Realistic STA 111 Restore and Test

Repairing and testing a Realistic STA111 Receiver from the 1980's. I didn't have a service manual on this one, so I couldn't do a full alignment check on the tuner section. The tuner seemed to be working fine, luckily.

[@JFM1170]

I was in able to get a schematic for the receiver but I recap the Power Supply and it works fine now

[@rcfred_689]

Hi - I have one of these receivers. Do you offer repair services?

[@hivimusic7815]

Just bought one here in Germany and it seems to be ok. The sound is really impressive for this size. One thing I want to fix is the transistor you have replaced. As you mentioned, it's getting very hot. Could you please name the exact sparepart description aka name (origin is 2DS325). THANK YOU and nice video btw

[@elecchal444]

Would really like to know this too. Thanks.

[@elecchal444]

I changed mine for a TIP31A but it behaves exactly the same - gets really hot even when the amp volume is low. I suspect the problem lies elsewhere.

[@elecchal444]

I suspect ground leakage from the sink of the transistor is making it hot. It should not be grounded but mine had no insulator.

[@snake55555]

i have this model and i seem to be having an issue with gradual distortion every time i turn it on. sounds ok at first but gradually it gets worse until it the crackling becomes unbearable...any ideas?

[@jordan390a]

Leaky capacitor....after some time in use, it starts to pass DC.....

[@jordan390a]

Is the schematic inside that manual...? I have one which has an FM issue as well as a distortion issue on AM/FM....

[@tonyquinn3941]

Hi , I'm having the same issue did you get a response. I cannot. Seem to source a schematic anywhere!

[@JFM1170]

Hi can you tell me where I can a schematic for the STA-111? I have a power supply problem with my unit, the relay takes a long time to engage.

[@peterfranks-ue]

The schematic appears lost in time. My relay has stopped engaging, have you had any luck fixing yours?

[@JFM1170]

Clem I did have luck ,what I did was I recapped the power supply it cost about $13 and a half hour of my time. It fired up and has been working great. All the caps I got from Mouser. Bad caps will cause the relay not to engage.

[@SilverShips]

My STA-11, which seems to be a similar unit with a different tuner, has a bad diode in the relay board marked D711 and reads as a .37 ohm resistor. Unfortunately the diode does not have markings so without a manual I myself and not able to replace it. It appears to be a zener. Maybe this will help someone identify the trouble on their relay board.

[@jeanmarcgravel9699]

I have the same problem, now the tuner never turn ON, I changed the two capacitor that were leaking as Xraytonyb did but still have the same problem,. Any help to go further?

[@JFM1170]

@@jeanmarcgravel9699 Try changing all the Caps first parts are cheap. Worked for me.

[@williamstaten8102]

Cool video! I have two realistic sta-2600. Like having the midrange knob. I would rather have individual out put transistors. There easier to find new. The all in ones are hard to find and often used is all there is available. Seen a lot of the all in ones in newer Panasonic and technecs receivers.

[@josephlalock8378]

stk zero series also had the 0039 and 0059 (maybe others) which were quasi complimentary darlingtons(not that i know a whole lot about the terminology but i know a little) i've got a pair of 0039 in my mcs 3835 i'm restoring. i like the sound.

[@flightmaster178]

I just replaced an STK-463. Seems to sound great. I read though it's like 20 watts per channel.

[@rogerchurch3804]

stks dual darlington power packs capable of great powerful sound.

[@erikgallimore5131]

How do you feel about upping the capacitance of the main filter caps say by 20ish percent?

[@mdzacharias]

It's the infamous "brown glue gone bad" that corroded the diode and resistor. Seen it many times. You see it first at he peripheral edges of the glue. Can be resistive and / or corrosive. It's not always cap leakage.

[@aklef]

Yep. This time it was just glue tony.

[@jordan390a]

I just received the service manual for mine...which is the original version...I got the manual from an online source and he creates great copies. I hope to dig into mine very soon. The biggest difference I can see between the 2 versions is in the AM/FM PLL cktry.....

[@tonyquinn3941]

hello, did you manage to get a circuit diagram for the sta - 111? I am desperate for a copy, will pay!

[@gweagraff]

I just recently got one of these and it seems to be working very well, except the volume control has a bit of scratchiness. I tried cleaning it with deoxit, and it will clear it up for awhile but it won't stay that way. Maybe I'm just not cleaning it in the right spot. Did you have to do anything to the volume control? All other knobs are fine.

[@xraytonyb]

My volume control was OK, fortunately. You may need to do a more thorough cleaning of the pot, or you may have dirty contacts on a selector switch.

[@gweagraff]

@@xraytonyb I just cleaned it up again and it seems to work (for now, anyway). But I also noticed the scratchiness is only in the left channel, even if the balance is set all the way over to the right. How would I do a more thorough cleaning?