Potential VR cutterhead problem?

[PMST]

Hi!

Today i have noticed a distortion in the side signal from one of my VR cutter heads. I have tested the head and both channels read pretty much exactly 4ohm, so nothing seems weird there, although this sounds like a blown speaker! I have tried different diamonds too. Any one got any advice on what else it could be?

The audio is cutting totally fine, just this noise in the low end of the side channel

[PMST]

I should add, this distortion is only in the sub bass region

[PMST]

One more thing, there is no crazy sub signal in the side channel, so that isn't the cause

[SueDenim]

And you should also state that you don't run the audio through Souri's main unit, so that cannot be the cause of the issue either.

[PMST]

Good point!

hardware player / volume knob / cutter amp / cutter head

Souri has replied saying cutter head killed, must return, but with the ohms reading perfect, audio cutting perfectly and no fuses blown, i still wonder if it is something else.

One point, i cut a lot of records, so possibly just wear and tear that doest show up when taking readings of the coils?

[SueDenim]

Might be the mechanical 'linkage' rather than the coils themselves

[PMST]

Might be the mechanical 'linkage' rather than the coils themselves

Can you expand on that, keen to understand as much as possible about these things, and the mechanical side is something i am not too familiar with!

[Dogtemple]

I was thinking that it’s a mechanical thing too, although I have never seen this head in person.

Anything having become loose or fractured could cause vibration/distortion. I suspect if you try feeling about for anything loose or rattling, even just a tiny amount, you may find a clue to the issue.

[PMST]

Thanks, unfortunately i couldn't find anything particularly loose. I've had to send off for a repair, hopefully i can find out at least what it is for future prevention! I'm cutting at a moderate level for the genre, ohms read right, no blown fuses and generally no other issues, very frustrating. It happens though and hopefully i can find out exactly what the cause is.

[tragwag]

my Souri head showed these symptoms before it became totally unusable.
it starts in the low end, then becomes an audible "farty" distortion tone, which moved up the spectrum the more I used it.
I thought it was just that particular source track, but it's the head.

I used mine really moderately too, peaks around 0dB.
it just got old and worn, wear and tear like you said.
I was cutting with it 40 hrs a week for a few years, and I could tell it was an earlier model than my other Souri system too.
At least 5 years old before I got it.

it might not be a worthwhile observation, but I could see some bubbling/cracking of the finish on the cones that hold the head linkage together.

[PMST]

my Souri head showed these symptoms before it became totally unusable.
it starts in the low end, then becomes an audible "farty" distortion tone, which moved up the spectrum the more I used it.
I thought it was just that particular source track, but it's the head.

I used mine really moderately too, peaks around 0dB.
it just got old and worn, wear and tear like you said.
I was cutting with it 40 hrs a week for a few years, and I could tell it was an earlier model than my other Souri system too.
At least 5 years old before I got it.

it might not be a worthwhile observation, but I could see some bubbling/cracking of the finish on the cones that hold the head linkage together.

This sounds exactly like my problem. Souri has it now for repair, so will get it sorted, but yes, it crept in, got gradually worse until audible. I actually thought i had a earth issue a month or so back, something in the low end which i then found wasn't earth and was more of a rumble, and it came and went. This was likely the start of this issue, until it started farting in the side signal. Likewise i cut non stop, so i suppose it is just something to keep an ear out for and deal with.

[PMST]

Souri has the head and has checked it over. It is a mechanical issue. Getting fixed up now and fingers crossed my other heads don’t go down!

[Vice Fiori]

Good point!

hardware player / volume knob / cutter amp / cutter head

Souri has replied saying cutter head killed, must return, but with the ohms reading perfect, audio cutting perfectly and no fuses blown, i still wonder if it is something else.

One point, i cut a lot of records, so possibly just wear and tear that doest show up when taking readings of the coils?

A nice ohms measured not exactly mean that your coil´s ok. I repair a Westrex that measure everything fine, and the right channel are so burnt that expand the wires and start to rasp on sides, making distortion...
But it can be maybe something about your linkages, even something deataching from glue parts like the dome or glued linkages.
It´s hard to tell as it cannot be touched, but a major problema to have this "krenky distortion" happen when the link between the drivers are loose, it not push correctly, just vibrate the sides that lost the glue and the distortion appears..
It you not sent to souri, I´ll tell you to put a layer of superglue between the link and the cone, let it dry and see what happen...

[PMST]

Good point!

hardware player / volume knob / cutter amp / cutter head

Souri has replied saying cutter head killed, must return, but with the ohms reading perfect, audio cutting perfectly and no fuses blown, i still wonder if it is something else.

One point, i cut a lot of records, so possibly just wear and tear that doest show up when taking readings of the coils?

A nice ohms measured not exactly mean that your coil´s ok. I repair a Westrex that measure everything fine, and the right channel are so burnt that expand the wires and start to rasp on sides, making distortion...
But it can be maybe something about your linkages, even something deataching from glue parts like the dome or glued linkages.
It´s hard to tell as it cannot be touched, but a major problema to have this "krenky distortion" happen when the link between the drivers are loose, it not push correctly, just vibrate the sides that lost the glue and the distortion appears..
It you not sent to souri, I´ll tell you to put a layer of superglue between the link and the cone, let it dry and see what happen...

Hi!

Souri has sent it back saying he could not find a problem. It should be here tomorrow, I’ll try what you said and let you know. Thanks! Also, I sent a PM

[Vice Fiori]

Good point!

hardware player / volume knob / cutter amp / cutter head

Souri has replied saying cutter head killed, must return, but with the ohms reading perfect, audio cutting perfectly and no fuses blown, i still wonder if it is something else.

One point, i cut a lot of records, so possibly just wear and tear that doest show up when taking readings of the coils?

A nice ohms measured not exactly mean that your coil´s ok. I repair a Westrex that measure everything fine, and the right channel are so burnt that expand the wires and start to rasp on sides, making distortion...
But it can be maybe something about your linkages, even something deataching from glue parts like the dome or glued linkages.
It´s hard to tell as it cannot be touched, but a major problema to have this "krenky distortion" happen when the link between the drivers are loose, it not push correctly, just vibrate the sides that lost the glue and the distortion appears..
It you not sent to souri, I´ll tell you to put a layer of superglue between the link and the cone, let it dry and see what happen...

Hi!

Souri has sent it back saying he could not find a problem. It should be here tomorrow, I’ll try what you said and let you know. Thanks! Also, I sent a PM

Oh come on.. really? ahahahaha
Ok, try simple things first:
-Try to make a record on different volumes: -6db, -3db, 0db and +3db rms, each channel separated and together, see when the distortion starts and what channel.. record this and sent it to us
-Superglue on the joint parts, just one perfect drop on the linkages between the rod and the cone when it´s attached, let it dry starting on 10min or 30 if it´s not done.
- try to move the links that make the "v spring work" (that black glued part) up and down, see if it´s not deatattched
-Try to test qhen it glued, but maybe you have problem with the driver.
-Why souri dont give you the option to remade the drivers? 0.o

[Dub Studio]

Sometimes the alignment of the drive coils in the air gap is the issue. Try loosening the bolts holding the drivers in the place and adjusting their position slightly. This will slightly move the drive coils relative to the air gap, so be careful and listen for an improvement in sound. Once it sounds clean again, lock off those bolts

[Vice Fiori]

Sometimes the alignment of the drive coils in the air gap is the issue. Try loosening the bolts holding the drivers in the place and adjusting their position slightly. This will slightly move the drive coils relative to the air gap, so be careful and listen for an improvement in sound. Once it sounds clean again, lock off those bolts

It´s a real point to see too, maybe one drive are moved or even not moved, but start to risp on the magnet sides/wall of the coil.
As VR head dont have a second apring and hard linkage parts, when one head moves, tha other move from the sides, not the linkage itself, and with time this movement can be acomodated and still there, like if you bent something and stay on that position.
Even on professional head, you cant imagine how frustration if to calibrate a Westrex to not tethering from the sides of the coil (btw, Im modifiying mine to use a aluminum torque tube and a more light/strong magnets, it´s gonna be like "a mini westrex".. ahahahaha)