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RAAL HSA-1b Amplifier

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The HSA-1b by RAAL-requisite is the world’s first switch drive amplifier for their world renowned Earfield™ headphone monitor. Built to direct drive the SR1a and switch to power conventional headphones or spekaers. Offering both unbalanced single-ended RCA and True-Balanced XLR input alongside a rock-solid precision 24-step attenuator for balance at all listening levels.

True Ribbon™ SR1a. The world's first Earfield™ headphone monitor now with OEM Switch Drive Amplification available!

Three Package Options Available

• HSA-1b

• SR1a + HSA-1B / Roller Carry On Case

• SR1a + HSA-1B / Interface Box / Roller Carry On Case

• All with a 5 year Manufactor Warranty


• Schiit Jotunheim R Direct-Drive Amplifier or RAAL HSA-1b Ribbon/HP/Speaker Amp (drives SR1a directly!)

RAAL SR1a Headphone - Specs

Earfield™ open baffle. Floating near ear, does not enclose ears.

0.2 Ohms with cabling. *Used in series Ribbon/Amplifier Interface.

Amplifier Interface
*Ribbon/Amplifier Interface. 6 Ohms. Use any loudspeaker amplifier.

Amplifier power rating

91 dB/1W

111 dB

Frequency Range
30Hz - 30KHz

32 ohms

425 grams

* Applies only with RAAL Interface Box. No separate loudspeaker amplifier required with Schiit Jotunheim R DAC/Amp Or HSA-1B package.

RAAL HSA-1b Ribbon/HP/Speaker Amp - Specs

Load Impedance
.03 ohm - infinity

Output Power (one channel driven)
10W/8 ohms, 20W/4 ohms, 40W/2 ohms, 55W/1 ohm @ 1khz/sine

Ribbon & Headphones Drive
RAAL-requisite SR-1a, Dynamic &Planar Magnetic

Speaker Drive
8 ohm, 4 ohm, 2 ohm Loads

Freq Response
100mv/ in/sin 15hz-500kHz

Power Bandwidth
100kHz (-3dB) at 1khz

Frequency Range
30Hz - 30KHz


Signal to Noise Ratio
< 90dB

Input Impedance
40 kOhm

< 0,5V/40kOhm

IN1 - RCA pair, IN2 - XLR pair

Max Power Consumption
150W, without signal 25W

H3.54" x W8.58" x D12.6"

11.7 lbs

HSA-1B & SR1a