Biamping with a cd player
An oscilloscope (even a very modest one) and a test tone CD or LP or function generator set to sine wave output at a few frequencies across the audio spectrum will help you get the same signal levels to your speaker terminals. "If" the amps are not identical gains, no need to go to that trouble, just a multiple test tones cd, and you can measure at the speaker terminals using a simple digital ac volt meter to get identical volts into both mid/high and bass terminals. Cheers George |
consecutive serial numbers. That’s good, they "should" be identical gains, let us know how you went. They have input level controls anyway, so if the mids/highs or the bass seems louder you can trim it back Just remember the carpenters saying, "measure twice, cut once" Same goes for wiring up something like this "double check before turning on" Cheers George |
Excellent... Thank you George. Will let you know, on this thread, how it turns out. Have been doing well with just one amp driving the Kappa 9's... Even on the "Extended" mode on the Kappa's, at very loud levels, I can't get the one WOPL PL 700 amp to clip, overheat or trip the protection circuits built into these beasts. I am running the Phase Linear fans on the amps... that helps to make sure there'll be no issues. That WOPL upgrade tested output on both amps were over 500w per channel. Plus, with the WOPL replacement/upgrades the amps do well @ continuous loads into 2ohm and beyond. Now very stable driving speakers that dip into the crazy low ohm levels. Also, back in the day Infinity speakers were matched with Phase Linear amps at a lot of the audio demonstrations. For some reason they worked very well together. Makes sense on the vertical biamp. Have only done horizontal. Will be going vertical... On that graph you sent it shows the Kappa 9's dropping below 1ohm... That's pretty nasty. No wonder they got their nickname. Skip |
joysjane OP OK, you’ve got 2 x Phase Linear 700’s the same? They are 33khom each input impedance = 15kohm at 1.2v sens, the Oppo will see. This fine, the Oppo can do this at 100ohm with 2.1v. Yes vertical Bi-Amping is better as each amps power supply is then only having to drive one bass unit, so in theory it’s better for bass. Which ever way you go be careful with your hookup, the Phase Linear are very powerful, but not very stable, and the Kappa 9's are a very hard load. http://www.classicspeakerpages.net/IP.Board/uploads/monthly_2016_03/Kappa9Impedance.jpg.340a528e36b9... Cheers George |
joysjane Yes of course it can, and simply, if the two amps are the same, I do, when I use a cpd or dac that has a digital volume control. It’s the best sound you can get this way. "If your serious about doing it" what dac/cdp do you have? and what are the two amps? what speakers? (amps need to be the "same" amps or "identical in gain" or have a "level control on the louder" of the two if different.) If your dac or cdp has enough volume and has low output impedance <200ohm most are, there is no problem driving 2 x same gain poweramps with input impedances of more than >33kohm each, most are. And do vertical bi-amping, (substitute the pre for dac or cdp in the pic) http://www.av2day.com/wp-content/uploads/2014/05/biamp2.jpg I use these on the dac/cdp output, https://www.google.com/search?rlz=1C1CHZL_enAU820AU820&q=gold+rca+splitter&tbm=isch&source=univ&sa=X&ved=2ahUKEwjXsqjd8_PhAhUB7XMBHb9IBdIQsAR6BAgJEAE&biw=1408&bih=858 Cheers George |
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