Great job! When in High School, I had one of these around 1980 that I bought for $100 at a pawn shop. Feeling nostalgic, may pick one up if I can find one for a good price.
It’s a decently performing unit. Not the most powerful but will drive speakers to fill a smaller space with more sound than you will probably need. Finding one in good shape shouldn’t be hard and won’t break the bank. Thanks for the comment!
Even if the bias is way off it shouldn’t burn the output transistors’ emitter resistors. More likely the receiver was well used with poor ventilation and they burned gradually. Definitely replace the resistors, upsize wattage if they’ll fit and keep them far away from printed circuit board.
That’s interesting. Here’s the link to the service manual if you don’t already have it: elektrotanya.com/realistic_sta-78_sm.pdf/download.html#dl. There are 6 diodes that I see (per channel) of the amplifier board, plus a pair of diodes (per channel) used for temperature compensation. I’d be curious which one(s) failed! If the Zener diode(s) D601 and/or D602 failed, that would point to a fault in the power supply, probably failing filter caps. There are some diodes to prevent signal overload, and a couple that appear to be in the overload/shutdown circuit. If I were you, I’d replace the diodes and then grab a voltmeter and just verify the voltages are ±10% with those in the service manual. Adjust the bias balance according to the service manual. I was able to get mine to almost zero.
I have the chance to pick one up for $100 locally, so no shipping charge. The seller says that all the controls need to be treated with deoxit, but otherwise it is in good shape. The only exception is the case which needs just a little work, which I can do. Do you think it's a worthwhile buy for the price? Thank you in advance for your advice. I really appreciated your video
Thank you for your kind words. You haven’t said where you are located. In Canada, generally speaking these receivers tend to command higher prices than the prices I’ve seen for similar units in the United States. I’m sure the prices there also vary by location, and local supply and demand. If I recall, I paid about $100 for mine. As you saw it didn’t need much work or materials, but be aware that you’re buying a piece of 45 year-old equipment which may develop problems or require recapping, new bulbs, etc. I would tell you that if you’re in the Greater Toronto Area, $100 seems fair. Yes, you might be able to find a comparable receiver at a garage sale for less but that would be pure luck. I just checked on Facebook marketplace and at this moment, there are two of these units for sale within 60km and the (asking) prices are $400 and $500 which I think is outrageous. The STA-78 a good-sounding decently powered receiver, and it is from the golden era of analog receivers. I would seriously consider it for $100 if you’re permitted to thoroughly test it first.
I have one, did the same things you did a couple years ago to mine. What do you think of replacing the power capacitors? Usually im of the mindset if its not broken, don't fix it .
I'm in complete agreement with you. If you're getting no hum with zero signal then the filter capacitors are doing their job. And if they're fine, why replace them? I had another receiver (I think it was a Realistic STA-225) which had a bad electrolytic cap in the signal path. I had isolated the bad cap but went ahead and recapped the whole pre-amp board because I was already there. But I was getting no hum so I left the power supply capacitors alone. Replacing the filter caps would have accomplished… nothing. So I think you made a good call.
Good question! The festoon LEDs I have are DC only, the same with the LED strip I have. I would have had to inert a diode (or bridge) in the circuit, and possibly a capacitor to control flickering. I probably would have had to add a dropping resistor because the rectified DC would be around 16 volts, too much for my 12v LEDs and I would have had to get the resistor just right so that the LEDs looked just like the lamps they were replacing. The dial lamps in that receiver run off AC but the tuning meter LED comes off the DC supply that also runs the Stereo FM LED but it has its own dropping resistor which would have to be changed. So, yes I considered it but decided I’d wait until another day. I also wanted to keep the video to 10 to 12 minutes which i find is the sweet spot for most viewers (on my channel, at least). Besides, I really wanted to use the receiver! 😊
Beautiful, mid 70s Realistic receivers come up for sale on Facebook marketplace all the time. That’s where this one came from. Often sellers don’t know what they’ve got so they don’t ask much for them.
Acting on behalf of your brother, I must inform you that you did not secure the proper permissions to use or promote his underwear. A cease and desist is in the works. His sweat bands can be used under the provisions of the UN’s Bjorn Borg agreement (1978).
Mr. Brown’s Basement has ceased and desisted the use and promotion of said undergarments at least for the time being. They will be returned forthwith. Damages and costs were assessed in my brother’s favour in the amount of 20 kg. of freshly picked, unpeeled black walnuts. They will be delivered by courier.
@123QuoFan Please check the fine print on the cease and desist order. Walnuts are acceptable compensation under the Rob Petrie / Danny Thomas exclusion of 1963. Please refer to this url for details: m.ruclips.net/video/BGXtYLps7DA/видео.html Glad to hear Ms. West recovered from her aquaphobia attack. She had also always suffered very badly from hyperhidrosis. It’s possible that the incident that occurred wasn’t my water bottle at all… I wonder if she’ll Like & Subscribe?
I've checked with Justice Willie Gingrich and you have overlooked the superseding H.R. Pufnstuf decision. Please seek out better legal representation. I believe a former U.S. city mayor has some time on his hands.@@Mr.BrownsBasement
I'm sorry, the walnuts have already been sent. If it makes things any better, they were individually inspected by Mr. "Rocket" J. Squirrel for quality assurance. With a little imagination (and a little seasoning) they look and taste just like candied pecans. I understand the former U.S. city mayor has had his hands full after being interviewed in the most recent Borat documentary. His Certificate of Standing to practice law was in force at the time but it's since been withdrawn.
Great job! When in High School, I had one of these around 1980 that I bought for $100 at a pawn shop. Feeling nostalgic, may pick one up if I can find one for a good price.
It’s a decently performing unit. Not the most powerful but will drive speakers to fill a smaller space with more sound than you will probably need. Finding one in good shape shouldn’t be hard and won’t break the bank. Thanks for the comment!
Thank you so much. I’ve got the same unit here. A couple resistors burned up. Could this be the result of misaligned amplifiers?
Even if the bias is way off it shouldn’t burn the output transistors’ emitter resistors. More likely the receiver was well used with poor ventilation and they burned gradually. Definitely replace the resistors, upsize wattage if they’ll fit and keep them far away from printed circuit board.
@ thank you very much
@ upon further inspection, it was a diode that burned. It also burned the nearby resistors, but the diode was the source of the heat.
My pleasure.
That’s interesting. Here’s the link to the service manual if you don’t already have it: elektrotanya.com/realistic_sta-78_sm.pdf/download.html#dl.
There are 6 diodes that I see (per channel) of the amplifier board, plus a pair of diodes (per channel) used for temperature compensation. I’d be curious which one(s) failed! If the Zener diode(s) D601 and/or D602 failed, that would point to a fault in the power supply, probably failing filter caps. There are some diodes to prevent signal overload, and a couple that appear to be in the overload/shutdown circuit. If I were you, I’d replace the diodes and then grab a voltmeter and just verify the voltages are ±10% with those in the service manual. Adjust the bias balance according to the service manual. I was able to get mine to almost zero.
I have the chance to pick one up for $100 locally, so no shipping charge. The seller says that all the controls need to be treated with deoxit, but otherwise it is in good shape. The only exception is the case which needs just a little work, which I can do. Do you think it's a worthwhile buy for the price? Thank you in advance for your advice. I really appreciated your video
Thank you for your kind words. You haven’t said where you are located. In Canada, generally speaking these receivers tend to command higher prices than the prices I’ve seen for similar units in the United States. I’m sure the prices there also vary by location, and local supply and demand. If I recall, I paid about $100 for mine. As you saw it didn’t need much work or materials, but be aware that you’re buying a piece of 45 year-old equipment which may develop problems or require recapping, new bulbs, etc. I would tell you that if you’re in the Greater Toronto Area, $100 seems fair. Yes, you might be able to find a comparable receiver at a garage sale for less but that would be pure luck. I just checked on Facebook marketplace and at this moment, there are two of these units for sale within 60km and the (asking) prices are $400 and $500 which I think is outrageous. The STA-78 a good-sounding decently powered receiver, and it is from the golden era of analog receivers. I would seriously consider it for $100 if you’re permitted to thoroughly test it first.
I have one, did the same things you did a couple years ago to mine. What do you think of replacing the power capacitors? Usually im of the mindset if its not broken, don't fix it .
I'm in complete agreement with you. If you're getting no hum with zero signal then the filter capacitors are doing their job. And if they're fine, why replace them? I had another receiver (I think it was a Realistic STA-225) which had a bad electrolytic cap in the signal path. I had isolated the bad cap but went ahead and recapped the whole pre-amp board because I was already there. But I was getting no hum so I left the power supply capacitors alone. Replacing the filter caps would have accomplished… nothing. So I think you made a good call.
Just curious why would you take the lamps out and clean them, why not just replace them with LED's?
Good question! The festoon LEDs I have are DC only, the same with the LED strip I have. I would have had to inert a diode (or bridge) in the circuit, and possibly a capacitor to control flickering. I probably would have had to add a dropping resistor because the rectified DC would be around 16 volts, too much for my 12v LEDs and I would have had to get the resistor just right so that the LEDs looked just like the lamps they were replacing. The dial lamps in that receiver run off AC but the tuning meter LED comes off the DC supply that also runs the Stereo FM LED but it has its own dropping resistor which would have to be changed. So, yes I considered it but decided I’d wait until another day. I also wanted to keep the video to 10 to 12 minutes which i find is the sweet spot for most viewers (on my channel, at least). Besides, I really wanted to use the receiver! 😊
Are you selling?
Beautiful, mid 70s Realistic receivers come up for sale on Facebook marketplace all the time. That’s where this one came from. Often sellers don’t know what they’ve got so they don’t ask much for them.
Acting on behalf of your brother, I must inform you that you did not secure the proper permissions to use or promote his underwear. A cease and desist is in the works. His sweat bands can be used under the provisions of the UN’s Bjorn Borg agreement (1978).
Mr. Brown’s Basement has ceased and desisted the use and promotion of said undergarments at least for the time being. They will be returned forthwith. Damages and costs were assessed in my brother’s favour in the amount of 20 kg. of freshly picked, unpeeled black walnuts. They will be delivered by courier.
Nice try -- it was 20 kg of candied pecans! FYI, Ms. West is doing alright, currently vacationing in Narnia of all places.@@Mr.BrownsBasement
@123QuoFan Please check the fine print on the cease and desist order. Walnuts are acceptable compensation under the Rob Petrie / Danny Thomas exclusion of 1963. Please refer to this url for details: m.ruclips.net/video/BGXtYLps7DA/видео.html
Glad to hear Ms. West recovered from her aquaphobia attack. She had also always suffered very badly from hyperhidrosis. It’s possible that the incident that occurred wasn’t my water bottle at all… I wonder if she’ll Like & Subscribe?
I've checked with Justice Willie Gingrich and you have overlooked the superseding H.R. Pufnstuf decision. Please seek out better legal representation. I believe a former U.S. city mayor has some time on his hands.@@Mr.BrownsBasement
I'm sorry, the walnuts have already been sent. If it makes things any better, they were individually inspected by Mr. "Rocket" J. Squirrel for quality assurance. With a little imagination (and a little seasoning) they look and taste just like candied pecans.
I understand the former U.S. city mayor has had his hands full after being interviewed in the most recent Borat documentary. His Certificate of Standing to practice law was in force at the time but it's since been withdrawn.