SL1200MKII Imbalance Issue

[Meloski]

I started this thread in another forum and it went a couple of pages. When I play any record I do have a issue where the left channel dominates the right, not just a little bit but enough to throw off any soundstage Ive gone through the entire line, cartridge to speakers, checking and cleaning connections along the way. Below are some of the highlights from the other forum. Perhaps there is someone here that can offer the miracle cure for my issue.

My reference album is the XX, great sound stage and dynamics. When I listen on Spotify everything falls right into place (except for the dynamics as compared to the lp.) However, when I put on the record lately I've noticed The sound leans to the left. My first thoughts were the azimuth is off, it checked out fine, anti skate is perfect, turntable is level. Am I overlooking something? I running a very stock SL1200MKII w/ a AT440MLa. I'm thinking it may be time for a tonearm upgrade. New speakers have revealed quite a lot, not all good.

I also checked out the anti skate itself, setting for balanced zero counterweight and zero anti skate, some slight drift out at the first 1/4 of the record, no drift 1/2 of the record for 2 inches in either direction, very slight drift out last 1/4 of the record.

All the albums are effected the same way. I think i've exhausted all of the outlying factors. Cartridge is aligned properly, all contacts are clean, anti skate checked out fine, swapped cables around phono pre is new and operating correctly. I think that the original tone arm wires have just become old and oxidized as the effect was a slow gradual process.

The difference is far more pronounced than a toe in or room acoustic issue.

The investigation continues. I don't think it is a cartridge issue I have swapped out two DJ carts that I had lying around with no difference. Swapped the leads into the phono stage and the issue switched sides (it is a new Lehman Black Cube Statement) so I don't believe that there is a issue there. I've cleaned and inspected all connections from the cartridge to the speakers. I opened up the RCA plugs and they seem fine although there is a plastic coating inside so I couldn't get too deep. The issue will persist with any record that I play. The lean is a little more than slight now and I think it has slowly gotten worse. It may be time to open up the tonearm base and inspect the connections there.

This has become rather frustrating. Swapped tubes around, no change. Mess with cart alignment no change, alternative carts have not made a difference. Dug into the underside of the TT inspected tonearm connections, seemed fine. Moved cables around, cleaned everything. CDs sound fine, streaming music no issues. I'm just about ready to dump this TT before I invest any money into it and just buy something new.

All other sources are just great. Speakers are new less than 100 hrs.

[Macca]

Swapped the leads into the phono stage and the issue switched sides (it is a new Lehman Black Cube Statement) so I don't believe that there is a issue there. .[/I]

This is it then surely? Try another phono stage. Just because it is new doesn't mean it is working right.

[Andrei]

It looks like you have exhausted all possibilities. You could rewire the the internal wiring of the tonearm. It is a decent thing to do anyway because the internal wiring of the 1200 (at least those prior to the 5G) are known to be poor. It does not seem all that likely tbh as the symptom might be different - intermittent crackling for example.

If you go down that route KABUSA https://www.kabusa.com/frameset.htm?/1200bld.htm have a rewiring kit. There is also an excellent thread here in the Techiepedia with step by step instructions and photos.

Another option is to borrow a different tonearm.

[struth]

Inclined to agree with Martin again. First thing would be to try another phono stage, or try yours with another deck, if you know anyone close by, or you could send it to someone to try I guess. Its not very big.

[Meloski]

If it were a phono stage issue wouldn't the issue remain in the same channel when the leads were switched, where in this case the issue jumps to the other side.?

[struth]

Think you contradicted yourself there. if you swap leads going into phono stage does it remain the same? if it remains the same side then the TT is ok. if it moves then it is either the stage or further on. one other thing to try is plugging the phono stage into, say the cd sockets as you say it works ok.

[Meloski]

I think we may be getting somewhere here. When I switch the leads going into the phono stage there is no change. When I switch the leads coming out of the stage the issue jumps to the other channel.

[struth]

Well the TT is ok. It is the phono stage. One thing to check is the stage will probably have dip switches on it for each channel. you need to make sure that both channel's switches are in the same position or you could cause something similar. I dont really know the setup for the black cube but the switches are often on the bottom or on back...occasionally inside.

[Meloski]

Issue Resolved!
When investigators are working on a crime the first thing they look for is the obvious and most of the time thats exactly what happened.

I'm a bit embarrassed here. After an exhaustive investigation I was about to send a email to the Lehmann audio, the manufacturer of the phono stage, as the issue was pinpointed to the phono stage. When I turned over the unit to get the serial number I noticed the dip switches were out of place. Apparently, through her confession, my 10 year old had messed with the switches and threw everything off.

The switches have been returned to their proper setting and everything is fine.

Thank you for all of your input. Not all a waste I did learn a lot from your advice.

Cheers,

Michael

[struth]

"The world is full of obvious things which nobody by any chance ever observes." Sherlock Holmes


Glad its sorted mate

[allthingsanalogue]

Glad to hear you got it solved.

Sometimes the most obviuos awnswer is the hardest to find!

:D

[Bacek]

Some time ago I had similar issue and the resolution was similar. But in my case one of the dip switches was broken (there was no contact). So attenuation for one channel was 6dB higher than for the other.