The Secret Society of Lathe Trolls

I'm pretty sure all velocity reference levels are peak to peak. ABG said the math is much easier with peak to peak. I wouldn't know.

Since the only way to accurately measure level is with a Buchmann-Meyer light pattern, RMS wouldn't be practical visually.

As you state, the head has to be able to handle the peak power provided without distortion or its of no use. I meant that more power would get you less high frequency distortion up to the power limits of the head. That's why the later Neumann SAL74 has 600W amplifiers over the 150W VG66 when drivin...

What I'm trying to measure is AC voltage of the speaker output so I can supply the correct amount of power to the cutter head. You are using power and voltage interchangeably. They are not. Power is measured in watts. P=I^2*V. Voltage is V. I is current. I've read various posts in this forum where ...

1. The orginal Grampian cutting amp provided in the US by Gotham was a 150 watt unit. I think the Brittish RA7 amp was 100 watts. That's about 5-7db hotter than a 30 watt amp will deliver. The gain of the amplifier will mostly determine the output level. A 150 watt amplifier with a gain of 20dB wil...

Remember that the microscope inverts the image.

A loose connection in the depth current circuit is a likely culprit. I agree with Mossboss. The depth current meter is at the output of the circuit (but doesn't get feedback from the solenoid). I'd keep an eagle eye on the depth current meter for any instability or jumps. It wouldn't hurt to re seat...

concretecowboy71 wrote: Is this just something that might happen every now and then? These things are old and quirky I know, but is there something deeper I should look at?

It shouldn't. If it just happened this one time I doubt you will be able to chase it down. If it happens again you will have something to go on.

Sum to mono and see if it goes away. If it doesn't it's system malfunction if does it's the program.

philbrown wrote: Sorry, I think you're confused. If you delay the preview you negate the preview effect.

Try this. They put a single roller for the longest delay time necessary and use a DDL to get the rest.

My first question would be is there an easy way to set the end screw to allow more real estate for a five inch cut with no paper label considerations? and if so would it be easy to put it back for the standard settings? Yes, you can do it all from the front panel. No mods necessary. If you really w...

Serif wrote: "...Move dial indicator and its "feeler" to a diameter of approximately 15 inches on the top surface of the turntable. ...Slowly rotate turntable to see what runout (vertical variation) occurs. If total indicated variation exceeds

Well, there you go! Let's have the machinists weigh in.

Turntable flatness is not correctable in the studio. But the turntable's maximum perpendicularity to Earth's gravitation _is_ its minimum "run out." Flatness is the wrong word. I looked up a definition for runout and I found "The radial variation from a true circle." I think "true" would be the rig...

[quote="concretecowboy71" In the case of the LS-76, although it's possibly only of academic interest, here, and I have no access to a real-deal Georg Neumann, but the microscope focus on The Lathe can not be trusted to set the tt run out. He's not talking about run out. He's talking about turntable...

One more thought. Check the rod between the turntable and the turntable motor. Make sure both screws that hold the rod to the turntable are tight. It's hard to get to that.

Gold : What did you mean for slide in the first point ? The dovetail that arm that holds the suspension moves along. The main part that slides to move the cutter head across the disc surface. How long time for replacement the oil in the turntable ? have you idea. The heavy oil never needs to be rep...

I prefer to use a dial gauge to check turntable flatness. I think it's easier and more precise than focusing on the grain. If you are sure the turntable is flat then the problem lies elsewhere. 1. Make sure the slide is oiled. 2. Play with the dashpot and see if the instability improves. 3. Check th...

I would love to hear what Al Grundy said about the Tracing Simulator and how it functions. Probably a broad question, but what can you tell us about it? There is a JAES paper on it that is in the Disk Recording Vol. 1. In the broadest sense it pre distorts the signal to cancel tracing distortion. T...

I did it manually. Drop head, groove guard gets a two count. Lead in gets a five count. I think my spiral is about 30 LPI. Just get the dimensions right and make it look good.

Who has one? Even Ampex couldn't figure out how to put a preview head on an ATR and developed a digital delay line for the program signal for cutting. ATR Services, the company that remanufactures the ATR 102 made an ATR 102 preview deck for Sterling Sound. They manufactured an extended deck plate ...

I once cut a 5". I did the lead in by hand. No big deal. If you want to automate it I would re purpose one of the Tracing Simulator cam/microswitch sets. You could set that for the diameter of choice and install a toggle switch to switch between that and say the 7" setting. That way you aren't screw...