Yes, a Sansui QRX-6500 Bluetooth connection needs no soldering. Best path: a Bluetooth receiver with RCA output into one of the two AUX inputs (150 mV / 50 kOhm; the set documents both 2-channel and 4-channel AUX positions). If AUX is taken, use a Tape loop. Rated 4 × 33 W RMS into 8 ohms, it is the archive's first four-channel amplifier documented here, driving front and rear speaker pairs natively.
Figures on this page were checked September 2026. Every table row carries its source.
What the QRX-6500 brings
| Item | Value | Notes | Source |
|---|---|---|---|
| Production run | 1972–1974 | Approx. 3,650 DM; 470 W max consumption; early Sansui quadraphonic contribution | HW, CR |
| Power output | 4 × 33 W @ 8 Ω | RMS, 20-20,000 Hz, 0.5% THD; 4×37 W at 1 kHz; 4×60 W into 4 ohms; dynamic 190/280 W | HW, CR |
| Phono inputs | 2 × 2.5 mV / 50 kΩ | Maximum input 330 mV; microphone input also documented | HW |
| Line inputs | 2 × AUX · 4-ch · Tape | 2-ch AUX and 4-ch AUX at 150 mV / 50 kOhm; Tape Play 1/2 in 2-ch and 4-ch modes on both Cinch and DIN; Discrete 4-ch input | HW |
| Speakers | 3 front + 2 rear | Front and rear headphone jacks; Pre Out 1 V; Dolby NR adapter | HW |
| Weight | 22 kg | 536 × 181 × 363 mm | HW |
Source codes: HW hifi-wiki.com · CR classicreceivers.com. Data as of September 2026.
Choosing an input on the QRX-6500
AUX input (2-channel)
RecommendedTwo AUX positions share the 150 mV / 50 kOhm spec, one built for 2-channel and one for 4-channel source material. Stereo Bluetooth belongs on the 2-channel position, where a line-level Bluetooth receiver with RCA output connects directly.
Tape monitor loops
Good alternativeFour tape play connections run across 2-channel and 4-channel modes on Cinch and DIN, with record outputs at 100 mV and 30 mV DIN. Hitch Bluetooth onto a loop's play jacks, choose that tape position on the monitor, and bring the monitor back to off for the other sources.
Phono or microphone input
Not for line-levelThe two phono stages take a cartridge's 2.5 mV and clip at 330 mV, and the microphone input wants a mic-level signal. Bluetooth fed into any of them at line level would overload it, and the turntables would lose their inputs.
QRX-6500 setup in three moves
- Use the 2-channel AUX
The tape loops stay free for recorders; stereo Bluetooth lives on the 2-channel AUX.
- Connect and supply
Bluetooth receiver RCA out to the 2-channel AUX, USB power attached, and your phone pairs with it once.
- Level check last
Volume down, AUX selected, then upward. Fixed/line output on the adapter, if present, is the setting to select.
Notes for QRX-6500 owners
- The archive's first four-channel amplifier (verified): the QRX-6500 is the first receiver on this site whose amplifier sections are specified in quadraphonic mode, with 4×33 W RMS into 8 ohms and discrete 4-channel input routing documented in the specification sheet.
- Front and rear, separately powered (verified): the three front and two rear speaker pairs are independently driven from the same four amplifier sections, a layout that distinguishes the QRX-6500 from every stereo-only receiver documented here.
- The 4-channel AUX is not a second stereo AUX (verified): the 4-channel input expects quadraphonic source material across four jacks; a stereo Bluetooth receiver belongs on the 2-channel AUX position alongside the tape loops.
The short list for the QRX-6500
- Bluetooth receiver with RCA output, LDAC or aptX HD the pick of the list
- 0.5–1 m RCA cable, one run
- USB power so the receiver stays on
FAQ
Plug a Bluetooth receiver with RCA output into either of the two AUX inputs and select AUX. If both AUX positions are occupied, use a Tape input through the tape monitor. No internal modification is needed.
Per hifi-wiki: Phono 1 and 2 at 2.5 mV / 50 kOhm (max 330 mV); two AUX inputs at 150 mV / 50 kOhm; four Tape Play connections (2-channel Cinch, 2-channel DIN, 4-channel Cinch, 4-channel DIN, all 150 mV / 50 kOhm); a Discrete 4-channel input at 150 mV / 50 kOhm; and a microphone input.
Continuous output is rated 4 × 33 W RMS into 8 ohms across 20 Hz to 20 kHz at 0.5% distortion (4 × 37 W at 1 kHz), rising to 4 × 60 W into 4 ohms, with dynamic power of 190 W (8 Ω) and 280 W (4 Ω) below 0.05% distortion.
Three front and two rear speaker pairs, per the documentation, giving the QRX-6500 the most speaker capacity documented in this archive.
blafili B3 Bluetooth Music Receiver
RCA + XLR + optical out, LDAC and aptX HD, OLED status display. Matches the QRX-6500 line-level inputs without adapters.
- Full connection and amplifier specifications (Phono 1/2 2.5 mV / 50 kOhm, max 330 mV; Aux 2-ch 150 mV / 50 kOhm; Aux 4-ch 150 mV / 50 kOhm; Tape Play 1/2 2-ch + DIN + 4-ch 150 mV / 50 kOhm; Discrete 4-ch 150 mV / 50 kOhm; Mic 6.3 mm jack; Tape Rec 100 mV, DIN 30 mV; Dolby NR Adapter; Pre Out 1 V; 3 front + 2 rear speaker pairs; 4×33 W RMS at 8 ohms 20-20,000 Hz 0.5%, 4×37 W at 1 kHz; 4×60 W at 4 ohms; dynamic 190/280 W; THD below 0.05%; weight 22 kg; years 1972-1974; approx. 3,650 DM; 470 W max): hifi-wiki.com/index.php/Sansui_QRX-6500, accessed 2026-09-25
- Manufactured 1973 to about 1975; 33 W/ch into 8 ohms when all four channels are driven and 37 W/ch individually; Dolby NR; three AC outlets on the back panel: classicreceivers.com/sansui-qrx-6500, accessed 2026-09-25