I finished to build 2 pairs of monoblocks (Dynaco MK3s from scratch with VTA boards). The amps do sound great! But I ran into an issue when attempting to biamp each speakers: i removed the jumpers between the speakers posts and wired one monoblock to the tweeter/mids and another one to the woofer. Turned the first one on, all good. But when I turned on the other connected to the woofer, I got a squeal which moves up in pitch as more current reach the output tubes.
Same thing happened with the other speaker. I triple checked everything, it’s not coming from the amps or the speaker cables. With only one amp connected to the woofer (nothing connected to the mid/tweeter), same result. If I put the jumper back on between the posts, everything is fine.
I did test the speakers with the jumper removed and no wires attached: on the woofer posts, I read 4 or 5 ohms and there is continuity while I can’t get a reading between the m/t posts (and there is no continuity). If I wire an amp to the m/t posts, then (and only then) I get a reading of 4 or 5 ohms. So I guess the issue is in the crossover… any idea what it could be and how to fix it? I found some threads online where people did biamp these speakers, so I guess it’s possible But since I’m using monoblocks, could this be the problem?
Some suggestions would be much appreciated!
Same thing happened with the other speaker. I triple checked everything, it’s not coming from the amps or the speaker cables. With only one amp connected to the woofer (nothing connected to the mid/tweeter), same result. If I put the jumper back on between the posts, everything is fine.
I did test the speakers with the jumper removed and no wires attached: on the woofer posts, I read 4 or 5 ohms and there is continuity while I can’t get a reading between the m/t posts (and there is no continuity). If I wire an amp to the m/t posts, then (and only then) I get a reading of 4 or 5 ohms. So I guess the issue is in the crossover… any idea what it could be and how to fix it? I found some threads online where people did biamp these speakers, so I guess it’s possible But since I’m using monoblocks, could this be the problem?
Some suggestions would be much appreciated!