Balance control?

@theophile its not an inexpensive cartridge. 

My post was general not specific to one individual member. I hope you solve your problem.

O-scopes are cheap these days, mine was about $225 on Amazon for a two channel. You can visually overlay the channels from a test record through the entire signal chain all the way to the speakers.  Easy to spot an imbalance.  

That is an excellent suggestion wlutke. No guesswork. Measure cartridge channel balance at phono leads. Measure cartridge channel balance at phono eq outputs. Measure preamp channel balance at preamp output. Measure channel balance at power amp outputs.

Measure at every stage for channel balance. The only other factors are room/speaker interface( measure with Sound Pressure Gauge at listening position?) or get ears checked for equal hearing response in each ear.

L/R channel balance is definitely something that can drive me crazy. I’ve obsessed over it before. There are many sources of L/R imbalance in a 2ch audio system:

• acoustics / room
• cartridge - even high end MC cartridges are often spec’d at most to <= 0.5dB, sometimes as high as 1.0 or 1.5 dB!
• cartridge & arm setup
• mismatched tubes (usually this has to be a fairly large mismatch to notice, > 15% at least)
• speakers (really any transducer)
• speaker & listener positioning
• bad cable or contact connections (in particular, bad headshell contacts or leads have caused this for me in the past)

A test LP with a "center image" track (like the HiFiNews one) can be useful to help isolate imbalances. A "mono" switch on your pre/phono or a mono adapter cable (patch in as needed) can also be useful for diagnosis.

I have 2 high end preamps I alternate use of here: one without balance control (VAC Master), one with (ARC Reference 6). The Ref 6’s balance is implemented in such a way that engaging it does NOT degrade sonic performance. However some would argue the digital IC chip it uses for volume control compromises baseline performance, balance correction engaged or not. I enjoy both preamps. The Ref 6’s balance control is really nice but I try to not depend on it (because it’s not there with the VAC).

Clean all you cable connections, and sometimes I will swap channels L/R on certain slots (which takes experimentation), or tubes, in an effort to cancel out imbalances. For example, if you have a room asymmetry that makes R seem dominant, and you have a cartridge that is also R dominant (even after careful setup), swap the phono cabling so the cartridge’s R side reinforces the L instead of exacerbating the R imbalance. You would have to be willing to swap L/R image for this (which strangely doesn’t bug me). Some kinds of offset swaps you can do without mirroring channels.

My older preamp, Rogue Hera, has a high quality stepped attenuator for the main volume control (very transparent) and a cheap Alps Blue potentiometer (I can always hear the effect of these next to a higher quality control) for the balance control. When you engaged balance, the Alps got spliced into the circuit. That definitely affected SQ, and I couldn’t abide that. So any penalties of using the balance control will depend on implementation.