Has anyone successfully implemented a Guardian-86 or Guardian-686 speaker protection board in your Adcom or similar SS amp? I have determined my Adcom 5400 is Japanese made, therefore Version 1 without the speaker protection board. I do not want to put my irreplaceable Infinity Renaissance 80 speakers at risk. Or are there good speaker protection alternatives?
Guardian-86 or Guardian-686 Implemention
- Thread starter maives
- Start date
Register to hide this ad
I have finished the incorporation of the Neurochrome Guardian-86 speaker protection boards into my Adcom GFA-5400. This effort was combined with replacing all electrolytic capacitors on the power supply board, including 15,000 uF 63v Cornell Dubilier filter capacitors and the remaining Rubycon high ripple capacitors. And wow, what a change. Incredible improvement in articulation, especially bass response, but also the high end clarity improved.
I was not fond of having to drill holes in the chassis and the maker of the Guardian advised against cantilevering the Guardian on top of the power supply board, which would have only required two holes drilled into the PCB. So I am including some photos for those that want to duplicate what I have done. The platforms were fabricated out of 1/16" plate aluminum. They mount onto the speaker output posts without the need for drilling any holes. The same approach would probably work for many other amps. After fabricating the mounts, they were anodized just for a higher end look.
Although the Guardian-86 boards were not cheap, they arrived in the US the next day after ordering using UPS 3 day. They are very well made and miniaturized. There was some limited rewiring needed on the Adcom both to power the boards and to re-route the outputs.The power to the boards were measured at +58 VDC, which was not problem for the Guardian-86. The Guardian-86 can take +15 VDC to +90 VDC
Although I planned to replace the capacitors on the amp boards with Nichicon UKL capacitors, I attempted to remove the boards and found that the MOSFETS were strongly attached to the heat sink and I felt trying to get them off would be tricky and might result in disaster. If anyone has had success in this regard I would like to get your advise.
So all in all I would call this a successful modification with the goal of protecting my beloved Infinity Renaissance 80 speakers. The Guardian-86 clearly did not degrade the sound.
I was not fond of having to drill holes in the chassis and the maker of the Guardian advised against cantilevering the Guardian on top of the power supply board, which would have only required two holes drilled into the PCB. So I am including some photos for those that want to duplicate what I have done. The platforms were fabricated out of 1/16" plate aluminum. They mount onto the speaker output posts without the need for drilling any holes. The same approach would probably work for many other amps. After fabricating the mounts, they were anodized just for a higher end look.
Although the Guardian-86 boards were not cheap, they arrived in the US the next day after ordering using UPS 3 day. They are very well made and miniaturized. There was some limited rewiring needed on the Adcom both to power the boards and to re-route the outputs.The power to the boards were measured at +58 VDC, which was not problem for the Guardian-86. The Guardian-86 can take +15 VDC to +90 VDC
Although I planned to replace the capacitors on the amp boards with Nichicon UKL capacitors, I attempted to remove the boards and found that the MOSFETS were strongly attached to the heat sink and I felt trying to get them off would be tricky and might result in disaster. If anyone has had success in this regard I would like to get your advise.
So all in all I would call this a successful modification with the goal of protecting my beloved Infinity Renaissance 80 speakers. The Guardian-86 clearly did not degrade the sound.
