Consonance Opera Cyber 211 mods

I have the Opera 845S monoblocks. I replaced the Audience AuriCap coupling caps (2 x 0.1 and 2 x 0.47uf) with Jensen Copper PIO caps. I got a very significant improvement. In the last few days I have replaced the RCA input sockets with CMC silver plated copper RCA sockets. I also replaced the shielded wiring from the RCA's to the input stage tubes with silver plated teflon insulated coaxial cable. This gave a remarkable improvement in sound especially in high end detail and dynamics. The amps are now a huge improvement from stock in my hi-end system. Regards, David.

Having just finished some extensive mods to my 211, I just thought I'd look here to see if anyone weighed in. Thanks David. It would appear that this amp has good design in need of much better parts.

I have been tackling my 211s one at a time. I first changed out the auricaps, internal wire, IEC, binding posts, and RCA with VCAPs, vhaudio copper air teflon, furutech IEC with an external fuse holder, and Eichman binding posts and RCAs. After about 100 hours of burn in the changes were remarkable - faster, more detail, more low end control, simply more engaging.

I then took the second amp and did the same thing, plus, with lots of advice from Nick at HiFi Collective, I changed all of the resistors along the signal path, in around the 5687 and 6922 tubes - 20 resistors in all. Lots of work. Oh, and I relocated the RCA input to the new side panel near the 6922 tube to eliminate the very long internal run past all the transformers and torroids.

After about 20 hours, this amp blows away the first one and keeps getting better - it's at about 60 hours now. I never imagined that resistors would make that kind of difference - a bigger improvement than the VCaps so far. Far more detail than I could imagine, makes the first amp sound like its playing through a towell.

My next step is to add the resistors etc to the first amp, plus build a new bridge rectifier, which converts the AC to DC driving the 211. The OEM part literally costs about 10cents. Nick tells me that this change should also be significant.

Assuming the rebuilt bridge rectifier is another big step I'll repeat that on the second amp, and then - not sure what else to do. Big bucks for new output transformers.

You are as game as Ned Kelly! I haven't gone any further than my previous post as I was so impressed by the improvement that I didn't think it could get any better. I thought about placing the RCA sockets on the side of the amps near the front but didn't like the thought of drilling through the sides. I did have a short connection through the ventillation slots for a few days but when I wired it all to the original rear position it still sounded as good. One thing I thought really improved was the background noise in the speakers. It was much lower with the new cable even though it was still running past the toroids. I did try to run it a bit further away from the toroids so that probably helped. I guess I should replace the speaker terminals with copper types but as for the IEC I would prefer to hard wire solid mains cables to the amps. Can you explain the improvements you are getting with the new resistors (what types are they) and internal wiring. The internal wiring seems so short and point to point that I didn't think I could do much with it. My amps are the latest 845S types with the bias meter on the front. You must have a lot of patience to work on these amps as everything is buried down inside making it difficult to get in without burning everything in sight. What improvement do you expect by replacing the filament rectifier? Are you going to use discrete fast soft recovery types? Do you know how to post photos on this site? I can't figure out how to do it otherwise I would have done so. Best regards, David.