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Please help - What’s going on with my turntable.


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This is a bit long winded I’m sorry.  
 

TT = project RPM 5 Carbon


My TT is playing left channel high and I’ve tried everything I can think of including a change of cartridge with no improvement.  I’ve tried 2 different amps and 2 Different phono pre amps. 
Also tried several different RCA cables. 
I’ve switched the left and right wires on the cartridge and that simply reversed the problem and played right channel high. This happened on both cartridges. 

Also switching left and right RCAs also just reverses the issue. 
I have also tried the anti skate in every position. 
I even cleaned the contacts where the wires connect into the cartridge.

 

As a last resort I’ve pulled the cover off the connections where the RCA cables go into the TT and the white wire (left) was squished by the screw down cover. The left isn't the problem though.  I thought I could see a small imperfection in the red wire (right) but now i can’t see that. 
 

In this process I have found that the left channel is full of sparkle and detail where the right channel is dull like a blanket has been thrown over the speaker. So maybe it’s not softer it’s just not playing back with any detail. 
 

There is no issue with digital

playback so it’s not the speaker. 

 

I’ve got an old pioneer TT that plays fine and balanced (but sounds pretty rubbish)

 

I’m at a total loss to what is happening and at my wits end trying to find the problem. 


Any advice? 
The store I bought it from (Challenge HiFi) are 500 Kms away so taking it to them isn’t really an option. 
 

arrrgh. Help ?
 


 

Edited by JOH1975
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By cartridge tags do you mean the pins on the cartridge or the sockets on the wires in the tone arm?

 

Rewiring the tone arm doesn’t sound like fun. Probably not something to attempt myself I shouldn’t think?

Edited by JOH1975
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7 hours ago, JOH1975 said:

By cartridge tags do you mean the pins on the cartridge or the sockets on the wires in the tone arm?

 

Rewiring the tone arm doesn’t sound like fun. Probably not something to attempt myself I shouldn’t think?

 

The later:

 

Michell Cartridge Tags Silver Plated Pack Of 4 | Cartridges, Turntable  accessories, Silver

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I would think the tonearm rewire would be a worst-case scenario.  The problem is more likely to be in the wire connections, soldering, plugs, headshell connection, etc.  A lot of problem-solving to do, but I'm confident that the cause can be identified.

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9 hours ago, xlr8or said:

You may need get yourself a new tonearm. What's fitted on there at the moment? Is it the 9cc Evolution tonearm?

 

It is the 9cc evolution tone arm. 

How can the arm have an effect on balance or detail from channel to channel - the wires just run down the middle of it don't they? Or am i missing something?

 

Regards
Jarrod

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As @Telecine has eluded to the problem appears to be with the wiring at the cart end, internal wiring housed inside the tonearm/base assembly or the RCA end. I agree that you should test for continuity with a DVM at the cartridge end to determine if the cartridge tags are loose. You can also measure resistance. From there you can work back to determine where the problem is.

 

I suspect this may have occurred through negligence of the seller or manufacturer fitting a new cart. They may have jerked the leads and loosened the tag connection. It sounds as if there is a single strand or 2 connected that is giving the inconsistency in channel output. The problem probably sounds worse as the cart coils warm up and the tag ends heat up and expand.

Edited by xlr8or
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3 minutes ago, xlr8or said:

As @Telecine has eluded to the problem appears to be with the wiring at the cart end, internal wiring housed inside the tonearm/base assembly or the RCA end. I agree that you should test for continuity with a DVM at the cartridge end to determine if the cartridge tags are loose. You can also measure resistance. From there you can work back to determine where the problem is.

 

I suspect this may have occurred through negligence of the seller or manufacturer fitting a new cart. They may have jerked the leads and loosened the tag connection. It sounds as if there is a single strand or 2 connected that is giving the inconsistency in channel output. The problem probably does not sound as obvious with warm up time.

Ok. Now i'm gonna sound like a real dummy - DVM?


I'm not sure i'll be able to solder such small wires.
 

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15 minutes ago, JOH1975 said:

Ok. Now i'm gonna sound like a real dummy - DVM?


I'm not sure i'll be able to solder such small wires.
 

 

Digital Voltage Meter.

 

Any competent turntable specialist will be able to effect the repair for little cost.

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6 minutes ago, Telecine said:

 

Digital Voltage Meter.

 

Any competent turntable specialist will be able to effect the repair for little cost.


Thanks - I'll go get a DVM (i'm all over the lingo :)

No one here that is that competent except for @tagstrip who wasn't overly keen to work on a turntable. Maybe i'll be able to convince him to help with some soldering???

 

I wonder if just as a bit of a test just a bit of wiggling and clamping of the wire could help with the connection.

 

DVM first though... oh and lean how to use and read it....

 

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Both will be OK, you will use the ohm/resistance scale. 

The Supercheap looks similar to the Jaycar, and the Jaycar is half the cost, I have one and it's been OK for my basic use.  https://www.jaycar.com.au/low-cost-digital-multimeter-dmm/p/QM1500

Anvil Electronics, 42 Margaret St, Mount Gambier, is a Jaycar reseller, phone them to see if they have them in stock Ph. 08 8725 3366

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14 minutes ago, audiofeline said:

Both will be OK, you will use the ohm/resistance scale. 

The Supercheap looks similar to the Jaycar, and the Jaycar is half the cost, I have one and it's been OK for my basic use.  https://www.jaycar.com.au/low-cost-digital-multimeter-dmm/p/QM1500

Anvil Electronics, 42 Margaret St, Mount Gambier, is a Jaycar reseller, phone them to see if they have them in stock Ph. 08 8725 3366

I bought a cheap one from bunnies. 
now to work out what I’m trying to read. That’s tonight’s job. 

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Plug the leads into the meter.  Set it to the ohm scale - Ω , it measures resistance. There are different scales of resistance, set it to a lower one.  Put the two probes together, the resistance should be 0, this shows that there is continuity in the circuit (ie, there are no breaks in the cables).  So if you put one probe on a headshell wire and the other probe on a RCA contact, you should be able to measure continuity.  The standard headshell colours are (but sometimes these are not followed) -

  • White: Left channel cartridge positive.
  • Blue: Left channel cartridge negative.
  • Red: Right channel cartridge positive.
  • Green: Right channel cartridge negative.

 

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Ok so when I test the white cable with the multimeter set to 20k ohms I get a reading of 1.16  and when I test the red I get a reading the same 1.160

 

im putting the probes from the multimeter on the connector at the stylus (still attached to the stylus) and on the outside rim of the rca socket at the other end. 

Edited by JOH1975
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Forget all of that. I can’t get a steady reading from anything. 
 

i really have no clue!!!

 

just gonna get rid of the bloody thing. Chuck it in the bin. I don’t have the patience for **** that doesn’t work. 
totally infuriating. 

Edited by JOH1975
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Guest Mr Thorens

Select 200 ohms in the multimeter. Furtherest green number on the left. 
 

then measure red cartridge wire to inner red RCA. 
 

green red cartridge wire to outer red rca

 

white cartridge wire to inner white rca

 

blue cartridge wire to outer white rca. 
 

all should be around zero

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