Yes, a Sony STR-7055 Bluetooth connection needs no soldering. Best path: a Bluetooth receiver with RCA output into the AUX input (150 mV / 50 kOhm per the service manual). If AUX is taken, use a Tape Play loop. Rated 45+45 W into 8 ohms at 1 kHz below 0.2% distortion, with dynamic power to 136 W, this is the quiet overachiever of Sony's early-seventies line.
Figures on this page were checked September 2026. Every table row carries its source; the service manual is the governing document and one reference work's diverging input block is noted as superseded.
The STR-7055 on paper
| Item | Value | Notes | Source |
|---|---|---|---|
| Production run | 1972–1976 | Long run for an early-seventies Sony; approx. 1,398 DM in German lists | HW |
| Power output | 45 W/ch @ 8 Ω | 45+45 W at 1 kHz below 0.2% THD; 55+55 W into 4 ohms; dynamic power 136 W (8 Ω) and 200 W (4 Ω) | SM, TVK |
| Phono inputs | 2 × 2 mV / 47 kΩ | Per the service manual; one reference work lists 1.8 mV, superseded | SM |
| Line inputs | AUX · 2 × Tape | AUX and both Tape Play inputs at 150 mV / 50 kOhm; DIN record output at 30 mV / 82 kOhm | SM |
| Speakers | 2 pairs | Headphone jack on the front panel | HW |
| Weight | 15.3 kg | 300 W max power consumption, 40 W idle | HW |
Source codes: SM Sony STR-7055 service manual (archive.org rtv_sony_str-7055, governing) · TVK The Vintage Knob · HW hifi-wiki.com (input block superseded by the manual). Data as of September 2026.
Where the STR-7055 takes a source
AUX input
RecommendedThe service manual fixes AUX at 150 mV / 50 kOhm, and that is the number this page carries. Any line-level Bluetooth receiver with RCA output plugs straight in.
Tape monitor loops
Good alternativeBoth Tape Play inputs read the same 150 mV line spec, and the record side is generous: a 250 mV output for a deck plus a DIN record socket at 30 mV / 82 kOhm for European equipment. To borrow a loop, feed its play jacks, call it up on the monitor, and return the monitor to off afterwards.
Phono inputs
Not for line-levelTwo MM phono stages wait at 2 mV. They take a cartridge, not a line-level source: Bluetooth output fed there would overload them, and the turntables would lose their inputs.
A three-step hookup for the STR-7055
- AUX first
Send Bluetooth to AUX and keep both tape loops open for decks.
- Make the connection
RCA output of the Bluetooth receiver into AUX, power over USB, and one pairing session with your phone.
- Check the sound
Volume at the bottom, switch to AUX, bring the level up. Set the adapter to fixed/line output when it provides that choice.
The fine print on the STR-7055
- Three figures for one amplifier, and the manual explains most of them (verified in part): marketplace listings quote 35 W or 40 W for this receiver. The service manual's own tables show why: 45+45 W at 1 kHz below 0.2% distortion sits next to a lower full-bandwidth rating, which accounts for the 35 W quotations. The 40 W figure has been reported to belong to the STR-7055A variant, a claim this page could not independently verify at check time. This page keeps the manual's numbers.
- Wiki versus manual, resolved (verified): one reference work's input block lists AUX at 140 mV / 100 kOhm and phono at 1.8 mV; the factory service manual reads 150 mV / 50 kOhm and 2 mV, and the manual governs, per this site's standing rule.
- A receiver that idles quiet (verified): 40 W idle consumption against a 300 W maximum, per the same reference work.
What you need for the STR-7055
- Bluetooth receiver, RCA output, LDAC or aptX HD preferred
- 0.5–1 m of RCA cable
- A USB source to power the receiver
FAQ
Plug a Bluetooth receiver with RCA output into the AUX input and select AUX. If AUX is taken, use a Tape Play input through the tape monitor. No internal modification is needed.
Per the service manual: AUX 150 mV / 50 kOhm; two phono inputs at 2 mV / 47 kOhm; Tape Play 1 and 2 at 150 mV / 50 kOhm, with a DIN record output at 30 mV / 82 kOhm alongside the standard 250 mV record output.
The service manual rates 45+45 W into 8 ohms (55+55 W into 4 ohms) at 1 kHz below 0.2% distortion, with dynamic power of 136 W into 8 ohms and 200 W into 4 ohms. Marketplace listings quoting 35 W reflect the full-bandwidth rating; the 40 W figure has been reported as the 7055A variant's rating, unverified here.
Yes, on the recording side: a DIN record output at 30 mV / 82 kOhm alongside the standard record output at 250 mV. For Bluetooth, use the RCA connections.
blafili B3 Bluetooth Music Receiver
RCA + XLR + optical out, LDAC and aptX HD, OLED status display. Matches the STR-7055 line-level inputs without adapters.
- Rated power (45+45 W into 8 ohms, 55+55 W into 4 ohms, at 1 kHz below 0.2% THD; dynamic 136 W / 200 W), input sensitivities (AUX 150 mV / 50 kOhm; Phono 2 mV / 47 kOhm; Tape Play 150 mV / 50 kOhm; DIN record 30 mV / 82 kOhm; standard record 250 mV), PRE OUT/MAIN IN: Sony STR-7055 service manual (archive.org, identifier rtv_sony_str-7055), specifications tables read from the page images, accessed 2026-09-24
- Power cross-check (45+45 W at 1 kHz below 0.2%, with a lower full-bandwidth rating also listed): The Vintage Knob, Sony STR-7055 page, accessed 2026-09-24
- STR-7055A variant note (a 40 W per channel rating quoted from the 7055A owner's manual at Audiokarma; original thread unreachable at check time, unverified here): Audiokarma forum thread, accessed 2026-09-24
- Production years 1972-1976, weight 15.3 kg, approx. 1,398 DM, 300 W max / 40 W idle consumption, 2 speaker pairs: hifi-wiki.com/index.php/Sony_STR-7055, accessed 2026-09-24; note this source's input-sensitivity block reads 140 mV / 100 kOhm and 1.8 mV, superseded by the service manual