Help? Bi-Amping With A Pair of Roksan KA-1 Amplifiers


Hello. I need some help with trying to multi-amp with my two Roksan Kandy KA-1 integrated amplifiers. I have a pair of B&W DM640 speakers (may upgrade soon) that are bi-amp capable. I am trying to figure out exactly how to drive the upper frequencies with one amp and the lower frequencies with the other amp.

The later models of the Roksan amplifiers have a trim capability which is supposed to help balance the outputs when bi-amping- I think. My amps do not have the trim function. My amps do have what looks like pre-out and pre-in RCA (L+R) plugs that are bridged with a metal jumper bar. The pre-out is called a “Remote Out” but I think this is a pre-out.

When I pull the jumper bars on the amps, the output on the pre-out (remote out) seems to be very low level and I am not sure I can balance the HF and LF outputs to make this work? Of course, I will remove the jumper bars on the speakers as well.

My question is, can I pull the jumpers on the “remote out” and “Pre-amp input” on both amps and then connect one amp to the other and wire the speakers in bi-amp mode?

I contacted Roksan and their answer was too vague for me as they said I can do this “If the amps are wired correctly". Not much help for a newbie...... Any help would be very appreciated.

Than you in advance,

Bryan


128x128voiceofvinyl
I think I would call Roksan back, and ask to speak to a technician about bi-amping with their amps....sounds like you got someone who obviously didn’t know. You could also stop and visit with a dealer to get some input.

Since you have the two amps and what appears to be a fairly high resolution system, you should be able to hear some benefit from doing the bi-amping. I noticed an improvement in the size of the soundstage, separation, bass dynamics, and clarity when I bi-amped my system (different amps than yours)....not a huge change, but audible enough to pursue....just takes things to the next level without changing the overall sound signature of your system. You could always just split the music source signals between the amps, and do a "vertical" bi-amp configuration and end up with separate volumes for each side. (vertical is when you use two identical amps...one on the left, one on the right... each with one channel to the woofer, and the other channel to the mid/tweeters.)

I hesitate to urge anyone to experiment with expensive equipment, but that’s exactly what I would do if in your shoes if you don’t get any help. All the inputs and outputs should be line level if you stay away from the phono stage inputs for anything except phono. If you keep a speaker load on the amps, the volume down, and proceed with caution (no shorted speaker wires), you should be able to figure some things without doing harm. Best of luck!
@knotscott. Thanks for the reply. I'm afraid I don't quite understand the "vertical' bi-amp approach. In this approach, I have to keep the Right channel outputs of each amp connected to the right speaker, one set for the highs and one set for the lows, conversely for the left?

Also, how do I feed my front end phono and CD player? There are only one set of left and right outputs from these components. Do I pull the pre-out and pre-in jumper bars?

Sorry to be such a novice at this but I am trying to do this right.

Thanks.
One amp is doing mids and highs, and one is doing bass duty.

Don’t pull anything leave the jumper bars intact, on the Integrated.

Remove the jumpers on the speakers

Hook the one with no trim to the left and right speaker bass sections.

Hook the one with trim control to the mids and highs, left and right speaker terminals.

Kinda different, but will work as good as you’re gonna get it. Just two volume controls. One for the bass one for the mids and highs, with trim
(balance, treble, and bass (hopefully)), on the mids and highs.

It's pretty straight forward, You might want to use a little heavier speaker cable on the bass (copper is the best) and better quality for the mids and highs, No need to get crazy just smaller, better cable. Be careful with clad wires they can be on the bright side. Silver over copper, that kind of stuff.  pure copper, pure silver, some clads if they are thought out, properly...

And don’t be sorry, I never have been, apologised a time or two but NEVER sorry... :-)

Regards
See if this link takes you to an article about bi-wiring and bi-amping, and scroll down to the last diagram pic near their conclusion that illustrates the difference between vertical and horizontal bi-amping...might help you visualize.
https://www.audioholics.com/frequent-questions/the-difference-between-biamping-vs-biwiring

Here's another link that has some pics - http://av2day.com/2014/05/bi-amping-vertical-vs-horizontal/

Either Vertical or horizontal bi-amping could work for you, but it’s important to pick one and not confuse them. There are pros and cons with each. Regardless which, you will be doing "passive" bi-amping using your speaker’s internal crossover ("active" bi-amping is another option for some situations, but it doesn’t sound like it’s feasible for you at this time).

The "vertical" method dedicates one amplifier solely to the left channel, and the other amp solely to the right channel. The markings for "Left" and "Right" on the output of your amps become irrelevant....one is going to become the woofer channel, and the the other the mid/tweeter channel. Split your music source signals between the two amps....left output from CD to input of the amp going to the left speaker, and left output phono to the phono input of the amp going to left speaker.... then right output from CD to right speaker amp, right output phono to right speaker amp. Left and right sides are completely isolated from each other, and will have separate volume controls in this configuration....the stereo effect will occur at the music source. Make sense?

p.s. It just occurred to me that you will need a y-adapters for your CD and phono cables.