A Pioneer SX-780 Bluetooth connection is a five-minute job. AUX is the natural input (150 mV line level); either of the two tape loops works as an alternative. The SX-780 has no pre out/main in, so an external adapter with RCA output is the whole story. LDAC or aptX HD keeps the source honest.
SX-780 at a glance
| Item | Value | Notes | Source |
|---|---|---|---|
| Market period | ≈ 1978–1980 | Silver-era, made in Japan | CR, HW |
| Power output | 45 W/ch @ 8 Ω | RMS, 20 Hz–20 kHz, 0.05% THD | HW, AK |
| Phono input | 2.5 mV / 50 kΩ | MM cartridge | HW |
| Line inputs | AUX · Tape 1 · Tape 2 | 150 mV / 50 kΩ, RCA | HW, AK |
| Speakers | A + B | Two pairs, switchable | CR |
| Weight | ≈ 11.2 kg | 24.7 lbs | HW |
Source codes: CR classicreceivers.com · HW hifi-wiki.com · AK original SX-780 owner's manual (AK Database) · HFR highfidelityreview.com. Data as of September 2026.
Hookup points on the SX-780
AUX input
RecommendedLine level at 150 mV with a solid 50 kΩ load, made for external sources. The Bluetooth receiver plays as soon as you turn the input selector to AUX.
Tape 1 or Tape 2 loop
Good alternativeTwo full monitor loops, handy if you also run a deck. Select the matching Tape button to listen, and remember to switch it off for the other sources.
Phono input
Not for line-levelThe MM phono stage carries roughly 35 dB of gain. A Bluetooth receiver already outputs line level, so phono will overload and distort.
SX-780 setup in three moves
- Choose AUX
The cleanest path on this receiver since it has no pre out to consider.
- Wire the receiver
RCA out from the Bluetooth unit into AUX, USB power attached, pair once.
- Set levels
Volume low, select AUX, then bring it up. Fixed/line output on the adapter if available.
SX-780 quirks worth knowing
- No pre out/main in (verified): unlike bigger Silver-era Pioneers, this loop does not exist, so AUX or Tape are the only sensible entries.
- Loudness button (verified): leaves the circuit engaged at low listening volume; switch it off for a neutral Bluetooth source.
- FM tuner condition varies with age (unverified): alignment drift is reported on some examples; irrelevant for Bluetooth use. Unverified
Kit for adding Bluetooth to the SX-780
- Bluetooth receiver with RCA output, LDAC or aptX HD preferred
- 0.5–1 m RCA cable
- USB power for the receiver
FAQ
Yes. The SX-780 has a dedicated AUX input rated at 150 mV, plus two tape monitor loops. A Bluetooth receiver with RCA output plugs straight in without any modification.
45 watts per channel RMS into 8 ohms across 20 Hz to 20 kHz at 0.05 percent THD. Enough headroom for most bookshelf and midsize floor-standing speakers in a home room.
Pick a receiver with RCA output and LDAC or aptX HD support so the wireless link does not become the weak link. Power it over USB and leave it permanently connected.
blafili R1 Bluetooth Receiver
Clean RCA output, plug-and-play on the AUX input, no app required. The straightforward partner for a straightforward receiver.
Spotted something off, or own this receiver and want to share a photo? Write to yourfriends@blafili.com. Photos are published under CC BY-SA 4.0 with full credit to you; corrections are verified and applied with thanks.
Share a photo or correction- Specifications and input configuration: hifi-wiki.com Pioneer SX-780 page
- Model overview and market period: classicreceivers.com Pioneer SX-780 retrospective
- Input sensitivity and power detail: original SX-780 owner's manual (AK Database) and highfidelityreview.com