{"id":9029,"date":"2020-05-05T21:04:29","date_gmt":"2020-05-05T21:04:29","guid":{"rendered":"https:\/\/stevepedwards.today\/stevepedwards.com\/ElectronicsStuff\/?p=9029"},"modified":"2020-05-05T21:04:29","modified_gmt":"2020-05-05T21:04:29","slug":"technics-su-600-repair-minor-faults","status":"publish","type":"post","link":"https:\/\/stevepedwards.today\/ElectronicsStuff\/technics-su-600-repair-minor-faults\/","title":{"rendered":"Technics SU 600 Repair &#8211; Minor Faults and Section Function"},"content":{"rendered":"<div lang=\"pl\">\n<div lang=\"pl\">\n<div lang=\"pl\">\n<div lang=\"pl\">\n<div lang=\"pl\">\n<div lang=\"pl\">\n<div lang=\"pl\">\n<div lang=\"pl\">\n<div lang=\"pl\">Technics SU600 Specifications:<\/div>\n<div lang=\"pl\">Continuous Power Output per Channel:<\/div>\n<div lang=\"pl\">30 W :-\u00a0 20 Hz - 20 kHz at 8 \u00e2\u201e\u00a6, (Total Harmonic Distortion 0,07%)<\/div>\n<div lang=\"pl\">50 W :-\u00a0 1khz DIN at 8 \u00e2\u201e\u00a6<\/div>\n<div lang=\"pl\">Input Sensitivity\/Impedance:<\/div>\n<div lang=\"pl\">Phono MM :-\u00a0 2,5 mV\/47 k \u00e2\u201e\u00a6<\/div>\n<div lang=\"pl\">Tuner, CD, Aux, Tape :-\u00a0 150 mV\/22 k \u00e2\u201e\u00a6<\/div>\n<div lang=\"pl\">Frequency Response:<\/div>\n<div lang=\"pl\">Phono :-\u00a0 RIAA -\u00b10,8 dB<\/div>\n<div lang=\"pl\">Tuner, CD, Aux, Tape :-\u00a0 5 Hz -70 kHz (-3 dB)<\/div>\n<div lang=\"pl\">Signal-to-Noise Ratio:<\/div>\n<div lang=\"pl\">Phono :-\u00a0 71 dB (72 dB IHF-A)<\/div>\n<div lang=\"pl\">Tuner, CD, Aux, Tape :-\u00a0 90 dB (98 dB IHF-A)<\/div>\n<div lang=\"pl\">Power Supply\/ Consumption:-\u00a0 240 V 50\/60 Hz ; 250 W<\/div>\n<div lang=\"pl\">Dimensions (W x H x D):-\u00a0 430 97 x 240 mm<\/div>\n<div lang=\"pl\">Weight:-\u00a0 5,0 kg<\/div>\n<p>The minor faults are:<br \/>\n<iframe loading=\"lazy\" title=\"Technics SU600 Minor Faults\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/q80QGDKeCeo?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><br \/>\nThe rectified DC rails at the 4700uF caps are slightly asymmetrical around +\/- 47V DC and +\/- 15V DC:<br \/>\n<iframe loading=\"lazy\" title=\"Technics SU600 17V rails\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/jcSa_F4RCeY?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><br \/>\nI've got loads of leads and connectors ordered so can do some waveform testing soon on the stereo signal mismatch, and get to hear some music through this and do a power measurement when the 100W, 8ohm resistors arrive from China...<br \/>\nThe full wave DC rectification is spot on at the diodes around 100Vpp or 50V peak per rail:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-9070\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/IMG_20200505_194229757-1024x576.jpg\" alt=\"\" width=\"840\" height=\"473\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-9071\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/IMG_20200505_194242196-1024x576.jpg\" alt=\"\" width=\"840\" height=\"473\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-9011\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/pin5shortgnd.png\" alt=\"\" width=\"848\" height=\"327\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-9078\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/Diodes_Resistors.png\" alt=\"\" width=\"684\" height=\"566\" \/><br \/>\nNote the subtle voltage difference - 43.3V and 43.1V lines - by a small difference in the 2W resistor values of 330 and 390 ohms. These rails power pins 2 and 3 of the SV13102A power amp. The audio ins are pins 11\/13, with 12 at ground:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-9081\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/svi3102inputs.png\" alt=\"\" width=\"576\" height=\"375\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-9095\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/SVISchema.png\" alt=\"\" width=\"642\" height=\"692\" \/><br \/>\nAs these resistor values have actually drifted with age also, there is a volt or 2-\u00a0 difference between the positive and negative rails, but the +\/-15V.3V are clamped by the stacked Zener diodes:<\/p>\n<h6>Part #:-\u00a0<span class=\"part-number\">MA4075-L<\/span><\/h6>\n<div class=\"information column\"><b>Part Category:<\/b>-\u00a0Diodes<br \/>\n<b>Manufacturer:<\/b>-\u00a0Panasonic<br \/>\n<b>Description:<\/b>-\u00a0Zener Diode, 7.3V V(Z), 2.48%, 0.4W, Silicon, Unidirectional, DO-34<\/div>\n<div>\n<h6>Part #:-\u00a0<span class=\"part-number\">MA4068<\/span><\/h6>\n<div id=\"part-details\">\n<h6 class=\"information column\"><b>Part Category:<\/b>-\u00a0Diodes<br \/>\n<b>Manufacturer:<\/b>-\u00a0Panasonic<br \/>\n<b>Description:<\/b>-\u00a0Zener Diode, 6.8V V(Z), 5.88%, 0.37W, Silicon, Unidirectional, DO-34<\/h6>\n<\/div>\n<\/div>\n<p>These Zeners don't quite add up to +\/-15.1V but 14.1V from their specs...?<br \/>\nThe +\/-15V rails power the AN6552F phono stage op amp:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-9102\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/AN4558-1024x576.jpg\" alt=\"\" width=\"840\" height=\"473\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-9043\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/AN6552.png\" alt=\"\" width=\"888\" height=\"590\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-9092\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/an4558SSchema.png\" alt=\"\" width=\"824\" height=\"473\" \/><br \/>\nand the M5218 tone amp:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-9100 size-large\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/M5218-scaled-e1588880535168-1024x576.jpg\" alt=\"\" width=\"840\" height=\"473\" \/><br \/>\nTechnics SU600 Specifications:<br \/>\nContinuous Power Output per Channel:<br \/>\n30 W :-\u00a0 20 Hz - 20 kHz at 8 \u00e2\u201e\u00a6, (Total Harmonic Distortion 0,07%)<br \/>\n50 W :-\u00a0 1khz DIN at 8 \u00e2\u201e\u00a6<br \/>\nInput Sensitivity\/Impedance:<br \/>\nPhono MM :-\u00a0 2,5 mV\/47 k \u00e2\u201e\u00a6<br \/>\nTuner, CD, Aux, Tape :-\u00a0 150 mV\/22 k \u00e2\u201e\u00a6<br \/>\nFrequency Response:<br \/>\nPhono :-\u00a0 RIAA -\u00b10,8 dB<br \/>\nTuner, CD, Aux, Tape :-\u00a0 5 Hz -70 kHz (-3 dB)<br \/>\nSignal-to-Noise Ratio:<br \/>\nPhono :-\u00a0 71 dB (72 dB IHF-A)<br \/>\nTuner, CD, Aux, Tape :-\u00a0 90 dB (98 dB IHF-A)<br \/>\nPower Supply\/ Consumption:-\u00a0 240 V 50\/60 Hz ; 250 W<br \/>\nDimensions (W x H x D):-\u00a0 430 97 x 240 mm<br \/>\nWeight:-\u00a0 5,0 kg<br \/>\nThe minor faults are:<br \/>\nThe rectified DC rails at the 4700uF caps are slightly asymmetrical around +\/- 47V DC and +\/- 15V DC:<br \/>\nI've got loads of leads and connectors ordered so can do some waveform testing soon on the stereo signal mismatch, and get to hear some music through this and do a power measurement when the 100W, 8ohm resistors arrive from China...<br \/>\nThe full wave DC rectification is spot on at the diodes around 100Vpp or 50V peak per rail:<br \/>\nNote the subtle voltage difference - 43.3V and 43.1V lines - by a small difference in the 2W resistor values of 330 and 390 ohms. These rails power pins 2 and 3 of the SV13102A power amp. The audio ins are pins 11\/13, with 12 at ground:<br \/>\nAs these resistor values have actually drifted with age also, there is a volt or 2-\u00a0 difference between the positive and negative rails, but the +\/-15V.3V are clamped by the stacked Zener diodes:<br \/>\nPart #:-\u00a0MA4075-L<br \/>\nPart Category:-\u00a0Diodes<br \/>\nManufacturer:-\u00a0Panasonic<br \/>\nDescription:-\u00a0Zener Diode, 7.3V V(Z), 2.48%, 0.4W, Silicon, Unidirectional, DO-34<br \/>\nPart #:-\u00a0MA4068<br \/>\nPart Category:-\u00a0Diodes<br \/>\nManufacturer:-\u00a0Panasonic<br \/>\nDescription:-\u00a0Zener Diode, 6.8V V(Z), 5.88%, 0.37W, Silicon, Unidirectional, DO-34<br \/>\nThese Zeners don't quite add up to +\/-15.1V but 14.1V from their specs...?<br \/>\nThe +\/-15V rails power the AN6552F phono stage op amp:<br \/>\nand the M5218 tone amp:<br \/>\nThe LED Power and Safety on lights work off the 12V line (8.8 RMS winding).-\u00a0 This is rectified by the single diode D701 and capacitor C701:<br \/>\nAt power on the first Power LED lights immediately, but the Safety LED is only connected to ground once the power amp diagnostic switches pin 7 high (0-4V) at the gate of Q602 FET, which turns on the base of Q603 NPN to allow the Safety LED a path to ground:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-9085\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/M5218schema.png\" alt=\"\" width=\"867\" height=\"502\" \/><br \/>\nThe LED Power and Safety on lights work off the 12V line (8.8 RMS winding).-\u00a0 This is rectified by the single diode D701 and capacitor C701:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-9098\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/8VRect.png\" alt=\"\" width=\"284\" height=\"203\" \/><br \/>\nAt power on the first Power LED lights immediately, but the Safety LED is only connected to ground once the power amp diagnostic switches pin 7 high (0-4V) at the gate of Q602 FET, which turns on the base of Q603 NPN to allow the Safety LED a path to ground:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-9104\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/Fet-1024x576.jpg\" alt=\"\" width=\"840\" height=\"473\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-9089\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/LED-Drive-1024x542.png\" alt=\"\" width=\"840\" height=\"445\" \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-9090\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/05\/LEDsOn.png\" alt=\"\" width=\"277\" height=\"764\" \/><br \/>\n&nbsp;<br \/>\n&nbsp;\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Technics SU600 Specifications: Continuous Power Output per Channel: 30 W :-\u00a0 20 Hz - 20 kHz at 8 \u00e2\u201e\u00a6, (Total Harmonic Distortion 0,07%) 50 W :-\u00a0 1khz DIN at 8 \u00e2\u201e\u00a6 Input Sensitivity\/Impedance: Phono MM :-\u00a0 2,5 mV\/47 k \u00e2\u201e\u00a6 Tuner, CD, Aux, Tape :-\u00a0 150 mV\/22 k \u00e2\u201e\u00a6 Frequency Response: Phono :-\u00a0 RIAA -\u00b10,8 <a href=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/technics-su-600-repair-minor-faults\/\" class=\"more-link\">...<span class=\"screen-reader-text\">  Technics SU 600 Repair &#8211; Minor Faults and Section Function<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-9029","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts\/9029","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/comments?post=9029"}],"version-history":[{"count":0,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts\/9029\/revisions"}],"wp:attachment":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/media?parent=9029"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/categories?post=9029"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/tags?post=9029"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}