (more on that later).
So this is where we tap the PC Board of the input modules. It is just past the main 10K Master fader and just prior to the pan matrix, the PCB pad is marked O1 on the PCB. From here the orange wire that is seen going off left of the image goes to a DB9 connector that will end up on the front plane of each input module. I chose to do it this way so as not to have to modify the already heavily populated backplane. This could be done mind you but it takes some PCB surgery two spots for each module and that's 64 operations that must be done right in close quarters. NO THANKS!
SOLO IN PLACE MOD:
This is a mod kit that is offered by JLM Audio Australia (you may have seen them at AES NY in the DIY Audio booth).
It is both easy and awesome to implement.
This is a mod kit that is offered by JLM Audio Australia (you may have seen them at AES NY in the DIY Audio booth).
It is both easy and awesome to implement.
