maxg Posted June 7, 2004 Share Posted June 7, 2004 I was thinking of entitling this one - do hookers wear kneepads - but I guess that would not be suitable - here goes - brevity not included... Tony takes his Systemdec to Vangellis to get the arm / cartridge fitted and leaves it there (because Vangellis is really anal about this sort of thing and takes hours to do it). Vangellis fights with the thing on and off for a couple of days and cant get it to sound good (trying 3 arms in the process - and adjusting everything adjustable in the world). So he swaps it out for an old Mitchell engineering tables he has - and fits the clearaudio cartridge to an arm I cant remember the name of - through wired. Tony takes it home and then calls me - problem!! Simply put the problem is that the woofer is doing the mad dance of the dervishers whatever is playing. Tony runs a pair of CDM1's at the moment (waiting for his 802's - long story - dont go there). Woofers are moving in weird and wonderful ways say an inch in and out as soon as the volume climbs. Now some of this is the volume level - but when we play the same stuff on his CD player the woofer movement is tiny in comparison. I go through a number of possible changes on the system for Tony to try - resulting in Mr Hamfisted losing a channel. He tells me he has blown a channel on the phono stage (project). I doubt this as it is not easy to do on that unit - but take his word for it until I can get over there. Yesterday I manage to escape the house at around 12:30 - armed with my phono, powersupply, screwdrivers and cables. Get to Tony - the system is playing - but only one channel. Ho-humm. First things first lets replace the phono stage and see if that is the problem - er no. I say er no because as my hand lands on the first of the RCA's connecting TT to phono the head separates from the cable. I think we have found the problem. Trouble is the cable is built in to the arm - Tony doesnt have a soldering iron - or indeed anything reomtely resembling a tool of any form. So armed with: 1. A pair of nail sissors. 2. A screwdriver. 3. A spare RCA cable. 4. Sellotape 5. Lighter I have to effect a fix (MacGyver again!!) Amazingly I managed it - not the most sartorial of fixes - but we have 2 channels working and no obvious impact on balance. It takes over an hour to do - I have to do the whole thing kneeling on the floor in front of the system holding the cables in mid air as there is nothing obvious to rest on and the fixed cable coming from the TT is not long. First conclusion - tony doesnt hoover very often! Second conclusion - wires coming out of a TT are not the sort you can strip with your teeth. Anyway having got the whole thing up and running and proven the Project is working fine we set about the sound. During the course of listening there are innumberable calls to Vangellis who swears the resonant frequency of the table is sorted out and out of the way and the suggests half a dozen possible causes and fixes. After a lot of play - and I mean a lot of play - we discover the main source of resonance is this damn cable itself. It is picking up vibrations from anywhere and everywhere and transmitting these down the wire to the cartridge and back into the system causing woofers to jump. IT still sounds OK - not brilliant but ok - but the life expectancy of the speakers at this rate is measured in days and god only knows what it is doing to the vinyl. We try the table (on tony's very expensive and supposedly isolated stand) in a dozen different positions and heights - resting on the gamut of things we can find in Tony's room (from upturned glasses to polystyrene packaging) with varying degrees of success. Of course I am doing all of this kneeling in front of the damn system. Every time we change something - we listen and compare to the CD (DSOTM as the test). I think I am now fully cured of listening to that record! By 6 in the evening I am exhausted - the woofers are still dancing - and I swear I will never ever buy a suspended table!! Why? Well not only is the cable causing problems but each time you breath near the vicinty of the table is bucks and sways like life on the ocean waves. Each sway is accompanied by dramatic movements in woofer excursion - something aint right!! One really funny thing. At first all woofer movements are outwards. At some point during one of our changes - this reverses and the woofer excursion becomes initially inwards. I am beginning to think we have invented a new form of Seismic measurements here! Another peculiarity. At some point in proceedings we tried my phono stage. This exhibited exactly the same problem when the capacitance was set to the recommended 100 mF. My phono stage is, however, god in terms of flexibility and purely out of interest we tried the setup with higher capacitance. Well wouldnt you know it - when we wacked the capacitance up to 350 mF all the woofer movement stopped! WTF???? We would have left it there - but it did very strange things to the sound. In the end I left Tony - at least working in stereo - but not much beyond the point he was when I arrived. I think he will be selling that table soon unless Vangelis can get over there and do a better job than me.... Of course if anyone has any ideas of other things to try we are both all ears....as long as these are things Tony can do on his own - I never want to see that TT again!!! Quote Link to comment Share on other sites More sharing options...
chops Posted June 7, 2004 Share Posted June 7, 2004 And I thought jt1stcav was the only one who wrote books around here! Quote Link to comment Share on other sites More sharing options...
No Disc Posted June 7, 2004 Share Posted June 7, 2004 My first thought is use the process of elimination. Determine if the proximity of the table and cartridge with the speakers and sound is causing the problem. Get an really cheap and extra long rca cable and move the table to a distance away from the speakers (another room or 5-9 meters). My guess is the cartridge is picking up bass vibration. Good luck. Tim Quote Link to comment Share on other sites More sharing options...
jdm56 Posted June 7, 2004 Share Posted June 7, 2004 my advice for your friend: throw the turntable/arm/cartridge in the nearest available dumpster, sell all those big, black, flat circular things, and buy a nice universal player! Quote Link to comment Share on other sites More sharing options...
Griffinator Posted June 7, 2004 Share Posted June 7, 2004 the mighty mdeneen saving the day again. Brilliant response! Oh - and to the person that suggested throwing away... Dollar-for-dollar, I'll put up the same price turntable against your universal player and trounce it every time. You get surround. Big whoop. I get beautiful analog sounds and way better cover art. Quote Link to comment Share on other sites More sharing options...
maxg Posted June 7, 2004 Author Share Posted June 7, 2004 Thanks Mark, That is the direction we were heading in our conclusions. Vangelis has agreed to go round to Tony to sort the thing out so we will wait and see what he achieves. Quote Link to comment Share on other sites More sharing options...
maxg Posted June 7, 2004 Author Share Posted June 7, 2004 Griff, Agreed 100% - unless of course this universal player is truely universal and plays vinyl too. Now there is an idea.... Way too much invested in vinyl now to consider anything else! Quote Link to comment Share on other sites More sharing options...
jdm56 Posted June 7, 2004 Share Posted June 7, 2004 Yo Griff, I'll give you the cover art points! I do miss the big pics and big print of LP packaging. But I definitely do not miss the muss and the fuss - cleaning, anti-stating, cleaning the stylus - with EVERY RECORD SIDE PLAYED....ARGH! As for sound quality, LP's can sound very good except for the background noise level, wow and flutter, occasional pops and clicks, and the various audible distortions. Other than that, they're great. Quote Link to comment Share on other sites More sharing options...
sunnysal Posted June 7, 2004 Share Posted June 7, 2004 would be a good time to put into place a subsonic filter that rolls eveything off below 15hz...I have that on my marantz preamp and it helps with warped records, etc. tony Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted June 7, 2004 Share Posted June 7, 2004 Would having the correct speaker cable polarity have anything to do with this? C&S Quote Link to comment Share on other sites More sharing options...
sunnysal Posted June 7, 2004 Share Posted June 7, 2004 of course mark you are right, I just meant that the sub-sonic filter would at least make the system usable (ande protect the woofers form overexcursion) until the bugs could be worked out...letting those woofers pump out and inch or so could cause permanent damage. regards, tony Quote Link to comment Share on other sites More sharing options...
maxg Posted June 8, 2004 Author Share Posted June 8, 2004 Just as an update. Tony has arranged for Vangellis to come round Wednesday evening to sort the thing out. In the meantime he took the lid off the unit and apparently this improved the performance dramatically - this implies, as Mark stated, that the suspension is awry somewhere. I guess it is going to be a simple adjustment issue on the suspension. I will try to be there when he fixes it - so I know what to do in future. Certainly impressive symptoms - I have never seen a woofer dance like that - didnt know they could. Will also keep an eye out to make sure he doesnt just slip in a subsonic filter now I have that heads up too. Quote Link to comment Share on other sites More sharing options...
artto Posted June 8, 2004 Share Posted June 8, 2004 Is this particular arm damped? If not, possibly this is whats missing. Some arm/pickup/TT combinations require the arm to be damped. The Decca pickup is a fine example, especially on a highly compliant suspended TT like a Linn for instance. Quote Link to comment Share on other sites More sharing options...
garymd Posted June 8, 2004 Share Posted June 8, 2004 Great story Max. I hope Tony gets things worked out. BTW - Some of us actually enjoy the big flat round disks and the work/play involved in the process (not to mention better sound quality). Quote Link to comment Share on other sites More sharing options...
maxg Posted June 8, 2004 Author Share Posted June 8, 2004 Just for reference Tonys arm is the Roksan Tabriz ZI spec: http://www.roksan.co.uk/tabzi_tonearms.html Not sure about the damping.... Quote Link to comment Share on other sites More sharing options...
artto Posted June 8, 2004 Share Posted June 8, 2004 Max, so far as I can tell from Rokosan's website, none of their arms are damped. Also, in doing a search on the TT (since I'm not familiar with it), it seems a number of people have modified the damping in the suspension springs. http://reviews.iwon.com/pscAudioReview/Systemdek,IIX/PRD_121364_1597crx.aspx I'd be willing to bet that this is a damping issue as Mark previously alluded to, either having to do with the arm/pickup/TT combination, or possibly just the TT suspension. Quote Link to comment Share on other sites More sharing options...
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