Tis true,...the Teac A2300S, SX and SD (SD adds Dolby B) are tough to beat rosumer performers, featuring strong AC hysteresis motors, and lots of bang for the buck. AC motor machines will outlast their DC motor counterparts. The Teacs listed here use all 3 AC motors. any A series will still need some work, belts, proper lubrication, calibration, and possibly heads, but only if their wear gaps approach 6mm in width. If you are going the Teac route, I would STRONGLY SUGGEST buying one of the Teac A3300S variants, such as the SX. The A3300 series brings along 10" reel capability to the party as well as improved specs. These are the best bang-for-the buck of all the Teac A-series machines If you are dead set against buying any deck which is capable of running 10" reels as well, remember this. For the price these 10" reel capable decks sell for, adds greater value down the line, should you decide to resell and upgrade to another deck. The A3300S variants offer flexibility, capability, room to grow, and long lasting trouble free performance.
I own a dozen A series machines, as well as 30 series and X series Teacs. I've bought and sold at least 6 more including an A4300S and A3300SX 2 track Multitrack Series. I've worked on a lot of Teac A-series decks, but never for failures, mostly worn out heads, tape path, calibrations and aluminum electrolytic capacitor replacement. The keep company with my Otari, Revox-Studer, Crown, Pioneer and Akai reel to reels. None of these I'd need to trade for anything else, since each one is a top notch performer. The Akai is the least performance oriented of the bunch, having better specs that when I got it, but not as good as the others. BUT, the GX280-D performs better than it's advertised specs, essentially flat frequency response from 30hz-23khz @ 7.5 ips. It has 2 AC motors, but only 7" reel capable. Still its a better deck than many other Akai's using motors and capstan motor speed control near identical to that used in Revox-Studer machines with the pabst AC motors.
The Teac A4300S would be the deck I endorse for anyone getting into the open reel hobby but ONLY IF they are dead set on owning a 7" reel machine,and not 7" or 10". The A4300S features 2 level-capable VU meter controls, which provides 2 different meter/scales levels, allowing for +3db and +6db operation, should you want to run hotter modern tape or record hotter and not pin the meters constantly. I would advise any deck that you purchase be capable of calibrating internally to use modern tape formulas as well. Modern tape is easier on the heads and tape path wear. It will also be capable of significantly improved audio recording quality, as well as take hotter record levels without distorting.Higher record levels allow you to enjoy a better S/N ratio, less tape hiss overall (at 7.5 ips) without using any noise reduction.
New tape is plentiful, long playing in traditional 1800' (7.5" reels) or 3600' which fits on 10" reels. At 7.5 ips, 3600' equals 90 minutes of recording time per tape side, or 3 hours total both directions. Double these times if you run the deck at 3.75 ips, which I never recommend if you seek the best sound quality. New tape is also guaranteed to work, and comes with a warranty, being not that expensive when compared to say a reel of used or NOS Maxell, which is the only used-NOS tape I'd trust long term.
A 10" reel of used or NOS Maxell tape costs at least as much and considerably more in many cases that brand new ATR MDS-3600, Capture 930 or Recording the Masters LPR-35/180. The 7" reels are expensive for what you get, the least expensive of the bunch being Maxell UD, which isn't in the same universe sound quality-wise as any of the 3 tape brands/models I listed above. The larger 10" reels tend to be more expensive than 7". That said, you can buy cheaper 10" plastic NAB reels for 1/3 or 1/4 the cost of the metal NAB reels. If you look and are ready to pull the trigger there are often great deals on the 10" reels.
As far as the Teac decks, I would concentrate on the models I listed above, but with the later tapered black plastic control knobs, and rounded Monitor, Bias, and EQ switches. These are the latest and last of the A series decks, with the newest electronics and best specs of the entire run. 1978-79 are the best years IMO, the newest caps you'll find. Unless the machine has been opened, it should be plug and play after some deep cleaning, and preventative maintenance, which is likely overdue. Down the road if you really like the medium and the deck,, at minimum, provided the head wear is under 3mm and everything works, , I'd get the power supply electrolytic caps replaced as well as select electrolytic caps on the audio boards. Better performance, will result, and the deck gets calibrated once new caps are in, setting the deck up to work with modern tapes.
The Akai GX4000D will need transistors replaced if they have not been done yet, 2SC458 and 23SC945 transistors are known troublemakers in these decks. Mouser Electronics sells KSC1845FTA transistors, which are the modern low noise substitutes to replace the 2SC458 and 2SSC945 transistors in the akai decks, Again, power supply caps and select audio path caps should be considered overage and replaced at this point, being well over 40 years old. They were only supposed to last 20-25 years, and are severely degraded at their age.
Of the 2 brands, honestly the Teac models will be better overall, but the GX4000D can be made solid and capable of decent performance. Just know there are no new heads available for the Akai decks and standard metal heads cannot be made to work on them. The Teac units using metal heads can be readily replaced with available new heads is need be and don't suffer from the transistor issues the Akai units do. Also, if the Akai deck you buy used the Sanyo LD3141, a primitive Op-Amp, this is it's Achilles Heel. There is no new modern substitution for the LD3141, the work around modification is a circuit with multiple components mounted to a Eisenhower Silver Dollar sized circuit board piggybacked typically to the play and record audio boards. This will need to be built and installed in place of the LD3141's as they all fail sooner or later. The sound they make when failed is like the waves crashing on the beach,overcoming the audio being recorded or played back by the machine. I've changed the LD3141's on many units, sometimes going thru 3 or 4 before getting on NOS without issue.
AS Sanyo discontinued production by the mid 80's, even the NOS replacements are nearing 40 years old, failure being only a matter of time, not chance.
