The Infinity Black Widow Tone Arm

I purchased a beautiful Thorens VN-150 refurbished with a really cool looking Infinity black widow tonearm, however when received, the tube on the tone are was bent, what appeared to be a flex bend in the arm and also the arm itself moved around horizontally where the cross bolt goes through the tube at the base of the arm. The arm is being sent to a metal specialist to get the bend out, and I asked about that loose arm movement and was told all Infinity arms move around in all directions, where they are attached to the vertical section, which could be described as very similar to say a VPI Uni-Pivot design, moving in both vertical and horizontal planes. I was not aware the Infinity arm is a Uni-Pivot design and moved around in all directions (in the socket) for lack of a better word. Can someone please explain what type of design the Black Widow is, and why would it move around and feel loose where the horizontal bolt runs through the arm tube to the arm bearings section of the arm? I don't know enough about the arm, and am use to arms that have no play other than vertical, where they attach to the actual vertical base of the tonearm. Is there a "design reason" this particular arm moves around where it is attached to the main vertical section of the base. Could this be an early version of the Uni-Pivot design???

 

A bit of research would suggest the tone arm is graphite, not metal. No bending that!

 

Based on what they're saying here, it does seem to be what we now call Uni-Pivot. But it's also clearly intended to be perfectly straight, so no bend in it is intentional. I don't see how a bend is going to be repairable really.

 

The arm came in two versions: carbon fiber (called graphite in it's day) and aluminum.

 

Thanks so much for your reply. It's actually being sent to a machinist to try and straighten the black tube out, so you think this is not so good?
I would just feel so much better if anyone out there would absolutely confirm at the base of the arm, where it is secured with the small horizontal bolt, that the arm is loose and moves around at that point. It does not feel like a smooth Uni-Pivot design, it just feels like there is something loose, I'm just a bit worried about that movement. You can grab that area of the arm with two fingers and it moves around freely, certainly not locked in a vertical position.
I do see what you are referring to, that the stylus can move around when a record is off center, keeping the stylus against the grooves, which is most certainly what the new Uni-Pivot design does, it moves horizontally as well as vertically. I just want to make sure I'm on solid ground here.

 

The arm rides on two knife edge pivot arms that sit in slots of the pivot head. The two "L" brackets cover the arms. Remove the two screws that hold these covers and the arm lifts out. It is not fixed in any way to the rest of the pivot head.

 

I've owned two uni-pivot designs, and I'm not sure I'd call either of them smooth. It's an inherently wobbly concept. I don't think there's anything wrong with that aspect of it.

 

That is a great picture of the arm and I really appreciate everyone jumping in here, big time. I'm not sure I fully understand Wardsweb response. I think you are saying this arm assembly does indeed have some movement and play, and is NOT rigid, so it truly is some sort of early Uni-Pivot design. I do find it strange that Infinity would not talk about that in the specifications, as most people who noticed that the arm moves around where that bolt goes through would ask the same question. I did notice that the great picture you provided looks like it might be a newer version of my arm, as mine did not have that big black thumb nut right as the tube goes into the vertical part of the arm, mine has nothing, and I really do not know if mine is carbon fiber or aluminum, and I have sent it back now, so I can't check it out. One other thing that came up is some of these arms had provisions for damping fluid, mine does not. I'm wondering if the damping fluid arms were newer arms and is the pictured arm with the black thumb nut a newer arm, and finally is the carbon fiber the newer arm or is the aluminum tube the newer tube. When one goes back this far, who knows what you are getting. I could have Dave put a Rega Moth (OEM) 202 arm on the turntable and dump the Black Widow, but the cost will be around $230.00 more to add that arm, however I do know the effective mass of the OEM 202 arm is much greater than the Black Widow, so anyone who would like to give their opinion on that move is welcomed to chime in, as it's not too late for Dave to make that change. One advantage is the Rega (OEM) 202 is new with new wiring and it certainly won't move around like the Black Widow does. So, folks, what do you think??

 

I believe the Black Widow is a low-mass tone arm that makes it a good match for some cool older cartridges like the Denon MCs. I don't have first hand experience with it though. The greater mass of the Rega probably puts it more in line with modern cartridges.

In general though, I think the bent arm makes any hand-wringing over the unipivot motion a moot point. It's probably trashed beyond reasonable repair. But hey, if you want a BW, here's one for $199: http://www.ebay.com/itm/Infinity-Bl...382?pt=LH_DefaultDomain_0&hash=item43dc9a2126. Spending that on a new one is going to be a better move then attempting to fix a bent tonearm, and probably less money.

 

The Black Widow was a top class are in it's day but is meant for use with high compliance cartridges like Shure V15s.

 

I would seriously consider doing that. I would also seriously consider taking whatever advice Dave offers.

 

To be clear everyone, the arm suffered a very slight bend downward due to the protective plastic covering the whole table. It did not take a "hit" of any kind. It was (most likely) a pulling down of that plastic when I seated it in my custom made endcaps. (The double-walled box showed no sign of "excessive force.")

FYI, it IS the aluminum tube version. My machinist has repaired other arms with minor bends. He uses a jig and knows how to do it properly. In fact, it's already repaired. I will get it Sunday morning and re-check the bearings with an extensive play test...as well as the usual non-play test checks.

To ease the OP mind, I have also offered an RB-202 with upgraded wiring at a discount. And, if the re-straightened arm fails any tests, I have a second BW to offer the OP.

It also goes without saying, when repacked, the protective plastic covering will be used in a manner as to cause NO pressure on the arm tube this time.

D

 

Again, thanks for all the input! Dave has contacted me, and he is willing to help me, he is just great in that respect. I do indeed have the Shure V15 Type V-MR cartridge with a nice NEW stylus, which is absolutely a perfect fit for the Black Widow arm. Dave has told me, my version is indeed the aluminum tube and his machinist did get the bend out of the arm, but he wants me to have what I want and I told him, I want to take his advice. I think he leans towards the Rega OEM Moth 202, but he loves the Infinity Black Widow as I do, so folks, I'm faced with the big decision. Move forward with the repaired really cool looking 40 year old Black Widow that matches my cartridge perfectly, OR go with the brand new Rega OEM Moth 202 arm with stainless stub and counter weight that has an effective mass of approximately 6-7 grams MORE than the Infinity Black Widow and it has a full warranty. I think both of us "lean" towards the Moth 202, but Dave is in no hurry, and I would like to put this decision up to some of you guys that know what you are doing, as this is one beautiful renovated Thorens VN-150 turntable Dave has made for me, and I want it to be sooooo very right, so, please, please, put your vote in, I need your input to make this decision.

Thanks so much!

 

You already have the perfect cartridge for the Infinity. I'd stick with that.

 

I'd go with the Moth if I were you. Your Shure will work with it also, and IMHO the Moth is a better arm with more versatility.

 

THIS IS GREAT, ONE VOTE "MOTH" ONE VOTE "BLACK WIDOW" Come on folks, jump on here and vote! Please let me know why.
By the way, how do you post a picture from your computer on here?? I would love to show this beautiful turntable off, if I knew how to post a picture.

 

While I don't have personal experience with either arm (but I am running an RB101 on my RP-1), I'll take the design that's 4 decades newer, personally. I think with it's much more mainstream design the Rega will match better the majority of carts. The Widow sounds like it would be...selective.

 

I haven't used a Black Widow since the late 80's (didn't own it but used one a lot on a table at work.) I have owned a few Regas- the only one I really like is the Audio Mods.

 

If you an find a Magnepan tone-arm you might want to get it. It's pretty much an updated, more user-friendly and sturdier version of the Black Widow made only for a few years in the '80's, well after Infinity had stopped making the Black Widow. Definitely designed for high compliance cartridges like the V15 series, and a poor match for most MC cartridges.

 

The Black Widow. I think I will refer to it as "The Spear of Song."

 

Dave was kind enough to post pictures of this beautiful turntable he built for me. I appreciate input from people like Dave, who have experience with the vintage tables and arms. As you can clearly see, the plinth on this table is top shelf. You are seeing the Infinity arm. I would still appreciate some Forum input. I can keep the arm as it is in the picture or get the Rega (OEM) Moth with several upgrades for just a bit more, and Dave has offered to help me with the cost of the Rega. Here is what he furnishes with this Rega change over:

1. Rega (Moth) OEM RB-202 new arm with full warranty (aprox. 9 g effective mass)
2. Wiring completely reworked with new Cardis wiring from the Cardis clips and wiring, to the ART Pop RCA plugs
3. Rega stainless steel stub at end of arm
4. Rega stainless steel counter weight at end of arm

( VS )

1. 40 year old Infinity Black Widow arm (3 g effective mass)
2. Original wiring
3. Original plastic RCA plugs
4. Original cartridge clips
5. No warranty
6. Fantastic beautiful stainless look with red Black Widow logo!

There are several things to consider. Brand new technology and new clips, new wiring, new RCA plugs and the Cardis cable is worlds better than the old Black Widow standard cables. The Infinity arm, although extremely light (3 g) and a perfect match for my Shure V15 type V MR cartridge is extremely fragile. It can be easily damaged by an accident like removing the dust cover or even if you brush across it lightly with your hand or arm, it can easily be bent, as it was by pressure from a plastic cover when shipped. I think the Rega OEM arm might be better moving forward if used with other cartridges when my Shure cartridge dies. The Rega arm is much more sturdy and will not bend with a light touch or brush by a hand. There is no question the Black Widow is a sexier tone arm, but will it hold up in the long run??? What do you think?

 

I would vote for Infinity's Black Widow tonearm any and every day!

There were three different versions of the Black Widow:
- Aluminum stepped tube (first version)
- Carbon/graphite stepped tube (first graphite version)
- Carbon/graphite tapered tube (second version)

The whole tonearm itself does sit loosely on the main vertical knife edge 'bearings'. It has a loose up and down feel so it does move vertically, but just a little. When mounted properly, and weighed down with a cartridge and balance weight it is extremely stable and does not move during record play. When it is not adjusted correctly for angles and weight, it can be less stable and might 'chatter' during playback of high amplitude grooves. This is a user problem and due to lack of attention to the proper adjustment of this amazing tonearm.

One of the most important aspects of 'mating' a cartridge to an arm is to make sure that the compliance of the cartridge is taken into account. This requires matching the effective weight of the tonearm to the compliance of the cartridge. What is amazing about the Black Widow is that not only is it the lowest effective weight so it is compatible with the highest compliance cartridges, but small weights can be added at the cartridge mount and the balance tube ends to increase the effective mass and bring the natural resonance of the combination into the ideal 10Hz range, making it one of the most versatile tonearms ever made. These were considered the very best to mate with the Shure V-15, ADC, Empire, all high and ultra high compliance cartridges. I've never heard my Shure V15-VMR sound better! and I have tried over a dozen of the very best arms to compare!! There is something magical about this arm. Its beautifully simple and elegant engineering and execution make it very unique in the tonearm world. Most over complicate their designs to overcome inherent design challenges, but Infinity figured out how to simply avoid most of the challenges!

You can read some of the expert reviews to see how they consider these some of the best sounding tonearms out there. They compare well with tonearms that cost several times their price back when they were first made, and only got better with the carbon/graphite arm tubes.

Can't recommend fixing or straightening the aluminum tube as it will cause internal cracks and crystallization/hardening of the tube aluminum material, effecting the arms internal and structural resonances. Best is to replace the tube. I have heard of upgrades to the graphite arm tube being done on some of these with excellent results. Actually it is effectively a big upgrade as it brings the aluminum version to the 'first graphite version', which had a big improvement in sound since that version was actually considered to be the best version of the Black Widow arm!

 

The Magnepan was nothing like the Infinity Black Widow. The former is a unipivot, the latter is a double knife edge.