Sony’s Last Flagship Cassette Deck – The TC-WE675 repair & Review

Ask any enthusiast when the compact cassette heyday was and you’ll get a different answer. Some say the ‘70s – when decks had mechanics to rival industrial machinery, limited noise reduction, big analogue level metres and flakey heads. Some say the ‘80s – when soft-touch mechanical transport controls became all the rage before full-logic electronic controls took over, when dolby C, DBX and the HX Pro headroom extension became commonplace, and when feature counts governed popularity.

Some say the ‘90s – when Dolby S brought further improvements in noise reduction expected in an era where the compact disc had taken hold, but when the big manufacturers were making their last great decks before mechanics were cheapened and electronics simplified in a bid to minimise costs and maximise every last penny of profit from a waning format..

Nobody, however, would tell you that cassette peaked at the turn of the millennium. The 2000s gave us the cheapest mechanisms yet, blighted by wobbly plastic flywheels, lousy motors and average electro-magnetic heads. Cassettes had largely been relegated to the car and the living room hi-fi was now an integrated mini, micro or midi system with an inbuilt cassette deck or two. CD was king and minidisc was the format of choice for many who wanted to record their own media, until recordable CDs became affordable and knocked the minidisc from its short-lived perch.

Sony 675 Front View

By the mid 2000s the choice of hi-fi component cassette decks on the market could be counted on one hand. There were a couple of models from Teac, some pro audio units from Tascam, a Yamaha or two, possibly an Aiwa and a three-strong lineup from Sony. None approached the quality or technical innovation that any of these companies once produced, but they weren’t designed to. They were designed simply to provide a means for people with cassette collections to play them back in reasonable quality, and to record tapes for the few vehicles that still came with a cassette deck as standard equipment.

The TC-WE675 reviewed herein was Sony’s last flagship cassette deck. It was available from 2001 to 2011, and was part of a three-strong lineup. The basic model who’s model escapes me had mechanical controls and little else in the way of features. The TC-WE475 brought full-logic soft-touch controls to the table, along with digital tape counters, automatic recording level, memory and timer functions, a pitch control (+/-30%) and a myriad of other gimmicks. Broadly speaking it is the same as the flagship TC-WE675. The 675 gives you the ability to record on both decks (the 475 records on deck B only) and a couple of small electronic upgrades, but otherwise there is little to distinguish the two.

I owned a TC-WE475 from new. I had a full Sony stack at the time including a TA-FE370, ST-SE370 and CDP-XE370, a system that I would one day like to reassemble. I wasn’t a discerning listener back then yet I have fond memories of how that system sounded, particularly the amp. The amp was based on an STK output amplifier module and had an excellent low-noise preamp stage, with plenty of inputs. When I saw a TC-WE675 for an unusually reasonable price I couldn’t help but wonder how it would sound all these years later, connected to the system I have now.

Despite agreeing not to, the seller shipped the deck with Hermes. Wrapped only in a sheet of cardboard with no internal packaging what-so-ever, the fact that this deck survived its journey to me is nothing short of a miracle. In truth these aren’t especially well constructed. The front panel is a single-piece plastic moulding, and the top case is so flimsy that it can be shifted a few millimetres side-to-side when it’s sitting on a shelf.

My TC-WE475 was much the same – though perhaps as an indication of how unpopular cassette decks were at the time, and how little thought was put into their manufacture, the amp, tuner and CD player were constructed to a much higher standard despite being virtually identical in design. Perhaps I’m being a little over-critical of the Sony; the plastic used is of decent quality, and there are plenty of great decks built with a lot of plastic in their design – Denon’s highly rated DRM-740 being one of them.

Sony 675 Center Front

Both the 475 and 675 are loaded with features. You get a pair of full-logic decks, in the case of the 675 each capable of recording and supporting types I, II and IV with automatic tape type selection. Deck A has a switchable pitch control and both decks support autoreverse playback, playback in relay formation and high-speed dubbing from tape to tape. The TC-WE675 also supports relay recording where a recording starts on a tape in deck A and finishes on a tape in deck B, and simultaneous recording of the same source onto tapes in both decks.

Both decks A and B have digital tape counters with a memory reset function and music scan to detect tracks on a tape providing there is at least 4 seconds of silence between them. This feature works quite well though it can be tricked by quiet passages within songs. It can skip 30 tracks in a single pass.

Deck A has a programming mode whereby up to 28 tracks (14 per side) can be programmed in any desired order. Few cassette decks had this feature though it is quite common on CD players especially of the time. Though it’s really a gimmick, it does have its uses with cassettes where the album tracks were reordered to fit the length of the tape. Many early albums were produced in this way, and using the programming features it is possible to reassemble the tracks in the correct order providing you don’t mind the gaps between them, not to mention the wear on the mechanisms and the whirring and clunking while the deck winds the tape and flips the heads as necessary.

None of these features are particularly unusual in a cassette deck from the mid ‘80s and beyond. Neither are Dolby noise reduction (B and C) with the HX Pro headroom extension. Dolby S. Had been largely abandoned by this point, though production of the TC-WE475 did overlap with the Yamaha KX-580SE which was dolby S-equipped, and possibly late models from Aiwa too.

The Dolby implementation is quite aggressive, especially where Dolby B is concerned and I’d tend not to use it. Though in truth I have never cared much for Dolby and leave it off. There are few if any pre-recorded tapes encoded with Dolby C, and any tape encoded with Dolby B can be played without any Dolby at all with the only side effect being a brighter top end. Only the 675 can record with Dolby, though the 475 does support both Dolby modes in playback. The 675 also has a switchable MPX filter to avoid the carrier frequency when recording FM radio broadcasts.

Unlike the 475 which has no adjustments for bias or equalisation besides its automatic tape-type selection, the 675 has an automatic calibration procedure to set the bias current and equalisation characteristics for any tape. I was surprised to see this feature and even more surprised to find that it works surprisingly well. So too does the automatic record level adjustment, which sets the recording level based on the peak level of the playback source before recording. Unlike other automatic level systems the level can be fixed and left unaltered as the recording progresses, so there are no sudden changes in level and no variance in noise on the tape. It can also be left in fully automatic operation whereby the level is continuously adjusted during recording, and is not too aggressive when used in this manner. Alternatively the system can be defeated and the level adjusted manually.

There is a headphone jack for monitoring the incoming source and listening to the deck in playback, but there is no volume control and its output is deafening. I’m not sure why they bothered implementing one at all. As this is a two-head deck you don’t get realtime monitoring of the actual signal recorded to the tape, only what is being received through the deck’s inputs.

Sony 675 Rear

Rear jacks can interface with other Sony equipment of the time. Normally used with a CD player or minidisc player, the remote jacks provide synchronised recording functions much like you’d find on an integrated system. The control protocol implemented on the 475 and 675 and Sony’s catalogue of components from 2000 onwards differed from the standard of previous designs and the two are incompatible. The manual makes reference to improved functionality being introduced in future components, but as the general consumer interest in hi-fi dwindled neither those components nor features ever materialised that I know of.

The specs aren’t remarkable. 0.1% RMS Wow and Flutter (NAV), 1.8% total harmonic distortion, 73dB signal to noise ratio and a 30Hz – 19kHz +/-3dB frequency response at -4dB with metal tape. Unweighted signal to noise ratio at peak level is 55, 57 and 58dB with type I, II and IV cassettes respectively. Output level is 0.5V at 47KΩ. Fast winding time is 100 seconds for a C60 cassette.

Sony 675 Overall Inside View

Internally the build quality is ‘meh’, though not unexpected for a ‘last gasp’ model. There’s an EI transformer of a decent size, simple power supply circuitry and electronics mostly integrated into a few integrated circuits. There isn’t a single screw holding the mainboard in place besides that of the RCA connectors and the bracket clamping the three voltage regulators against the back panel. Instead there are plastic locking pegs which leave me wondering exactly how tight the costs were on these machines.

Sony 675 Power Board

The mechanisms have a lot of plastic in them albeit decent plastic, though important parts such as the retainers for the door springs are metal. The flywheels are plastic with little weight to them. If you install the wrong belts the added tension can cause the flywheels to move off axis causing a cam-like effect that doesn’t help speed stability. Used with an appropriate belt however the mechanisms will exceed their quoted specifications and provide perfectly acceptable performance.

Sony 675 Rear Of Tape Deck B

The mechanisms are driven by a solenoid and a few plastic gears, metal arms and metal and plastic linkages. It’s a basic design and one that has stood the test of time. Its simplicity does mean it should prove reliable in the long run even if that does mean compromises have to be made in performance.

Sony 675 Close Up Of Belts

Changing the belts is relatively simple. There are two in each mechanism, one driving the capstan flywheels from the motor and another driving the reels from the primary flywheel. Belt kits are readily available online.

I purchased a kit from DeckTech which arrived quickly and worked as advertised. They are based in the UK so there are no import fees, their belts are well priced and unlike other kit suppliers they are knowledgeable about the product they are selling, and happy to discuss specifications. It says a lot that they are the only company to mention wow and flutter in their listings. Poorly manufactured and cheap belts, such as those supplied in large bulk packs from China, are almost guaranteed to cause excessive wow & flutter. A good quality belt of the correct dimensions is essential if you’re repairing any cassette mechanism. A cheap mechanism with a good belt will stand a better chance than a good mechanism with a rubbish belt.

Sony 675 Rear Of Deck A

The original belts in my unit were badly stretched and the replacements noticeably improved torque especially in winding operations. Any cassette deck that has been sitting idle or has seen little use in its life is almost guaranteed ot need fresh belts to ensure stable speed and consistent performance. In later decks including this one, a failed capstan belt can prevent some parts of the mechanism from operating and can cause tapes to become jammed. If you encounter one of these machines or later machines from Teac et al (the Teac V-615 is a common culprit) and the doors won’t open, don’t force the eject button. Simply spin the flywheels by hand until the mechanism releases.

Swapping the belts is done by removing the mechanism from the front panel, and removing the door and its spring. You can then access two screws mounting the motor, allowing the belts to be removed. The reel belt is installed first, linking the forward flywheel with the take-up pulley. Then it’s a matter of threading the new belt around the forward flywheel and over top of the reverse flywheel, hooking it over the convenient pin next to the motor, hooking the motor pulley onto the belt and lowering the motor into place.

This is one of the simplest mechanisms to service. I didn’t take any pictures of the disassembly and a complete how-to guide is beyond the scope of this piece, but it’s self explanatory once you get the top cover removed and the full service manual is available online for free. It’s a job that anyone can do with a couple of Philips screwdrivers and a little care and patience.

Sony 675 Main Board

Setting the speed is accomplished via a pair of trimers on the main board for each deck, lined up neatly next to the flat flex cables. The pots are marked for high and normal speeds though by nature of the circuit both have an effect in normal speed. You put the deck in service mode by holding down the deck A forward play button and the deck B record mute button simultaneously whilst turning on the power. This allows you to set either deck to high-speed mode by pressing the dubbing button during playback.

Using a frequency counter (or the free WFGUI app) and a 3kHz calibration tape, you adjust both decks to read 5980Hz (+/-80Hz). You then switch to a normal playback speed and adjust each deck’s respective normal speed trimmer to give a 3000Hz (+/-80Hz) reading. Deck A has an additional trimmer for the pitch adjustment. When switched on and the pitch control centred, this should be adjusted to 3000Hz when in the normal playback speed

Sony’s tolerance for inaccuracy is telling. Most good decks of decades past would call for a tolerance of +/-30Hz or less in their service literature, but here 80Hz is considered sufficient. I suppose in reality most people wouldn’t hear the difference, but if you have perfect pitch you certainly will. With new belts and careful adjustment it is possible to get the speed to within 15Hz which is excellent for any deck. There is slight wow and flutter present in sustained piano, but the plastic flywheels and cheap mechanism are to credit for that.

Next I set the azimuth. You can do this with an oscilloscope and the appropriate tapes. Or you can do it by playing a known good tape with a lot of treble content, summing the output to mono and adjusting for the brightest treble response. Azimuth is adjusted via torx screws either side of the heads, and access is easy with the tape doors removed. The manual doesn’t give any indication that these doors will come off and they are stiff and easy to break if you aren’t careful.

Sony 675 Front Doors Off

With all the work done I popped in a head cleaner and demagnetiser before sitting down to listen. The heads in this example were mint as if they had never been used. The sound is crisp and clean with a lot of top-end sparkle. My repair of this deck coincided with the sad loss of Meatloaf so I played Bat Out Of Hell II which was the only album of his I had on cassette. The Sony lapped up the driving rhythms in ‘Out Of The Frying Pan’ and ‘Good Girls Go To Heaven’, but was no less apt at portraying the emotion in ‘Objects In The Rear View Mirror’ and ‘Lost Boys And Golden Girls’.

Deck A is the better sounding of the two. The screened cable running from its head is shorter and its signal path on the PCB is also shorter. Whether this was a major contributing factor I’m not sure. In the case of both decks the background noise was low. It isn’t the quietest tape deck on the planet, nor does it drown the music in hiss.

I suppose if I had to some up its sound I would describe it as pleasant. Maybe a bit soft in the bass, but sparkly in the highs with a slightly forward lower midband and recessed upper midband. Its sound is slightly warm in tonal colour, Highly forgiving of poor recordings or worn tapes but good enough to make a great recording very enjoyable and easy to listen to.

You could say this was a sad and sorry way to bid farewell to the cassette’s 40-year coexistence along-side vinyl, CD, Minidisc, DAT and even the digital compact cassette. In some ways I’d have to agree. This was far from Sony’s finest cassette deck. In fact, Sony peaked before other manufacturers, as their focus was clearly on their newer tech rather than optimising an ageing format.

This is not a cassette deck that would shame the best of cassette’s heyday which, if you ask me, was definitely the ‘90s. The 675 is very much a product of its time. And really it’s better than it has any right to be.

This was a deck that would do an admirable job of playing back collections of cassettes built up over decades. It’s a no-fuss tape deck with plenty of frills should you wish to use them, and great performance even if you don’t. There’s no pretence here; it’s just a very decent ‘2000s tape deck.

The good news is that they sold quite a few of them and they’re still abundantly available and affordable. Cassette is making a comeback and most of the best decks have been snapped up or are being flipped for silly money, but there are still a few bargains to be had. This is one of them. Providing it has seen at least semi-regular use, its age means that it should work out of the box without any complicated or costly repairs. If yours doesn’t work, it probably just needs a few belts which isn’t a difficult undertaking for anyone with even basic mechanical aptitude. If you can change a plug, you can put belts in this deck.

If all you want to do is play or record some tapes, you can’t go wrong with a TC-WE475 or a TC-WE675. Whether Sony will follow Teac’s example and bring a new cassette deck to market, only time will tell. Whether cassette will see the same resurgence as vinyl, only time will tell. But while there are still plenty of these in the wild, it’s a fine deck for the money.

By Ashley

I founded Audio Appraisal a few years ago and continue to regularly update it with fresh content. An avid vinyl collector and coffee addict, I can often be found at a workbench tinkering with a faulty electronic device, tweaking a turntable to extract the last bit of detail from those tiny grooves in the plastic stuff, or relaxing in front of the hi-fi with a good album. A musician, occasional producer and sound engineer, other hobbies include software programming, web development, long walks and occasional DIY. Follow @ashleycox2

14 comments

  1. I had a guy sell me the 475 on FB marketplace for 75 bucks. I think he thought he was pulling one over on me because he said everything worked great. Got home and the tapes would not rewind on either deck. Even if it works, a deck these old needs cleaned and serviced. I had already planned on it because the belts are only 10 bucks on Amazon! I replaced the belts using a good YT video Everything works perfectly now. I got these belts in the USA and they have great reviews- https://amzn.to/3vRTTq5

  2. My deck has serious speed issues. I recorded some tapes and played them in another aiwa in my grandma’s. The tape sounded SLOW ! Thought the aiwa lost speed, but then in my TC-WE475 sounded slow too….
    So I left running the deck a couple hours and bingo!!
    When the deck heats up, the pitch increases. A LOT about 1.25x speed, which makes impossible to calibrate as it would change among time.
    I´ve changed the motor by another matsushita spare i got. The problem now occurs fastly, so it´s not the motor but THE DECK.
    (Thats why maybe I wasn’t able to calibrate at all…..) Im proud of good ear and notices instantly.
    The speed control in the service diagram shows a transistorized circuit with a lot of transistors that i dont understand well… … So I would need electronic help out of putting oil and that silly things.
    If not here, we could talk on philipsd6280@gmail.com or my telegram @LikeACatAOA

  3. Yo!

    Yesterday I took from a language classroom an UNUSED TC-WE475 from 2007. That’s like a miracle and I was so excited…!
    Now I see it’s a bit “plastic” than I thought…. It broke in less than 2 tapes. The belts starting to go creamy even never used. Sad life for that belts… instead of real cauche, Sony shitted here.
    I have some trouble with it.
    -A only playing deck-
    I don’t like how it sounds. Even with the pitch control, I got the sensation it’s not running really at adequate speed. Maybe an electronic problem (? I got a Matsushita motor spare, could be better than the mabuchi?
    -B recording: –
    The recording volume is slow even turning the knob and all my soundcard to maximum. Compared with other tapes, volume in the peak meter is almost double. I need much more recording volume from this deck!
    -Speed calibration.
    I didn’t want to touch the pots cause I thought it’s factory calibrated. But maybe time altered speed as I put a new belt too….
    I do calibrate with an original tape and the same music on CD, run both and when the audio syncs and don’t separate voices and rythms I guess it’s calibrated.
    Is that a good way? Cause I don’t trust about the accurate speed in the pre recorded music tapes but are intended to be recorded in studio decks calibrated (?)
    It’s like, I don’t trust anyways in buying a 10$ 3KHz ebay tape recorded in “someone’s living room deck”

    1. It is normal for unused belts to degrade regardless of the equipment. What brand of new belts did you use, and did you replace both belts in both decks? The best way (really the only way) to correctly adjust the speed is with a calibration tape, adjusting with music doesn’t really work. Pre-recorded tapes aren’t accurate, they are duplicated at high speed on duplication machines, they are not recorded one-by-one in a studio deck. I use the original Sony-specified torque and speed calibration tapes, but they are hard to find now.

      1. What a shame about high-dubbing recorders, that surely made the cassette very less hi-fi and damaged it’s reputation. But it’s my best since can’t afford a very expensive tape to calibrate a cheap deck….
        Brand of the belts … I went to electronic shop in my city and fitted the more approximate from a bag with no brand. In both decks identical belt.

        I’ve seen that deck uses Sanko motors which are not Sankyo or Matsushita or Mabuchi… It’s good? It sounds me “Chinese”.

        Still needing info about the volume recording cause it’s too low. I turned 2 pots inside rec L R volume and now it’s loud but still not enough, I guess I decalibrate L-R equilibrium . I use a creative SB0270 which RCA volume output is high. I don’t trust a preamplifier between than can add noise and saturation a cut freqs so I’m wondering about modding the deck

        1. Those bulk pack belts are always rubbish, no wonder you’re having speed issues. Start by fitting a decent set of belts from DeckTech (eBay). Do you have another tape deck that you believe runs at the correct speed? If you do, record your own speed calibration tape. If not, you’ll either have to buy one, find someone who can make one for you, or send the deck to a service tech to have it sorted properly. The motors are fine. You might put a drop of oil in them beneath the pulley when you have them off to change the belts, but other than that I wouldn’t change them.

          The correct calibration procedure for the recording level is in the service manual. Did you mark the original position of the pots before you adjusted them? The recording level should be fine with a standard line-level source, that sound card does not put out full line level as it is designed to be running into a pair of cheap amplified computer speakers. Unless something is broken, the frequency response of the deck should be fine; modding it won’t give you any benefit. If you feel it’s not right for you, you’d be better off buying another deck.

  4. I’ve appreciated reading your article about this SONY cassette deck.

    While I certainly agree with most of your competent opinion on this deck I can offer my own thoughts and ideas about this kind of later years SONY decks.

    You must ignore every technical aspect to like them, after that it’s pretty fine if you find the right unit. But if you have disassembled earlier decks or had an experience with for example a Technics of the same era you’d be quite disappointed. And I am not referring to the transport with plastic fantastic flywheels or the flimsy belts. It’s AMAZING what SONY managed to achieve with this design and materials, the specs are actually very good for what it is. Where it falls short, without even looking at it is the noises it makes while you control the unit and everything you touch feels cheap and flimsy. The Dolby switches and the direction toggle were HARD when the units were new and will continue to be hard and imprecise even when the actual switch underneath is lubricated (it’s a design issue), the doors are very finicky and go off square if you push them on the wrong side (other design issue)… they can also be DISLODGED from the bottom hinges if you insist on closing them off square when they offer resistance. The counters are quite small and buried in. They don’t even have stand-alone feet, the front are integrated into the front panel, the back seem two plastic bottle caps and you can ELECTROCUTE yourself just by testing the unit as the incoming mains supply is connected on-top of the transformer board on two unprotected spades.

    Programming… nice appreciable feature, but lower end models of this design dropped BIAS calibration. If you use SONY cassettes an HF would sound decently enough, but you’d probably have to resort to a TDK AD or HF-S to have a neutrally sounding tape. I’d be fine with that if SONY wasn’t the manufacturer of some underbiased cassette tapes like the UX: I (historically) paid twice an HF and it sounds even worse!?

    How does it really sound? CLUNKY. All dual cassette decks don’t have the most refined mechanism of them all, but this wave of SONY decks sound very hollow and clunky during operation. According to my ears the reproduced sound is a bit metallic and caved in, although quite bright and clear. The problem has nothing to do with the frequency response which is good even W&F figures are fine. Yet if you had a comparable Technics deck of the era you it could even equalize the tape at 3 kHz, something only very selected and expensive 3 head decks could do, and often to a lesser extent.

    I’d be fine with all of this if you wouldn’t find out when servicing these units the azimuth is oftentimes off both side A to side B and DECK to DECK for what I remember. I can only speculate with limited production time they adjusted them very roughly and they shifted with time thanks to sub-optimal flimsy design (much like the door hinges, which are badly designed but also suffer from structural weakness). Adjusting by ear while possible usually leads to inconsistent results, one might even manage to align to the right wave but with inverted phase L to R where the Lissajous curve will look flipped.

    I consider the azimuth issue bad as it should not normally shift over time. I am pretty sure if you get a unit without BIAS calibration, use an unfriendly tape like SONY’s own UX to record (which is fine if you can calibrate it) because of the azimuth issue you can end up with a pretty dismal sound even when flipping side on the same deck, for example reproducing directly SIDE B of a cassette recorded on the same deck but when SIDE A was inserted facing forward, basically recorded when the head was flipped but read with the head in normal position as if it were SIDE A.

    To correct an issue like this you need a reference cassette and at least a volt meter and much better an oscilloscope, which is out of question for most users. I wouldn’t say stay away from these decks but you ought to know that an uncalibrated/unaligned cassette deck can quickly defeat all the passion and enthusiasm you might have for the topic.

    1. All of your points are certainly very valid. However this deck should be analysed in the context of its target market. This wasn’t aimed at cassette enthusiasts or ‘audiophiles’. Nor were Sony ever going to put the R&D into building a high-end mechanism for a dying format, when they already had a useable mechanism on the shelf that was already being mass-manufactured for micro / midi systems. This deck was aimed at the buyer who more often than not had the matching Sony components, and wanted a matching cassette deck to play their old tapes, or to record tapes for the car. Most of these decks I’ve seen were hardly used from new. The buyer of this particular deck probably also had the matching 570-series components, and maybe a matching minidisc player, and it was all the home hi-fi they ever needed. When I had my 475 from new, I didn’t care about azimuth, wow & flutter or frequency response; heck I didn’t even notice the issues with the build quality. And the fact that there are still so many of these decks around, and all that generally goes wrong with them are stretched belts and head mis-alignment, I’d say they’re actually fairly robust. They did a job for the price, and did it well.

  5. The problem with even the very best cassette decks isn’t the deck, its cassette itself. They break. They’re not archival in any sense of the word. So your treasured music on cassette will eventually become unlistenable, something which doesn’t happen to LPs or CDs, both of which also sound better!

    1. This is true. For me my interest in cassettes is nostalgic only. Along with CD it’s the format I grew up with, I was born at a time when the LP was all but dead. I think a good cassette on a calibrated well-maintained machine can sound very good indeed, but nothing on an LP or CD. And yes, degradation is an issue, though quality tapes can last a very, very long time. I’ve seen some tapes that are 50 years old and still play perfectly.

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