Yes, an Onkyo TX-8500 Bluetooth connection needs no soldering. Best path: a Bluetooth receiver with RCA output into an open high-level input (150 mV / 50 kOhm; the set documents three tape inputs including one Dolby loop). If those are taken, the third tape remains. Rated 110 W/ch into 8 ohms, it opens the Onkyo shelf in this archive.
Figures on this page were checked September 2026. Every table row carries its source; the MKII wattage spread is disclosed rather than settled.
TX-8500 facts and figures
| Item | Value | Notes | Source |
|---|---|---|---|
| Production run | 1976–1978 | Approx. 3,500 DM in German lists; mkI and mkII builds documented | HW |
| Power output | 110 W/ch @ 8 Ω | Continuous at 0.1% THD; 150 W into 4 ohms; FR 15-30,000 Hz | HW, HE |
| Phono inputs | 2 × 2.5 mV / 50 kΩ | MM stages per the specification sheet | HW |
| Line inputs | 3 × Tape · Dolby | Three tape inputs at 150 mV / 50 kOhm plus a Dolby in/out loop at the same level | HW |
| Speakers | 3 pairs | Headphone jack on the receiver | HW |
| Weight | 25 kg | The mkII transcription block lists 28 kg and 160 W/ch at 0.05% | HW, HE |
Source codes: HW hifi-wiki.com · HE HiFi Engine transcription (Wayback snapshot) · CR classicreceivers.com (MKII wattage context). Data as of September 2026. The MKII's wattage quotes differ across sources and are disclosed in the FAQ rather than settled.
Hookup points on the TX-8500
AUX or tape input
RecommendedThe documented high-level positions, three tape inputs and a Dolby loop, all sit at 150 mV / 50 kOhm. Any line-level Bluetooth receiver with RCA output occupies one of them without adapters. The set documents no AUX-labeled position, so the tape positions are the line-level homes.
Tape monitor loops
Good alternativeWith three tape positions, the TX-8500 offers the most loop capacity documented in this archive's Onkyo and Kenwood shelves. Feed a loop's play jacks, select the tape position to listen, and switch the monitor back off for the other sources.
Phono inputs
Not for line-levelThe two MM phono stages expect a cartridge's 2.5 mV. Line-level Bluetooth output would overload them, and the turntables would lose their inputs.
A three-step hookup for the TX-8500
- Pick a high-level input
Three tape positions plus the Dolby loop give room; AUX-style selection follows the receiver's own labeling.
- Connect and power
Bluetooth receiver RCA out to the chosen input, USB power attached, pair once with your phone.
- Level check
Volume low, select the input, then raise. Fixed/line output on the adapter if it offers the option.
The fine print on the TX-8500
- Onkyo's shelf opens at 110 watts (verified): the specification sheets and retrospective coverage agree on 110 W/ch into 8 ohms for the base receiver, with the mkII transcription block reaching 160 W and 28 kg, and this page keeps the base record with the variant noted.
- Three tape positions, one a Dolby loop (verified): the TX-8500 documents more tape capacity than most sets here, and the Dolby in/out at 150 mV doubles as a processing insert, a layout the KR-9400's Dolby NR loop parallels.
- The MKII wattage spread, disclosed (verified): the transcription's mkII block reaches 160 W/ch at 0.05% while the MKII retrospective page quotes 110 W into 8 ohms and 150 W into 4 ohms. Both carry their attribution here; neither is smoothed into the other.
Before you start with the TX-8500
- Bluetooth receiver with RCA output, LDAC or aptX HD preferred
- 0.5–1 m RCA cable
- USB power for the receiver
FAQ
Plug a Bluetooth receiver with RCA output into an open high-level input and select it; the set documents three tape positions at 150 mV / 50 kOhm plus a Dolby loop, all at line level.
Per the specification sheets: two MM phono inputs at 2.5 mV / 50 kOhm; three tape inputs at 150 mV / 50 kOhm; a Dolby input and output at 150 mV / 50 kOhm; three speaker pairs; and a frequency response of 15 Hz to 30,000 Hz. The sheets document no AUX-labeled input.
Continuous output is rated 110 W per channel into 8 ohms (150 W into 4 ohms) at 0.1% distortion per the specification sheets, and retrospective coverage of the MKII variant quotes the same 110 W into 8 ohms as underrated, alongside a 150 W into 4 ohms figure.
The references document two builds: the transcription lists an mkI at 110 W/ch (25 kg) and an mkII at 160 W/ch (28 kg) with a wider-bandwidth front end, while the MKII retrospective page quotes 110 W into 8 ohms and 150 W into 4 ohms. The wattage quotes for the MKII differ across sources, and this page carries the base-model record with the MKII spread noted.
blafili B3 Bluetooth Music Receiver
RCA + XLR + optical out, LDAC and aptX HD, OLED status display. Matches the TX-8500 line-level inputs without adapters.
- Full connection and amplifier specifications (2× Phono MM 2.5 mV / 50 kOhm; 3× Tape In 150 mV / 50 kOhm; Dolby In/Out 150 mV / 50 kOhm; 3 speaker pairs; 110 W/ch at 8 ohms, 150 W at 4 ohms; THD 0.1%; FR 15-30,000 Hz; weight 25 kg; years 1976-1978; approx. 3,500 DM): hifi-wiki.com/index.php/Onkyo_TX-8500, accessed 2026-09-25. The set documents no AUX-labeled input.
- Variant blocks (mkI: 110 W/ch at 0.1%, 25 kg, 570 × 160 × 455 mm; mkII: 160 W/ch at 0.05%, 28 kg, FR 3 Hz-30 kHz): HiFi Engine, Onkyo TX-8500 manual page (hifiengine.com, bot-gated to direct fetches; verified via Wayback snapshot 20190922160658), accessed 2026-09-25
- Modern retrospective coverage of the TX-8500 MKII ("the line receiver at the time", "an under rated 150 watts per channel into 4 ohms and 110 watts per channel into 8 ohms"): classicreceivers.com/onkyo-tx-8500, accessed 2026-09-25