Moving from a stereo amp to a dual mono set up
I thought this would have been not much a change and easily accomplished.
Boy was I wrong. I found a second Plinius SA102 on Audiogon a few months ago at a great price. I had it drop shipped to Ralph Abramo for a good going through. A few weeks later and it was done so I drove to his shop to pick it up. I asked about how to set up the amp for dual mono. A easy thing to do. Change the position of a switch in the back and connect the speaker wires to both R / L positive leads and connect the input to the right channel.
My speaker wires are Straight Wire Cresendo 3's. The leads are not able to reach the 9" spread to the positive speaker connections of the amp. I spoke with Straight Wire, they can alter the cables to a 12" long lead so they can reach. OK, shipped them out yesterday.
Now considering my electrical plug issue. One more plug is something I do not have. I have a older PS Audio AC filter that can receive up to 8 inputs. But I do not like the idea of running 2 high power amps through it. I want to do directly into the wall for my power.
I called an electrician and he is coming over next week to do a Job Walk. to see what it will cost to add a new circuit to my power panel and run the wires for a new plug.
Then there is the physical amp to deal with. I need a second stand to get the amp off the floor.
I will have to disconnect and move my existing equipment and stands around to make the system visually balance out.
Then there is still one question I am not sure of. Do my current XLR cables from Preamp reach across to the new positions of the amps. Are they long enough?
All this equipment is between the speakers. I like where the speakers are right now.
OP I am impressed with your ability to make it all happen simultaneously. Those are some impressive amps, congrats on finding a rare 2nd unit. I just glanced at this: Stereophile Review of Plinius SA Sometimes I recommend the idea of potential bridging, i.e. start with an amp that can be bridged, exactly what you did. I think of it more for tube power, hope one affordable/less heat less heavy Stereo Amp is enough power. If not, get a second one (phased spending can be a reason), OR, IF you change to less efficient speakers, NEED more, get a 2nd one. I suspect you are doing it out of ’now or maybe lost opportunity’ more than need. I recently noticed impedance taps become limited on McIntosh models when bridged, and reading testpilot’s comments, I looked, Plinius only lists 8 ohms when bridged: You really haven’t experienced the full benefit of “true” dual mono amplifier set up as you are using 2 stereo amplifiers “bridged” where amplifier phase of one channel has been inverted - that is why you are now using the positive L and R terminals for a single speaker. Bridging typically halves the minimum impedance the amplifier can safely handle, lowers the damping factor, and increases THD and noise. Bridged amplifiers are typical limited to speakers with a nominal 8 ohm impedance with no significant dips below 6 ohms. " ////////////////////////// I found this review of Canton Model 3.2 (You mentioned model 3) Stereophile Review of Canton Reference 3.2 "My estimate of the Canton’s voltage sensitivity was a high 91dB/2.83V/m; this loudspeaker will play loudly with just a few watts. However, its impedance plot (fig.1) indicates that the partnering amplifier needs to be comfortable driving a low impedance. The magnitude remains below 4 ohms for almost the entire bass and midrange regions, with a minimum value of 3 ohms at 360Hz and a current-demanding combination of 4.6 ohms and –45° electrical phase angle at 88Hz, a frequency where music can have high energy levels." I presume you told Plinius which speakers you have. When replacing my speaker’s 16 ohm L Pads, I asked here and learned about very slight frequency shifts if I used 8 ohm taps on my Cayin instead of it’s 16 ohm taps, and that some guitarists choose which tap to use to purposely get slightly different sounds out of their tube amps playing live. Your Canton’s 91 sensitivity helps (assuming 3.2 and 3 are the same), you shouldn’t need to push them hard, and bi-wire using different cable type for lows is still an interesting option, your speaker’s readily provide for that. Your amp offers class a (whole lotta heat) and class ab (a timed 10 minute switch?), are you able to easily or always hear differences, or do you use class a only for special content, short periods, all winter?
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