This is the Realistic STA-2100 offered by Radio Shack in 1979. It’s a very nice and clean looking unit that was made by Foster Electronics. The build quality is excellent. The STA-2100 utilized a toroidal transformer and pumps out 120 watts per channel RMS. A later version, the STA-2100D was manufactured without the toroidal transformer due to cost cutting measures.
The receiver also has a pretty good 4 gang tuner FM tuner. Overall the receiver is probably under rated by most collectors so you can still pick them up at a fairly reasonable cost and the quality and looks are just as good as some of the more sought after receivers.
One change that Radio Shack made from the STA-2000 to the STA-2100 was that they moved the power button from the left of the volume knob where it sat mixed in with all the other buttons to the right side just above the headphone jack where it was more easily visible.
The Realistic receivers are very well built and well laid out electronically. Here you can see the big toroidal transformer as well as the large capacitors. There is a pervasive rumor that Realistic quit using the toroidal transformer due to a patent lawsuit with Pioneer. However, a commenter that worked at Tandy during that time has stated that there was no lawsuit. The change from toroidal to standard transformer was made because of cost and other considerations and not legal considerations. One of those considerations was to keep the the price competitive after upgrading to Dolby licensing for the 1980 STA-2100D & STA-2200 releases. Here is his comment:
“There was no ‘patent dispute’ and the STA-2100 was built in one of their own Tandy plants. Marantz, Sansui, and many others were using Toroidal transformers in their units at the time. Pioneer does not own this design as these transformers were made by Bando Electronics Co., Ltd. 875-2, Shibukawa, Gunma, Japan, and were outsourced to the production plants during assembly of these units. Bando Electronics Co., Ltd still makes them to this day! The Transformers were replaced in 1980 with the standard transformer due to cost cutting and phasing and revisions. I worked for Tandy in the QC labs in TX from 1976 to 1983 and I can assure you there was NO lawsuit from Pioneer or any others on this, or any other Realistic receiver… This was a business and competitive practice not a forced judicial reduction.”
The Realistic STA-2100 retailed for $599.95 and was Radio Shack’s top of the line receiver in 1979. Other features included:
- Linear Phase IF filters
- Dual-Gate Mosfet FM
- PLL Multiplex
- Wide dynamic range phono preamp with selectable sensitivity
- 10 dB attenuator
- 3 tone controls
- 25 or 75 microsecond De-emphasis for Dolby FM
- Muting
The Realistic STA-2100 sells for around $100-$1200. One fully serviced and in excellent condition sold for $1200 on 10-19-2025. Another in very nice fully functioning sold for $1100 on 9-25-2025.
The Best Quality 120wpc receiver ever built .
Agree! I blind tested a/b a realistic 2100 and a pioneer sx1050. The realistic went home with me.
“Just picked up” an STA-2100D….. it literally is in my car (bought it at lunch today)! I can’t wait to get home and hook it up. I have been a Pioneer/Technics owner, but this pristine unit came up on FB and I snagged it for a song. With me luck! :)
I have owned both of the two receiver’s. STA 2100 / STA 2100D
There’s a big difference between the two, because of the transformer and the way it is built. The 2100 is actually more powerful with less harmonic distortion.
The warmth of the unit and the clarity is outstanding and the bass has a good depth at 16 hz.
I own the STA 2100 Now, As well as a Pioneer SX 1250
The 2100 and the 2100D (initial version) tests and sounds the same as the 2100. The initial 2100D used a very large conventional transformer and made about 145 watts per channel when tested and matched the distortion levels of the 2100. The initial 2100D also had the same physical layout and configuration as the 2100. Radio Shack did make substantial revisions to the 2100D annually following its initial release.
The original had a toroidal transformer but with a dispute with Pioneer the later ones had an ordinary tx
Hello, I have a STA-2100D , got a simple question: do the lights come on the receiver as soon as it is plugged in? If I have the receiver in FM mode, the lights on the front all come on as soon as it is plugged in. No power to the amp until the power button is pressed though. If it is in phono or tape mode the only light is on the receiver channel dial. Thanks for any reply.
There was “NO patent dispute” and the STA-2100 was built in one of their own Tandy plants. Marantz, Sansui, and Many others were using Toroidal transformers in their units at the time and Pioneer does not own this design these were transformers made by Bando Electronics Co., Ltd. 875-2, Shibukawa, Shibukawa, Gunma, Japan and were outsourced to the production plants during assembly of these units and Bando Electronics Co., Ltd still makes them to this day !. The Transformers were replaced in 1980 with the standard transformer due to cost cutting and phasing and revisions. I worked for Tandy in the QC labs in TX from 1976 to 1983 and I can assure you there was NO lawsuits from Pioneer or any others on this, or any other Realistic receiver. How this ridiculous rumor got started is beyond comprehension of common sense. The Lab-400 Turntables, the Mach Ones and many other Realistic products went through cost cutting design changes. This was business and competitive practices not forced judicial reduction. Hope this helps.
Thanks for the info! I have updated the post to reflect your input.
Finally someone else willing to share the truth! Everything stated above is 100% accurate.