Monoblocks did not work


Help me with this problem pl. I had one Classe CA-400 driving Dunlavy V'S with all Classe front end. I was very happy with the sound, so happy I refused to upgrade for 3 years. That the power bug hit me. What if I buy another CA-400 and run each as monoblocks. I did, with all other components remaining same( same IC's going to each amp). The result was way worse than expected. Thin , hashy, ambient sound. Power of 800W/ch (into 4 ohms) became 2400 W/ch, still bad sound. What happened? How do I make use of the beast (120lbs) that I have aquired?
nilthepill
How are you running these amps ? Bi-amped ( vertical or horizontal ) or bridged ??? From the input that you've stated about power output per channel, i'm assuming bridged.

For sake of clarity and those that may not know the different terms, vertical biamping uses one stereo amp per speaker. Channel A runs the bass section of the speaker and channel B runs the mids and highs.

Horizontal uses one channel of each amp for the bass and the two channels of the other amp feed the highs.

Bridging takes the two channels of a stereo amp and converts them into one BIG channel. You then need two amps in order to make a stereo pair.

All three of these arrangements sound different even though your using two identical amps. Bridging typically gives the highest voltage levels possible out of the three different arrangements but usually results in a much harder and thinner sound. Sean
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Sean and Snook2 I bridged each amp to form one big channel. Amps are bridgable. Gregm thaks for the tip, I will be sure to look it up. I should mention that, Classe did recommend Vertical biamp than the monoblocks. But need, Two sets of interconnects (same brand) with Y-splitter at the pre-amp. I bought extra pair of speaker cables same length, same brand. IC would be tricky, since I have to deal with y-splitter. Probably would inquire with the Straightwire tommorow. But I don't want spend extra $500-600 with same results, without proper feedback from Agoners. Thx.
p.s. Let me tell you that my current sound using only one CA-400 is GREAT, but sound stage depth improvement is desired-without moving the speakers!!
Nilthepill. I am no techo, but I think bridging ups the wattage but makes the speaker load look twice as difficult. So maybe the sound you are getting is what the Classe would sound like into a 2ohm load - could be, and no doubt someone will correct me if I am wrong - please be gentle?

I would be very tempted to peek inside the Classe and see if I could link together the hot connections on the left and right input RCAs without doing any real damage (or get someone competent to do it for you - possibly a better result than using Y connectors, and a darn sight cheaper than buying additional interconnects.
I don't know if your CA400s are also balanced or not, but I recently vertical bi-amped a pair of McCormack amps using RCA ICs, and I accidently switched one amp to the balanced mode and got sound like you describe.

Do the CA400s have balanced switching of some kind? Other than that, I would make sure all speaker cables are attached to the correct speaker and amp terminals for the way the monos need to work. Good Luck. Craig
Hello Nilthepill:

Yo are on the right track except you strapped your amps mono. By bridging you increased output power hower reduced current from the amps thus losing some control of the speaker by the amplifier as now the amps see the load at half the previous impedance. In other words, If your speakers are a 4 ohm load, in bridged mode each amp sees a load of 2 ohms. This would account for the bright and hardness you now experience!

If you can biwire your speakers, remove the jumpers and do so. I am assuming that you have one long run of interconnect, and have the amps next to the speakers. If so, you'll find with a short run of speaker cable you can use almost anything! As to splitters, even a cheap pair of Rat Shack splitters will give you an idea of what is possible.
Use them on the amp end and then use one channel of each amp on the woofers, and the other channel of the amp on the tweeters. I can virtually guarantee this will result in improved sound!

Paul