Channel Balance on Dynavector XV1-S

Thanks very much for all your responses. I tried switching the cart tonearm cable connectors from R to L and sure enough the discrepancy moved sides which means it's the cart and not the phono pre. There was a 15-20% difference in output and to me that warrants a repair.

Hessec, I have the Hi-Fi News test lp, on which tracks 3 and 4 are the Channel Balance tracks. I'm using the Basis Vector Alignment Jig and have used it to the best of my not totally incompetent ability (no snark intended). The anti-skate is set with an lp that had a large grooveless section.
Larryi, I'm curious about your statement about a balance control. If all the links in the line are properly balanced and working correctly wouldn't the final balance be correct, and therefore wouldn't using a balance control just be glossing over a problem as well as being more resistors in the line?

Either way, the cart is pretty clearly in need of repair so off it goes and I'll deal with a pretty compromised setup for 4-6 weeks.

Moryoga,

I use the balance control to make pretty fine adjustments which I am sure involve a whole lot of different factors, including room acoustics affecting balance. Balance controls can also be used to compensate for channel imbalances of cartridges. My current cartridge has a small imbalance where one channel is a little less than 1 db lower in level compared to the other.

When I had a Levinson Ref. No. 32 linestage in my system, I could make really fine adjustments to channel balance (allowed for .1 db increments of change). I was really surprised to find that while 1 db of volume change with music playing is not something one can reliably hear, one can hear a .2 db shift in channel balance (noticeable with the position of a centered vocalist or with mono recordings). To me, life is just easier with a balance control when it comes to fine tuning a system.

The Vector alignment guage is an extremely accurate device that allows for very precise alignment. I have noticed that a tiny fraction of a millimeter off and the tonearm profile will be grossly mismatched with the outline etched on the guage. When everything matches, the alignment agrees with that of the Feickert alignment tool. Hence, if you did the alignment per the Basis instruction, you should have the cartridge perfectly aligned and there is no issue in that respect.

Moryoga, Azimuth is a mechanical alignment of the needle in the groove, and is probably best set mechanically (visually-microscope). The fosgometer measures a voltage, as a surrogate marker for alignment. There may be discrepancies in the phonostage so best to leave this out of the circuit. There may be an electrical imbalance in the cartridge, and it would be wrong to misalign the needle to compensate. I would also try another test record, they are not perfect, and I have very different readings on the "fos" with different records.
For me it is all too hard, and I don't trust the test record, and I don't trust that electrical output means physical alignment. I suspect some high tech oscilloscope using a calibrated test record, minimising cross talk is the only "practical" way to do it properly.
Another way is, if it ain't broke don't fix it, in other words if the sound is good don't fiddle:)
That's as far as I've got, happy to learn from others.

Thanks Dinster. This process stated because there was an obvious sound difference between the 2 channels.
The plot has also thickened in that I packed up the xv1s for shipping to repair and put on my old Dynavector 20x on as a fill in cart and wound up getting the exact same readings. I took the phono pre out of the loop. I figure there's only a few options left. Since the signal issue changes evenly when I change the tonearm wires on the cart pins from L to R, I think that this rules out the Foz and the test LP as variables. I either have 2 carts that have the exact same balance issue with the exact same output values or there's something going on with the tonearm wiring. I called Technetron NYC and asked for some advice and they said it's highly unlikely that the tonearm wire is the issue as they thought with wires it will either work or not. As unlikely as it seems, I might have 2 carts with the same issue. I'm going to make an appointment to bring the carts and tonearm to them to have it tested professionally as I'm obviously out of ideas and in over my head with figuring it out.

Hi Moryoga: Changing the azimuth will affect the channel crosstalk, but will not accomplish much for the channel balance. A difference in channel output levels (balance) is better addressed with separate channel gain controls in either the MC headamp (if that is what you use), a phono equalizer (if that is what you use), or the line preamp (but this would entail different settings for analog and digital sources). Barring separate gain controls, the cartridge manufacturer may have to readjust (or even rebuild) the cartridge.

At any rate, could you verify that you have checked the channel balance under the following two conditions?

1. Switch the channels at the tonearm cable output connectors, and check the channel imbalance.

If this flips the channel imbalance, both the cartridge and the tonearm wiring or connector contacts are suspect.

2. Put back the tonearm cable output connectors, then switch the channels at the headshell lead clips, and check the channel imbalance again.

If this causes the channel imbalance to flip, the tonearm cable, internal wiring and connectors are innocent, but the cartridge (including the condition of its output pins) needs investigation.

It is a good idea to periodically clean every electrical contact in the tonearm system, including the cartridge output pins, the headshell lead clips, and the tonearm output cable.

hth, jonathan