Discussion in 'Audio Hardware' started by englishbob, May 27, 2014.
I don’t know...my Benz Micro Wood SL has compliance of 15 and VTF of about 1.7-1.8.
If there was an issue with the 1200 arm ringing or feeding back at high volumes I'm sure that club DJ'S would have encountered it. I never did in my years of playing in clubs and I've never heard any DJ I know say anything about it either.
I don't think the aluminum arm has this resonance. I never got it with my MK2 when testing in the same way and Kevin sure never reported it.
I don't know what it would take with the magnesiums arm to really hear this resonance outside of testing but I think it's clearly there given the Hi-Fi News test graph.
So how is the feel of the 1200GR? More substantial than the iriginal? A little easier to set up carts or about the same ? I know the new ones are built differently that's why I am curious ! Thanks
I emailed with Kevin about this issue and sent him the link to the HiFi news test. Of course he had some interesting insights:
He wrote that over the years, it has been common to measure tonearm resonances, but it is difficult to take accurate measurements. As he understands it, the way it is done is by mounting a very light transducer to the arm wand. Then you play a frequency sweep record and attempt to pick-up any energy that the cartridge sends into the arm wand. A perfect arm behaves as an acoustical ground point, which means it does not vibrate at any frequency. But if it did, this test would reveal it.
Further, he wrote that, presumably, the G arm has a few points of resonance, as all arms do. "What you don't know is how, if at all, that colors the sound. Resonance in an arm wand could cause the output to increase or decrease at that frequency depending on whether it is in or out of phase with the cartridge motion."
He went on to write that this sort of resonance is never on purpose. It is just the outcome of a particular design and choice of materials. It would be useful to know exactly how HiFi News did their test and generated that graph. But in real use, he said, that if you played a frequency sweep test record, and it produced a flat output from 20-20Khz, then these resonances are unimportant. "And of course, no one did that!"
So, anybody care to take on that task?
Well, we already mentioned that back2vinyl did this test on his GAE earlier in this thread, that's where some of this discussion stems from. Of course, there is no way to establish a real baseline to compare the Technics against, so he compared the two tables he had on hand (Technics vs Orbe with SME V) using the same cartridge, and also compared the outputs of the tables to the CD of the same source. I think he eventually moved the SME V to the Technics.
Right, I forgot about that. That starts here, right?
I went back and looked, and I don't know that the testing is really conclusive. He got differing results running the test under a variety of conditions (some the lock was on/off, some an auxiliary weight was used -- and seemed to eliminate the peak). It also doesn't tell us if the anomaly he seemed to measure was audible.
Well, that's asking for a lot, who can decide what is audible to you, and if back2vinyl says it is audible, does that mean you believe it is too? My point was just that, contrary to your post from KAB, at least one test has already been done in this very thread, and while not perfect, and not conclusive, it is out there for any of you with the 1200G to try and duplicate, or to show where it is inaccurate. But as I said, you would have to establish some kind of baseline as he did with the Orbe and the well designed SME V tonearm, just running a frequency sweep with only one table doesn't show much except the response of the cartridge on that table, you don't know what is due to the arm or plinth or platter or other parts of the table. As for audibility, that would really be tough to show
You're right. But it was actually Kevin that said nobody had done a test. I did send that link to him though...curious what he makes of it.
But Kevin is KAB, right?
I should chip in I guess since some tests I did have been mentioned here. There were two things I found when measuring the frequency response of the Technics tonearm on my GAE - one was a mysterious "hill" at around 85 Hz that kept coming and going and the other was some little anomalies in the FR when comparing it with the SME V.
The first thing to say is that you can safely forget all about that "hill". Whatever it was, it was nothing to do with the tonearm and completely disappeared the next time I moved the turntable to do a tonearm change. It must have been some stray vibration probably arising from some other equipment that was nothing to do with the turntable. I have never seen it again since.
I did very extensive testing over many months trying to find any sign of the resonance at 300 Hz that Hi-Fi News referred to, and I was never ever able to replicate it. I used the test LP supplied as part of the Dr Feickert Adjust+ Pro testing suite, which I've always found to be very high quality. I did lots of tests - for example, in the Pro version of the Adjust+ suite, there is a tonearm resonance test based on a sweep from 30 Hz to 500 Hz which is aimed specifically at picking up resonances such as the one described by Hi-Fi News and this test, done many times, revealed no stand-out points of resonance at 300 Hz or any other frequency.
Another test I often did was to record the tonearm playing a pink noise track and then compare the recording with the original. What I always found when doing this was that the SME V would always return a nice smooth curve - not flat, because the cartridge imposes its own EQ on the recording, but very smooth. The Technics tonearm would return a curve that was almost smooth but had the occasional little ripple in it, like the ripples shown in those charts I posted way back. Those little ripples were always there in every test but they were incredibly tiny and I would think totally inaudible.
Being a bit of a perfectionist and an OCD type person, I wound up keeping the SME V arm on my GAE because I loved that perfectly smooth curve, and I put the Technics tonearm into storage, where it remains today. But I honestly don't think there's anything wrong with the Technics tonearm and I think it offers very nearly the same quality as the SME V at a fraction of the price.
I'm not saying it isn't possible to make the Technics tonearm resonate at 300 Hz in certain conditions. All I'm saying is, I was never able to detect that resonant peak when playing either pink noise or a sine sweep on a test record and therefore I don't think it appears, or has any effect on the performance of the tonearm, in actual playback conditions.
I seem to be the only one doing a test in which I hear something. I think the test I did (on KAB's recommendation) may be irrelevant when it comes to stylus induce vibration in the arm but could be relevant when it comes to microphonic induced vibrations. I have a tube in my phono stage that is very sensitive when tapped and I've found certain interconnects make a lot of noise when touched. As Kevin pointed out, everyting will have a sensitivity to certain frequencies. I still think it's good to track down these frequencies and try to mitigate them but in the case of the G/GAE tonearms, listening tests indicate that there is not a problem.
BTW, the last couple pages have been mostly about the 1200G tonearm and possible resonances, partly stemming from the measurements Paul Miller made in the Hi-Fi News review of the GAE, and below is from the recent GR review ...
While the ’1200GAE’s cold-drawn magnesium tube
delivered one very clear resonant mode at a remarkably high
300Hz, the alloy equivalent here demonstrates a very different
and more complex series of resonances more in keeping with
other S-shaped tonearms we’ve tested in the past. Bending
modes at 85Hz and 150Hz are joined by a trio of higher-Q
resonances at 215Hz, 270Hz and 310Hz – the latter showing
some ‘reflection’ back from the bearing – and what appears
to be the detachable headshell flexing at 590Hz. The gimbal
bearings themselves have a very small degree of play while
friction is very low at 5-10mg and the 8-9g effective mass
renders the arm well suited to moderate-to-high compliance
MMs, including the popular Ortofon 2M series. PM
Are there any differences between the G and GR tonearms other than tube material? The G is quite different from the MK2.
I’d love a link to the GR review, if there is one.
Pretty easy to find, but here's the google link for the pdf via oslohificenter.no ... https://www.google.com/url?sa=t&rct...ink-FileLink&usg=AOvVaw1FNEill9v2Y5RgNPUrOGci
Thanks--it wasn't turning up in my search results, and I thought you might be quoting from the print mag.
Thanks for posting that.
Unrelated to the resonance question, but since you have removed the G’s arm from the deck, could you tell what they used for tonearm wiring? Kevin of KAB has a GR arm and confirmed it uses a tinned copper wiring, and indications from elsewhere in this thread are that the G uses the same wire, but Kevin expected they would use the all copper wiring previously used in the M5G version.
I'd like to help but I'm not sure I can answer that. As I say it's in storage at the moment but my memory is that it drops out as a complete assembly with two RCA phono sockets in the base into which you plug the tonearm cable. There isn't any visible wiring and you would have to start disassembling the tonearm assembly if you wanted to find any bare wires, all of which would require a level of curiosity beyond what I have at the moment!
It's very easy to pop off the base if anyone wants to have a look. There's a bazillion screws and you take them all out, remembering which screws go in which holes. The rubbery base then just prises off and underneath there's another solid base with a few more screws, which is easily taken off, and then there are just three screws holding in the arm assembly. It's not in any way challenging - it's just a bit time consuming because there are so many screws. The only thing to watch is that when you reinsert the screws for the rubbery base, you have to be careful not to strip the threads because the smaller screws go into a non-metallic material which can't cope with over-tightening. There's a very good YouTube video but it doesn't caution against over-tightening.
snorker, I read a post regarding this topic by a forum member either earlier in this thread or on another thread, and he found out that Technics used the tinned copper wiring for the SL-1200G magnesium arm. He also found out that the tinned copper wire is actually the more expensive option. He went into details why that is, but I can't recall them now.
All I can tell you is that the new arm beats the KAB-rewired arm on the SL-1200 MKII. I have both decks.
Are you saying that you've actually swapped arms between tables to compare? Or you're just comparing the 1200G table to the 1200 MKII table?
When corresponding with KAB about the G wire he had this to say:
"If the G arm truly uses tin plated wire, than all the reviews on this table are faulty in my opinion.
Tin just obscures fine treble detail. You’re the second one to say Panasonic confirms tin plating!"
I don't know that I have enough experience to agree or disagree but I can't hear a problem with treble detail. It is hard to believe that Technics would put all that engineering into the table and then chintz on a few dollars (cents?) worth of wire. They must have a good reason for their choice.
Edit: As I am reading the Hi-Fi News GR review it occurred to me that since the captive leads have been eliminated in the GAE/G/GR tonearms, the total amount of tin-plated wire has gone down substantially. I wonder if this is why "reviewers" aren't agreeing with KABs assessment of how this wire should sound?
I believe KAB indicated the new arm doesn't fit the old 'table, so that's a no-go on the swap. He must mean 'table-to-'table.
Yeah, I know Kevin believes the tin plating is bad because he says it attenuates treble. I don't know...it sounds plenty detailed to me, but I suppose it could be even more so with different wiring.
From my limited research the tin-plated wire is actually more expensive, so it does not appear to be a function of saving money on the wire itself. Perhaps it's a labor saving measure, as it may be easier to solder. However, longevity is supposed to be better because the tin plating makes it more corrosion resistant. If it indeed even uses the tinned copper wiring...I saw their email, but I'm not sure they knew what they were talking about (it was the US subdivision, not the Japanese plant that sent the email, though they claim to have confirmed with the factory). However, nobody's actually cracked one open to check.
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