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#1
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Unamco Laboratories TT + Pickering XV cartridge
Hi!
I recently bought a Unamco Labs turntable from ... judging from the looks,70s or 80s. It was dirt cheap (50 eur) but I'm little bit confused about adjusting of this thing. The tonearm has an adjustable weight of couple of grams at the opposite end of the cartrigde side. It's connected to the tonearm with a very thin piece of metal wire, so it hangs around, so to speak. In the turtable there is a /\/\/\/\/ shaped very thick metal wire, which I can use to tighten or loosen the weight. The function of this thing is, as far as I can tell, to adjust the antiskating. Like You all hifists out there know, the XV15 has itself the brush tip which does this function quite well. There are 8 possible positions of the weight, but I'm quite not sure which one to use, that I don't brake the stylus ! How should I proceed ? (I've been too afraid to actually play anything with it! Just a couple test tunes.) And BTW; does anyone know about Unamco Laboratories company ? Is it still around, and from which country is it ? Best Regards; Mikko Heinonen Finland |
#2
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Unamco Laboratories TT + Pickering XV cartridge
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#3
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Unamco Laboratories TT + Pickering XV cartridge
"Per Stromgren" wrote in message
But, you can adjust the antiskating force until the pickup stays when "dropped" onto a flat groove-free surface on the LP, for instance between the inner grooves. If you have a test LP, perhaps you some part of it without grooves for this purpose. The idea is that the friction force that pulls the stylus will make it go inwards (because of the geometry) but be balanced by the anti-skating force so that it does not go either inwards or outwards. Try both extreme cases and you will se what happens. This approach is flawed. The skating force is due to the use of an offset cartridge mounting. The drag of the cartridge stylus on the groove creates a force vector that is resolved as a stating force acting around the arm's main pivot point. The problem with using a groovless record is that it creates less drag than a regular record groove, and therefore it develops less skating force than is found in normal use. BTW, since the groove's speed varies with radius, so does the skating force. |
#4
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Unamco Laboratories TT + Pickering XV cartridge
On Thu, 5 Aug 2004 12:29:30 -0400, "Arny Krueger"
wrote: "Per Stromgren" wrote in message But, you can adjust the antiskating force until the pickup stays when "dropped" onto a flat groove-free surface on the LP, for instance between the inner grooves. If you have a test LP, perhaps you some part of it without grooves for this purpose. The idea is that the friction force that pulls the stylus will make it go inwards (because of the geometry) but be balanced by the anti-skating force so that it does not go either inwards or outwards. Try both extreme cases and you will se what happens. This approach is flawed. The skating force is due to the use of an offset cartridge mounting. The drag of the cartridge stylus on the groove creates a force vector that is resolved as a stating force acting around the arm's main pivot point. But that is exactly what the above procedure tries to adjust for. When the drag force plus the antiskating force equals zero, your anti-skating force is applied correctly. The problem with using a groovless record is that it creates less drag than a regular record groove, and therefore it develops less skating force than is found in normal use. Do you know by how much? I suspect it is well within any error caused by the above adjusment method and... BTW, since the groove's speed varies with radius, so does the skating force. .... the variation caused by differing skating force due different radius. And, most anti-skating systems, Unamco's included, does not take radius into account. What method do you suggest, bar reading the manual? Per. |
#5
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Unamco Laboratories TT + Pickering XV cartridge
Per Stromgren wrote in message . ..
Like You all hifists out there know, the XV15 has itself the brush tip which does this function quite well. There are 8 possible positions of the weight, but I'm quite not sure which one to use, that I don't brake the stylus ! If you mean the antiskating weight, not much will break. The correct way to adjust it by looking up the manual... :-) From novice point of view, shouldn't this antiskating adjustment vary from cartiridge to cartridge, so I should get a copy of a pickering manual instead of the Unamco ? (Getting either manual is really hard, I know) But, you can adjust the antiskating force until the pickup stays when "dropped" onto a flat groove-free surface on the LP, for instance between the inner grooves. If you have a test LP, perhaps you some part of it without grooves for this purpose. The idea is that the friction force that pulls the stylus will make it go inwards (because of the geometry) but be balanced by the anti-skating force so that it does not go either inwards or outwards. Try both extreme cases and you will se what happens. (Hope you got that, it does not look very clear...) Got it. It makes sense to me. I don't have a test LP though . Do you happen to know any stores in Sweden that would sell replacement belts for the TT ? I noticed that the belts are quite gray and worn when I opened the player to attach a grounding cord from the TT to my amp. It played perfectly though. Thanks for your advice! Regards; Mikko |
#7
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Unamco Laboratories TT + Pickering XV cartridge
On Sat, 07 Aug 2004 09:47:00 +0200, Per Stromgren
wrote: (His web is in Swedish, I hope your mother toungue is Swedish, or that you are old enough to have picked it up in school...) Sorry to scare you, there is an English version as well, click on the Brit flag. Per. |
#8
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Unamco Laboratories TT + Pickering XV cartridge
Per Stromgren wrote in message . ..
Most antiskating systems are adjusted proportiional to down force. An educated guess is that every "step" in the anti-skating adjustement on your Unamco is 2.5N (0.25 grams), going from zero and up. If you are really, really inteterested I perhapd could find the manual for you, a friend of mine still has an Unamco in service in his hi-fi system. Sorry that my answering took so long, I've been very busy this week. About the manual: That would be really great! Currently, I live (study, networking technology) in Sweden, so posting the copy isn't impossible either. Of course, I'll pay you something about the work involved! No, I'm afraid not, but check with Josef Svalander, he has been around long enough to know about the Unamco, and sells belts. http://www.svalander.se/vinyl/remmar.htm Ask Josef also about the anti-skating adjustment, he may even remember that. OK. I'll contact him. By the way, really good site, they seem to stock all kinds spare parts for the turntables ! Regards; Mikko |
#9
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Unamco Laboratories TT + Pickering XV cartridge
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#10
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Unamco Laboratories TT + Pickering XV cartridge
Per Stromgren wrote in message . ..
I will check with my friend, as soon as he is back from his vacation trip in a week or so. In the mean time I suggest that you adjust the antiskating ad hoc and stylus force with at stylus scale. I don't have the TT here with me in Övertorneå, so I'll have to wait until I go to a vacation and back to Finland. I don't have a stylus scale either, so I'll have to manage without one. (And I bet that must be expensive piece of equipment!) One more question: How can one tell, when it's time to replace stylus ? I tried to look at the stylus when I bought the TT with a magnifying glass,but with a little success; it just looked like well... stylus . Did you get in touch with Josef? No, not yet, but soon I will. Regards; Mikko |
#11
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Unamco Laboratories TT + Pickering XV cartridge
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#12
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Per Stromgren wrote in message . ..
I will check with my friend, as soon as he is back from his vacation trip in a week or so. In the mean time I suggest that you adjust the antiskating ad hoc and stylus force with at stylus scale. I don't have the TT here with me in Övertorneå Oh, gosh, we're talking serious northern hemisphere here, I can tell! Yeah, Otherwise I live in Helsinki, it's been quite a change to move up here in north. , so I'll have to wait until I go to a vacation and back to Finland. I don't have a stylus scale either, so I'll have to manage without one. (And I bet that must be expensive piece of equipment!) Not necessarily, I would guess 15-20 EUR or so. What ? That's really cheap. Maybe I'll invest to that too, that isn't too much for my budget. One more question: How can one tell, when it's time to replace stylus ? That is a hard one. You need at least 10 times magnification (i.e. a loupe) and a feeling for what a new stylus look like. Do your LPs a favour: buy a new one if you are not VERY sure the stylus is newly installed. Alright, I'll keep that in my mind. All this LP playing stuff seems more like science than enjoying good music ! Speaking about science... Now that I can ask for experts opinion; what do you think about actually washing the used records ? There is some discussion about this on the usenet, but I haven't made up my mind should I wash my records or not. Some chemists even trade secret recipes for the ultimate washing solution... I can gather that you shouldn't wash the LPs with isopropyl alcohol or with any kind of strong solvent, that will most likely irreversibly damage the LPs. Well what should I use then ? Water ? or nothing ? Or give up the idea ? Regards; Mikko |
#13
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In article ,
dxrd wrote: I can gather that you shouldn't wash the LPs with isopropyl alcohol or with any kind of strong solvent, that will most likely irreversibly damage the LPs. Well what should I use then ? Water ? or nothing ? Or give up the idea ? I've heard quite a few conflicting reports about the use of isopropanol or other alcohols for cleaning LPs. Some people believe that alcohol-based solutions will leach the plasticizers out of the vinyl, making it more brittle and subject to damage. Other people believe that this is not a significant problem, for reasonable dilutions (e.g. 1 part isopropanol to 3 or 4 parts distilled water) and short surface-exposure times (i.e. wet it, clean it, dry it off rapidly). It's certain that you should *not* use any alcohol- or solvent-based cleaner for acetate/lacquer/shellac discs - it'll destroy them! The Nitty Gritty company uses a water-and-alcohol solution as their standard cleaning product. VPI apparently uses an alcohol-free (water-based) solution. The Library of Congress has a recommendation for the manufacture of a solution which they like for cleaning vinyl and other records. Its active cleaning ingredient is Triton XL-80N, a surfactant made by Union Carbide / Dow Chemicals. It also includes some ammonia (needed only for cleaning acetate discs, which can develop white deposits due to fatty-acid degradation of plasticizers) and an ingredient which inhibits microbe growth and can also disinfect records which have mold/mildew growth. This solution contains no alcohol of any sort. See http://www.loc.gov/preserv/care/record.html for complete procedures, and heed their warnings about the safety (or lack thereof) of the chemicals involved. I clean albums using a "Record Doctor II" (low-end Nitty Gritty wet-wash-and-vaccum system) and a homebrew alcohol/water/surfactant solution similar to the Nitty Gritty solution. For really cruddy records (e.g. used ones with lots of fingerprints) I often pre-wash with a water-and-detergent solution to remove the worst of the oily crud, blot dry, and then wash-and-vacuum with the machine. One such thorough cleaning should be plenty... as long as you avoid re-fingerprinting your records, it should only be necessary to brush off dust with a conductive brush before playing. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#14
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Thanks alot for your suggestions and help!
Maybe I'll go for the hand cleaning method though, I think I can spare some hours in the weekend once or twice in the year for washing my records. Altough I'd like to get hold of that stuff the government uses, it seems to be really heavy-duty . Well, speaking of the manual method, does anyone know what is the "correct" technique for cleaning up the discs ? I know that this has also been discussed in the newsgroups, but here we have a perfect opportunity to collect the ultimate newbie guide to the record handling and listening Here is how I would do it: 1. Dip the disc very quickly to the cleaning solution, 2. wash along the grooves with a brush* 3. Finally rinse off the detergent with a plenty of distilled water 4. Dry with a piece soft cloth eg. towel * Brush of unknown variety, I don't think anyone sells RiKuRd ClEaNInG brushes these days. Sorry for the jammed typewriter keyboard ;-). BTW; This nitty-gritty thing, isnt it just a regular tt without the tonearm ? If I salvage one old TT from the scrapyard, it shouldn't be impossible to make one by myself... I'd like to see pictures of the official machine. (And yes, I'm being very cheap ) Regards; Mikko |
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