Back to Basics Service - Pioneer SX 3600 Part 1

This series is geared to those who are just getting into the hobby of vintage audio gear service and restoration. In part 1, we will do an initial evaluation of the receiver, build a simple current limiting device and use it to safely power up the receiver.

[@xraytonyb]

0:14 Intro 1:45 First Look at the Receiver 5:11 Removing the Cover & First look inside 10:12 Looking at the Power Supply Diodes and Capacitors 15:04 Visual inspection of the amplifier transistors and circuitry 19:44 Cleaning the dust from the PC Board 26:24 Building a simple current limiting "Dim Bulb Tester" 36:45 Using the dim bulb tester to power up a receiver 40:39 Testing for DC offset on the speaker terminals 48:23 looking to see if the power meters indicate any output 49:24 Connecting speakers and demonstrating how the bulb limits the current 54:29 Demonstrating how the bulb limiter protects against a short circuit (don't try this at home) 57:26 Multimeter - The first piece of test equipment you should acquire for this hobby.

[@edmaster3147]

Tony, really enjoyed this episode and your sharing the knowledge of this hobby, right from the basics up. A deep bow for you sir, you are making the world a better place. Leading by example I certainly hope. Thank you.

[@dennisfrancis1126]

Excellent! Excellent! Excellent! This vid is exactly why you are my favorite 'repair/restore' channel in all of KZbin land. As someone who is recently retired and thinking about venturing into this hobby (with minimal experience and test eq.) this is precisely what I, and others like me, need. Thank you Tony!!

[@shane6326]

Tony I know i'm echoing what so many of your viewers have already stated a million times over!!>>>>> you share your knowledge with the world for free and thats so rare to see in this world today and i cant express how grateful i am for all that you do> I hold you in the highest respect and appreciate all that you do! may God bless you and your family abundantly! i'm 51 and a dummy at electronics but your videos have taught me so much n makes me eager to learn more. I wish i could meet up with you and shake your hand! Love and respect to you all the way from Bombay india! yup Tony you have followers in the mystic crowded land of india too! God Bless U brother!

[@xraytonyb]

Thank you for the kind words!

[@TrevorsBench]

Very comprehensive, nicely done, thanks Tony

[@mackfisher4487]

It's nice that you create videos for the beginner, regardless of what knowledge I have or think I have I always learn something from your videos.

[@wickerbill7793]

These were under rated receivers in their day. They were affordable but not cheaply made. I have an SX 680 that I purchased new that blew a channel years ago but still works great today and an SX 535 that I purchased at a yard sale for $50 that I got working for $150. What I like about them is the silver face plates and the colored illuminated dial. And for what was considered an entry level, budget stereo, for my ears put out good FM reception especially when I lived in Los Angeles when FM stereo was really cool playing America, CSN&Y, Doors, on stations like KUTE, KNX-FM, KLOS, & KMET, (The Mighty Met!!). They still sound good for my ears while driving my 10” JBL’s. Footnote: when I moved to the SF Bay Area in the mid 80’s what a disappointment I experienced with FM radio. The only decent FM station was KFOG that was stuck on Bay Area bands, not that they were bad, they were & are actually great bands but at the time the Bay Area stations offered little diversity in music. Just my opinion from an old fart @ 76 yrs old. ✌️

[@michaelgreen86]

You forgot KNAC... Pure Rock 105.5 !! L.A. FM was the best!

[@dxhighendamplifiers]

Finally....i am deeply tired of tubes and FM reception....thanks god you return to the basis.

[@Brian-Burke]

Hi Tony. I absolutely love the idea of these videos. As much as I like your regular videos, I'm just not there in terms of understanding it, so this series is much appreciated. I hope the advanced viewers don't mind you going back to basics. Again, thanks Tony.

[@gime3steps]

I really like this video Tony, thanks so much!

[@moon1985bc]

very good video for beginners.

[@ChadCruzen]

Another kudos from me. I've been watching your videos for probably a few years and am just starting to really get into repairing equipment. I appreciate everything you've done and love that you're bringing it back to the basics.

[@MA-uy5vz]

Tony this video is perfect. Just getting into this hobby. My first stereo in the 1980’s was the Pioneer 3600. I bought one on eBay and plan on rehabbing it. Thanks for sharing your vast experience.

[@andyleibrook6012]

I have this receiver. My grandpa bought it new. I've done many tube radios and was planning this to be my 1st receiver redo. This should be extremely helpful.

[@keybutnolock]

Wow, three at once ! Thanks for this feast of fun. I am half way into this first of 3 and enjoying the style. Very entertaining and instructional (is that a word). Going to be another Tonython weekend for me. Thanks again.

[@johnsalas8155]

Excellent work. I wish I could of found you 13 years ago when I started this hobby. Anywho very much appreciated for all your knowledge and sharing this video.

[@carlveilleux5744]

I have a SX-720, which is basically the same unit as the SX-3600 but with a black dial. It looks great, and I absolutely love the sound of it! I have limited knowledge in electronics, but I watched many of your videos and although I don't understand everything I appreciate your explanations and craftsmanship, and I'm excited you made videos about the Pioneer unit I own. Thanks!

[@normanwalz8636]

Really enjoying these “back to basics” video series both you and bandersentv have put out this last couple of weeks. Many thanks!

[@IgorIglesias]

I loved the idea, thank you Tony!

[@VAD-man]

Great introduktion. Thank you sir. Ill get right at it...

[@jdmccorful]

Thanks Professor! Enjoyed watching.

[@timp9848]

Thanks Tony, your tutorial was excellent!

[@garygranato9164]

thank you so much for taking the time to properly explain the basic's. subscribed !

[@gerryeneral4609]

Excellent concept for the video (beginners), and well presented. Bravo.

[@jackgabbert3233]

Hello Tony, I've been watching a number of your videos for some time now and like so many other's I'd like to say thank you. Very much appreciated as I'm trying to learn this craft. Best Regards and Happy New Year. Jack

[@roseelectronics4582]

where do you find devices to work?

[@tygertyger8597]

Great info Tony. I found a Pioneer sx3700 at an estate sale that works very well. All I had to do was clean out the sawdust (and regular dust) in it because someone had used it in a woodworking shop. lol I'm going to test the DC offset now that I see how to do it. Many thanks.

[@Redheadedlady55]

~Knowledge shared...thank you.

[@1982travm]

Thank you! Thank you! Thank you! 😊

[@tedcuff9155]

I have an SX 3700 to restore. 45 watts per channel. Keep the tips coming! Good video.

[@barryf5479]

I used to be a TV bench tech when going to college. We took our dusty stuff outdoors on a wheeled cart and blew it off with an air compressor. Theoretically one could generate a static charge with compressed air but we never had any trouble with that. That way, we wouldn't come in contact with any of the components.

[@johnnytoobad7785]

I built a Velleman (60w) Power Amp from a kit back in 2003. The build-instructions instructed the customer to build a a dim-bub tester using a 40 watt bulb and the circuit board has taps to connect it and disconnect the main circuitry to check the PS. I thought this was a great idea for a kit. I built some Heathkit test equipment (back-in-the-day) and they never suggested anything like that to test the PSU's. Still using those amps !

[@michelc.1722]

Thank you very much i love your Videos. I have a little Sansui 310 Receiver from 1971 and the DC offset is 150 mV DC on the output. It has to do with the Design of this kind of Receiver.

[@johnnytoobad7785]

Looking forward to this series. As both an audio-electronics "fabricator" and a software geek I'm always interested in the "minimalist" approach. Otherwise Mr. Murphy tends to crash the party...:)

[@garybrummer7692]

Love it, thanks. try doing one on BASIC troubleshooting of a pcb. thats what i had trouble with for a long time, not a wire and a switch and a bulb but a PCB. thanks again.

[@dzee9481]

Tony, I love to watch your videos when you go over the schematics and today those are getting hard to find. I did a restoration on a Marantz 2270 and I found out that the schematics had at least 4 revisions, and finding the correct version for the device you are restoring.

[@xraytonyb]

That is quite often the challenge. Sansui quite often will make multiple revisions during production. It can be difficult to know what version you have and if you have the correct service documents. Sometimes, much research is required.

[@richardp4172]

kzbin.info/www/bejne/parbgnWQeLFsgZo&ab_channel=RichardP

[@t1d100]

Super!

[@Luke-12V]

Nice!!!!!!!!!!!!!

[@justovision]

A key thing in understanding the reason for the "dim bulb" I'm not sure you mentioned (and why it has to be incandescent) is that the resistance of the filament is proportionate to the temperature (and power). At low current a high-watt bulb won't heat up, and as you showed, it drops very little voltage because it has very little resistance. As it approaches its wattage rating the resistance rises until it will pass no more current than what the bulb is rated for.

[@jamesmdeluca]

The blue display is known as a "vacuum flourescent" display. In the dim bulb wiring, you can improve safety by having the Hot wired to the center contact of the socket instead of the aluminum base. I believe that connection can be found visually (no meter needed yet). In addition to the speaker output DC offset, you can verify the DC output of the L/R record outputs (for tape recorders, i.e. cassette or reel to reel units).

[@xraytonyb]

Although Pioneer used a VFD for the display in these units, they referred to it as "fluoroscan" for marketing purposes. This always made me chuckle, because fluoro is short for fluoroscopy, which is when we use low level radiation to produce an x-ray image through an image intensifier (known as a fluoroscope in the old days). Currently, Fluoroscan is the name of a manufacturer that builds mini fluoroscopic surgical c-arms. Interesting stuff.

[@Digital-Dan]

I found a solder sucker that compromises between the totally manual and the totally automated. It has a heated tip but a manually operated vacuum device. Didn't cost much, comparatively.

[@bmboldt]

This is perfect for me. I gor my BS in EET in 1989 but have been a software engineer pretty much my entire career. Now I am retired and want to fix up some vintage gear and brush up on the electronics I learned in college. Have a Sherwood S7100A that needs a little fixing up. It hums a little when it is on. Doesn't matter what input it is on and the volume knob doesn't increase the hum. I am hoping to figure out how to deal with that.

[@xraytonyb]

I'd check the big filter capacitors on the power supply.

[@bmboldt]

@@xraytonyb I disconnected the filter cap and measured it. It is a 2200 uf 65 V cap. It measured at 2000 uf and my cheap component tester showed 0 ohms ESR. The capacitance probably could be a little greater and I assume the ESR isn't a problem it is just really small. I don't have a replacement laying around to try. Wish I had your supply stock. Maybe I can try and add a smaller cap in parallel to see if that makes any difference. Really was hoping the cap measured way off and would just order a new one.

[@michaelscottcutler3627]

I recently found an SX-3700 in the trash I plan on restoring. I'm assuming it's very similar to the 3600. This video will help. Thanks.

[@paulpaulzadeh6172]

woow what a camera you have Tony

[@andydelle4509]

Audio power amplifier repair 101: The real purpose of the output transistors is to protect the fuses from blowing! Those of you experienced in the craft know how true this is!

[@xraytonyb]

Agreed!!!

[@RectifiedMetals]

Question, speaking of the glue. I was working on a piece that was only a year old. It looked like gorilla glue. I like the idea because it comes off easier than most of the stuff used. What is the opinion of using gorilla glue for stability? What do you think?

[@erictarbox]

Safety concern; wire the “Hot” side of the connection to the bottom contact and the “Neutral” connection to the side contact (screw terminal). This way the Voltage is further away from the troubleshooter.

[@christopherrobins8262]

Always like your channel , one small comment you have left an exposed hot terminal on your lamp dimmer cct for an accidental touch by the hand.?

[@tonyfremont]

One day while driving, just around the corner I spied a receiver sitting on top of a garbage bin. Turns out it's an SX 580. It looks to be in great shape, but I haven't dared to put power to it yet. One man's trash....

[@len9518]

How do you determine how many watts, the bulb should be?. I may have mentioned this a couple of years ago, but I applaud your use of a trackball, especially the Logitech. Great minds think alike.

[@xraytonyb]

Look at the back of the device. On the label, it should give power requirements, the wattage listed is the maximum theoretical wattage that the unit will consume. That is a good starting point. If a device is listed as 45 watts, I would start with a 40 or 60 watt bulb, depending on the condition of the unit. If you just want to see it power up and the caps charge, use a smaller bulb. If you want to turn up the volume to listen to it (at lower volume), use a slightly larger bulb. Hope that helps.

[@syedmahdi8947]

Sir, I have a SAE-2500 with ch A blown can you please suggest me what are the precautions I should take before turning On.Thanks.

[@johnb5519]

I made a trip to the auto wreckers to get a spare tire and came across a wrecked van that had a Kenwood kr7070a hanging out the back doors, and when going in from the side door to untangle the cord from underneath some junk, I noticed the Pioneer sx3600 in there. The guy let me have both for free. Not having any fancy equipment, I made a dim bulb power setup, and tried the Kenwood first. What a tank, it works fine, but the fm is garbled throughout the tuning range. The pioneer needs all the switches cleaned. The volume control is acting up. When I switch it from mono to stereo, so far with it in fm there is no sound or signal strength on the meter. Should I clean the switches first before digging in any farther.

[@MichaelBeeny]

I think it unlikely you would damage the tweeter in a speaker with DC in a fault condition, mainly because even a very cheap speaker would have at least one capacitor in series with the tweeter. The midrange (if fitted) will also probably be OK. The bass unit WILL be the casualty with a burned out voice coil. If extreme DC was present, it can push the cone and rip out of the frame. I've even found that the voice coil has welded it's self to the magnet. DC and loudspeakers never has a good outcome!

[@tubeDude48]

I have an SX 3500

[@steveh1273]

What about using a 3 prong plug with hot, neutral, and ground as part of the dim bulb tester?

[@xraytonyb]

Wouldn't make any difference, if the device under test is not also a 3 prong powered unit.

[@VioletGiraffe]

For the current-limiting bulb, wouldn't it make more sense to cut the neutral wire? That way you have less risk of electric shock if you accidentally touch something (e. g. the bulb socket).

[@xraytonyb]

In most cases, I doubt that it would make a difference. If, however, the "hot" line would be shorted to neutral or earth through another path, the current would still be limited by the bulb if it were wired through the live/hot line. A lot of viewers expressed concern about the socket I used in the video, as it has exposed terminals. To their point, it would be better to use a socket with insulated terminals, such as a socket that has "pig tail" wires instead of screw terminals that could be spliced into the power cord and then insulated with heat shrink tubing. I have never had an issue, but it is possible to come in contact with the exposed terminals on this type of socket. Thanks for the comment!

[@DAVIDGREGORYKERR]

That receiver is ready for a Motorola based AM Stereo decoder.

[@johnsweda2999]

A bit of copper type inside and outside on the vac soldering a wire with a crocodile clip *I should point out that LEDs and cfl's do not work as current limiters,* and in Europe you can't get contestant lightbulbs anymore not at that power your suggesting 60 Watts Max I've not seen for many years that even 100 w no more. You can put in line with a fuse a small bulb protection for the speakers

[@machintelligence]

Try E-bay for all manner of wattage and voltage incandescent bulbs. There is plenty of new old stock out there.

[@xraytonyb]

Traffic signal bulbs are still available in higher wattages because of the older style traffic signals still in use. They are also much more durable than standard incandescent bulbs.

[@johnsweda2999]

@@xraytonyb yeah that's interesting to know thanks

[@Nick-zo5dp]

We're do ypu get clear bulbs I can't find 60w or 100w clear bulbs locally only 40w for stoves or appliances?

[@roseelectronics4582]

you can put 2 of 'em in series

[@markk.4941]

They don't have to be clear. Can be frosted or even colored, as long as they are incandescent.

[@larryshaver3568]

i've heard that alot of dumbing down has gone on in the electronics business.So it doesn't surprise me that build quality has decreased notice-ably

[@MrDoneboy]

Shouldn't you check the DC offset, thru the terminals where the speaker wires go in?

[@marka1986]

He was doing that on the board where those terminals go.

[@JunaWaAmin]

Sir, I found this link on Reddit and I enjoy this video very much. I inherited that particular reciever mod. Fortunately my grandfather left it in super working condition. I just like to ask if you know anything about an AKAI GX-620 Reel to Reel? I know the motors are not working but I know nothing of working motors. Please get back to me, sir. Thank you.

[@xraytonyb]

I don't do a lot of work on reel to reel decks. There are a lot of mechanical issues that can happen as well as the motor capacitors in some units. I got a lower-end Sony unit last year and will be doing a video on it sometime in the future. Maybe someone else in the comments section knows these units?

[@justinsmith3904]

Hello I was wondering where you get the enlarged schematic circuit drawings ? Thanks

[@xraytonyb]

I print them on a printer that can handle 11x17 paper

[@DAVIDGREGORYKERR]

Then a metal nozzle should be better than resin based.

[@jluis5188]

8:33 I went OCD. DOHH. oh well tossing it.

[@eatshitgoogle]

10:36 FULL BRIDGE RECTIFIER!!!

[@DAVIDGREGORYKERR]

Strange that it is not a Class A design for maximum fidelity

[@grahambambrook313]

Tony, I don't like the lamp holder you use, it has exposed terminals which have mains voltage on them. Easy to inadvertantly lay the edge of a hand across, or pick up by if knocked over. There may only be 6 V ACROSS the lamp but without an isolation transformer there's mains voltage with respect to earth. Painful, at the least!

[@xraytonyb]

I've never had a problem, but I see your point and agree with you. There are sockets with wire leads that can be used, which would be safer. Thanks for the tip

[@grahambambrook313]

@@xraytonyb Probably much less of an issue on your wall-mounted set up but Sod's law could easily apply to a free-standing example; and we have 240V this side of the pond. :-) Thanks for this and all your other vids!

[@Discretesignals]

Those cheap porcelain light fixtures hide the connections well. Plus they got some heft to them.

[@NiHaoMike64]

@@xraytonyb An alternative would be to modify a cheap power strip (might have to open several to find one that can easily be modified) to connect one outlet in series with the others, then plug in lamps into the remaining outlets. Can also use space heaters or hair dryers for really high power stuff.

[@DAVIDGREGORYKERR]

If people don't mind having the original dial system replaced with a LCD display and digital tuning then it should be better and more accurate tuning.

[@len9518]

Tony...there are no "highs" in your audio, making your voice sound muffled.

[@kevinmccool3719]

😭😭

[@tubeDude48]

Uni-T Amp meter is OK, BUT many of the Uni-Trash DMM are CRAP!! Plus there manually set! errfff

[@xraytonyb]

It really all depends on the model. Some are autoranging and some are manual ranging. Some are better quality and some are pretty low end.

[@marka1986]

Generally prefer manual ranging. It's too bad in recent times that many manual ranging meters are made cheaply and therefore a lot of people associate manual range with cheap. Not always so. Think B and K, Beckman, Simpson etc. A while ago and maybe still alot meters were the same as Cen Tec. Our distributor sold the same meter at 2x the price with same insides. They are sort of OK till you got a problem and once you open it to disassemble the switch all the contacts fall out. Junk lol

[@jked7463]

The problem with this amp is that guy's need POWER, POWER, POWER. LOL. I lived for years with a Kenwood KR 3090 with 28 watts per channel. With efficient enough speakers, which I had, it was enough power. Unfortunately most current speakers are lower efficiency. Even the Klipsch legacy speakers have been updated with low impedance woofers to keep up with the horns. So even those are working the amp hard in the bass. Get some efficient speakers and play away and enjoy.