Pioneer SX-3900 Restoration Service retransistor recap LED SSR calibration

Description: PLEASE NOTE: This auction is for a RESTORATION SERVICE OF YOUR RECEIVER - The RECEIVER IS NOT INCLUDED. You can purchase this service, send your receiver to me, and I will restore it according to the following description. I have restored dozens of these receivers, and the quality of parts and workmanship you will get will be unmatched. I source my parts from Mouser so no chance of counterfeit parts. If you receiver is broken, it can be repaired (at an additional cost) and upgraded simultaneously. The image with the new components shows a sampling of what will be replaced - the exact count is described below.While maintaining the designers' original philosophy, your SX-3900 will be upgraded and modified to take care of a few design flaws that crept in with this model and to deal with the fact that this is a 40 year-old piece of electronics.In the rebuild, exactly 120 capacitors will be changed (48 of them will be WIMA MK2 film), 11 transistors (including 2 current regulator diodes), 5 Zener diodes, 8 transistor sockets to thermoplastic connectors, 12 bulbs to LEDs, and a high current SSR will be added. All audio path capacitors will be metal film or audio grade capacitors. Nearly all will be upgraded to 105 degree 10,000 hour (originally from 85 degree 1,000 hour). All capacitors, transistors, current regulators, and Zeners will be obtained from Mouser Electronics - No counterfeit junk. The power amplifier will also have 4 mini-heatsinks added and the trimmers will be replaced for added thermal reliabilitiy and longevity.Specifically:1) The receiver will have each and every electrolytic capacitor changed to a high-end modern component. All the capacitors used will be WIMA MK2 (low value film), Nichicon ULD, Nichicon Gold UFG or Nichicon UKL for audio path capacitors, Panasonic EEU, Rubycon YXM, or United Chemicon EKM (filter caps) and ELE, or similar. Nearly all will be105 degree 10,000 hour (except for the audio electrolytics and main filter caps).2) The two filter caps will be upgraded from 15,000 microfarad to 22,000 microfarad for increased power supply stability. 3) All 12 lamps will be exchanged for LEDs, so no more incandescent lamps to burn out. If necessary, the 3 lamp sockets will be upgraded to rubberized housings, as the original sockets tend to crack and break due to age.4) The 2SK34 FETs (that are a known weak point) will be exchanged for Current Regulator Diodes that handle much higher voltages, significantly lowering the risk of power supply failure.5) The power supply will have all transistors and Zener diodes replaced with modern cooler-running devices. New thermal interface media will be applied. Additionally a Pioneer modification will be implemented by switching out a certain resistor for a Zener diode (as applicable in older revision SX-3900s). 6) The output transistor connectors, which are known to crack and short out the unit, will be replaced with thermoplastic connectors.7) A slave Solid State Relay will be coupled to the power switch, so no risk of sparking the contacts and burning out the unavailable power switch, especially with the filter capacitor upgraded.8) Wires will be rerouted to allow for improved thermal circulation. Additionally, all transistors and diodes on the power supply and the driver transistors on the power amplifier will be reflowed to prevent cold-solder joints.9) All switches and potentiometers will be lubricated. Big switches will be disassembled and physically cleaned.10) The power amplifier will be re-calibrated, as will the Flouroscan meters. Trimmer pots will be replaced, and 4 mini heatsinks will be added. 11) Tracking will be adjusted on the FM tuner section and it will be peaked.12) All inputs, outputs, functions, switches, knobs, potentiometers, displays, and lights will be tested.This is the TOTL (top of the line) Pioneer silver-faced Flouroscan monster receiver, the SX-3900 which was Pioneer’s top of the line Fluoroscan receiver and the last of the silver faced receivers. 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.

Price: 750 USD

Location: Lubbock, Texas

End Time: 2024-08-15T23:47:29.000Z

Shipping Cost: 125 USD