[jmpiwonka]

spun a few records last night.
i got the tonearm used. i got everything set up, then plugged the tonearm cord up to the preamp. put it on phono, turned the volume up slowly leaving the tonearm sitting on the rest, don't hear anything. well, that's good i guess. turn the volume up pretty dang high, still nothing. i start thinking maybe one of the tonearm wires is bad or something, i expected a little life from it.
so i tap the base and the plinth a few times with my finger thinking i'll hear a faint thump or something. hear nothing and i'm thinking something isn't working.
at that point the only think to do is spin a record to see what happens. i was thinking i was going to have to start trouble shooting. well, once i dropped the needle it came to life  aa
still have lots of listening to do and some tweaking i'm sure. it has just a grado black on it now. i'm gonna get something nicer but not for a while, actually, i doubt it even has enough time on it to be broken in. bass response is real good on this table.

ok here are some pics.

before
after1
after2

a few things. i didn't get as much mortite in the platter as i planned. i wanted to give this thing a listen after i got the armboard and tonearm mounted.
i read that these platters have a tendency to ring. i tapped it and it sounded like a freeking tuning fork. i added some mortite to that but still some more to do.
also might add some mortite to the base too. no feet on the base either. i'll probably make a plywood bottom piece to screw to the base and add some feet to that.
the armboard is a little thick as i thought it may have been. i put a little peice of cork gasket material in between the tonearm and the cartridge. if i spin a thicker record i'll have room to bump the vta up some which is easy. a little 3mm t handle allen wrench to turn a little screw.
the tonearm is a sumiko premier ft-3, oh yeah, don't have any damping fluid for it yet...

[TheChairGuy]

Mortite is murder on your hands/fingers (I've used it many times for TT tweeking in the past) - your skin is raw after using it long enough and enough of it.

Plast-i-Clay or other modelling clay works every bit as well and is not tacky to your skin.

I enjoy your re-hab post on the old Empire!

John

[jmpiwonka]

yeah the mortite does stick to the fingers. if i damp the base, i'll probably use clay for that.

i forgot, i sanded the base down, walnut stain, then some yellow tinted shellac. i like the way the finish turned out. my camera kinda sucks 

i wanna go home and listen to this some more but i got stuff to do this evening...dammit 

[Wayner]

Sweet!

I had a nice 208 with the original tonearm that I rebuilt and sold to my friend's kid. The platter of these turntables are incredibly balanced. I might suggest that doping up the under-rim to get rid of ringing may cause excess wear on the bearing (by being out of balance). On the otherhand, the tolerances between spindle and bearing are tight, which is in your favor. You may want to consider removing the mortite and using Plasti-clay as John suggests as I have a concern about the interaction between the mortite and the aluminum.

Anyway, nice project. I'm sure it sounds great.

Wayner

[jmpiwonka]

yeah, i thought about the balancing part. that's the reason i used moretite, it's pretty easy to apply an even amount all the way around the platter.
i didn't think about any interaction between moretite and the Al.
this guy used the moretite.
http://cognitivevent.com/av_empire.html (look just above middle of page)
i also considered getting the silicate paint additive and the stair paint like he put on the bottom of the platter, but i had the moretite already...hmm.

[Wayner]

I recognize the website from a while ago. Well, monitor his site and see if it's an issue. I'm not saying it is but it certainly is worth keeping an eye on it. I'd hate to see it start to corrode on ya! I think you will find the 208 platter can really deliver.

Wayner

[jmpiwonka]

yeah, i've sent him an email before. i'll send another and ask him if he's noticed anything.

[jmpiwonka]

what can i do to the grado black to help it out.
it seems a bit strong in the low end and the highs seem a bit rolled off.

i've thought i've heard a few places where there was some disortion from the cartridge, but i went back and listened to the cd to compare and it's almost always on the cd too. i guess that's good.
this was from some lp's that have a bit of electronic effects on the instruments, so really there was distortion but it was reproduced accurately from the vinyl.
the midrange of this cartridge is good though.
i went and bought a few albums that i have cd's of so i can do comparing.
the albums were, Tortoise-it's all around you, the sea and cake-everything, the brave and the bold (album of cover songs, will oldham aka: bonnie prince billie with tortoise as his backing band), and will oldham-i see a darkness.
the tortoise album is definately the hardest to play...i also played elvis costello-spike but the album had alot of surface noise so i didn't bother to listen real closely.
it's funny, i mostly listen to jazz but i haven't really spun any of that yet...

i haven't been keeping track of time but i'm pretty sure i'm not at 50hours yet....will the highs open up some?

i still need to try adding some damping fluid in the arm. i think i read that hobby stores have that right?
i might try the longhorn mod. is it as simple as getting some of that bar stock (well i have it already) and cutting a notch in it so that it will fit tight in the front of the cartridge and maybe putting a dab of silicone to keep it there? do you put anything inside the bar stock? (and of course i'll adjust the VTF after the mod).

[Wayner]

What spacing did you use from the spindle center to the arm pivot center?

Wayner

[jmpiwonka]

222.1mm i think it was.
i had the mounting destructions for the arm so i mounted it at what they said.

i used this protractor.
http://www.theanalogdept.com/bk_protractor.htm

i might be being a little picky about the highs...but we know how that goes.
will they improve as the cartridge breaks in?
one of the main reasons i went with the Sumiko arm is because it is damped so it should work well with Grado's.

[Wayner]

222.1 roughly translates to 8 .75". This should produce a .25" overhang, assuming the arm's design intent is 9". So the distance from tonearm pivot to stylus should be 9.00". I think you should verify this. Also, I would forget about your "one alignment gauge fits all" thing, as it DOESN"T WORK FOR ALL ARMS!

I really get into the geometry of these damn machines, and I think that stylus alignment is extremely critical, especially concerning 2 things, tracking and record wear (from tracking distortion).


Wayner

[jmpiwonka]

thanks, that's the kind of stuff i like to read.

i'll check pivot to stylus distance when i get home.

[jmpiwonka]

best i could measure, the pivot to stylus distance is 9".
on the protractor that i linked earlier it has different arcs for different effective arm distances. when i set it up, the stylus followed very closely to the 230mm arc.
9*25.4=228.6

[Wayner]

Good, very good. Now find out if offset angle is right. There should be some lines that you match a straight surface of the cartridge body to. Because you installed the arm in a distance designed by the arm manufacturer, there usually is a surface of the head (usually right in front) where the front surface of the cartridge should be parallel with.

After that make sure that the VTA (vertical tracking angle) is set correctly....that means with the stylus resting on a unmoving record, the arm centerline is parallel to the record surface. If you have a tone arm that is made out of tubing, you can reference the top or bottom surface. If the tonearm body is cast, it usually has a taper to it and that trick won't work. For now just eyeball it and see if the arm in general looks parallel to the record surface.

The RIAA standard is 20 degrees and cartridge manufacturers build this into their cartridges to make set up easy. However, many record cutters screw around with VTA so there certainly is a plus or minus to this from record to record.

Yea, these steps are a pain in the ars, but will be worth it in the long run. The problem is that record masters are cut on a lathe with a linear moving cutter, kind of like the linear tracking tonearms. They move in a straight line. In theroy, there is no tracking error. Now we have a fixed pivot tonearm that makes an arc. Do you see where the problem is? an arc can't follow a straight line.

Wayner

[Wayner]

Go to this website and down load the Baerwald Excel calculator at the bottom of the page.

http://www.enjoythemusic.com/freestuff.htm

You can plug in values at the top of the 3 columns (use mm) and see the curve change. Notice that the 222.1 mounting distance may not be the best choise.

Wayner.

[jmpiwonka]

ahh, i can't go to that link here at work. i think someone was using up the bandwidth to download their carppy sounding mp3's...so the IT guy got some software that blocked out certain sites. most music sites i can't go to.
i'll have look later or email my brother to download it and then email that to me...

VTA is good.

[jmpiwonka]

i got my brother to download and email me the excel file.
if i'm looking at it right, it looks like 210.4mm is the best mounting distance, i'll have to check the numbers, like angle of the head and stuff when i get home to make sure it's all right.

funny thing, i just looked at the mounting instructions for an Audioquest PT-9 arm, i think it has the same geometry as the sumiko premier ft-3. the audioquest says it should be mounted 210-211mm from the spindle...

[TheChairGuy]

funny thing, i just looked at the mounting instructions for an Audioquest PT-9 arm, i think it has the same geometry as the sumiko premier ft-3. the audioquest says it should be mounted 210-211mm from the spindle...

Yeah, both arms are made by Jelco of Japan...ditto for many (all?) of the Linn arms.  That's why they all share 'Linn' geometry, cutouts, etc (at several times the cost, oftentimes ).

John

[Wayner]

Yes, 210mm is about 8.26". That is more like it. Not 222.1 like your earlier post says. That puts you about .50" too far away.
Actually the distance many modern day 9" tone arms are designed for is 210.82mm which translates to 8.3", giving a .7" overhang. With about a 24 degree angular offset, your really close to the baerwald perfect curve.

Wayner

[jmpiwonka]

 

i'm pretty sure the sumiko directions stated a mounting distance of 222.1mm...wonder why that is.
oh well, i'll get the arm moved in some and see how it works out.