How to test for proper channel balance

gmcman

I have been recently messing around with the HiFi News Test LP and have noticed the left side is louder than the right. I kinda thought I was hearing that through the speakers slightly, but given my room acoustics I didn't really pay much attention to it.

The TT goes into a Phonomema 2 -> Yamaha CX-1000-> B&K ST-202-> SDA-2B

I hear left bias in the headphones from the CX, and the sound meter right in front of the speakers with the IC removed, reads 2db higher in the left. I swapped RCA's from:

TT into the phono pre

phono pre to pre

pre to amp

used different pre inputs

When I swapped the TT to phono pre, there was 1db difference, when I changed the rest it was 2db, I even swapped the cart leads and still left bias.

I haven't changed the speaker cables but I want to say it will move to the right, not sure but could be a x-over issue. This is why I want to know the best way to check for channel level so I can continue my tests.

Granted the CX-1000 is aging but it's brand new looking inside literally, no bulging caps, looks fresh off the assembly line. I don't have another pre to test just yet or amp, the cart is also aligned and changing the antiskate makes no difference.

All ideas welcome.

SCompRacer

Just to be clear, when you said swap cart leads, did you swap right and left channel from the turntable, that is connect right to the left and left to the right inputs on the phono pre? Or did you just try different cart leads and interconnects and did not swap R and L channel?

By swapping right and left channels from the table to the phono pre, if the problem moves, it points to the turntable/cartridge. To test a pre amp, same thing, reverse R and L IC's to the amp. With an amp, swap R and L speaker cables at the amp.

What kind of turntable/arm? Detachable headshell?

EDIT: I also have a HiFi News Test LP. They include a nice large cartridge alignment protractor with it.

gmcman

I did swap L to R.

Technics 1200, stock arm, LP Gear Zupreme headshell, DL 301 MK2 cart. Even when I swap leads L to R, the bias is still to the left. Seems to narrow down the amp or the speakers but not sure if a "stereo" signal is appropriate to measure the bias.

Track i'm using is Side 2, Track 5...Azimuth test and the test tone is noticeably louder on the left. I have played with the cart and readjusted but still strong on the left. Tomorrow I will swap speaker leads and try the CD player.

lanchile

it can also be the Balance control or the potentiometer!

gmcman

Wanted to add i'm using the Direct Mode, no tone controls or balance.

lanchile

gmcman wrote: »

Wanted to add i'm using the Direct Mode, no tone controls or balance.

in that case it can be the potentiometer (volume control)

gmcman

I re-aligned the cart and it was slightly off, way off from a technical standpoint. The stylus tracked about 1MM inside the arc at the innermost point, now all is good somewhat.

I can't hear any bias through the headphones, much more smoothness especially in the inner groove. I have reduced bias in the left speaker but it's still there, this time only 1.5db instead of just slightly over 2db. The LP's sound noticeably better but the test track shows bias on the left.

Now I went ahead and just hooked the phono pre directly to the amp, removing the pre from the equation.....the bias is still there. When I put everything back to normal and swap the speaker cables at the amp.....the speakers measure the same, perfectly even.

Could this be a capacitor issue? I have done the TL mod to the 2B's and they have at least 5-600 hours on them.

gmcman

I started another thread in the Speaker section as this is more than just a TT issue.

dudeinaroom

Every a/v receiver I have used seems to be louder on the left channel, with the exception of the Denon I am using now, It is right channel heavy. I would suggest using the speaker level controls and dropping the left channel volume down. After doing so run through all of your sources and see if makes it better.