Roland SRA-50 Working Stereo Power Amplifier Mixer

Compact Roland SRA-50 power amplifier mixer with 2 MIC and LINE inputs, LINE OUT, and BASS/TREBLE adjustment functions.

Internal cleaning was performed using air blowing, and normal operation has been confirmed.
Input signals were applied to MIC, LINE 1, and 2, and it was confirmed that they output normally from the speakers.
PHONES also output normally (this mutes the sound from the speakers).
LINE OUT also outputs normally.
BASS and TREBLE controls are highly effective.
Rubber feet have been replaced.
As this is a used item, there are signs of age-related wear such as scratches and dirt on the exterior casing.
No claims or returns accepted.

A key feature of this amplifier is that sound is output immediately upon powering on.
Typically, medium to high-output amplifiers have a muting relay in the speaker output, which prevents sound for several seconds.
Many older amplifiers suffer from issues where the muting relay contacts degrade over time, leading to no sound or reduced volume.

Without using a muting relay, it's normal to hear loud noise from the speakers when powering on. However, this unit electronically mutes, resulting in only a small pop sound upon power-on.
There is no sound when powering off.
This is a testament to the ingenuity of Roland's design team.
The absence of a muting relay reflects the professional audio philosophy of delivering signals to the speakers losslessly and stably over the long term.

Furthermore, this unit is an AB-class analog amplifier equipped with a heavy, large toroidal core transformer. Many people appreciate its sound, and it remains popular today.
Subsequent models in this series have transitioned to PWM Class-D digital amplifiers.

- Model: SRA-50
- Input Terminals: MIC, LINE 1, LINE 2
- Output Terminals: Speaker Terminals, LINE OUT, PHONES
- Adjustment Functions: BASS, TREBLE
- Power Supply: AC 100V, max 84W
- Maximum Output: 50W x 2 (4Ω)
- Design: Compact 1U half-rack size chassis
- Overload Indicator: Yes
- Manufacturer: Roland
- Accessories: Instruction Manual (copy)