Ongoing Expensive Cart Issue (ideas welcome)

[Todd Fredericks]

This issue seems to be ongoing for over a decade. Actually about 12-13 years (sadly).
 
I own a VPI Aries 2 with the original arm plus junction box. The pivot spike has been upgraded.
 
What's the issue?
 
Every several years the right channel of my cart seems to get blown. This has happened with various Dynavactor MC carts and a Soundsmith MM cart. I've swapped the headshell clips and have sent them to the cart distributers to examine. Blown right channel or opened coil.
 
Based on some recommendations over the years I have changed phonostages (currently, I use an EAR 834P), various interconnects., etc. The thought was it was suspicious that it always seems to be the right channel getting damaged.
 
A few years ago, I thought the problem was solved (I think someone here had the idea). The cueing mechanism seem to be dropping too quickly and maybe that was damaging the cart.
 
I swapped the old curing mechanism for a new one and several years have gone by without an issue.
 
Sadly, until last week.
 
Right channel again.
 
The cueing mechanism seems to be a bit on the fast side and I swapped it out for a new one. I was going to add some silicone but remembered I had a spare new one.
 
I'm not too sad about the cart because it was getting on old side and was considering a retip.
 
However, it's the right channel again. That concerns me. What if this happens again (and again). It's getting pretty expensive over the years.
 
What else can possibly be causing this? My records are normally in clean, great shape. I always hit mute when I change sides. I'm not noticing any crazy static. I use an Audioquest brush.
 
Could it be the old JMW arm and the junction box? Could it be the wiring or something else.
 
It's most likely not the wiring in my home. I've lived in three different homes during this time span.
 
My McIntosh C46 preamp and MC202 amp are the only constants during this whole saga. However, I (hopefully) cannot imagine one of them to be the cause.
 
I'm just curious if anyone may have some troubleshooting thoughts.
 
Thanks for any ideas?
 
Todd

[bhjazz]

That's pretty crazy stuff, Todd. Sorry to hear that. I have a few questions.

Could you describe "blown" for us?
Does that channel just stop one day or does it slowly get there?
Is it in the middle of a record or during a needle drop?
Do you hear anything happen?
Did this start to occur after upgrading the pivot spike?
Finally, how do you do your cartridge setup and anti-skate?

[Todd Fredericks]

Thanks for your help with this.


Could you describe "blown" for us? - The channel is silent/dead. No signal coming out at all. Several years ago when I sent the first damaged one to Mike Pranka (US Dynavactor distrubutor). He said one of his tech guys mentioned that the coil opened up (possibled due to it being shorted out). He thought it may have been caused by my old phonostage. I owned it for several years and never had an issue with it. I eventually switched over to the EAR. Everything was good for a few yeares and then the probelm happened again with the Soundsmith cart. Soundsmith was not sure what caused it but they were kind an offered a replacement (which was fine and I still own it). I eventually went with a new Dynavector (I missed the sound) anmd it was find for a few years and then the issue happened again (right channel again). That's when the though here was maybe the cueing device. Everything was fine until last week.

Does that channel just stop one day or does it slowly get there? It's pretty immediate. I've noticed that when the issue starts after lowering the cart onto the record two things could happen. There's either a brief nano second of the signal cutting out of the right channel and then it seems to be dead or it's immediately non functional. Then I relaize the issue has happened again (usually after several years).

Is it in the middle of a record or during a needle drop? During the needle drop.

Do you hear anything happen? As I mentioned, sometimes I can hear the channel shorting out. This happened again recently the other week. Or it seems to be immediately silent/dead. Nothing was wrong with the records I played at the previous listening session to indicate this issue was happening again.

Did this start to occur after upgrading the pivot spike? No. It happened a few times before the spike update (did it in 2018) and just now recently. VTA looks/sounds good. VTF is good. Nothing seemed off listening wise. Everything sounded great.


Finally, how do you do your cartridge setup and anti-skate? I've set-up the cart using various protractors over the years. JMW-10 VPI jig, HIFi test record protractor, MFSL Geodisc (many years ago). Tracking force with a Shure SFG-2 stylus gauge. I forgot to mention I upgraded the old VPI counterweight with a VPI dropped one (Harry made shure I got the correct one for the arm). I use the Soundsmith counter intuitive with it. I use the twisted wire choice for the natural anti-skate. Nothing seems off wioth this using test records and during listening. Everything seems to track very well.

I hope this helps.

[Harry]

Usually when a cartridge shorts out one channel it is caused by an electrical signal going through the coils and frying them.  It can also be mechanical shock with the Dynavector as the coils are attached to the cantilever by wires the size of human hairs, but not with the Sound-Smith as that is a Moving iron and there is no direct connection.

I'm leaning towards a back EMF from your phono going in to the cartridge and frying the wires.  Might be something else but that would be my first looking point.

HW

[Waxxy]

I can't help solve the problem, but I've had three carts lose a channel while installed on my Aries II / JMW-10. Two Dyna Karats and one AT33ev. The first Karat was almost 10 years old so I was not overly concerned. Dynavector offered a trade-in on the dead 17d2 Karat towards a new 17d3 unit at the time so I grabbed one. The new 17d3 lost a channel within a month but was replaced under warranty. No problems with that cart since, but I recently noticed a dead channel on my Audio Technica AT33ev.

I'm not at all sure what might be causing the problem, but please do post here if you happen to find the solution.

[bhjazz]

I am stumped as well. Was thinking it could be due to tonearm leads but that seems rather far-fetched.

[Todd Fredericks]

Usually when a cartridge shorts out one channel it is caused by an electrical signal going through the coils and frying them.  It can also be mechanical shock with the Dynavector as the coils are attached to the cantilever by wires the size of human hairs, but not with the Sound-Smith as that is a Moving iron and there is no direct connection.

I'm leaning towards a back EMF from your phono going in to the cartridge and frying the wires.  Might be something else but that would be my first looking point.

HW

Hi Harry, thank you for sharing your thoughts about this.

I'm stumped if it's EMF coming back from the phonostage because this same issue happened when I owned a different one. Also, as you mentioned this would not be the case with the Soundsmith.

I wonder if it's the RCA cables I have hooked up form the junction box to the stage? I've switched them out over the years but who knows. The other day I swapped them for a verified low capacitance pair. Maybe some of the ones I hooked up didn't have the greatst sheilding? I'm not sure if this would cause the issue but I'm trying to think of any scenerio that might.

Or is there a possible issue with the wiring of the arm or junction box? This is an older Aries TT and maybe something needs attention.

I live in Westwood, NJ. Would it be possible to bring the arm/junction box (or even the Aries TT) over to have someone make sure everything is okay there? I don't think I'm to far away from VPI. If that makes sense let me know?

---

I am stumped as well.  Was thinking it could be due to tonearm leads but that seems rather far-fetched.

Thanks for your thoughts. Maybe static? I do use an AQ brush but who knows.