This is the Pioneer SX-3900 which was Pioneer’s top of the line Fluoroscan receiver. It’s the big brother to the SX-3800 and was introduced in 1980 at a retail price of about $800.00. It represents Pioneer’s transition from analog receivers to the more contemporary digital receivers. In fact, the SX3900 basically has both analog and digital features. As you can see it has an old school analog tuning dial, the mechanism is mechanical, as well as a five digit digital tuning display. The displays use fluorescent bulbs hence the nick name fluoroscan.
The blue fluorescent display is beautiful and one of the more iconic displays in vintage audio. Still, the FM Quartz Locked SX-3900 was not all looks. It pumps out 120 watts per channel with less than 0.005% total harmonic distortion and is built with quality engineering. It also incorporates a non-switching amplifier.
You can see from the pictures that the SX-3900 has illuminated push buttons for certain functions as well. Some other features are:
- 2 high pass filters
- Tone turn-over controls for bass and treble
- Adapter loop switch
- FM de-emphasis
- Tape duplicate
- 2 phono inputs
Measuring in at 20.7 x 6.9 x 17.8 inches the SX-3900 is pretty big and weighs roughly 46 pounds. It is similar inside to the Pioneer SX-D7000 which, oddly, was on the market at the same time. The SX-D7000 moved even more toward the digital side and had all push button and slider controls and no analog dial.
It’s a little hard to see in the picture but the SX-3900 has a large toroidal transformer that is tucked in on the left side and sits sideways like a tire as opposed to flat like most transformers. I suppose they had to economize on space given the number of features the unit has. You can also see the large heat sink in the middle. These units generate a lot of heat so it’s not a good idea to stack anything on top of them.
The Pioneer SX-3900 represents the end of the analog era and the beginning of the digital era. And, being from one of the pre eminent audio companies of the time in Pioneer, they are popular. However, I would say that, given the features, performance, and iconic nature of this receiver, they tend to be under valued.