Hi, I have an active speaker system based on Crimson Elektrik power amp modules that I put together a number of years ago. They use CE1704 issue VII modules for the bass, and CE608 issue 5 for the midrange; the piezo tweeters are powered by OPA544 power op-amps. I am about to replace all of the electrolytic capacitors in all of the modules as they are probably all 40 years old! I bought the CE608s new over 40 years ago and they have been working perfectly daily since then and are entirely 'untouched'. The CE1704 modules were bought from AndrewT about 10 years ago.
Anyway, to the point. I remember reading on here that Brian Powell, who designed the amps, posted details of how to upgrade issue 5 modules to issue VII, but I have looked and the details are no longer downloadable. It also appears that Brian's latest post was about 2 years ago. I would like to carry out the upgrade while the speakers are 'down'. Does anyone have the details of this upgrade that they are willing to share?
Cheers, Keith
Anyway, to the point. I remember reading on here that Brian Powell, who designed the amps, posted details of how to upgrade issue 5 modules to issue VII, but I have looked and the details are no longer downloadable. It also appears that Brian's latest post was about 2 years ago. I would like to carry out the upgrade while the speakers are 'down'. Does anyone have the details of this upgrade that they are willing to share?
Cheers, Keith
Hello Keith
It is possible to upgrade the Crimson issue 5 to issue VII but you need all the special equipment and it takes ages. It is not cost effective compared to replacement PCBs. I have issue VII modules as spare parts which I refurbish now and then. I am also producing newer generations of the PCB called PWR9 and PWR12. They are so much better than the old ones. These use 4 plastic power output devices. Let me know if I can help further. The latest PCB is in the link
It is possible to upgrade the Crimson issue 5 to issue VII but you need all the special equipment and it takes ages. It is not cost effective compared to replacement PCBs. I have issue VII modules as spare parts which I refurbish now and then. I am also producing newer generations of the PCB called PWR9 and PWR12. They are so much better than the old ones. These use 4 plastic power output devices. Let me know if I can help further. The latest PCB is in the link
An externally hosted image should be here but it was not working when we last tested it.
Thanks Brian; that new PCB does look good! I have now changed all of the caps on the old boards and there is a noticable improvement in the sound - also, one of the 608s had dropped in level by about 6dB but it is back to full level with its new caps.