pioneer SX 434 Restoration and tune up

Cleaning the controls and replacing a few weak capacitors is in order for this old classic receiver.

[@jensholm169]

I am listening to classical music on FM as I write. Had one about -78-80. Now I have another one. It is actually a sweet sounding piece of the hifi legacy

[@oscillatorjones3891]

I just sold an SX-434! I replaced a noisy transistor in the pre-amp , Cleaned the controls and replaced some pilot bulbs that were out. Yes, It was fun to get to those controls! Good sounding unit. Mine was made in Korea. My Dad had the Dick Smith ESR meter. I use the Cap Wizard. It has the audible "beep" so you don't always have to look at the display.

[@eggshellskullrule7971]

I have an sx424. Sounds warm and the tuner is sensitive enough. For the US$30 spent buying it, I'm happy.

[@kagome122885]

My dad has one of these, and it just looks and sounds so good! He is going to get his SX-434 restored, and I remember listening to it with vintage Fisher floor speakers. The volume control needs to be de-oxidized, and when my dad said he was thinking of getting the whole thing restored, I said "Do it!" to him. There's something very special about vintage hi-fi equipment. I would pair this receiver up with some good vintage speakers and a JVC JL-A40 direct drive turntable.

[@martyjewell5683]

This is a heck of a nice receiver. My first stereo receiver purchase in 1974 was this SX-434 (15wpc), it powered a BIC-920 turntable and KLH model 31 speakers all for a cost of under $240. I currently use an SX-434 in my kitchen system and it drives a Nakamichi BX-1 cassette deck and Boston Acoustics A-40 speakers. It is commonly sold on ebay in the $100 price range and is great value for a small two channel system offering AM/FM, phono, tape loop, aux and mic inputs, 15wpc and THD/IM of under 0.9%. Fuhgeddaboudit.

[@waltschannel7465]

Great commentary about capacitors at the beginning of the video. Those older Japanese high end caps were the best!! Fun resto project. Even before you put your magic on it, that's a nice receiver!!

[@ArthurJS123]

Your opening always reminds me of a roller derby show from the 70’s.

[@patnoah7850]

Very well done video I have 1 of these it belonged to my grandfather from 1975 excellent radio and record player sound thanks for an awesome video

[@zx8401ztv]

Good old receiver :-) Dodgy new caps, good thing you gave them a test. It's a sod when you cant trust new.

[@Daca241]

Nice job man,just wanted to say thank you. I have been watching your videos for quite some time and few days ago i managed to fix my Akai am 39.Even though i didnt know much about audio electronic i managed to do it.Keep up the good work and thanks for everything.

[@Dzonemp]

I still listen to AM. Our local station has been around a long time. The community counts on it for news and weather around town.

[@simonparkinson1053]

I worked on one of these for a friend, the problem was really loud crackling, which I think was independent of the volume control setting. Traced to a transistor in the preamp. Looking on the underside of the transistor, there was a silver circle around the centre lead, conductive silver migration from the device leads into the plastic of the transistor case. Replaced that transistor and the corresponding one in the other channel, which was also showing signs of the same problem. The other preamp transistors were ok.

[@ArthurJS123]

And thank you for dispelling the capacitor shotgunning fallacy. Sometimes I wonder if it was not for capacitors and DeOxit that we’d have nearly as many electronic “restorers” on KZbin. DeOxit has become a KZbin sensation, along with shotgunning caps. It’s unfortunate.

[@12voltvids]

Arthur's Hallicrafters Kitchen & Audio Lab Deoxit is a good cleaner. One of the best I have used. I use it along with nutrol. Caps can and do dry up but only certain ones. The majority never give any problems. Filter caps in switching power supplies have higher failure rates only because of the high frequencies and high ripple currents. Filters operating at 60 hz rarely give trouble.

[@kgsalvage6306]

You have some good stations there in Canada. Boston, More than a feeling!

[@isiahbethel5956]

You took the words out of my mouth about the cap deal

[@RegiPavan]

I just got one SX 434 kind of beatup on the outside with both outputs cooked... Someone was inside before and did a mess. Hope I can get the right transistors for it.

[@BillyLapTop]

Back in the early 80's I acquired a Pioneer SX 950. It had a power supply issue and I fixed that. The AM section was quite hot but narrow. I got the receiver for the main purpose of converting the AM section to C-QUAM AM stereo. I had the chip and kit and the installation went fine. But I never got the quality AM stereo sound I was hoping for. As you mentioned, these AM tuners were not broad enough for the good music sound that previous generations had. I figured I'd leave well enough alone and used it as is. Due to the US FCC not taking a position on AM stereo formats, less and less stations converted to any of the formats and in the end, the mode sizzled out. I used to listen to WQXR-AM in New York City using 2 identical 1940's Zenith Wave Magnet radios offset to upper and lower side bands to hear their stereo format. It was interesting but really a waste of resources. It was worth a shot though in both cases. Great video, glad you took the preventative steps with some of those caps.

[@12voltvids]

BillyLapTop The caps in the audio circuits would be the most likely ones to cause audio distortion when they dry up. As you could see from looking at the base of one it was starting to look like the rubber was drying up. Occasionally a transistor will get noisy, certainly have had that on other units. At least these are discrete components so they are totally serviceable.

[@hondaphan4172]

@@12voltvids I know this vid was from six years ago but I thought I'd ask a question anyway and possibly get a response. I took possession of my dad's(RIP) SX-434 around 8-9 years ago. It was working perfectly when I got it and the only thing I had to do for it was replace the tuner faceplate bulbs with LED's and also the stereo & tuner needle bulbs for good measure. I also cleaned the glass and aluminum face....looked so much better.I had it in my garage (I live in the Atlantic City area so it does get pretty cold around here) and several years later I started getting audible distortion in both channels whenever I turned the volume past the #2 position...didn't matter if I was listening to FM or the CD player....it was there and it's still there. I also noticed the right channel is louder than the left one. These days I just don't turn it up past the #2 position and I use it for background music in my basement workshop but I'd love to return it to its former glory as it has A LOT of sentimental value to me. I have never checked to see if there's a reputable, reasonably-priced shop within 60-90 minutes away from me (yet!) but before I do that I'm wondering if I should just replace the caps in the power supply like you and see if that does the trick before I search for a shop?

[@LifeLifemoreAbundantly]

Good videos -it looks like you get a good amount of work for a supposed gone by business.

[@5argetech337]

I have an old Fisher TX - 250. With tune omatic Circa 1968 also a more recent rs1050 Studio standard receiver from the 1970s. Both need a total recap job.

[@dirkbonesteel]

Unrelated question. Have seen some people replacing car batteries with large capacitor banks. Besides the electrocution issue anyone have any opinions on that?

[@tomscotland]

I have one of these in daily service, and also a 535 in need of repair. What are the symptoms of failed or failing capacitors? Mine would pull the speaker cones in and make a dreadful noise...any ideas?

[@andrewdouglas8019]

I have one it worked for few minutes until my bro tried to hook up powered speakers and now there is no sound , got regular speakers hooked up and when I power on there is a little thump through the speakers but can’t get any sound in any channel , fuses on back seem fine , any ideas I don’t want to sell it if it’s an easy fix ?

[@bassblaster505]

I want to get my hands on an SX434. I have a 636 I fully rebuilt and love the sound of it.

[@clifffton]

434 wasn't near as nice. Entry level stereo...

[@Synthematix]

sony ta-636 ? i have one of those the sound quality is unreal

[@bassblaster505]

Pioneer SX-636. bigger brother of the 434 in the video. that sony does look nice too

[@tomjohn3364]

bassblaster505 i have a sx636 had it since it was new. Just died makes a loud humm. Any thoughts what could be wrong.

[@bassblaster505]

Tom John Could be a number of things. Output transistors could be shorted. Or, while much less common, the issue with mine was the 2SA726’s in the differential pair failed, causing the PNP output to go into full conduction making it appear it was shorted, when it was actually doing its job. EDIT: It could be the 2SC1451. it’s infamous for going open, and when it does it takes the entire amplifier stage out with it

[@Bushougoma]

22:17 Lots of things affect the ESR like working voltage, ripple current, case size, temperature 85 C vs 105 C, etc. The newer Anatek versions of this meter redesigned by Bob Parker don't have the ESR table anymore instead it has a vague reference chart where you have to extrapolate the ESR from a curved line based on capacitance and working voltage. This tells me they didn't have that much faith in the accuracy of the old chart. As for the new caps look at the datasheets for their ESR to see if they're in specification. Hopefully the caps you have are from authorized distributors otherwise all bets are off. The market is flooded with fake caps that look like the real thing and don't meet the specs of the genuine article when new.

[@jimreardon6599]

Lots of fake parts on the market. Even when you buy in a retail store there is no guarantee that you will not get fakes, and no store will accept returns. They all have it printed on a big sign on the counter or on the receipt. No warranty and no returns, so you take your chances. These days all bets are off. Just my 2 cents of advice from my limited experience buying parts. online sellers are pretty much a guarantee that you will get counterfeit or used parts.

[@Bushougoma]

You're buying from the wrong online sellers I was referring to companies like Digikey, Mouser, and Newark / Element 14. Your chances of getting fakes from these suppliers is slim. Now if you're not in the US then suppliers become more limited. I have no electronics suppliers anywhere near me wish I did I'm pretty much reliant on Digikey for parts. Luckily first class shipping is only $3.50 so even small orders are financially feasible.

[@12voltvids]

I generally buy my small components from Lees in Vancouver as ordering anything online is cost prohibitive. When they charge 20.00 to ship a 5.00 part you know something is wrong. I just ordered a ECH42 tube for my old radio that blew a tube. Tube cost 5.00, shipping 11.00 as the cheapest way to get it here, and there will probaby be a 15.00 broker charge added. By the time the tube gets here it will have cost more then the radio that I am fixing. Unfortunately Main electronics, which had a huge inventory of tubes shut down and sold all their inventory to online sellers. So now I get my as55h0le reamed out every time I need to order a part.

[@SDsailor7]

That is the reason if I need a part for one of my rtr's or receivers I wait and combine the two as far as ordering parts so that it comes out cheaper on the shipping. I feel your pain.Cheers

[@kgsalvage6306]

They really liked to layer the boards back then.

[@rimmersbryggeri]

IS that dial VF or just a blue filter?

[@ReganMarcelis]

I had NO Idea about the capacitors being over rated to change and how you explained it. I heard Eddie Vedder/Pearl Jam! These videos are spectacular and teach so much if people WANT to learn. I watch every single one but I dunno your name yet?... Live Stream?... Putting exactly what unit your working on in the title or sub title (at least) is good to build up your wiki when people search a particular item not only will they have diagrams but actual videos from YOU...

[@MicheIIePucca]

Curious what you run for your AM and FM transmitters at home?

[@12voltvids]

Michelle Pucca The fm unit is just one of those mp3 players that plugs into cigarette lighter. Got it at a clearance place many years ago for 5.00. It has only a about 50 milliwatts. The am unit is 400 milliwatts C-QUAM am stereo that I built. The video for the build is on my channel. I bought it as a kit on ebay. Sounds great and of course plays on mono radios just fine and sounds even better on stereo radios. They don't have much range. A block or so. Just string enough for testing radios.

[@glenngoodale1709]

Do you have any short wave radios that you are willing to sell ? ... Another great video

[@coreyfellows9420]

Last year i got a sx424 in the mail.... no idea where it came from.. It had my name and address on it.. Must of bid on it or something haha

[@litzdog911]

Yay!!!

[@12voltvids]

Sounds good doesn't it?

[@neaionqwe]

made in 1974 -76 ? older than me ,and still works

[@litzdog911]

1974

[@chainedenintenloup]

OwO, a french station

[@ReganMarcelis]

Now that I know more and fixed three plasma's and two LCD's with your help I want to go further..... Nano Technology? Fixing the parts that you replace like Mosfets, etc? I have a question, what creates the heat from a "part" like a plasma chip on a buffer board even though it has no moving parts? I am to the point of understanding ,more that that question popped into my head... I understand why a hard drive would get hot with moving parts, what about the stuff without moving parts, what is working to create the HEAT? Video?... I will always thank my FREE HP 42" Plasma PL4260n for leading me to YOU... BTW: From what I seen, JVC's seem to have the best most durable parts in tv's. etc. Why does JAPAN seem to make the best or am I off and its just what I seen?.. I have a LT-32576 LCD that won't die except the light engine I broke and replaced as I put a strong magnet on the back by accident not realizing it would take the board out and ended up with no picture but sound which led me to the FREE HP for parts that led me to YOU! I am on a 37 inch LG now from 2016 that is stunning but when I bought it for $20 earlier today on OfferUp, it didn't work at all. :P -Steve

[@jaccurtis5789]

Here before the thumbnail

[@Pico_Farad]

It's much like a Sanyo DC 2000

[@FordGranada75]

It's easier to unscrew the transistors from the heatsink to remove the main board and leave the heatsink in place.

[@clausolsen856]

Nope. You can't get the board out because of caps blocking the right angle.

[@crashbandicoot4everr]

Are CapXon caps crappy?

[@12voltvids]

Well they certainly arn't Rubycon quality.

[@rogerwillams2814]

my god it seems the 434 is a bit of servicing headache ! the way its desinged its layed out weird ! i was trying to get a look at the output stages ..... i think they got better as the years went by on making these receivers ....

[@ReganMarcelis]

Can you fix a Computer PSU., liker a good brand, Corsair? That would be a Big Hit! ...Put a CAUTION ON THAT VIDEO THOUGH...... Buying and fixing a GPU now like a GTX would be amazing, they are so lower priced that you can only get them fairly cheap now BROKEN! YOu would make allot of money. My motherboard broke the other day when I put my new build together, I smelled it then it shut down, I know it blew a cap but I never fixed a ASUS P5QL-EM. BTW: Your new videos look great, these are the videos that will pay off long term, tghe stuff new term for views should be computer stuff, gamers stuff, etc! See what the KZbinr Tech Yes City does?... You can be like him except buy broken to FIX! Make money doing it as well if know what to get. GTX 960, 1060, 1080, ETC....

[@jasejj]

Always amuses me that North Americans were so obsessed with receivers, as opposed to separate amplifiers and tuners. The designs were always compromised as a result, and were the cause of the "dumb designs" that were hard to work on, that you refer to. The dumb ones were the people who bought the stupid things.

[@12voltvids]

Jason james Separate components were always available here. They just cost much more than receivers. Integrated amps cost more than receivers and separate preamp and power amps even more. Salesmen always pushed receivers saying they were just as good and you were getting the radio eventually for free.

[@tigerbalm666]

One of the dumbest chasis design ever! WTF Pioneer?