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.

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.

Thanks for the great response to my post on the 845S monoblocks. As for NED KELLY, where have you been? He is only our most famous bushranger hero downunder in Australia (I am in Melbourne), GOOGLE him. I don't think I will get further into these amps as the sound I am achieving now is outstanding to my ears. Unfortunately I don't know anyone who has what I consider a better system and until I do hear something better I will just call a halt. I did make up some mains leads from 15A semiflexible 3 core wire. I fitted an Australian 15A 3 pin plug to one end and a silverplated IEC 15A to the other. I wasn't expecting much as I was already using some fairly heavy shielded ex. computer cables but the sound did improve a little with slightly better dynamics. Darned if I know why!

Regarding my 845S mono blocks, I have now replaced the original Shuguang 845B tubes with Psvane (Pavane) "Hi Fi Series" 845 tubes. These sound far better (to my ears) than the original 845B tubes ever did. Apparently their "Collection Series" tubes sound even better but at considerably higher cost. I believe Psvane make 211 tubes and it would be interesting to hear how they sound in a 211 amp. Has anyone tried their 845 tubes?

I now see from your photos that my 845S amps are only similar to the 211 types internally. My resistors look as if they might be an upgraded type from the previous model 211/845 amp. As for the Psvane 845 'Hi Fi' grade tubes I am using, I read that they are discards from the Collection Series (T) testing which may have found themselves in the trash bin except that if they are good enough they can make the 'Hi Fi' tube spec. Anyway, I like their sound better that my stock 845B tubes. I added 3 in parallel 0.47/1600V film caps across the 1000VDC rail electros plus a 0.47/600V film cap across each of the two B+ rails. I would have bypassed the -ve bias supply rail too but forgot, and I can't be bothered taking things out again to get to that area. The power supply bypass caps seemed to give a little better focus at the high end and I'm very happy with that mod. I've also replaced the speaker terminals with silver plated brass (they were sold to me as copper!). I use Cat 6 speaker wire (bi-wired) and last night I changed the way I had configured the pairs. The hi end has now become more extended. Previously the Cat 6 exhibited quite high capacitance between wires, however the way I have it now the capacitance is much lower. I guess the next move is to replace the filament bridge rectifier block with some fast recovery diodes. Hopefully this will make the amps a little quieter when I stick my ear in the speaker. There is only the slightest buzz in the speakers at present.