The Secret Society of Lathe Trolls

When this happens, check to see if the drive nut is slipping. That nut is the only thing which connects the motor output shaft to the feed screw so it's vital that it works consistently. This may sound odd, but I've had more success with the drive nut turned the other way around. You could try takin...

Chief suspect for me would be the dash pot spring's tension changing with both the heat and after several hours usage.
I wonder if we can find a replacement spring from somewhere as I think I have the same issue...

Discomo wrote: ↑

Sat Jul 11, 2020 12:05 am

Set the weight of the dashpot higher. 12g minimum.

So does this mean we should decrease the tension in the dashpot spring a little?

I understand your reluctance to risk blowing up your cutting head!
However, if you want to be super-safe, I recommend making your initial test cuts at -3dB and make sure you have fast-blo fuses in the holders.

Agreed - in my experience each cutting head does have a different response so someone else's eq curve isn't going to help you much. One additional thing to be aware of is that, if you tend to cut loud, then the corrective eq curve you'll need could be quite extreme at certain frequencies (particular...

As always, your parts and support for the community are smoking mate

At least to begin with, I wouldn't go the hardware RIAA encoder route. First off for both speed and simplicity, I'd try to replicate the main unit's curve using a decent eq plugin within your DAW. If you do this you'll find that the curve you end up with doesn't look much like a standard iRIAA curve...

Not that much to be honest, but I only check the weight once I've completed my 'warm up' tests so it's probably stabilised by that point.

Yes, I have similar issues to you but I don't think it's ambient heat levels that are causing mine as I'm in the UK so quite mild or just plain cold! I encounter the variable groove depth problem when I initially set the head down (lead in) and they continue through the first minute or so of the cut...

If the cut groove has an equal balance between left and right groove walls (i.e. one channel isn't quieter or more distorted than the other) then I'd suggest that the problem isn't with your cutting head. Much more likely that the source Stereo signal is being mono'd somewhere in your signal chain. ...

Without more detailed information, it's very difficult to even begin to understand where the problem(s) may be being introduced in the manufacturing chain. However, my first 'guess' would be that it's a plating issue. For example, you say you've used 2 plants, but do they both perform their own plat...

A very interesting and super-detailed study of lacquers used for broadcast transcription:
https://notrehistoirech.s3.amazonaws.com/uploads/z/l/Typology_guide_RTS_lacquer_discs.pdf

What 'kit' specifically?

Fantastic!
Nice job in working the problem and figuring out exactly where the issue was being introduced

Excellent! Glad I could be of some help.

I totally understand - It's quite easy to start second guessing yourself after you've been searching for the solution to a problem for days and weeks.
Hitting the reset button and starting again is sometimes the only way!

Sorry if this has been said before or you've already thought of it... but you really need to figure out where in the signal chain your drop-out issue is occurring. If you had a set of conditions under which the problem always (or nearly always) occurred then it would be easier. Once you can replicat...

Here's decent list...
https://thevinylpress.com/worldwide-list-of-phono-cartridge-retippers-and-rebuilders/

Personally, if you're in the UK, I'd give Expert Stylus a try first.

Excellent! Glad I could help...

The whole unit is called a dash pot and is there to damp vertical oscillation of the cutting head.
The fluid is usually some kind of light oil... e.g. motor bike fork oil or something similar.

Is it the whole head carriage raising up by almost 3mm as it moves across the turntable, or just the suction tube? If just the suction tube, double check the screw at the back of it is tight. Also try moving it across the turntable without the swarf jar tube attached as it might be placing pressure ...