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Old 6th Sep 2007, 8:55 pm   #1
Studio263
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Default Sony FH-7

What's this? An '80's tower system? Well yes but look at the size! The second picture shows it playing an LP, it really is that small.

Making perfect miniatures of familiar products is what Sony do best and this model from the mid '80's is a perfect example of that line. A thousand inferior immitations of the same idea that have been launched since have dulled the impact a bit but I remember these in Lasky's when they were new, simply stunning and staggeringly expensive. The system is made up of five seperate parts: The turntable, which is fully automatic and direct drive(!), the tuner, which employs digital synthesizer techniques (though oddly no pre-set stations, the memory battery simply remembers where the tuning was when it was last used), the amplifier, which is good for around 30 real watts per channel, the cassette deck, which is fully logic controlled and includes Dolby "B", automatic selection of normal, chrome and metal tapes (recording and playback), automatic music search and auto-reverse, though this works on playback only and the power unit, which is just really a huge transformer (and rectifiers) in a box and powers all the system except the turntable.

I've had the turntable for some time but have wanted to complete the system, so I was glad to see this one at the car boot and bought it for a nominal tenner. Of course the seller assured me it was in perfect working order, but we all know how seriously to take such claims...

Once cleaned and looking respectable it was time to try it out. The tuner seemed OK, it's the German version so has two SW bands instead of LW, a real boon with the digital tuning as one can find the stations very easily. It brings in Iran Radio (6250 KHz, English programme between 19:30 and 20:30 most evenings) like it was Radio 4, even when only using the rod antenna. The power unit also seemed OK too, but both the amplifier and tuner had problems. The amplifier looked simple, mostly OK but no left channel output from the turntable. Fortunately this was down to a defective op amp IC in the phono stage, a scrapped Philips CD player providing a suitable low-noise replacement (the original device was of Mitsubishi origin and the numbers on it were both brief and unfamiliar). Access was another matter, it's really crammed in there!

One would expect a cassette deck of this age to give a little trouble and I certainly was not disappointed! It was clear that the belts were stretched, the mechanism siezed up with old grease and the head worn. The first thing to do was to get the deck out and thoroughly overhaul it. Sony mechanisms of this period are beautifully made so it was a pleasure to do, though there are an awful lot of tiny parts to clean and re-lubricate. The pinch rollers were re-finished with coarse grit paper and the groove that the tape had worn through the head was carefully ground out with progressively finer grades of well oiled oxide paper followed by metal polish. On re-assembly everthing seemed fine, though the head azimuth was miles out and the playback level was low. Setting these up properly revealed a really good performance potential, wow and flutter being particularly well surpressed.

But on trying a recording disaster! There was no left channel! One tends to look for something simple at this stage but the diagnosis soon homed in on the Dolby IC's. Oddly these also contain the record head driving amplifiers and the output of one of these was stuck against the supply rail, oh dear. The usual sources (and even a forum request!) failled to turn one up, things were looking grim for the little Sony. Pouring over the diagram for the TC-D5M (in a different league but the same Dolby IC's are used in a circuit that it pretty similar) revealled something interesting though. The recording amplifier part of the Dolby chips is uncommitted, you can get to the inputs and the outputs. From there hatched a plan, disconnect the defective part of the chip and wire in an ordinary op amp instead. This should be easy as the original clearly has a differential input and uses negative feedback for stabilisation and EQ control. The LF351was chosen and one was mounted of flying leads to try out. Result - no change. What? how can that be? Looking at the circuit of the D5 again showed that although the feedback is complicated there is only one DC path which contains two high value resistors. Surely not, they never give trouble in modern Japanese equipment, they are so lightly stressed! Amazing but true, a completely open circuit 120K resistor was the cause of the trouble. Replacing it and re-connecting the original IC resulted in recording on both channels. I suspect that this is why the set was withdrawn from use in the first place, the tape deck had several stickers on the side from a Sony repair shop where it was taken in 1999.

With and Sony tape deck of this era it is wise to re-calibrate the recording current and bias once everything is working properly. sony had their own ideas about tape formulation and their tapes were more sensitive than the standard types. Using easily obtainable tape (such as SA or AD) results in dull recordings without some re-adjustment, so this was done while it was apart. The recording current controls did not have the range to get the level up enough with AD but fortunately the circuit is easy to modify, the level control is a 47K potentiometer fed by a 47K resistor, moving the resistor from the earthy to the "live" end of the potentiometer track doubles the level obtainable, this is usually enough (the same trick works on the D5's and is normally necessary there too).

So now it's all pretty and working again. The loudspeakers are missing but that will give me something to look for at next year's NVCF... These sets aren't everyone's bag but one thing's for sure - they don't make them like that any more!
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Old 7th Sep 2007, 12:35 am   #2
Tazman1966
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Default Re: Sony FH-7

Blimey, that's tiny!

Well done for your perseverance. a nice result.
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All the very best,
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Old 7th Sep 2007, 10:40 pm   #3
matthewhouse
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Default Re: Sony FH-7

Wow that's quite something. That LP looks a little exposed though!
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Old 8th Sep 2007, 5:33 pm   #4
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Default Re: Sony FH-7

Quote:
Originally Posted by Studio263 View Post
These sets aren't everyone's bag but one thing's for sure - they don't make them like that any more!
Well I think it's great. I love the turntable. Is it a linear-tracking one? The tone arm looks too short to be anything else.

I think I want one!

Tom
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Old 9th Sep 2007, 1:30 am   #5
Nickthedentist
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Default Re: Sony FH-7

Yes, a very nice system, from Sony's greatest period in my opinion. Fun to use, and no doubt very collectable in years to come.

I can remember visiting Comet with my grandmother in the early 80s. While she was getting her horrible plasticy Pye music centre fixed, I had a look round the shop. Two things stuck in my mind: the first CD player I'd seen (a top-loading Philips), and the record deck that your system uses!

I'm sure a version with built-in headphone amplifier also existed, a sort-of LP Walkman

Do you know what the original speakers looked like, so that you can keep your eyes open for a pair?

Nick.
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Old 9th Sep 2007, 10:38 am   #6
Tom_I
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Default Re: Sony FH-7

Quote:
Originally Posted by Nickthedentist View Post
Do you know what the original speakers looked like, so that you can keep your eyes open for a pair?

Here's a pic I found of one with its speakers, but no turntable.

Tom
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Old 9th Sep 2007, 10:44 am   #7
Nickthedentist
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Default Re: Sony FH-7

That's interesting, Tom, it looks like the turntable might have been an optional extra, which would explain why Comet were selling it separately.
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Old 9th Sep 2007, 11:23 am   #8
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Default Re: Sony FH-7

How early in the 80's was this system around?

I vaguely remember a similar looking system (at least the silver colouring, auto reverse deck and rotary switch on the tuner look familiar) when I went on an intermediate school camp to the Deep Cove lodge. Would have been in 1983 when I was 11.

The speakers were wallmounted, and no turntable.

Of course my memory could be failing.....
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Old 9th Sep 2007, 11:29 am   #9
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Default Re: Sony FH-7

I would think 1983 is almost exactly right, or possibly 1982.

Nick.
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Old 10th Sep 2007, 8:47 am   #10
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Default Re: Sony FH-7

You are correct, the turntable had to be bought seperately. There were four versions:

PS-Q3 - belt drive, no headphone amp, fixed signal cable, silver finish
PS-Q3A - as above but finished in black
PS-Q7 - direct drive, built-in headphone amp, plug-in signal cable,
silver finish. As shown in the picture.
PS-Q7A - as above but finsihed in black

The arm is a radial one but it is "L" shaped, the short bit of the "L" is at the back so the pivot is at the centre-back of the cabinet. The geometry is such that the pickup moves in a more or less straighr line jusr behind the front of the lid.

There were three models of the rest of the system (that I know of)

FH-3 - more if a radio cassette really, two parts, manual tuner, logic cassette, small loudspeakers. I saw a tidy one for 10 at a show recently and foolishly didn't buy it.
FH-7 (as shown)
FH-10 - more features than FH-7, double cassette, Dolby B+C, memory tuner, graphic EQ display, CD selector button, tape out etc. I have one of these too, they are very nice. Only half the power of the FH-7 though.
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Old 11th Sep 2007, 3:01 pm   #11
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Default Re: Sony FH-7

Here's the FH-10 with PS-Q3A turntable (see picture). It's about the same size as the FH-7 (a little taller, same width) though they struggled to get the double cassette deck in, it only just fits in the space. note the tape transport controls on the doors, there was no other space!

I've had this one for a little longer and it has a stroy of it's own. again the cassette section was troublesome. Even though it looks like it could be one of those horrid "one motor for both" mechanisms in fact each deck is seperate and has two motors each. For some strange reason the capstan motors run all the time the system is on (even when just listening to the radio) so the brushes had worn right through the commutators! As they are double-speed decks the replacement motors were tricky to source (in the end some minor circuit modifications were needed to accomodate what I could find). There is a "cassette in" switch in each deck which disables the keys when there is no tape, so I wired this through a double pole miniature relay so it switches the motor off too (one per deck).

The turntable shown is the PS-Q3A, which is the basic one with belt drive and no headphone socket. compare this with the PS-Q7 shown with the FH-7 system.
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Old 22nd Sep 2007, 8:45 pm   #12
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Default Re: Sony FH-7

Being an owner of a Sony FH7-MKII i can say that the music quality is really AWESOME!

It is serving as an amplifier attached to my computer. What i really want is a casette player for MKII -as though i have a hundred or more casettes, and a CD/DVD interface.

Even though the phono interface works fine, the signal levels from the computer (Line out) are far much for MKII's phono input. dragging the volume slide near "0" level worked for now, but i want something mooooooooore better for my beloved MKII.

I really wonder why doesn't Sony make these anymore, Sony was great at these kind of products.
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Old 24th Sep 2007, 12:45 pm   #13
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Default Re: Sony FH-7

It's easy to convert the phono inpit to line level if you don't have the record player, just disconnect the RIAA stage from the source selector switches and run the wires from the socket at the back in directly.

My FH-7 has a CD/Line input (1/4" stereo jack) on the front of the tuner, just select "tuner" on the amplifier and if there's anything pluged into the socket then that's what you get, perfect for the young people to plug their IdiotPods into.

The FH-10 gets around these problems but then there's only half the power, they give with one hand, they take with the other. Sony still make this sort of set but the quality has gone, even in cash terms they are about half the price (so in real terms that represents a very small fraction indeed).
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Old 26th Sep 2007, 10:21 pm   #14
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Default Re: Sony FH-7

Here's a look inside the little turntable. This is the PS-Q3A model from the FH-10 system (see earlier post), the PS-Q7 is much the same but there is a lot more inside it, the stuff for the direct drive motor and the (surprisingly complicated) headphone amplifier for example.
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Old 6th Oct 2007, 10:38 am   #15
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Default Re: Sony FH-7

Thats really nice; I have a hankering for my first quality music centre now! It was a PYE in silver, with a front loading soft touch solenoid controlled cassette deck with dolby, metal tape, led recording/playback meters, belt drive automatic turntable, audio technica magnetic cartridge......................................... I bought it in 1983,and give it away in 1990!!! Id love another one! ianj
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