Sony mini stereo system with amplified speakers

This early 2000s Sony stereo system is a really interesting construction. Let's see if I can make it work for a different purpose... Model numbers: HCD-T1, TC-TX1, SA-N11
Check out my KZbin channel:
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Also check out my other KZbin channels:
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[@DrCassette]

PLEASE NOTE: This video is to be continued in the near future.

[@DrCassette]

No, there won't be any further videos on the receiver and cassette deck.

[@phild8192]

I had one of these. It was a late 90s thing. It was brilliant!

[@westelaudio943]

Nice looking speakers, the one-cap-crossover isn't too bad in a small speaker system since the cones usually don't have a lot of annoying break-up resonances. The undersized coupling caps can be a benefit because they keep the woofers from bottoming out at low frequencies they can't play anyways. Maybe the transformer coil wire has delaminated from lightning damage...

[@TehMG]

Quite often an audible buzz from a transformer like this is because one or more of the laminations is vibrating with the magnetic field in the core of the transformer. It could also be the steel casing/mounting hardware of the transformer that is vibrating. It really doesn't take much, just a small part of one lamination that is slightly loose will cause a buzz. Usually during manufacture, transformers are dipped in varnish which fills in gaps and holds the laminations together to help, among other things, prevent buzz. While this can certainly be annoying, it doesn't mean anything is wrong with the transformer and does not affect its operation or reliability. You can try applying some varnish or nail polish to the sides of the transformer laminations it might reduce the noise.

[@PileOfEmptyTapes]

Agreed on loose laminations. A while back I got a 13.8 V power supply that was humming like crazy - turns out the transformer's lamination packs were held together with nuts & bolts and some of them were loose. Tightened them up good, and lo and behold, only a faint hum remains. Recently I also learned that apparently you want to switch around the E and I parts at every layer for minimum eddy currents (and hence losses and hum) - this often isn't done, for plain economic reasons.

[@AlexRutiaga]

Imagine going from manufacturing the FH-7 MkII to this thing in only 20 years.

[@AttilaTheHun333333]

6:28 ...that voice over though 😂

[@DrCassette]

Just a little correction because I accidentally said "power supply" :)

[@23chilled]

I've got one of these. Not a bad system. The cassette deck makes the same sound. It's the belts have failed. The CD player issue is microswitches.

[@DrCassette]

Yeah, bad belts and microswitches. But I don't think this set would be worth any repairs.

[@hellion9547]

I got to say, your dump finds amaze me. Is it really that easy to take things from the recykle center in Germany? Or do you find them in containers outside houses? The recycling centers in Sweden are almost always highly secure and have staff that checks that nobody takes anything, it almost makes me not want to go there to throw stuff away ’cause I always see a lot of stuff that I want, that probably works just fine, but there is just no way of getting them there...

[@gideonbouwman4904]

Here in the Netherlands also, although i do have had some scores, like an Mac Pro, and some vintage Dynaudio monitors with foamrot :)

[@costellom5]

You can tell it's from the good days,all NCC capacitors,and those green ones might be nichicon.Also the copper bar fot the transistors,nice touch.Too bad about the transformer.As long it's a simple 12v,shouldn't be a problem if you want to replace.I had a Sony pre that had the transformers(main and standby,mostly main) that got quite hot.That one might have had some issues before,had some water marks in it,who knows. Cool find :D

[@AudioMobil]

This system probably wasn't cheap back then. But I guess I would only use the active speakers as well, not because it would not be worth fixing but because I have a basement full of junk that needs to be fixed and I will probably will never come around to fix it. The inside of the speakers was a little bit disappointing though. :)

[@EastAngliaUK]

its small but very good looking.

[@sdttnkara]

Acording to service manual the power ICs are UPC2505H. Sony service manuals are very easy to find.

[@DrCassette]

Haha, I totally forgot I could just look the amplifier chips up in the service manual :D Thanks for the info!

[@Shnick]

Not so much for finding parts though...

[@RWL2012]

I don't like "one active, one passive" speakers because the airspace and therefore tuning is different in one enclosure to another. The consequence of this was most noticeable to me in a pair of Sony SRS-A20 Walkman speakers I owned years ago - one speaker had noticeably more bass (what bass it had) than the other. I had a pair of Logitech X-140 computer speakers that attempted to solve the problem by placing the amplifier in one enclosure and the transformer in the other to "even out" the airspace, but those had other problems (air leaks through the controls). This system by the way is "micro" class, not "mini" which are bigger. And cardboard ports are better than plastic ports from my experience, as long as it's thick cardboard.

[@FSM_Reviews]

Really interesting indeed. I haven't seen anything like this.... Those speakers look and sound really nice though. It would be quite interesting to make those a pair of computer speakers.

[@Mouse2113]

Interesting design

[@HammyTechnoid]

There's always that hope that you'll get something fixed.. and then there's videos like this one.. no fix, no satisfaction.. but still thumbs up for the attempt...

[@DrCassette]

This video will be continued, I have not given up. I just ran out of time.

[@HammyTechnoid]

@@DrCassette Looking forward to the follow-up

[@DrCassette]

@@HammyTechnoid I will have to order some parts... this might take a week, but there will be another video on these speakers eventually.

[@dykodesigns]

There’s not much insulation in those speakers, I would have expected a bit more fill. The folded circuitboard design is really interresting, Sony is known for mastering 3D envlope design. Are they the masters of compactness?🧐

[@jackwiegmann]

Just bought this exact system, and sadly the CD and tape decks both don't function. it breaks my heart, as they're beautiful!

[@DrCassette]

That's unfortunately not uncommon with these older mini systems. Likely the CD player has a weak laser, and the cassette deck has bad belts. Both problems are fixable, but is a mini system worth the effort?

[@t.meijer8677]

@@DrCassette For sure it is worth the effort. It is a very nice little system with a very good sound!!

[@HDXFH]

Great for the speakers, neat

[@cocusar]

I also think the speakers are a nice thing to have by themselves without the receiver/cassette player. Interesting design idea, probably because the receiver didn't had enough space to add the amplifier. The amplifier by itself is weird, and I agree with you that the output caps are a bad thing; probably the first ones to go bad. Also, it's worth noting the baked section of the PCB on the top right section; what's going on? The transformer is probably not bad, but badly designed. Just swap it and that would be it.

[@DrCassette]

The 'baked' section of the PCB seems to have some low power voltage regulators, possibly for a preamplifier stage and certainly for the power LED.

[@ESDI80]

It could be loose laminations making all that noise. Remove the metal bracket and see if you can recoat the laminations with some varnish.

[@RealEpikCartfrenYT]

Transformer buzzing is normal. My cheap LG boombox has a loud transformer, but it still works flawlessly. I used to have a radio with an even louder transformer, but the speaker blew on it

[@DrCassette]

All transformers will hum slightly, but they should not emit a loud buzz. It won't stop them working, but it will stop me enjoying music. But if you can tolerate this much background noise, good for you.

[@EastAngliaUK]

my EPOS sub woofer has a loud buzzing at the back I can hear as soon as its on so only use the speaker for main music as you don't hear it then.

[@anirbannaskar7665]

Judging by the shape of the chip, it looks like two LA4440 in bridge mode.

[@zelenizub2036]

It screems 90's.

[@doitmyself8623]

the noise maybe caused by poor input ground or volume control missing just a guess

[@bassblaster505]

UPC2505H 13.2V 4 Ohm 1% THD 19W bridged 13.2V 2 Ohm 1% THD 33W bridged max possible is 14.4V 2 Ohm 10% THD 45W

[@DrCassette]

Thanks for the info!

[@johnsweda2999]

I don't think the Transformers is bad it's right up against the capacitors there's no shielding a thin piece of metal between the capacitors Earth to the body of the transformer should sort it out it's always been like that and the bridge rectifier has very little filtering. Maybe moving the big capacitors horizontally might help

[@DrCassette]

What are you talking about? Please give me some sources. As far as I know electrolytic capacitors don't interfere with transformers like that.

[@johnsweda2999]

Well I think you're right with a small transformer like a choke but having a massive transformer like that so close to the electronics has got to add interference maybe not in the capacitors themselves so much but the other electrical components must do? If it's rotated 90° maybe alright. anything I come across using mains transformers like that is always shielded by a plate between the transformer and the circuit board. is the transformer Earth properly to the metal plate heat sink?

[@DrCassette]

@@johnsweda2999 I think you didn't catch what I said in the video: The buzzing is NOT in the audio signal (if it was that indeed would be the transformer interfering with the electronics), the buzzing is MECHANICAL, the transformer itself is making noise.

[@nijhuisrb]

De 470uF elko's zijn geen output elko's, de ICs staan in brigde mode dus halve voedingspanning.

[@DrCassette]

Thanks for the info!

[@markhorner1474]

Hey DrCassette, I have a Philips mirco Stereo system and the speaker to it sounds very good with great (high sound quality 1/5 audio) i'm sure you will like how it sounds for sure! PS: Are you oringnally from Germany? Just to let you know... I'm born with Autism (High Functioning) disability!

[@DrCassette]

I am from Germany, and I do still live in Germany.

[@PileOfEmptyTapes]

Transformer buzz aside, you could probably slap together an external passive "preamp" with a 10k log volume pot in a tin (think cMoy style) and call it a day... minimum voltage gain for the µPC2505H is 34 dB, so that stage probably has more than enough gain.

[@DrCassette]

The speakers will be connected to the headphone output of the sound mixer seen towards the end of the video. This headphone output does have a volume control, so I'm good. I just need to replace that buzzy transformer.

[@zarathustra20]

Long ago Sony used to be a premium brand - then they started making junk like this!

[@EastAngliaUK]

good they used RCA in puts.

[@graboid116]

If it doesn't work out just bypass the amplifier and just wire the speaker to another amplifier system at least you will have a nice pair of speakers

[@DrCassette]

No, I want to have the amplifier working properly. That's what makes these speakers so useful.

[@abdulmokta48]

If only Sony used premium parts inside that amplifier, would've been epic.

[@jackwiegmann]

Is there a VU meter for the cassette when recording?

[@DrCassette]

No, I don't think so. It's a very basic cassette section in this system.

[@ttheone3518]

i have a similar micro stereo system, although it's from JVC

[@DrCassette]

These micro stereo systems were quite common ten years ago.

[@Wilson84KS]

Ich hätte gerne die Gehäuse vom Receiver und Tapedeck, wohnst du weit weg von Kassel? :-P But the glue sucks, at first look you think "nice, they used a lot of connectors" but then you see the glue. But nice thing all in all, love that about Sony, had always interesting ideas, but when it's about sound quality, I like Philips most, don't ask me why, they hit the frequencies always like my ears like them most.

[@DrCassette]

Ich wohne bei Hannover, da wird wahrscheinlich nur Versand in Frage kommen...

[@Wilson84KS]

Aber doch garnicht so weit weg. Danke dir erstmal für die Antwort. Wäre es ein großer Aufwand für dich mal zu schauen was das kosten würde? Den Inhalt brauch ich ja nicht, daher wärs wohl nicht so schwer, wenn du magst, sag mir doch mal bescheid was du insgesamt dafür willst und wir gucken dann weiter. Den Inhalt kannst du ja im Folgevideo rausholen, bin neugierig was da so nen Lärm macht, schätz mal der Laser-Träger am Anschlag. Aber die wären echt Klasse für meine Lötstation und das Labornetzteil, welches ich noch baue, mag es schön genormt und stapelbar.

[@DrCassette]

@@Wilson84KS Versuch' mal, ob dieser Link funktioniert. Dann sollten wir uns private Nachrichten über dieses neue System zusenden können: youtu.be/addme/8WZ-CeVTTkLdE4UM1DKvP1EO7or7_Q

[@Wilson84KS]

Jop, hab ich, bin noch unterwegs und aufm Handy online, das Annehmen geht, aber "Inhalte teilen" geht wohl noch nicht in der mobilen Version.

[@DrCassette]

@@Wilson84KS Wenn das nachher nicht klappt, dann meld' dich nochmal hier.

[@alberttatlock5237]

It least it's using a transistor, not like most of the crap that's been made in the last 15 years

[@sobolanul96]

I have a mini stereo system that started buzzing after the electric company sent almost 260v to my sockets. After this incident the system still works ok, but the transformer buzz is very annoying

[@DrCassette]

The transformer probably got rather hot causing the windings to delaminate. This doesn't mean they are bad electrically, they are just not held in place anymore, so they can vibrate with the magnetic field of the transformer, causing the buzz. Something similar may have happened to the transformer in these speakers, or the vibration of sound played through the speaker caused the delamination to occur.

[@mitko_dsv1999]

@@DrCassette Interesting. Bought a Sanyo mini system and the reciever has a similar buzz. Maybe the transformer is the problem, it also heats up a lot, just displaying a clock in standby mode. But otherwise it works fine and I bought it for about €15 last year. Really wondered what the problem could be, and thanks to this video I now have an idea.

[@MrSeeker42]

Hi Doc. Informative video. I have found these speakers on sale in Eastern Europe and need your advice. I have the choice of having to buy either the Kurzweil KS40a studio monitors or the Sony’s. I’m looking for inexpensive Studio Monitors, basically with some semblance of Bass without breaking the bank. If I remember correctly these Sony’s cover a frequency of 60hz to 20khz whilst the Kurzweil are 75hz to 20khz. I’m guessing this means better bass on the Sony’s? What is your advice if I have to choose between these two options. The Kurzweils are new and I’m presuming that the Sony’s are not buzzing yet.

[@DrCassette]

I would suggest you go with the Kurzweil speakers, simply because they were designed for standalone operation. The Sony speakers were designed to go together with the stereo system, so they don't have any built-in volume control, and an extremely short power cable. The Kurzweil also seem to be bigger than the Sony speakers (which are very small). I doubt the Sony speakers can really go down to 60 Hz. The Kurzweil speakers also seem to have some sort of Bass Boost function, which may be useful.

[@MrSeeker42]

@@DrCassette thanks for your quick reply. I’m leaning toward the Sony’s because I don’t want to use another power source for the speakers I get for my battery powered 8-track multitrack digital recorder so this way I don’t have to plug the speakers into a wall to power them. Am I right in my line of thinking? In other words the Sony’s, being that they have an internal amplifier within one of the speakers, I can just plug them in via RCA and they will work immediately without another power supply. The Kurzweil doesn’t have an internal amplifier where I can just plug the speakers into my 8-track Recorder and expect them to work right away. The Kurzweil needs an additional power supply that the Sony’s don’t. This way I can do some recording and playback in the field on a camping trip only using batteries, yes?

[@DrCassette]

Both speakers, the Kurzweil and the Sony have built-in amplifiers. They will not work unless you supply them with power...

[@MrSeeker42]

@@DrCassette oops. Forgive me, I am a layman on a learning curve. Is there such a thing as battery-powered or rechargeable speakers ? It seems this is what I need.

[@MrSeeker42]

@@DrCassette I was hoping to find something like the Bose S1 that is chargeable and thereby portable. I don’t want to have to plug into a wall every time I record.

[@haskprvt]

Nur ne Idee: Im zusammengebauten Zustand gabs kein Brummen, richtig?! Vielleicht mag der amp einfach keinen offenen Eingang, is öfter bei den TDA15-filzlatsch, die 12 Volt schreien förmlich nach Autoradio, allein schon der SIP-Sockel.. :)

[@DrCassette]

Ich hatte gehofft, es im Video deutlich genug gemacht zu haben... Das Brummen ist mechanisch und kommt vom Trafo. Mit dem Audiosignal hat das absolut gar nichts zu tun. Das Brummen ist permanent vorhanden. Die ICs sehen für mich nicht nach TDA aus, eventuell sind das die ICs, die Sony in größeren Verstärkern als Treiberstufe vor der Endstufe eingesetzt hat... bei so vielen Pins wären die mir bekannten TDA-Chips schon Stereo-Versionen.

[@Honeyyumyum]

Thanks for this video I have a question if I removed my system control cable cord does that stop the stereo from turning on I removed it cause it have a shortage

[@DrCassette]

Unplugging the system control cable to the cassette deck should not keep the rest of the system from turning on. I haven't tried it though.

[@Honeyyumyum]

Ty I don't understand why it's not turning on

[@gaborkovacs8765]

Great video! But tell me please, how the hell, someone can solder something to a aluminium heatsink? This is not possible, This is just a thermal compound paste

[@DrCassette]

The plate in front of the ICs that holds them in place is made from copper. This copper plate is soldered to the board.

[@gaborkovacs8765]

@@DrCassette are You sure? Cant believe! Have the same system,

[@DrCassette]

Yes, I am sure.

[@SomeAngryGuy1997]

For the record, it is possible to solder something to that with a high-power soldering gun

[@leostechnikkanal]

Did the casette deck work ?

[@DrCassette]

The cassette deck had bad belts, so it didn't work.

[@HDXFH]

Junk Bad logic IC fault i'd say, had this on heaps of different units

[@DrCassette]

Could be a bad IC, but I'd guess it's just bad belts in the cassette deck and bad microswitches in the CD player...

[@HDXFH]

DrCassette i checked and they were ruled out, Logic IC in these new units are just retarded i have found

[@303nitzubishi4]

Aiwa mini system of The same vintage had the logic issue too. I do believe that was most of the reason for the class action suit