Realistic STA-2080 Repair

[@ProdigalPorcupine]

Thanks for the video! I used to lust after this model in the Tandy catalogue (UK) but I was only about 15 when it came out in '81. It sold for a staggering 369UKP (around 878USD at early 1981 exchange rate)! That's 1348UKP or 1697USD today! As luck would have it, when I was clearing out my wife's Grandad's rented house after he passed, I found one sitting at the bottom of a cupboard, covered in junk and barely visible. He had loads of HiFi gear - we thought we'd got everything of value and were about to lock up for the last time - it very nearly got left behind! When I checked it over I discovered the reason it'd been 'put aside' - one of the ceramic capacitors on the bridge rectifier had broken down and smoked. That was all that was wrong with it! I just snipped it out... I think a couple of bulbs were blown as well. After a few years of service the mains switch burned itself out. That was a tricky repair as it has a second switch grafted on its back (anti turn on/off thump, I think) but nothing I couldn't handle. Curiously, the FM receiver's front end dual gate mosfet failed and it went deaf. It wasn't connected to an outside antenna to be static/lightning damage so I think it was just bad luck. I replaced it with what I had and it works perfectly. I'd urge anyone who comes across one of these receivers to grab it! They're absolutely superb performers and excellent build quality. Mine still has all the original electrolytics and it still sounds great. That damned wire wrap, though!

[@3dsmaxrocks699]

Such a beautiful piece. Would love to go back in time when I saw these sitting on the shelf..... on a summer afternoon as a teenager. Nice job!

[@WECB640]

This is when RS was really good. Thanks Tony for all your fine restorations and the memories they rekindle.

[@algrabenbauer]

Hi Tony, I think everyone gets unhappy people making sour comments. I have been in and also owned a TV shop since 1968. Your comments and descriptions of how the gain of transistors change with current is something I kind of knew but never gave it much thought. I am on one one KZbin video with me talking about tubes with Shango066 about two years ago. Keep up the good work, Sincerely, Al

[@AlanEmerson]

Always enjoy the videos with Realistic equipment. Reminds me of my childhood spent at Radio Shack stores. More please!

[@richardmacphee2367]

Love the 2080 I got one from goodwill for 19.99 they said it lights up but no sound, took it home plugged in a pair of speakers and no sound, after looking at it a few minutes I noticed the jumpers were missing, note to self, turn down the volume when hooking the jumpers up lol, love your videos, keep them coming, the sta 2080 looks good next to my sx 880 😎

[@braddokken9191]

Thank you Tony. Cool to see how well built those Realistic receivers were. When I got into them later in the 80's their quality had already dropped.

[@Rancejunge]

Wow you have taught me aa lot here! Great solutions and info. Many thanks! I have 7 STA-2100 would love to see you rehab one of those.. One thing I always do since I have them apart for repair is replace all electrolytic caps with audio grade plus higher voltage rated ones. I also replace any transistors that where known to be failure points. I know it is a lot more work but I want them to last.....maybe over kill on my part. Love your presentations well done!

[@ashleycox432]

Tony, Your videos, methods of repair and commentary are excellent. Fantastic work, thank you for your efforts in producing content of such a high standard. I've been caught out using a dim bulb when making adjustments and troubleshooting protection circuits before now. I'm with you on component matching between channels, I couldn't have a 'lopsided' amp - it would drive me mad. The only thing I would do is check bias after letting the amp heat up and get it as bang on as possible, even though a couple of millivolts either way probably won't make much difference in terms of distortion. It would be interesting when you do the power tests to see a frequency response sweep to see how linear the amps are in terms of power output. Any good amp should meet its full power rating at 1kHz, but only the great ones will hit full power at 20Hz.

[@Edisson.]

Hi Tony, a great example of how to replace components that are no longer produced and revive such a beautiful receiver 👍 I'm like you, I like it a lot, I used to have all my audio in this design, I sold everything and exchanged it for a newer one, today I that's a shame because it had its charm. I'll add a little trick, if I'm repairing separated paths, I'll use a repair tape and rivet hollow rivets into the holes in the PCB (I use sockets for tinned wires, they're thin-walled and there are a lot of diameters), this little trick will ensure the mechanical strength of the newly installed components. Yes - I want a continuation, I'm interested in the protective circuit 🙂 Nice day 🙂 Tom

[@bradfordaudio]

Love this receiver Tony... I would love to see you do some additional work on this one; tuner alignment etc.

[@JamesE707]

Nice work Tony, watched it all the way through.

[@vaccarioou22]

Very instructive to see how you chose alternative power transistors and useful to learn that full power is sometimes needed for full operation. Valuable lessons - and love to see more of work to improve this amp. Many thanks

[@EdwardLehman]

There is knowledge in every repair on this equipment. It's now part of a history of audio many of us were using to hear some of the best music ever created. There's always good methods and direction to be learned from every video. As always , much appreciated.

[@qzorn4440]

Radio Shack and Heath Kit were great places for a farm kid to learn electronics back in the 60s,70s. 🥰 Thank you for the wonderful video.

[@jesiscott6048]

Very kind of you to leave those new old stock transistors for someone else to enjoy Tony! Bravo!

[@joostderidder]

excellent job. I'm a Tandy-Realistic-fan since years.

[@greenlanternseven]

Hello Tony from Meaford Ontario Canada :Realistic was beutiful in its prime using Nichicon caps and those NEC transistors were sweet ...SANKEN aka Sanyo make fantastic transistor s and are used in elite audio Hi Fi and are awesome replacements , I believe Reil of Japan aka Foster aka Fostex built those receivers

[@TheShackGuy]

Fostex didn't build receivers. Foster Electric did, but not any of the Realistic "super power" receivers. They were made by Tandy Electronics.

[@walterkeeth5060]

Hi Tony, I enjoy watching your repairing and repairing the old Realistic receiver. I own a STA 2100. I don't use it enough anymore because I also have a Pioneer SX-1250 that I am going to have to go through now because it just decided to not power up anymore. I know that you like the Realistic and thought I would let you know about it. If interested let me know.

[@markk.4941]

Excellent work! Enjoy your videos and have learned so much from them. I think I can now tackle my receivers. Pioneer SX580 someone gave me and I know nothing about it. 1986 Proton D940 I purchased new but now has no output, and just inherited a Sansui 9700. It will need a good cleaning as it came from a heavy smoker. Thanks for all the info in your videos.

[@craigm.9070]

Very interested in the power supply condition after 40+ years and what the repair(s) do to improve it. Excellent troubleshooting and revival of this classic - thank you for your time!

[@afnDavid]

Yes Yes Yes. The good core returns. Please continue with the excellent content.

[@andydelle4509]

As always Tony, a professional repair job including a modification. Like you, I have seen my fair share of hack jobs.

[@zambrano966]

Excelente Tony, sabes a mi me paso igual con un amplificador de potencia SAE modelo A202 al cual se le daño un cañal y tenia esos transistores con encapsulado MT200, pero a diferencia del este Realistic, el SAE usaba 4 transistores por canal. Los originales eran "2SA1076 y 2Sc2526 y los que use fueron los famosos 2SA1943 y 2SC5200 con encapsulado TO-3PL, funcionaron bien, aplique la misma que tu para sujetarlos, le puse una lamina de aluminio por encima y los sujete con sus dos tornillos.

[@zoranstojanovski8407]

Sound amazing, not just good looking. You can listen music 24/7 never get tired with this receiver.

[@gabiruracing]

nice allen huddy screwdriver from RC tools, and very nice job.... well done!

[@Poppinwheeeeellllllieeeeez]

Bravo on the pad restoration work. Great technique. Some guys poo-poo realistic gear and pass it by for the regular 3 brands, but there are definately some choice pieces. Sanyo is also overlooked, but also had some nice gear like the jcx 2600 of 2900.

[@radio-ged4626]

I have to agree, it's a really nice looking receiver. Looks like it performs well too. Great job.

[@davidhollfelder9940]

The pandemic accelerated/shortened the end of life cycle phenomenally .. for components as well as providers! This has affected not just this hobby, but the other hobbies I do also.

[@2aprotectsallothers592]

Thanks for everything Tony, I always learn something from your videos.

[@tonec3663]

Yes Please. Do another video on this Realistic receiver. It is rare to see anyone servicing this brand on KZbin or anywhere else.

[@Silent-Lucidity]

Splendid work, Mr. Tony!

[@PilotInCommand777]

Tony, I recently purchased a whole load of electronic parts, test equipment and lots of radios at an estate sale. Included were a lot of mt-200 case transistors. Lots of them are ECG replacements. If I could help you with any, let me know some part numbers.

[@xraytonyb]

Thank you for the offer. If you like, you can email me at: de dot w3xtb dot gmail dot com Thanks again!

[@jeffadams5510]

I collect and have one I've squirrelled away for many years. Bought it for a song and a dance cuz like you I think it looks VERY cool. Thank you SO much for the info and good look at the innards. Mine worked when stored but time has a way of messing with things. I'll power it up with a variac one of thes days and see where things stand :)

[@dhpbear2]

One tip: Drill the holes FIRST, then cut up the bar!

[@hodgie542]

Thank you Tony for Video I bought a StA 20 80 about a yr ago I really Love it Sounds great ..

[@afzaalkhan.m]

Another excellent informative restoration as always .

[@Attraktionbyran]

Great! Thx for all work you put into this.

[@rolfts5762]

Bt.full Amp, and well made videos as always. ,,Really enjoyable and interesting. Thanks for sharing.

[@excentor]

Sure we want more videos! nice job once again Tony!

[@g.fortin3228]

Great job ! The shack did have some winners in those years for sure. I just installed the very same sankens you removed and hoping they will be happy in the Nikko 220. Not finished with the driver board yet. Fingers crossed. Would be interesting to see your caps choices and if you change out any trans on the tone board for thatreceiver, and how to adjust the meters... if you do feel like putting out part two.

[@hestheMaster]

Fantastic power transistor repair video. We all should learn how to replace older ( crapped out ) transistors with a more modern option if available. It is not a gamble if you know your stuff like you Tony. See also Dan Horton's reply to the Trevors Bench comment below Tony. Don't gamble with counterfeit stuff on line. Too much out there.

[@johncoops6897]

36:29 - whilst the copper pads are nice, it's easier (and probably better) just to hard-wire the pins to the transistor leads with a loop of copper wire. I cut them from stranded mains earth conductors - we use stranded cables (rather than solid core romex) here in Australia, and there is a choice of 3 common gauges so it's easy to find the best size.

[@BrainHurricanes]

Great repair Tony.

[@johnwagner800]

xraytonyb, I always enjoy your work and will always listen to whatever you have to say. Sincerely, John Wagner

[@t1d100]

I had the idea to cut the pins off of the old/bad/original transistors and to use the bodies as the clamp bars (such as what you manufactured out of the aluminum bar stock,) for the new transistors. Of course, the bars you made are super excellent.

[@MidAtlanticRadioRepair]

Let's see more of this one!!! I love it!!

[@scrappy7571]

What is the Hfe of the new transistors, I didn't catch that if you mentioned it. Yes to more of this unit.

[@micrometer1484]

I'm following your repair to fix my STA-2080. I'm at the point of running the receiver on my DBT and it's finally dimming after new outputs and several components on the left amp. I saw that the receiver needs to be at full power for the 2 relays to click. I'm trying to check DC offset while on the leash. My question is do I need it at full power (relays on) to get an accurate DC offset measurement? I must commend you on your videos of these vintage receivers!!! I've learned so much from you and want to thank you for spending so much of your time to share your knowledge. Thank You!!!

[@micrometer1484]

I searched through Audiokarma and indeed I do need the relays on to get accurate dc offset measurements.

[@xraytonyb]

I always do the final DC offset adjustment, as well as bias with the amp connected to full mains power. You also want to wait about ten minutes for the amp to warm up.

[@micrometer1484]

@@xraytonyb Thanks, Tony!!

[@TheTrueVoiceOfReason]

As Genesis sang: Turn it on o-o--on, Turn it on, turn it on again.

[@hipolitofontanez3778]

Excellent audio output

[@mcgjohn22]

really nice work Tony!. I often wondered who was the contract manufacturer on these unit. Appears to be made pretty well.

[@TheShackGuy]

These were made by Radio Shack's Tandy Electronics. docs.google.com/spreadsheets/d/1laZVTI-3JgO9iTXwHc7I0mEpfSqb8O0bREcGWk10oiM/edit?usp=sharing

[@SinnerSince1962]

Please continue! There is little support for these, and I have one! 😊.

[@paulschreuder4211]

Love your video's Tony! tnx for sharing

[@len9518]

Looking through old Radio Shack and Lafayette Radio catalogs, I've noted many identical models, just with diferent nameplates.

[@TheShackGuy]

Fascinating. Please list the "Identical models" with "diferent namplates".

[@keybutnolock]

Yes please ! ) Any tips on restoring the face plate. Thanks for sharing.

[@alanmaier]

I bought a STA-2080 new. I should have kept it. It replaced a Pioneer SX-750 and utterly blew it away in terms of sound quality. The SX-750 had a really good tuner section, but the STA-2080 held it's own at tuning in distant FM. I have a STA-2100D now, but the 2080 had the edge.

[@danielknepper6884]

I've got a huge collection of realistic receivers and yeah , pioneer made better tuners

[@TheShackGuy]

@@danielknepper6884 higher end Pioneers used a 5 gang front end, while Realistics had 4 gangs.

[@TrevorsBench]

You can buy 2SA1494/2SC3858 complement as they are still in production. Cost is about $4 to $7 a piece

[@danhorton6182]

Hey Trevor, love your channel, I’m a subscriber, but this is wrong. Sanken stopped production of this package type many years ago and anything coming out of China is a counterfeit. There are several threads over on DIYAudio where people purchase these counterfeits and expose the dies. Some of them are decent, but most are garbage and none equal the performance of the originals. Places like CZH-Labs that state they have thousands don’t have original parts, only a couple of places have original MT-200 parts, one being B&D enterprise. Regardless, I’ve had to replace at least 3-4 dozen MT-200 devices and I always use either TO-3p or TO-264 depending on the situation. These newer smaller devices are superior most of the time anyways and I’ve never had a problem. I replaced 12 in a Kyrocera A-910 with TO-3P, the amp is bias pretty hot and it hasn’t skipped a beat in the year it’s been used. Edit: I wanted to add, these MT-200 devices out of China will work in most cases, but won’t be able to take the abuse of the originals and will not perform as well. A friend bought some (maybe a different device number) and they lasted in his amp for 1 day even though the specs matched up. I put some NJW1302/NJW3281 in there and they’re still going.

[@TrevorsBench]

@@danhorton6182 Inchange Semiconductor makes them. They are legit, quality is good and they are up for the task. I don't buy into the folklore that components out of China are fakes just like I don't believe everything I read on a forum. Lots of people (me included) have been burned buying garbage components on ebay or aliexpress and I expect this is why these opinions exist. Regardless, Tony's choice for replacement is a good one.

[@danhorton6182]

Hmm, may I ask where you get these Inchange Semiconductor devices? I have not heard of them specifically, but it would be neat to pick some up and have them tested against originals. I wouldn’t say the fact that fake devices coming out of China is folklore lol, everyone knows that they push out fakes, I’ve unfortunately run into many of them myself. Yes, they also put out good devices. I’m not saying all of it is bad. As to the forums, when you’re presented with photos and performance graphs it’s hard to deny that many if these devices are crap. As I mentioned some of them performed decently. Yes, Tony made a good choice. I would have likely used either NJW0302G/NJW0281G or MJL1302G/MJL3281G, but only because I have so many of them. I like the idea of the higher Ft, but likely wouldn’t matter in this circuit. I did a quick look, but any chance you could let me know what website Carrie’s the MT-200 Inchange devices?

[@scrappy7571]

Hi Trevor! Great to see you here, both you and Tony along with Jordan Pier, have taught me so much about theory, diagnoses and repair techniques for audio equipment. Could never get this from reading books or schooling. It's real life in the trenches. Thanks so much you guys!

[@TrevorsBench]

@@danhorton6182 LCSC sells them

[@philipslighting8240]

I love this. So well done. Top Man. Thanks. 👍

[@ericbachmann8037]

Yep…… I agree for a follow-up video. Power output test would be cool :)

[@martyh9309]

Hey Tony... Love this one! Was wondering if you looked at hFE to see if you could match the pairs as close as possible?

[@user-qj5cu2xj8t]

2nd for a follow up video. Curious if the power supply cap and transistor replacements increased the power output at all and are the tuner and phono sections on par with similar units of that era. My hunch is it is... but I don't have the test equipment to confirm it

[@DacMan777]

Another great job. Thank you. Mike.

[@PcLover81]

Tony, I'd love to see another video of this receiver with the new caps. I have an STA-2100D and it's rare to actually see anybody on youtube showing radioshack gear.

[@garysurovec]

I think I would have drilled and tapped a mounting hole in the correct spot for the new transistors. The pressure bar is "OK" but not exactly very elegant. Very rarely do outputs short for no reason or age. Most of the time there's an issue, bias, leaky drivers or caps etc... Nice fix though, I like your videos.

[@NICK-uy3nl]

You still have to adjust the VU meters, replace the display bulbs with cool LEDs and adjust the tuner

[@M-P-X]

Cool leds are not cool.

[@NICK-uy3nl]

LEDs really run cooler than bulbs

[@paulpaulzadeh6172]

Just wonder which transistor is better if you want minimum distortion, is it the one with high hfe or the one with lower hfe?

[@larrydaigle5254]

On my sta2100d, can I replace the vd1221 double diode with a nte177? The originals are obsolete! Thanks if you can help!

[@dannyfreitas2120]

your amazing.always watch your show,

[@paualdinicola]

Mine works, the watt lights are out and sometimes its choppy, can that maybe be solved by opening and cleaning? Tightening things? I love this peice and would love to save it to show my kids one day.

[@donaldscheer5206]

I Had This Amp! Bought It New! And At The Time, It Was A Real Power House!

[@MrDoneboy]

Tony. I thought Realistic had some good gear, back then.

[@johnloupis9344]

Has a Sansui G series look and that's not a bad thing.

[@NickNorton]

I still have my STA-2080 purchased new from Tandy (Radio Shack) back in the 80's. Hooked up to a pair of Realistic Mach One's - which the woofers are in much need of re-foaming.

[@TheTrueVoiceOfReason]

Or, as Mr. Krabs would say: " I'm smelling the smell of somerhing smelly."

[@dosman01302]

I have one of those beautiful receivers. It will play for 20 min or so then a relay switches off and no sound. They are beautiful though.

[@albshore8]

Have you ever heard of electrophonic t-6600c stereo system...It's the one we had when I was a child.

[@garygranato9164]

thank you for the vid tony

[@흑석김용호]

Someone has already repaired the amp. One side is sanken and the other side is (nec ?)

[@johncoops6897]

Yes, Captain Obvious. You realise that we all watched the video too?

[@vinylvinyl4180]

hello the realistic sta 2080 can it take 4ohms?

[@xraytonyb]

Yes, I belive it can.

[@vinylvinyl4180]

it's really not actually said that the realistic sta-2080 supports 4ohms. behind the amplifier says to refer to the instruction manual for 4ohms and apart from the repair service manual I did not find

[@xraytonyb]

The amp is very stable at 4 ohms. When you are talking about speakers, however, the impedance can be all over the place, regardless of their rated impedance. Crossovers and cabinet design can affect the impedance with respect to frequency. I've seen 8 ohm rated speakers have 2 ohms at some frequencies and 20 ohms at others, all because of the crossover and cabinet design. For example, when two drivers (such as the midrange and tweeter or woofer and midrange) "overlap" at a given frequency, the impedance changes. But back to your question, the 2080 is very stable at 4 ohms and possibly even lower.

[@mitkothemacedonian]

10mV across 0.94 ohms is 10mA of idle current. In my experience anything bellow 20mA is too little, especially at low volume.

[@xraytonyb]

The procedure has you read across only one of the resistors, so it was 10mV across 0.47 ohms for about 21mA. Sorry about the confusion.

[@mitkothemacedonian]

Sanken 2SC3858/2SA1494 would have been a perfect fit, and pushed only halfway of their rated power.

[@Parkhill57]

Obsolete. Tony made an excellent engineering choice.

[@vmhanlon]

What kind of adhesive was used to glue down the six copper patches?

[@johnnytacokleinschmidt515]

Meters out of their normal position. That may be why they seemed inaccurate.

[@MrDoneboy]

New Old Stock Vendors, Maybe ony?

[@MrDoneboy]

TONY! Lol

[@seanobrien7169]

sigh...Another 5 minutes writing a heartfelt, innocuous post reminiscing about my childhood experiences with this brand and Google/KZbin AI decided it was spam or porn or something...What did I even say? Who knows anymore....I am about through even trying to comment on this stupid platform...Love the creators, hate the platform with a passion that is growing deeper every day...

[@hellokitty4105]

I have this receiver and. 2100

[@amyabate4468]

Would love to see a video on how to adjust the L and R channel output meters!

[@ProdigalPorcupine]

You need a sig gen, a dummy load and a wattmeter (or scope) to do it properly, but if you don't have easy access to these, I'd set them up so they just look right and are closely balanced! 😁

[@sa8die]

keep up the great content,. im looking in being a rad tech,. ppl are aging,. and ppl are driving increasingly crazy,. yes many xrays,.lol

[@tubeDude48]

I'd stay away from flea-Bay or AliExpress

[@randyr.parker2698]

Follow up please 😁

[@mohammedajman3066]

Beutyfull resever look nice face

[@sa8die]

Yes First

[@WApnj]

I can't believe you said "needs cleaned up"... English is... 'needs TO BE cleaned up..

[@johnnytacokleinschmidt515]

This is everywhere.... "Needs replaced." I don't get it.... Needs to be replaced.....

[@WApnj]

@@johnnytacokleinschmidt515 I'm shocked at how many people say these things...

[@BrainHurricanes]

@@WApnj Or "I axed you a question"

[@WApnj]

@@BrainHurricanes Or . "I really like these ones..." 😵😬😵

[@michaelpaticchio2426]

Hi Tony If I remember correctly weren't the transistors in this receiver MOSFET transistors??

[@xraytonyb]

That was the STA-2200. Did a video on one of those as well. 😉

[@jdmccorful]

Good deal! Thanks for the ride along and education Prof. Tony.