Distortion in one channel with vinyl playback

lbr

lbr

monkey boy
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Yesterday, for the first time, I started to get some distortion in my right hand speaker during the louder passages in vinyl playback. It's consistently there.

Deck is a VPI Superscoutmaster with a VPI modded Dynavector cart.

No problem with other sources and if I switch the cables running out of the VPI junction box, the distortion switches channel. From this, it seems clear that there is no problem downstream of the turntable. My current theories are:

1) cartridge alignment. I doubt this as nothing has changed and there wasn't a problem before

2) cartridge broken - damaged sylus, cantilever or coils perhaps??

3) tonearm wiring - I've tried making and breaking the connections to cart and junction box. This seemed to make a very small difference but didn't solve the problem. Could this be the issue? Any way to test it easily?

4) Junction box itself is faulty. I have a spare junction box, so I can test this. I'm not going to do it now though as I'm in a shitty mood and I might throw something against a wall... :mad:

Anyone got any other ideas or suggestions as to what to try next to troubleshoot the problem?

Peeved of Hampshire
 
Hi lbr

I would use a multi meter on the cart tags to the wiring inside the box . If there is any change in value it would confirm a possible break or more likely a bad(dry) solder joint . I would also re-check the arm cart set up just in case something has changed .If you live alone and no one has access ,not applicable but if anyone has access ....well you know what i am suggesting .

If all of that pans out ,then it is probably the cart ,maybe a chip to the stlyi but my gut feeling is it may be a failure in the cantilever or generator,maybe a coil . A very slight change might be enough to cause your problem . I don't know how you can check this out. You say its a vpi mod ,was this done from new or later and has it ever been re-tipped ? The fact it happens on peaks suggests a fault happening when the styli and cantilever are at there most vigorous in terms of movement , so cart more likely suspect .

Not sure if this helps .

D Louth
 
Thanks Pure_Carbon - I'll try that if I don't get it sorted!

Thanks D Louth - that helps a lot actually. I'll dig out my Tandy multimeter when I get back home and have a look-see.

The cart was modded by VPI prior to point of sale and has been problem free for a while. It's only a few hundred hours old, so never retipped.

I do have a spare cartridge that I bought recently (a Lyra) to replace the VPI ultimately. It wasn't my plan to install it just now, but at least I have a spare and the means to check whether the problem is with the cart/cantilever. I'm keen to leave that as the test of last resort though as I hate setting up cartridges.
 
lbr, if you're a follower of the 12" , VE is a great forum , where all things turntably/cartridgy as well as music and LP quality is chatted about with no fighting or bitching.
Well, until last week when someone started a thread on.....cables and interconnects !!!
 
Hi lbr

Know what you mean ,i hate setting up carts to . Remember setting up a Kiseki Lapis once ,up to that point most expensive cart i had done,this was in mid summer and the fear and sweat lashed of me . I could have done with a nurse with swobs to mop my flooding brow. No such luck .

If you change the cart, and no problem then you know its the Vpi cart. If it continues then ,it may be something odd in the arm,but the multi meter should show that up. Unless its some odd mistrack caused by the output cable to the box. If i remember correctly they must be set just so to apply bias ,if the arm is a Vpi ? Check to see if that is it ,but i would have thought that that would affect both channels not just one.

Can any VPI owners share with lbr if they have ever had any problems as a result of that? And how it manifested its self.

Regards D Louth
 
When I had something similar a few years back, it turned out to be the stylus which I'd damaged on a previous evening.
Hopefully yours is the pins instead
 
Hmm that got me thinking. Before it happened, I knocked the deck slightly whilst playing a record and the arm jumped. I was really minor and didn't damage the vinyl at all, so I'd not really thought about it. Could that have caused any damage do you think?
 
Hi...

I've had this several times....and each time, as much as I tried to dismiss it and look at something else ''anti skate'' / arm level was the culprit.
 
in order from easy peesy to aaaah balls.
0. Tracking weight
1. Anti Skate/bias.
2. Azumith.
3. Alignment.
4. loose wires, tags, j-box.
5. loose wire, cart, coils.
6. Buggered stylus.

Check connections, then tracking weight, alignment etc if that doesn't do it swap the cart. If that fixes it, then send it off to Expert Stylus for assesment fixing.
 
Hi D Louth - I've been overseas with work all week, so have just been gathering ideas prior to tackling the problem this weekend. Wish me luck :)
 
Hi lbr

You don't need luck just plenty of natural light,a steady hand and patience,lots of patience. Oh yes be methodical ,try one thing at a time ,maybe write it down as you go on .

Regards D Louth
 
Problem sorted

C'mon you beauty :D

I want to sincerely thank everyone who posted their helpful comments here. It was these posts that convinced me to go back to basic cart set up first - I wouldn't have done that otherwise as I was fairly sure that the problem was more serious.

The culprit? Anti-skate.

The VPI SuperScoutMaster (and other VPI decks I think) offer two solutions for anti-skate. One is a mechanical system, a little bit different from the normal gut wire and suspended weight design, but still a gut wire and suspended weight design. The other, which is the approach recommended by VPI, is simply to put a twist in the wire which runs from the arm to the junction box.

I have always used this latter approach, but I have now installed the more traditional anti-skate mechanism and the problems are completely eradicated.

It's a little odd as I've run the twisted wire approach without any problem for over a year. However, I have been switching between 2 junction boxes (one XLR and one RCA) frequently over the last few weeks; my best guess is that the frequent handling of the tonearm cable has caused it to lose some of it's physical elasticity such that it is no longer exerting sufficient pressure to act as an effective anti-skate device.

Whatever the reason, it's not a problem any more. Again, muchos gracias to everyone.

Going to listen to some LPs now... :MILD:
 

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