With the changeover from acoustic to electric recording and cutting of disk in the 20's the first tonearms as we know them today were seen although these were mostly to be found on transcription desks as most turntables continued to use acoustic means of amplification well into the 50's even if consumer models using an electric pickup tonearm combinations were seen as early as in 1926 in Germany (Ebner as in Perpetuum-Ebner), in fact acoustic reproducers were manufactured in the third world as late as the mid 80's and are still being made in southern Asia for reproductions.
Here we list all tonearms know to be currently in production, for info on older models see Discontinued Arms.
Air Tangent Swedish air bearing tangential arm much beloved by Americans, a heavily damped armtube made out of magnesium, continuos VTA etc, and a sound to die for, unusually easy to set up for such an arm (air bearing tangentials are usually a bitch to set up and require constant readjustment). The current version is 1-D. Possibly the most desirable arm in the world with a price to match, around $8500 in the US (ouch), somewhat cheaper in Europe.
Audiocraft Makes an arm that has been described as "basically a Graham with adjustable dampening, easily settable VTA and a tapered arm tube", although it should be noted that it's not a clone, the company has been making similar tonearms for more than 20 years. The only page I could find that had any info on their products was this one hosted by Walrus systems in the UK and describes the AC-3300 and the 12" version that is named AC-4400.
Audiomeca From what I gather you can only get the Romeo arm with the Romance turntable in some markets, it's an otherwise interesting unipivot arm with a heavily damped armtube and on-the-fly VTA adjustment. The linear tracking SL-5 arm is however available separately mostly everywhere this brand is sold and is supposedly quite good, it's an electronically controlled servo arm rather than a air bearing unit like most of the popular tangentials that are on the market today and also has another unusual feature for such an arm : a removable headshell. Nota bene these arms were sold under the Pierre Lurne name a few years back.
Audio Quest Despite having just released a new line of tonearms AudioQuest has no information on their hompage relating to them. Their current lineup is consists of the PT-9 Basic, PT-9 Plus and PT-9 Extreme. These are all the same medium mass tonearm that features easily settable VTA, damped headshell, removable DIN tonarm cable and adjustable pivot damping. The difference between the models lies in the wiring, the Basic model has an oxygen free copper cable, the Plus model has the Anaconda cable and the Extreme model has the Audioquest Amazon wire, a "perfect surface silver" cable with teflon insulation. The links take you to the homepage of Elusive Disc an internet retailer that was the only site found with decent info on the arms.
Clearaudio Bought the Souther tonearm line and manufacture an improved version of the SLA-3 linear tracking arm called Souther TQ-I Mk2000 and also a cheper tangential called Tangent and a refined version of the TQI called Master TQ-I.
DaVinci Audio Manufactures the Grandezza that is available in 9, 10 and 12" sizes and feature a SME compatible bases and geometry so you will be able to fit them on any plinth or armboard that will accept a SME arm in addition to be able to make use of protractors intended for said arms, altthough the company also provides a protractor in PDF form that you can print out. The Grandezza is basically a a high end arm with the base and headshell made out of bronse and an armtube made out of ivory to archive de-coupling a la Schröder Tonearms, the bearing is a jewelled dual cardan one and the arm fetures a magnetic anti-skating mechanism but a quick glance at the company's hompage does not appear to give any technical information on the arm but recommends using it with some classic MC cartridges so I assume it has a fairly low effective mass, more info here.
Dynavector Makes a high end tonearm called DV-507, it's an updated version of their classic DV-505 product and counts in at a whopping 1,4 Kg, that is more than some turntables!, it's also the only mass divided tonearm on the market today. Hi-Fi Plus has a review of the DV-507 arm here and you can download the manual in a PDF format..
Expressimo Apart from making modifications for Rega tonearms, the company makes the Incognito 500C a modified Rega RB 250 that has a new counterweight and has been rewired (including a seperate earthing) and the Incognito 600C that is a RB 300 that has had a similar treatment, more info here.
Graham Engineering Makes a well regarded high end unipivot arm called the Phantom 44 which is basically an upgrade of their Graham Engineering 2.2 Tonearm available in a few versions, namely the 2.0 that is their cheapest model the new 2.2 model that features an improved bearing system (you can upgrade the 2.0 to 2.2 spec at a later date and if you think that unipivots are only for low mass MM designs the company also makes the Nightingale a combination tonearm and high end MC pickup just to prove you wrong.
Hadcock The company has gained a new lease of life since being taken over by Charles Hadcock in the middle of last decade with a marked improvement in the finish of their products, the product line has now been simplified with basically only one variant of the GH 228 Export 9" unipivot arm still being produced, it is for all intents and purposes the same as the Hadcock GH 228 versions the company was selling in the beginning of the decade except that the headshell has been redesigned and they are now only supplied with a steel armtube. The main product of the company however is the GH 242 series which is the same arm as the 228 but features an armtube that has an effective length of 243.8mm while the 228 has en EL of 228.6, this makes the arms geometry slightly more correct which means that is should track ever so slightly better than the 228. The basic GH 242 model is the GH 242 Export but other models include the GH 242 Export Cryo, the GH 242 Integra, the GH 242 Cryo and the GH 242 Super silver.
All those models are the same mechanically and only differ in the choice of internal wiring, the arm-tube is user replaceable and until fairly recently the company did offer an aluminium one as an alternative but that appears no longer to be the case. Note that this design like most other low mass unipivots works best with low mass/high compliance carts, however the unusual design of the contact point that is a hybrid of bearing and a pivot means that this arm is better suited to suspended turntable designs than most other unipivots.
Hadcock GH 242 technical specifications Type : Unipivot. Overall armtube length : 304.8 mm. Effective length : 243.8 mm. Arm mount type : hole. Mount hole size : 15.87 mm. Height above mount : 43 ~ 90 mm. Pivot stem length : 86.4 mm. Pivot to platters centre : 226 mm. Offset angle : 30°. Rear overhang : 62 mm. Pickup mount type : Standard 1/2 inch. Cartridge mass : 3 ~ 12 grams.
Hadcock GH 228 technical specifications Type : Unipivot. Overall armtube length : 307.34 mm. Effective length : 228.6 mm. Arm mount type : hole. Mount hole size : 15.87 mm. Height above mount : 43 ~ 90 mm. Pivot stem length : 86.4 mm. Pivot to platters centre : 212.85 mm. Offset angle : 23°. Rear overhang : 60.09 mm. Pickup mount type : Standard 1/2 inch. Cartridge mass : 3 ~ 12 grams.
Helius Designs Manufactures at the least 2 models of tonearms, officially they only make the Omega arm currently but that is a high end design avaialbe in a variety of options however one or 2 German turntable manufacturers are shipping high end tables with their Cyalene arm as standard but that is a simpler predecessor to the Omega.
Ikeda Sound Labs Makes a high end tonearm designed by Ikeda-san of Fidelity Research, a visually stunning design called IT 407, one of the factors that makes it so visually interesting is the does only have a single straight line with the exception of the armlift, all angles are rounded off etc., Ikeda-san says this is in order to get rid of sympathetic resonance's. Apart from that the design is in many ways similar to other high end Japanese tonearms, not the least some older FR designs, in particular it is reminiscent of the Fidelity Research FR-66S, but as such it is made entirely out of fairly heavy metals including stainless steel, aluminium, zinc & bronze alloy and brass, it has a detachable headshell type arm tube as is standard with such arms and the arm does in fact come with a very low weight headshell made out of Rojium. Other noticeable design feature of the arm is the tracing force adjustment which is so precise that a desired value can be dialled in. The arm is available in three basic versions, a 9", 12" and 16", apart from the usual practical considerations it should be noted that the Ikeda arm does not fully compensate for the greater arm mass of the longer tubes in the tracking force adjustment so the 16" can handle only handle up to 5 grams of pressure , while the 12" can handle up to 7 grams and the 9" up to 10 or so, this is obviously not an issue unless dealing with seriously vintage pickups. There was also a limited edition of this arm available that had all metal parts of it plated with gold (BTW all armtube sizes where available), it retailed for about 55% more than the normal models. The Ikeda arm has always had a rather limited distribution outside of Asia and in fact all the models that I have seen have only arrived with instructions printed in kanji, furthermore word has reached us that the production of the 407 is being stopped, however when this was written in Sept. 2005 a number of European and Asian dealers had it in stock and in fact a couple of Asian shops had stocks of the 12" and 16" variants of the gold plated special edition.
Immedia Makes a high end unipivot tonearm called RPM, optional damping and all the usual trimmings, and apart from the armtube made out of nothing but stainless steel.
Jelco Makes the SA-520 tonearm, it's an S shaped arm with a detachable headshell mostly sold to OEM's for use on DJ decks, but it's a fairly good arm for the price. The company also makes one piece straight line arms more intended for hi-fi usage but no information on the web.
Kuzma This Slovenian company makes 3 arms currently, the Stogi S is an viscous damped unipivot design. The Stogi is a similar basic design to the old Dual 555 and finally Stogi Reference is the company's top of the line arm. Note that the company can deliver their arms with a balanced wiring if you request it and that the arms from this company are often considered to be a bit of a bargain like so many other products from East Europe.
London A little bird whispered in my ear that the International is still being made in the UK in limited numbers, if you looked hard enough you might find a copy.
Mel Audio Makes a interesting viscous damped unipivot arm named Zeröha, but difficult to find for sale outside of Italy.
Microgroove Manufactures a fascinating tonearm made out of a flat piece of plastic rather than the more usual tubes, no company presence on the web but their German distributor has more info here.
H. H. Mørch Makes what may be the most interesting pickup arms made today, firstly off they are almost completely modular meaning that on one hand you can chose an armtube that fits the characteristics of your chosen cartridge perfectly and on the other hand you can start with a stripped down version of the arm and add options like on the fly VTA at a later date when you can afford to, apart from being flexible these are damn good. The actual models are the DP4 and the DP6. Here is a armtube/cartridge optimal compatibility list and if there are any Scandinavians reading this here is the DP6 Manual in Danish.
Naim Makes the Aro an unusually refined unipivot design..
Nottingham Analogue Offers a small lineup of unipivot arms namely the "budget" Interspace the more upmarket Space arms available in 9" and the Anna that is available in 10" and 12" lengths, all ot their arms utilise a carbon fibe armtubes and more info can be had here.