Tuners are listed in alphabetical and numerical sequence by model number. In parentheses after the model number are the year of introduction and most recent list price, and/or the original list price if indicated by "orig." Special thanks to David Rich of The Audio Critic for
copies of historical material from his reference library.
There are many Technics tuners in our On-Deck Circle that we'd like to consider listing here if our readers will provide some basic information on them (types of controls and features, and any personal anecdotes or comparisons to other tuners). Please post in our FMtuners group if you have any information about any of them. We have posted updated eBay sale price data in this section through August, 2011; data for "as is" or damaged tuners, or otherwise unrepresentative auctions, may be excluded.
Technics ST-8077 (1979, $300, front, back) search eBay
The ST-8077 is an FM/AM tuner with 4 gangs and 3 filters, an "Active Servo Lock" circuit that supposedly prevents frequency drift, two FM muting thresholds plus a defeat position, and a recording level check switch. Here's a review and some DIY ideas from Jim: "I have always found this thinline style tuner attractive and like the function of two green LED pointers on each side of the red LED station pointer. The green LEDs indicate the direction for fine tuning, then disappear when you are center tuned. Of the 3 ceramic filters, CF 101 is a rectangular metal "SAW" (surface acoustic wave) filter while CF 102 and 103 are the common 3-pin ceramic type. The audio stage looks to be a dual op-amp (an MC4558) followed by a discrete transistor for each stage (muting transistors). The sound is better than a lot of stock tuners and has good bass control and a pleasant midrange. Whether it was bad luck or a design problem, I've seen three of these tuners and two had problems. The first just quit working and had odd voltages and the second lost some volume on one channel compared to the other. The third one works fine. There is no fuse. The transformer is always energized and the on/off switch powers the 16 or so volts to the board. If I keep the tuner, I will fuse it on the high-voltage side of the transformer and add an MOV for good measure. I've modified several of these now and the best results were as follows: Remove the old 4558 op-amp, install an 8-pin socket, solder in place and plug in an OPA2604, OPA2134 or OPA2132 op-amp. I've tried others, too, but one of these three would be my sonic choice. I replaced the .47 µF electrolytics (C501/502) before the op-amp with 1 µF Black Gates, and the 3.3 µF electrolytics (C505/506) after the op-amp were replaced with 10 µF or larger Black Gates (pay attention to the + and -) on all. This made the bottom end fuller and sweetened the midrange. There isn't much room in this thinline for much more in the audiophile exotic department." See how one ST-8077 sounded compared to many top tuners on our Shootouts page. The ST-8077 usually sells for $15-30 on eBay, with highs of $127 in 3/06 and $111 in 9/06. [JR]
Technics ST-8080 (photo, inside1, inside2, back) search eBay
Although the 4-gang ST-8080 looks terrific from the outside, it's nothing special inside and certainly no competition for an ST-9030, ST-9038 or ST-G7 from a circuitry standpoint. Still, this tuner can be counted on to provide good sound for the money. See how one ST-8080 sounded compared to many top tuners on our Shootouts page. The ST-8080 usually sells for $35-60 on eBay, with a low of $8.50 in 6/06 and a high of $119 in 4/07.
Technics ST-8600 (front, closeup, back, schematics, block diagram and alignment guide) search eBay
and Technics ST-9600 (1974, photo1, photo2, inside, gangs, back) search eBay
Believed to be identical, these tuners both had 5 FM gangs and 4 ceramic filters, and 3 AM gangs. The ST-9600 seems to have been the Euro version of the ST-8600. Our contributor Daniel informs us that the ST-9600 has some unusual capabilities: its front panel functions include "servo tuning," rec/playback (amp/source/tape/FM low-noise), a pink-noise generator, output level and MPX hi-blend; on the rear panel, in addition to the usual antenna jacks, are tape deck rec out/playback, amp/tuner line in/line out, and multipath output jacks for an oscilloscope. Here's an excerpt from Technics' own literature for the ST-8600: "Low-noise direct FM-to-tape deck system sends pre-emphasized signal to deck for recording, with deemphasis in playback. Built-in pink noise generator for accurate level settings of tape deck. Unique pilot signal canceller permits virtually flat response to 18 kHz, without interference. Four 'Flat Group Delay' ceramic filters and 6-stage IF amp realize accurate 'wave form transmission' for superb clarity and inaudible distortion. Separate control and IF circuitry, with dual-level FM muting ('normal' and 'deep'). Switchable auto or manual MPX hi-blend circuit reduces noise on weak stereo broadcasts. 5-gang FM variable tuning capacitor. 4-pole MOS FET front end. Buffered MOS FET RF linear mixer. FM/AM linear dial scale. Output level control. 2 tuning meters. FM multipath output, 4-ch MPX output for discrete FM broadcasts." The ST-8600 usually sells for $75-150 on eBay, with lows of $17 and $50 in 5/07 and highs of $320 in 9/03 and $244 in 12/05. The ST-9600 is rarely seen on eBay and usually sells for $125-200, with a recent high of $278 in 5/09. It is more common and may be found for less on eBay-Germany.
Here's our contributor Paul Bigelow's great review of the ST-8600: "The ST-8600 (along with its companion SU-8600 amplifier) was Technics' bid for the upper end of the consumer market. A large silver-faced AM/FM tuner, the internal circuitry is quite surprising for a company known for pocket transistor radios and inexpensive tape recorders. Physical description: The dimensions (H/W/D) are 19-9/32" x 7-3/32" x 13-29/32" with a weight of 22.1 pounds. The faceplate is heavy and thick with four large Allen wrench-type cap screws holding it in place. The front panel is easily removed. The case is wood but is covered with a vinyl woodgrain covering, kind of cheap for what's 'under the hood' but more about that later. The internal chassis is painted black, not exposed metal. The tuner scale is covered by *real* glass. Two sheets of it: the external one (just for decoration) and the internal one that actually covers the scale. The scale is edge-lit from behind. In readability it reminds me of the Sansui TU-x17 models. Access to the circuit boards is easy. There are two tuning meters, a level output control, a stereo indicator and a two-step muting control as well as a switching arrangement to assist with recording and a high-blend switch. Internally there are two main sections, the RF/IF/detector board and the power supply/MPX/audio board.
"Circuit description: The tuning capacitor has 5 gangs for FM, 4 for RF and one for OSC. The AM has 3 gangs. There is a single RF amp 3sk40 followed by a balanced mixer consisting of two 3sk40. This is followed by the first IF transformer. Next are two 3-pin ceramic filters. A uPC555 IC dual IF amp follows. Two more 3-pin ceramic filters are next, followed by the third through fifth IF amps (uPC577). A sixth IF amp is next, then the ratio detector. The decoder is the SN76115N IC. This followed by the uPC1016C audio IC. This is the basic circuit. What makes this tuner interesting is that there are two IF paths. This is not a two-bandwidth tuner - the second IF path is for muting! This tuner has two levels of muting. There are two paths of audio as well: output from the audio IC as well as another path that promotes low-noise recording. The principle is sort of like Dolby with an emphasis that can be switched out. The AM section is discrete with separate RF amp, mixer, and IF transformers. There are no AM ceramic filters.
"Using: The FM markings are spot-on and the AM is virtually spot-on. Only the uppermost AM markings are slightly off. This tuner is sensitive, resistant to IP3 ['mixing products' - Editor] and has nice selectivity (85 dB specified). In many ways its performance reminds me of a Sansui TU-717 (in narrow bandwidth mode). The sound of the ST-8600 reminds me of the TU-717 as well. RF-wise, the only real complaint is the high stereo switching level. It's significantly higher than a Marantz 10B or an SAE Mark VI. I can always switch to mono if the noise bothers me. The AM section is superior. It is selective, sensitive, and very resistant to IF images. The AM tuning capacitor is frequency linear and the FM markings match up with the AM scale so only one scale is needed - very, very nice. The tuning knob feel (once properly adjusted and with damping grease used) is very smooth with little play. Conclusion: The ST-8600 is a sleeper, in my opinion. It is well built, very, very attractive, easy to service, and sounds pleasant enough (nowhere near my favorites, the Sumo Charlie and the 10B). I think the ST-8600 usually goes for less than $100. If someone were looking for an FM stereo tuner with a superior AM section, this tuner really fits the bill. No doubt, RF-wise, the ST-8600 tuner will outperform tuners currently in production today."
Technics ST-9030 (1978, $460/orig $400, front, inside, gangs, top, back, block diagram, schematic 1, schematic 2, schematic 3, alignment guide 1, alignment guide 2, alignment guide 3) search eBay
Part of Technics' "Professional Series," the FM-only ST-9030's rack mount styling is unlike typical Technics tuners, and it weighs a ton for its size. The ST-9030 is an exceptionally quiet tuner, with wonderful stereo separation. It has 8 gangs which, combined with its balanced mixer, give it overload and spurious rejection second to none. It has a linear phase LC filter block in the wide IF mode and 4 ceramic filters (230 kHz bandwidth) in the narrow IF mode. The ST-9030 is also one of the few tuners to provide a separate detector for both the wide and narrow bandwidths. In stock (unmodified) form, it has above-average selectivity, but its selectivity only improves slightly with narrow filters. Although the ST-9030 was apparently designed more for sonics than for extreme sensitivity, it surprised our panelist Eric by giving his modified Kenwood 600T a run for its money in a side-by-side shootout. (The 600T also has an 8-gang front end and excellent overload rejection, and the 600T is slightly more sensitive. Also, the 600T's array of filters gives it better selectivity, when properly modified, than Eric's ST-9030 which was modified with narrow filters.) The ST-9030's circuitry automatically selects the wide or narrow IF mode based on reception conditions, and it usually makes the right choice. In addition to the normal RCA outputs, the ST-9030 has tape output jacks that switch in a 19 kHz filter.
Our contributor Brian Beezley reports: "The ST-9030 is my favorite analog tuner. It is not the most sensitive nor the most selective tuner I've come across, but it has excellent overall performance in a no-nonsense, heavy-duty, rack-mount enclosure. It looks more like a piece of commercial equipment than a consumer item. In fact, my ST-9030 was once used as the receiver in an FM translator system. The ST-9030 has two MOSFET RF amplifier stages and a dual-MOSFET balanced mixer with a total of 8 tuning-capacitor gangs. The front end does not use AGC and is essentially bulletproof. I noticed only a little RF intermod when I pointed my outdoor antenna directly at a 14.5 kW station 2.3 miles away, a situation that yields a signal level of 0.355 volts at the antenna terminals (122 dBf). The IF strip has separate filter paths and ratio detectors for wide and narrow. Automatic frequency control can be disabled for fully manual tuning. Wide uses a single phase-linear LC filter block with just 23 dB of alternate channel selectivity. Narrow uses four 230 kHz filters, which I replaced with a pair of 110s and a single 150. The stereo decoder is an AN363, with an external pilot-canceling circuit. The audio output has adjustable level, but only the recorder outputs pass through an LC supersonic filter block. The tuner has multipath scope outputs and a 75-Ohm coaxial antenna connector. The RF adjustments near the tuning capacitor are under a metal shield that has no holes and must be removed during alignment. Replacing the shield shifted the oscillator frequency slightly but did not seem to affect anything else. I had originally intended to drill adjustment holes in the cover, but after seeing its minimal effect, I did not even bother to compensate for the slight frequency shift when I replaced it
after alignment.
"The ST-9030 has automatic circuits to select IF bandwidth and to engage hi-blend in stereo, and no mono/stereo switch. With today's crowded FM spectrum and the increasing number of difficult HD Radio signals, I did not want to rely on the automatic circuits. I converted the hi-blend switch to mono/stereo and the auto-IF switch to a hard selection of wide/narrow. I installed a postdetection filter to kill HD Radio self-noise, which I found very annoying without it. I also removed the remnants of the hi-blend circuit, which was applied in a curiously unbalanced way to the output channels, necessitating unequal de-emphasis capacitor values, which I then equalized. The tuning meter has an intentional dead band at its center, perhaps to hide slight AFC misalignment. Shorting a pair of diodes disabled the dead band and allowed better accuracy when manually tuning. The tuner has a nifty adjustment to match audio levels for wide and narrow IF modes, something I've not seen in other tuners. This is handy when retrofitting very narrow filters, which may drop the audio level as much as 2 dB. After modification and alignment, I measured the following: mono sensitivity of 17.5 dBf in wide and 19 dBf in narrow, stereo sensitivity of 40.6 dBf in wide and 41.3 dBf in narrow. Adjacent channel selectivity was 46.5 dB in narrow. 1-kHz THD was 0.07% in wide and 0.37% in narrow."
Our panelist David "A" says he has "a love/hate with the ST-9030 because it is pretty decent overall but ultimately disappointed me because of the layout, shielding, cabling and MPLX. This could have been a really great tuner if those areas were better, but hey, it was a $449 tuner, not a $999 tuner!" David adds, "I still think that the ST-9030 is one of the most 'moddable' tuners around. You basically get a very fine front end and a decent IF and detector for cheap. It is hard to split the circuitry because it is all on one board, but using the detector out into a modern MPLX makes it a contender." Our contributor Ryan says, "It is no wonder that this tuner has often been criticized for sounding harsh on the high end. There is an inherent design flaw in the shielding over the front end. It has no adjustment holes, so the shield must be removed to adjust the front end. When you put it back, it changes the capacitance and throws off the adjustment significantly. Ideally, you would have it realigned taking this into account, but if you don't want to do that, just remove the top lid and the front end shield and place a piece of plexiglass or even cardboard over the top. The sound should improve substantially." [But see Brian's slightly different view of this problem, above.] See how one ST-9030 sounded compared to other top tuners on our Shootouts page, and read more from David on the Ricochets page. The ST-9030 usually sells for $140-285 on eBay, but a pawnshop piece sold for just $47 in 5/05 and a "mint in box" ST-9030 went for $430 in 4/06. [DA][EF][JR]
Technics ST-9038 (1979, $600, front, closeup, back) search eBay
A very rare FM-only tuner, the ST-9038 was part of Technics' "Professional Series." Our panelist Jim was quite impressed by the sound of one ST-9038 compared to many other top tuners, as can be seen on our Shootouts page. When sold together with its separate programmable "Micom" (microcomputer) timer unit, the SH-9038 ($600 list by itself), the combo has gone for $240-320 on eBay. ST-9038s offered by themselves, without the timer unit, usually sell for $135-300 (with a low of $93 in 8/03 for a scratched-up one and a more recent high of $331 in 8/07). Strangely, an SH-9038 (that's right, just the timer unit) sold for $306 in 8/07. [JR]
Technics ST-9300 (photo) search eBay
and Technics ST-9700 (front, inside, gangs) search eBay
The FM-only ST-9300 and the 9-gang ST-9700 are two intriguing-looking tuners that resemble an ST-9030 on steroids and may have been sold only in Japan and Europe. Please post in our FMtuners group if you have any information about any of them. Our panelist David "A", who has owned an ST-9700, says it is one of the best tuners ever made, but modifying it to tune the U.S. FM band, rather than the Japanese band (76-90 MHz), is "no small engineering exercise. The ST-9700 is really phenomenal if you take the detector out and run it into an HA11223 or a LA3450! It holds its own in stock form and is clearly a formidable tuner (top 10), but doesn't quite match the standard overall of the TU-X1, L-02T or F-26."
Technics ST-G5 (1984, $220, front, back) search eBay
The ST-G5 is a very small and narrow, black, FM-AM digital tuner. Our contributor Brian Beezley provides this review: "The ST-G5 has a very low profile (only 2" high, including feet). It has 16 memories, 4 gangs and 4 filters, all of which are blue, low-GDT Muratas. Only the coils in the front end are adjustable, but the tracking was good. The wide IF filter is a 230 kHz MM followed by a 280 kHz ML, with a pair of 150 kHz MZ2s added in narrow. The tuner automatically selects IF bandwidth, but you can override its choice. The tuner has both 75- and 300-Ohm wire antenna terminals and there is no balun. A rear-panel switch selects 9/50- or 10/200-kHz AM/FM tuning steps. I didn't check whether the switch also changed FM de-emphasis. The main board looks difficult to remove. The ICs had NEC numbers that I didn't recognize. I measured 50-dB mono quieting sensitivity as 19 dBf and adjacent-channel selectivity as 23 dB. 1-kHz stereo distortion was under 0.05% in wide, and several tenths of a percent in narrow. The tuner will display signal strength in dB, but not accurately. I adjusted a trimmer to place the saturated reading at 100 dB. A no-signal reading then was somewhere below 20 dB. It displays even numbers so this yielded about 40 discrete signal levels, many more than the usual bar graph. 1-kHz separation was more than 50 dB in wide and somewhere in the high 20s in narrow. The de-emphasis was quite flat, showing only +/- 0.25 dB variation to 10 kHz and -1.25 dB at 15 kHz. The tuner has a pilot canceler. I thought the tuner sounded unusually crisp and clean, but a direct A/B comparison with my usual tuner revealed no audible differences. The ST-G5 has no postdetection filter. You must use the narrow filter for HD Radio stations or you'll hear a lot of HD Radio self-noise. The AM section sounded unusually good." The ST-G5 usually sells for $30-50 on eBay.
Technics ST-G6T (1985, $330, photo) search eBay
The scarce ST-G6T is a nice black FM-AM digital tuner. Here's another review from our contributor Brian Beezley: "The ST-G6T has a built-in timer that will turn on the tuner and anything plugged into the rear AC outlet (5A max) at a preset time, either once or once per day. The time is displayed when the tuner is in standby (it can't be turned completely off). Since it's always powered, I wasn't surprised to find the 9.6 volt, 270 mA LCD illuminator bulb burned out. I replaced the odd bulb with a common 6.3 volt pilot lamp and series resistor, and scotch-taped two spare lamps inside the cabinet. The tuner has 39 memories, 4 gangs and 4 filters. Only the front-end coils were adjustable, but the tracking was good. The main board uses surface-mount ICs and tiny through-hole resistors. The filters in my unit, all blue low-GDT Muratas, were a 280 kHz ML followed by a 250 kHz MX in wide, with a pair of 150 kHz MZ2s added in narrow. The tuner has a cute graphical IF bandwidth display. It does a little dance whenever you select a new frequency, apparently sampling the adjacent channels in deciding which bandwidth to use. You can override its choice. It tunes in 50 kHz steps and you can offset it 25 kHz to help reduce adjacent-channel interference. Adjacent-channel selectivity was 21.5 dB in narrow. The tuner has a binding post and shield clamp for bare 75-Ohm coax. It has the same numeric signal-strength indicator as the ST-G5. The ST-G6T lets you select one of three preset dB thresholds for automatic signal scan. 50 dB monophonic quieting sensitivity measured 19.5 dBf in wide and 18.5 dBf in narrow. 1-kHz separation was 50 dB in wide and 22 dB in narrow. The de-emphasis was unusually flat: +/-0.25 dB to 15 kHz. Output filtering was relaxed: 38 kHz sidebands were each 26 dB down and the pilot was 46 dB down from a single-channel tone. The tuner has no postdetection filter. The narrow IF filter is needed for HD Radio stations to eliminate very audible HD Radio self-noise. The tuner will run on 110, 127, 220, or 240 volts. You can select 9- or 10-kHz AM steps, but I didn't see any way to change the de-emphasis from 75 µS." The ST-G6T usually sells for just $20-50 on eBay.
Technics ST-G7 (1984, $525, black, catalog, silver, back, these are huge files:schematic, block diagram) search eBay
The ST-G7, a black quartz synthesizer digital FM/AM tuner, was the last great tuner made by Technics. (The silver version in our photo, taken from k-nisi's website, was sold only in Japan.) It has the electronic equivalent of 5 gangs and 4 ceramic filters. Most prominent on the front panel are a nice yellow-on-blue LCD display, AM and FM band selection buttons and 8 buttons for 16 preset stations. Behind a fold-down glass door are some useful features, including pushbuttons for Normal or Super Narrow IF bandwidth, signal strength readout in dB, and a recording calibration tone, plus the typical muting, stereo/mono, scan level, tuning up/down, etc. The tuner's computer automatically selects the optimal reception mode, including the proper bandwidth setting and whether the station is strong enough to be in stereo, but these choices can be manually overridden. On the back panel are the usual antenna jacks (both screw terminal and loop antenna jack for AM), a jack for a wired remote control, and a jack labeled "Computer I/O Terminal." We haven't tested this feature, but the following text appears in the lower middle of the front panel: "Computer System - This equipment includes the I/O terminals on the rear panel to connect with a computer system."
With a Terk "AM Advantage" antenna connected to its loop antenna jack, the ST-G7 showed off a sensitive and terrific-sounding AM section. Our sample was an international model with a Euro power plug. If you hold down the FM or AM bandwidth selection button, the tuning increments change from .2 to .05 MHz for FM and from 10 kHz to the European 9 kHz spacing for AM, but hold the buttons again and the tuning changes back. The .05 MHz tuning increments might be useful in off-tuning away from a strong local station in order to hear a weaker adjacent. The ST-G7 got a rave review from Don Scott in Stereophile, primarily for its excellent stock selectivity on FM, and it might be excellent with a couple of narrower filters. See how one ST-G7 sounded compared to other top tuners on our Shootouts page. The ST-G7 is scarce and only shows up a few times a year on eBay, where it usually sells for $130-215 (with a low of $39 in 3/06 and a high of $250 in 8/04). [EF][JR]
Technics ST-G70 (1988, $375, photo) search eBay
The ST-G70 is a very rare 5-gang digital tuner. We've never seen one on eBay-U.S., and the few seen on eBay-Germany have sold for wildly inconsistent prices (from under $50 to almost $200).
Technics ST-G90 (photo, front end schematic) search eBay
Even rarer than the ST-G70 and probably sold only in Europe, the ST-G90 is a 6-gang digital tuner. We've never seen for sale on eBay-U.S. but it might be possible to find one on eBay-Germany.
Technics ST-S4search eBay
The ST-S4 is a low-profile, quartz-locked digital tuner with Wide and Narrow IF bandwidth settings, a digital signal-strength meter with readouts in dB, and 16 station presets. An ST-S6 sold for just $13 on eBay in 3/07.
Technics ST-S6 (1982, $380) search eBay
The ST-S6 is a low-profile digital tuner that our panelist Bob says sounds good. It has the electronic equivalent of 4 gangs and its features include Wide and Narrow IF bandwidth settings and a digital signal-strength meter with readouts in dB. The ST-S6 generally sells for $20-50 on eBay, with a low of $10 in 12/07 and a high of $68 in 9/05. [BF]
Technics ST-S7 (1981, $350, black, silver) search eBay
Another in a series of good-quality but overlooked Technics digitals, the ST-S7 usually sells for just $25-60 on eBay (with a low of $10 in 3/07).
Technics ST-S8 (1983, $500, photo) search eBay
The ST-S8 is a very rare digital tuner with the electronic equivalent of 7 gangs. The ST-S8 has sold for as low as $56 (in 9/04) to as high as $141 (in 5/06) on eBay, and sale prices have been trending higher.
Technics ST-S505 (1984, $220, black, silver) search eBay
The ST-S505, the little brother of the sleeper ST-S707, is a very compact, low-profile digital tuner with 4 varactors (the electronic equivalent of gangs) for FM and 2 for AM. The IF section has 4 ceramic filters, 2 of which (CF 101 and 104) are used for the Wide IF mode and all 4 of which are used in Super Narrow mode. Our panelist Ray says that the ST-S505 "has surprisingly good selectivity in the Super Narrow IF position, good enough to rate this tuner a budget DXer. In side-by-side comparisons with a stock Pioneer TX-9800 and a stock Kenwood KT-815, the little ST-S505 was able to pull tough signals with effectively equal ability." The ST-S505's specs quote 25 dB adjacent channel selectivity, not up to McIntosh or Onkyo caliber but quite good. The specs for IF and spurious rejection are also pretty good, but image rejection is just fair. Ray continues, "Audio performance is adequate with full frequency range projected but with little depth to the image. The output stage is rather unusual, with no buffer amp but passive de-emphasis after the uPC1161C3 MPX chip. This means the load impedence will affect frequency response. That load should be at least 33K Ohm. This tuner is not a modifier's delight, as the power supply is quite wimpy and there is just no room in its little box, but it may be a good candidate for one of Bill Ammons's Filter Adder PCBs. One notable surprise, the external AM loop antenna plugs into a phono jack. Not having the stock antenna (everyone seems to lose these), I plugged in a Radio Shack small tunable AM loop. WOW! AM like the olden days. Recently the ST-S505 has been going for less than $50 on eBay - a bargain for an overachieving tuner."
Ray adds two caveats: First, "My review [above] enticed another of our FMtuners group members to buy an ST-S505, and thus began a long arduous project to make it right. Technics apparantly made several versions with no model number change. The differences are in the tuning modes and de-emphasis, 75 µS or 50 µS. Mine was a straight North American version with 75 µS and 120V only, though it did have a rear selector for 25 kHz/100 kHz tuning increments for FM and 9/10 kHz tuning increments for AM. The unit our fellow member bought did not have that rear selector but did have a front button for 25 kHz offset on FM. It also turned out to have 50 µS de-emphasis." Ray also opines that the ST-S505 "cries out for an output mod, a la what I did to the Hitachi FT-5500MKII, along with the addition of a pilot stop filter." The 25 kHz offset button mentioned above, found on European versions of the ST-S505, shifts the frequency up by 25 kHz when selected. The display changes to show an increase of 2 in the last digit.
Speaking of shifts: The ST-S505, like some other digital Technics, has a common problem in which the tuning reads .025 high. Our panelist Bob has the cure: "Looks like the zero is done by measuring across TP101 and TP102 with a DC voltmeter. These are bare wire jumpers on the board, identified as test points with a bold white circle on one end of the through hole, then adjusted with T101. Use plastic tools only. If this does not do it, go to the oscillator cap CT1 in the RF front end. Find a weak station around 106, tune it 'right on,' and adjust *carefully* CT1 until you are centered on the station (by listening). Do this in mono with muting OFF, but in Narrow bandwidth mode. A tiny little tweak will move a great amount on the dial, so do it very slightly. Check the zero adjustment again after adjusting CT1, then check the accuracy at the low end of the dial. If OK, you're done. If not OK, you'll need to adjust the oscillator coil, and then go back and forth and do CT1 again until it is OK for both. If this is too confusing or doesn't make sense, check back with questions." Our FMtuners group member Chris tried it and reported, "A little tweak to T101 was all it took, and the tuner is right on the money. Scans and locks right on frequency, and the lock even works with weak signals now." As Ray suggests, the typical eBay sale price for an ST-S505 is about $20-40, but one went for just $9 in 1/09 (now THAT is a bargain). [RFM]
Technics ST-S707 (1984, $270, photo, schematic, block diagram) search eBay
The ST-S707 is a small, surprisingly good digital tuner. Our panelist Bob says, "This was my $20 tuner of the week. It is small and thin, but full-featured. It has 5 gangs and 4 filters, including wide and narrow IF bandwidth settings. There is also an 'RF narrow' selection, which is interesting - I think it kicks in the fifth gang, at the expense of sensitivity. There are 8 buttons and 16 presets, with the second preset engaged by holding the button down for a half-second longer when storing or recalling. The signal level readout is in dB, very nice! It can be run in automated mode or manual on all functions, including wide/narrow, mono/stereo, and RF narrow. No MPX filter is included. The sound is good so far, but it was a quick listen. This is a cool tuner, well worth checking out for cheap $. I'll do audio mods and see what happens." The ST-S707 usually sells for $30-60 on eBay, with a low of $21 in 5/05 and an inexplicable high of $176 in 7/05. A mint one with original box and manual went for $95 in 12/08. [BF][EF]
