Some Empire Turntable History

[empirelvr]

You shouldn't sand down a pulley. That will shave metal and reduce the speed. Instead, you should use isopropyl alcohol on the pulley with a microfibre cloth.

This stuff is comparable to like 1500 grit (maybe a little finer than that) but I will keep that in mind for future reference.

You know, I'm not so sure Maraakate is off-base here or even treading on iffy waters.

I've often wondered if a little bit of sanding down might be good for the pulley on older idler and belt drive motors. On the four Empire's that have passed through my hands over the years I noticed all of them had pulleys that were on close inspection "encrusted" with rubber and other airborne pollutants and debris compacted on them. Alcohol alone never got them clean; it took a little emery cloth and some noxon/brasso to get them smooth and shiny again. The belt really seemed to grip the pulley afterwards again too, as a result. Plus, those pulleys seem to be really hard. I think it might be very difficult to wear them down enough to alter speed that radically.

In fact, I'm starting to wonder if instead of us trying to find belts that work perfectly with our Empire's, we should go the other way: find a good quality belt that lasts, fits, is fairly priced, widely and consistently available, and consistent in the speed error it produces on the tables, then alter our pulleys to make it work perfectly. A little "don't raise the bridge, lower the river." Hmmm.....

 

[empirelvr]

...If you have pictures of the original OE pulley setup I would be interested in seeing this as well...

As requested, here is a picture of the 980 arm with the rare factory anti-skate assembly. (FYI, the rod on the bearing assembly housing is a bit skewed. It should be pointing straight to the back in the 12:00 position, not the 11:00 position it appears to be in this picture.)

 

[monkboughtlunch]

You know, I'm not so sure Maraakate is off-base here or even treading on iffy waters.

I've often wondered if a little bit of sanding down might be good for the pulley on older idler and belt drive motors. On the four Empire's that have passed through my hands over the years I noticed all of them had pulleys that were on close inspection "encrusted" with rubber and other airborne pollutants and debris compacted on them. Alcohol alone never got them clean; it took a little emery cloth and some noxon/brasso to get them smooth and shiny again. The belt really seemed to grip the pulley afterwards again too, as a result. Plus, those pulleys seem to be really hard. I think it might be very difficult to wear them down enough to alter speed that radically.

In fact, I'm starting to wonder if instead of us trying to find belts that work perfectly with our Empire's, we should go the other way: find a good quality belt that lasts, fits, is fairly priced, widely and consistently available, and consistent in the speed error it produces on the tables, then alter our pulleys to make it work perfectly. A little "don't raise the bridge, lower the river." Hmmm.....

My struggle with the approach of "sanding down the pulley" to accommodate the current (mostly) junk belt aftermarket is that the Empire pulleys are not flat (which would be easy to sand). Instead, they are curved. It's extremely difficult to sand down a curved surface uniformly. You could generate wow and flutter issues by distorting the geometry of the precision curved Empire pulley. Since the highly accurate Esoteric Rek O Kut belt is now available, there's really no need to sand down a pulley just because one has an ill fitting EVG belt or similar.

I have two Elac Miracords and neither pulley is curved -- they are flat. The pulleys and OEM idler wheels run about 1% fast. So I sanded them down, and that fixed the issue. I can't imagine being able to achieve a good result had those pulleys been curved like on the Empire.

 

[LesE]

On the subject of speed, I've often wondered if my 698 would run slow using magnetic tape for a belt and if so, by how much. I recently got around to tying it with 1 mil X 1/4” magnetic tape and as I expected, it did run very slow with an average speed of 31.52 RPM. I made up a second belt using 5 mil thick ribbon and the average speed increased to 31.97 RPM. In comparison, the commonly available 23 mil thick belt runs at an average speed of 34.20 RPM. The following is a plot of the measured data for the three belts:



When looking at the speed versus thickness, an almost linear relationship is observed and while there are only three data points available, it's interesting that the straight line intersects 33.3333 RPM at 16 mils which is very close to the advertised 17 mils thickness of the Esoteric Sound True Speed Belt.




Les.

 

[bolero]

hey that is very interesting!

thx for posting

 

[Maraakate]

Okay, the rod and such looks easy enough to do. Is the rod wormed like that so you can tie the string for the weight in different spots to adjust it? How much (in grams) is the weight actually supposed to be?

Looks like I could whip it up without too much trouble if I ever get around to it.

Regarding the 1500 grit, the 1500 grit would have to be pressed down pretty hard for quite a bit to cause some real damage to the metal. It would probably clog up before it had a chance to do that if you're just using it to get rid of the rubber crud that has accumulated after 50 years.

However, there is 2000 and 3000 (and even 5000!) grit sand papers. This stuff I was using is just the "real" green linn paper and by the way it feels it's very similar to 1500 I think. Maybe a bit finer micron or something; but I just used it wet a little over the pulley to polish it.

 

[Maraakate]

Also, regarding the alcohol... If you know someone who uses DuPont at an autobody shop ask them to give a small cup of "3812 reducer". This stuff is somewhat of an auto body secret for getting bug tar and other stuck on goop from blend panels. This stuff would definitely take the crap off the pulley without having to sand anything.

This stuff will probably destroy rubber, so I would put it on a q-tip and let the pulley travel around it and then take another clean q-tip and wipe it off. It evaporates almost immediately once applied so the clean q-tip shouldn't find too much to pick up.

You could also try any PPG/DuPont/Sherwin Williams "wax and grease remover" or "bug and tar remover". Depending on the state you live in they may call it bug and tar remover to get around EPA compliance for reducers and wax and grease removers. That stuff is mostly mineral spirits with some other cleaners but they can remove the same stuff with a bit more elbow grease. Pure solvent thinner would probably work OK too.

 

[bolero]

I had a hard time getting the crud off the sides of the plynth, with just alcohol

there was residue and even what looked like raised burrs of metal, material from the plynth itself, on my 598 & 698, where the belt rides around it

I will look into some of that stuff, thanks

 

[monkboughtlunch]

On the subject of speed, I've often wondered if my 698 would run slow using magnetic tape for a belt and if so, by how much. I recently got around to tying it with 1 mil X 1/4” magnetic tape and as I expected, it did run very slow with an average speed of 31.52 RPM. I made up a second belt using 5 mil thick ribbon and the average speed increased to 31.97 RPM. In comparison, the commonly available 23 mil thick belt runs at an average speed of 34.20 RPM. The following is a plot of the measured data for the three belts:

When looking at the speed versus thickness, an almost linear relationship is observed and while there are only three data points available, it's interesting that the straight line intersects 33.3333 RPM at 16 mils which is very close to the advertised 17 mils thickness of the Esoteric Sound True Speed Belt.

View attachment 842301

Les.

The Esoteric Rek true speed is advertised at these dimensions: 38 inch circumference (0.188" X 0.015").

http://www.esotericsound.com/access.htm

 

[LesE]

The Esoteric Rek true speed is advertised at these dimensions: 38 inch circumference (0.188" X 0.015").

http://www.esotericsound.com/access.htm

True, although I was referring to the True Speed Belt for the 498/598/698.

TRUE SPEED BELT for Empire 498/598/698 Troubador turntables. 31.2 inch circumference (0.165" X 0.017"). This belt was designed by and custom made for us to provide accurate speed. Speed within 0.3% accuracy.

Les

 

[bolero]

I just found my calipers and measured the old dry belt I took off my Empire 598 or 698 ( and what I assume was the original )

it measured .15 thousands of an inch pretty consistently all the way around...I got a couple readings of .14 and .17 as well though

 

[empirelvr]

Okay, the rod and such looks easy enough to do. Is the rod wormed like that so you can tie the string for the weight in different spots to adjust it?

Yes. And if it was like the SME's rod, each "worm" may represent an increase of half a gram of force using the original weight supplied by Empire. Or maybe one gram; no instructions of the arm featuring the anti-skate have shown up online yet so there's no real way of knowing.

How much (in grams) is the weight actually supposed to be?

I have no idea. It wasn't until shortly before I wrote my original post that I found out the 980 arm was offered at some point with an anti-skate assembly. I don't even know what the weight of the nut I settled on for my old 98 arm was. It was strictly empirical (no pun intended) trial and error until I got a result I was satisfied with.

 

[empirelvr]

On the subject of speed, I've often wondered if my 698 would run slow using magnetic tape for a belt and if so, by how much. I recently got around to tying it with 1 mil X 1/4” magnetic tape and as I expected, it did run very slow with an average speed of 31.52 RPM. I made up a second belt using 5 mil thick ribbon and the average speed increased to 31.97 RPM. In comparison, the commonly available 23 mil thick belt runs at an average speed of 34.20 RPM. The following is a plot of the measured data for the three belts:

When looking at the speed versus thickness, an almost linear relationship is observed and while there are only three data points available, it's interesting that the straight line intersects 33.3333 RPM at 16 mils which is very close to the advertised 17 mils thickness of the Esoteric Sound True Speed Belt.

View attachment 842301

Les.

With each post we seem to get closer and closer to answering the mysteries of the Empire belt.

 

[Lastplace]

I came across one of these bad boys in a local antique store. Looks like a 980 tonearm. Is this TT worth pursuing?

 

[monkboughtlunch]

View attachment 844252

I came across one of these bad boys in a local antique store. Looks like a 980 tonearm. Is this TT worth pursuing?

What is the asking price? It looks to be in clean condition.

 

[Lastplace]

4 bills, the table is very clean, I did not see it operate.

How do you mount a cart on the 980 arm?

 

[bolero]

those are very highly regarded TT's

the knurled knob on the top unscrews, and there is a sled that the cart is mounted to, that comes out

works very well for changing carts, but those sleds are hard to find. someone is selling new ones that apparently fit, though.

 

[finkerbell]

The instructions for the Empire 980A can be found on the Vinyl Engine site (www.vinylengine.com).

There is an illustration showing (sort of) how to set up the anti-skating.

 

[monkboughtlunch]

4 bills, the table is very clean, I did not see it operate.

How do you mount a cart on the 980 arm?

4 bills is reasonable. Condition looks good. Can you audition it before buying? You could double check the motor and spindle bearings and make sure the pulley is not out of round.

 

[rocknroll1]

I just put on a new belt from esoteric sound on my 698 and after adjusting this and that, the speed is dead on 33.3. The previous owner had just put a new belt on it(he could not remember what brand) before I bought it a month ago and the closest i could get it was 34.25. Now these measurements are from using an app on my iPhone that I saw on this thread so i am not sure how accurate but it was consistent.