Roksan Kandy K2 - Channel Imbalance

[alastairpearce]

Hello,

I have a Roksan Kandy K2 Integrated & K2 Power Amp Combination, into B&W 683 S2 speakers. I have been really pleased with the performance of the system thus far, but since I have started delving into the fine tuning of speaker positioning I have noticed a definite channel imbalance - the right channel is consistently louder than the left.

I purchased the Isotek system setup CD - and on the Left/Right channel the spoken voice and castanet sound coming through the right channel is noticeably louder than the left.

I have ruled out a speaker issue by swapping over the speakers. I have also ruled out a cable issue by swapping over the cables at source, so it must be something to do with the amplifier?

I have also evaluated both channels using a Maplin sound level meter - playing pink noise first through the left channel only, and then the right channel only, and measuring each speaker output with the SPL meter placed close up to each of the respective speaker outputs (i.e. tweeter, mid-range, and both bass speakers). I started out with the volume control at about 9:00 on the dial.

I managed to achieve excellent repeatability of results with the SPL meter, showing tweeer and mid-range outputs to be identical. I think this demonstrates that room acoustics didn't affect the test.

The overall conclusion was that the right channel was consistenly 1.4dBc higher than the left.

Turning the volume up to the 12 o'clock position, and repeating the pink noise test to the left and then the right channel did reduce the difference, but only to 1dBc.

So,my question is, is this channel imbalance normal with most amplifiers? Should I be concerned with this, and do any other Kandy K2 users experience this imbalance?

There is no balance control on the Kandy, so the only way I can imagine compensating for the imbalance is to adjust the speaker placement. But to compensate for the systematic imbalance is going to potentially result in some funky speaker placements.

 

[Thompsonuxb]

It may be worth contacting Roksan and getting the amp checked or serviced or both.

If it's factory set (no tone or balance controls) I see no other option.

 

[dim_span]

swop cd players and do the same tests and see if you get similar results (could be the cd player?)

 

[davedotco]

I assume you have swapped left and right on the inputs, and the connects pre to power, just to be sure it's the amp, probably the pre-amp/integrated.

Most likely this is an imbalance in the tracking of the volume control, very common but mostly only noticeable at the lowest volume settings.

Speak to Roksan and tell them your issue, keep it simple, just tell them there is a noticeable difference and that you have isolated it to the amp. Tell them it really affects your listening.

See what they say.

 

[paulsue38]

I have the same problem and have spent months doing similar tests and working on room layout. Had my Arcam amp tested and it was fine. Came to the conclusion that the CD player has a fault and I have sent it away for testing and hopefully repair.

Paul

 

[BigH]

Yes try other inputs. Also swop over the cd inputs see if that makes a difference.

I don't think 1db at higher volume is that much, not sure if I could hear that. Yes amps do seem to have this problem at low volumes, I had it on my Arcam.

If it bothers you then I would try to change it for a new one.

 

[davedotco]

Yes try other inputs. Also swop over the cd inputs see if that makes a difference.

I don't think 1db at higher volume is that much, not sure if I could hear that. Yes amps do seem to have this problem at low volumes, I had it on my Arcam.

If it bothers you then I would try to change it for a new one.

Ganged pots like this will have an 'acceptable' level of imbalance but a dB or so at mid volume is quite a lot, enough to skew the soundstage if you are into all that.

Certainly have words with Roksan.

 

[SteveR750]

There was a thread about imbalance some time ago, and how it's always one sided no matter what you change (at the time I also had a K2). A few of us noticed it, and its infuriating. I really struggle to find the correct seating position to centralise everything. It could be defective hearing, though I had it tested 2 years ago and was fine; or it could be a psycho thingy. I'm ultra sensitive to off centre mono tracked instruments on a multi tracked recording, usually on older stuff (stand up Mamma Mia) the soundstage is bizarre to say the least when listening on phones.

 

[dim_span]

Anything up to 6dB channel imbalance is deemed acceptable by manufacturers. Anything up to 2dB is acceptable by anyone with normal listening habbits. For the analytical crowd demanding sub 1dB there is digital attenuation like in Accuphase amps. 1.4dB on a cheap ALPS volume pot is not a bad result.

Why would you buy a budget amp without balance controls if you find 1.4dB a significant imperfection?

For persppersctive, Mercedes has 10% variation in BHP that they consider acceptable. My BenQ PC monitor has 6 dead pixels deemed acceptable by the manufacturer. They will give me a new one under waranty only when I get 7 dead pixels.

because what happens is, you end up like a yo-yo ....

you bolt out of your listening chair everytime a new track starts, so as to 'fiddle' with tone control etc

 

[Vladimir]

Anything up to 6dB channel imbalance is deemed acceptable by manufacturers. Anything up to 2dB is acceptable by anyone with normal listening habbits. For the analytical crowd demanding sub 1dB there is digital attenuation like in Accuphase amps. 1.4dB on a cheap ALPS volume pot is not a bad result.

Why would you buy a budget amp without balance controls if you find 1.4dB a significant imperfection?

For perspective, Mercedes has 10% variation in BHP that they consider acceptable. My BenQ PC monitor has 6 dead pixels deemed acceptable by the manufacturer. They will give me a new one under waranty only when I get 7 dead pixels.

 

[Vladimir]

because what happens is, you end up like a yo-yo ....

you bolt out of your listening chair everytime a new track starts, so as to 'fiddle' with tone control etc

Balance controls. Not tone controls.

 

[Jota180]

Welcome to the world of 'cheap' consumer goods. Think your £1500 65 inch TV is expensive? Think again, a small professional monitor can sell for much more. It's all about tolerances and accuracy and at the consumer, mass market end, tolerances are much looser than they are at professional levels. You'd have to junk a lot of components to get the tight tolerances necessary for the pro gear and you sell less of them too so they cost much more.

Consumer stuff can have a surprising amount of variation between two notionally identical items.