Discussion in 'Audio Hardware' started by Phil Thien, Aug 7, 2019.
Brilliant. I am envious of your DYI skills.
Now that I've brought it upstairs, I can start to compare this table to the Technics SL-J33.
I always felt the vocalizations of Keith Jarrett (the "moaning" sounds many complain about while listening to Mr. Jarrett) were always a little veiled on the SL-J33, especially when compared to CD releases.
Not so with this new table/tonearm. Interestingly, I had swapped the cartridge in the SL-J33 figuring a new cartridge might help that critical vocal range. And yet I'm using the old cartridge with a T4P adapter in the new arm, it just sounds better in this setup.
Loving this thread...
Designed a plinth for CNC cutting with radiuses. This is more about testing my ability to cut Baltic birch and other high-end plywoods with consistency, than anything else.
Baltic birch (BB) and other plywoods can chip/tear/splinter like mad under certain circumstances. There are all sorts of solutions like downcut or compression cut bits. Downcut doesn't help on the flip side without backer, and compression bits require a bigger CNC unit than I have. So I've been working on a method where I can easily cut plywoods without these problems. I've been thinking of plywood made from exotic or dyed plywood for my final plinth, but don't want to get a piece only to feed it to the CNC gods. Anyway, I think I have a fool-proof method now.
While I was at it, I adjusted the width of the right-hand side of the plinth, so I could move the coupler for the tonearm leads. Needed that out of the way to play with my anti-skating ideas.
I think I have a clever idea or two for a cueing lift that I can DIY with off-the-shelf materials.
I need to work more, listen less.
That’s beautiful. Congratulations.
Very nice. reminds me of the old rek o kut wooden arm
Been working on isolation, trying different materials.
Specific problem was, setting coffee cup on table while playing something, resulted in pickup of too much noise. My reference is the Technics SL-J33, which still captures the coffee cup "tap," but not to the same degree. The SL-J33 has four spring feet (one in each corner).
After trying a bunch of different materials, I found that my wife's Ikea cork pot trivets did the best job of providing some isolation without destroying the sound quality. She had three, now she has two.
I CNC cut a few feet "caps" from the cork, including shallow pockets to capture the current BB (Baltic birch) feet and voila, about as perfect as I could hope. I can now listen and drink coffee.
I'm waiting on the power switch so I can finish wiring my prototype (need to make the ground wires look neat, too). Also need to figure out a wall mounting shelf (do I want vinyl storage? how will I route wires? will the phono preamp go on the shelf with the table?). While I'm thinking about the wall shelf, I'm sure some things will occur to me about how to improve the design of the final table.
I ordered an Ortofon 2M Red cartridge for the thing. Amazing how the surface noise dropped (from the old and near dead Technics T4P in a 1/2" adapter). We (wife and I) only have a couple of hours on the Ortofon, waiting for it to break-in some more.
Probably going to order a Grado Black or Blue next, just because I'm having a blast and want to try some different cartridges. I've got very little $ into this table, so easy for me to justify ordering some different cartridges to try.
Shot of current table with 2M Red cartridge playing red vinyl (more like orange, but) Roland Hanna Perugia:
I really wanted to love this Ortofon 2M Red, but so far I'm not a fan.
I've had some spotty distortion issues on piano past the halfway point on an album. In addition, I find the sound to be somewhat dull and lifeless. Great bass, but I think the high frequencies are somewhat lacking.
I increased tracking force to 2.0G (from 1.8G), and that helps with the piano tracking beyond the first half of the album, but the sound is still dull and lifeless.
I ended up googling "Ortofon 2M Red distortion" and find I'm not the only person battling distortion on this or the Blue.
One thread I found indicated a user with similar issues had closely inspected his cartridge and said this:
I have 2M Red and it's my unlucky purchase.
I had similar problem however I cannot guarantee my solution is able to help you.
Using 12x magnifying glass I inspected the magnet and the area around. I found out a very thin strip of plastic (the same plastic as the red body made of). It was inside of a protection tube where the magnet is situated.
Using very thin needle I removed the strip. The problem is fixed.
Ortofon 2M Red Distortion- Vinyl Engine
I figured no-way could lightning strike twice but this morning I grabbed a loop and took a look and there was a red "thread" of plastic hanging onto the tube that surrounds the shaft on the stylus (so opposite side as the post above). I removed this. Played an album and still find the high frequency to be lifeless.
Tossing my old VS215E onto this table immediately brings it back to life.
So I've ordered an Audio Technica AT-VM95E and I'll give that a spin.
Perhaps I'm not giving the Ortofon enough time to break-in, but I've got maybe a dozen hours on it and it hasn't changed one iota. Also, I've used the Shure method of planing the stylus in a groove for a couple of hours w/ the record not spinning.
I guess we will see.
Got my Audio Technica AT-VM95E yesterday afternoon.
What a night and day difference. Whereas the Ortofon 2M Red struggled with the piano in the second 1/2 or final 1/3 of an album, this Audio Technica doesn't miss a beat.
Also, cymbal crashes are improved, while not being over the top. So the dull, lifeless sound of the Ortofon is fixed as well.
My test for Piano have included a few albums, but Keith Jarrett's Eyes of the Heart was particularly difficult for that Ortofon. I double and triple-checked my alignment, nothing. I tried increasing tracking force to 2G (from the recommended 1.8G) and it improved, but was still "edgy."
That Ortofon 2M Red sure looked neat on my table, but the Audio Technica wins for sound quality.
Worked on anti-skating today. To test, I spun the platter by hand while the stylus rested on a blank CDR. Sure enough, the cartridge wanted to move to the center (spindle) rather quickly.
So I added a solder lug (bent) between the wand and the rear pillar, and a spacer washer of similar thickness in front.
To this I attached a string tied to a 1g weight, and used a bent cable tie as a fulcrum. With the string attached to the arm, the stylus stayed in one place on the CDR as I spun the platter.
So now I need a weight I can actually use (that 1g weight goes with a set that belonged to my father, and which I sort of cherish). I need to bend-up a piece of wire to make a better fulcrum. AND, I need some fishing line (I think that will work better than the string I robbed from my wife's crafts). I think I can find some old fishing line near a pond not too far from my house.
Sorry for the larger picture, there are a few people still watching this thread and the smaller pic doesn't provide enough detail.
Once you’ve addressed the skating, you might try the Ortofon again.
Fishing line works well. 6 lb. test line is ideal, because it’s thick enough to work with but adds no appreciable mass. Whatever you use, make sure it’s not monofilament because that stuff will take a ‘set’ when the turntable is idle. A permanent kink will develop where it drops over the little bent piece of zip tie. Fine silk thread (the polished stuff - back to the sewing kit perhaps?) also works well because it’s smooth and strong.
Consider also shortening the large loop of tonearm wire between the tonearm tail and the top of the conduit. That large loop is having a negative effect on tracking (because of the torsional drag causing by the wire height and twist) )and either positive or negative effect on skating/anti-skate, and is likely affecting VTF variably as the arm tracks across the LP (because of the height of the loop).
A very small dab of fine grease on the tip of the unipivot will also further reduce drag. Every tiny, incremental reduction in drag improves tracking and stereo imaging, and reduces the damping effect of friction.
Congratulations on a fascinating project.
I had been attempting to address the anti-skating possibility when I was experiencing the problem, via twists of the leads and even the application of pressure, none of it helped.
Still, I'm tempted to try it again, even though the Audio Technica cartridge was just bang-on from the word "go."
The 2M Red has received many similar complaints...yours is not an isolated case.
I tried some fishing line today, I think I like thread more (not the stuff in the pic, but the finer stuff I was using earlier). The fishing line just doesn't operate as smoothly as thread does, and I hadn't even considered the possibility of lines taking a set (excellent point). I have to go through the wife's crafty stuff again, to look for something more appropriate.
And you're right, the loop does need to be shortened. I can probably remove 3" or so while keeping a nice shape that won't allow the tail to wag the dog. Shorter can also only help with noise rejection I suppose. The loop is only as long as it is, because I started with 1/2 meter of lead and didn't want to cut too much off, figuring I'd trim it later once I knew for sure how long I'd want it.
Thanks for the insight and feedback.
That is my take as well. Googling "Ortofon 2M Red distortion" offers quite a few direct hits. I'm not indicting the line, I think I just got a dud.
Last night I bent-up some pieces of wire. This is .045" galvanized wire left behind by a commercial contractor installing a dropped ceiling.
I'd prefer stainless, but the hardware store doesn't have any. So I'll just add it to my eventual McMaster order. I've avoided placing lots of small orders, as the shipping adds up quickly. So I've got a wish list of sorts, I add and remove things as I find my way forward.
While I was bending my anti-skate "bracket," I figured, "hey, why not make the weight, too?" Pretty easy to measure-off 2g and then bend it into shape. I found it is also pretty easy to cut the weight once bent, so I could make a 3g and then reduce it to anything I want by cutting pieces off the bottom. I'm going to try a square cross-section next, that way I'll be able to know that cutting off one edge is approx. .x grams. Each piece of .045" stainless that is 12" long is approx. eleven cents, so this is an economical way to make weights.
Next time my wife goes to the craft store, I'm going to tag along and find a better string. For now, this stuff is working great, but thinner would probably be better.
Unfortunately, the DPDT on-off-on rocker switches arrived from Amazon, and they're incorrectly packaged. They're on-on, no middle off. So now I have to go back and find an on-off-on DPDT switch. I might just order a toggle from McMaster. At least I know the quality will be good.
I found a copy of the Hi-Fi News Test Record @ a used shop, and figured I'd put my DIY table through its paces.
I figured the anti-skating tests would be important as I was kind of shooting in the dark on setting that up, relying on listening to arrive at my setup.
My current cartridge is the Audio Technica AT-VM95E running at 2.1 grams, with an approx. 2.5-gram (I think, it has been a while since I made/weighed that thing) anti-state weight pulling .75" behind the pivot.
I was surprised I was able to pass all the tracking tests on the first side. Many report they can only pass the first and second, with far fewer passing the third and fourth. I tried using some lighter weights just to see what would happen. At 1.5g, I failed to track #9 at all, and #8 was dicey.
I then used the resonant frequency tests and I'm at about 11-13 Hz horizontally, and 10-12 Hz vertically.
A handy album to have at my disposal though, for sure.
Any further physical modifications to the arm?
Pretty much only the string used for the anti-skating weight (a polyester thread I found that I like a lot). For the last week or week and a half, I've been refining other aspects.
My thought had been that I should make the phono gear perform well at high SPL, and this would translate to better performance at my more typical moderate and late-night (lower) SPL.
So that included swapping the switching power supply I was using on the motor for a linear one. At higher SPL w/o anything playing but the motor spinning, I could hear a faint switching PS noise and that is now gone.
Next up was redoing the ground "scheme." I changed from a separate ground wire to the preamp, to running the ground over the shield of my signal cables, and reconfigured my ground harness on my table. Not only has my noise floor dropped, everything looks cleaner/nicer/less haphazard. I live within walking distance of five transmission towers, and the old ground method was picking-up RFI, audible at high gain with nothing playing. Very faint, but it was there, and is now gone.
While these contributors to noise were small, so small they could not be heard over a lead-in on an album, they were fairly easy to eliminate and I think can only improve performance.
At the same time, I've been trying different phono preamps. My ideal candidate would have an Aux input so I could change to my streamer. The TEC sometimes known as TCC units seemed to fit the bill. These were originally discrete, but now use opamps. The unit I got was a hum monster. I lifted the ground strap from the chassis and eliminated all hum, and switched to battery power to supply the 12vdc. And it is quiet, so quiet you have to be careful dropping the needle because the thing can be at nearly full output and you don't hear anything through the speakers.
BUT, it distorts on one track a a Keith Jarrett album, and the other preamps I've tried do not. It almost seems to be a case of clipping (it is at a point where Mr. Jarrett is really banging on the keys). I'll bet the earlier discrete models do not suffer this problem.
I've also tried a vintage Realistic (the one made in South Korea that has the improved cartridge loading). That sounds pretty amazing, given the age. Low noise, pleasant sound, big output. To use it, though, I'd need to add a passive preamp with volume and input switching. I'm thinking something like the Schiit Sys, it looks fairly well made. Adding a passive preamp w/ volume would really open-up the door to the selection of phono preamps available to me.
Next-up is finishing my wall-mounted cabinet and moving the table and some of my other gear onto it.
Then I'll swing-back to the arm. Finish my DIY cueing mechanism, shorten the leads, maybe carbon fiber replacements for the wood components (don't have high hopes for that based on reading, but want to try it myself).
Also, I wouldn't mind trying some other arm designs, like a knife-bearing type.
So basically I've been trying to identify the weakest area and focus on that. Right now my wife assures me the greatest weakness is the amount of stuff I have on the dining room table.
That looks great. I bet you’re learning a lot.
Keep up the good work!
Oh you have no idea. There have been some very helpful souls here and elsewhere.
Interesting tidbit: When googling whatever aspect I'm working on at the moment, many of the results take me to threads right here.
So many here have helped, without even knowing.
It apparently takes a village to build a turntable.
With my wall-hung cabinet finished and my table sitting atop, I was really enjoying the isolation between the music and the turntable.
But I had failed to anticipate a problem...
I live on a busy street, paved in so-so concrete. In Wisconsin. And as temperatures cool and tires and the ground get harder, we start to "feel" the traffic. And a few days ago it was pretty cool overnight and listening to some albums, the table was acting as a bit of an audible seismograph. It wasn't an enormous issue, I had to have it really cranked. But still, sometimes I have it really cranked.
I needed better isolation, so visited the hardware store and picked-up some 1/4-20 1" long expansion nuts (also known as "well nuts"). These are threaded onto the bottom of the table with the nut in the upwards position, and the flange down. I machined a few new plywood "feet" so the 5/8" flange of the rubber nut is snug at the bottom, but the 1/2" shaft is free to move. Then I placed those feet into the cork slippers I was using before.
This seems to have solved the problem for now, but has me thinking I need to improve the suspension in V2. There may be springs in my future.
Also you can see in the picture my little arm lift. I copied it from something I saw in my youth. I've seen similar on eBay, too. It just pivots and moves up/down on the arm's rest point, and allows me to easily pick the arm straight up. Or drop the arm straight, I guess. I mostly use it when I'm trying to lift the arm in the middle or end of the album, to prevent a shaky hand from doing damage. I have a design for a more conventional cueing mechanism on the bench, but it doesn't use anything to damp the speed so I suspect it will be a fail. A cueing mechanism may just be something I end-up buying. The Jelco models seem to get rave reviews. They're $100-ish, though. That is more than everything else I've got invested I think.
Anyway, pics of a sample foot, and cueing arm (below) The cueing arm is rotated out of the way (towards the back of the table). When I want to use it, I rotate it under the arm and just lift up. The large washer stops it from pulling all the way up. Then I just grab the finger lift and move it where I want it.
If you know what does or doesn't work for built-in isolation methods, anything that can be made easily with off-the-shelf parts, I'd love to hear about it.
I do appreciate all the help I've received here.
Oh that is the first album of the Keith Jarrett Kohn Concert. Finally found a copy in mostly pristine condition, save for the cover condition. I think it was $6.
You could try some of these, MP-2E - DiversiTech MP-2E - E.V.A. Anti-Vibration Pad, 2" x 2" x 7/8"
Really inexpensive , and you could probably make some enclosed feet that they could sit in to keep with your wood look.
Dental floss maybe? Or have you found the perfect material?
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