"echo" of near groove problem

[sat159p1]

Got a problem that sometimes I hear "low volume" echo of near groove which is later (not before) so this is not related to recording probably, but noticeable on my three record players when played. When music plays it's barely hearable but when you have fast trasients like speaking vocal or snare drum transient, it's there. Is it because of tight groove spacing? ("10" on VR)? I checked on the microscope but they are not overlapping/skipping/tracking problems etc.

[Greg Reierson]

Groove echo. Are you cutting fixed pitch? Can you expand the pitch at those spots?

[piaptk]

A pretty common problem especially with embossing. You can make the groove shallower or use a coarser feedscrew. I never use finer than 180 Lpi for this reason. Even Peter Kings records have it sometimes.

[tragwag]

high volume cuts with tight groove spacing are the main cause, with fixed pitch especially.
check in the microscope to make sure your groove depth/width are acceptable, and otherwise turn down the cut a little bit.

[sat159p1]

Thanks.

Well I know that cutting at higher lpi will give me no echo.. but I found it strange tthat grooves are not overlapping and still echoing (and the echo is for the groove above not delayed-played one). I've tried on high end turntable with grado stuff and it's gone. I also mounted a new stylus with 12g force (insyead of old one -20g) and the problem is gone on all playback turntables.

BTW, what microsope should I use to measure groove depth?

[tragwag]

I use a spencer scope on my 6N with a light, and 80X total magnification.
I have a 4X objective on there, and a 20X wide view eyepiece, though the light is how you really see what's going on.
Though I'm no expert, I compare to pressed record samples and go from there in terms of groove geometry.

In my case, I play to the lowest common denominator, the cheap turntables. Most of the purchasers of the labels who order my cuts have the crosleys, audio technicas, ions of the world and I have to make my cuts play on those.

Interesting that the new stylus did it, maybe it was stylus placement as well as the weight?
definitely check the groove depth going forward if you can.

[sat159p1]

thanks tragwag. I must look for that 'scope.

[Greg Reierson]

Thanks.

Well I know that cutting at higher lpi will give me no echo.. but I found it strange tthat grooves are not overlapping and still echoing (and the echo is for the groove above not delayed-played one).

Grooves don't have to touch to have echo. Echo happens when the first groove is cut. As the stylus cuts the groove it also compresses the lacquer a few mil each direction. The next time around the groove is cut into that compressed lacquer. After a little time, the lacquer relaxes, leaving a remnant of the original pass. It's like poking a marshmallow with your finger and then cutting it in half. After it's cut, the spot you compressed will pop back out a bit. That deformation contains the audio from the previous pass.

[jjgolden]

Groove echo also occurs in plating.

[Greg Reierson]

Yes, and I've never heard a good explanation of how that happens. Do you know?

My suspicion on that it doesn't, but we attribute added echo to that stage when, in fact, it's really just the lacquer relaxing further. But I could definitely be wrong...