The HDRX 100 is the full-power HDRX: 100 watts from four EL34s through a custom Straight Edge 100-watt output transformer, made at PRS's Stevensville, Maryland factory. Its circuit follows a Hendrix amp that Paul Reed Smith and Doug Sewell examined in 2018, one said to have been used at Woodstock.
Channels 1 and 2 are bridged inside the chassis, so the Bass Volume and Treble Volume blend into one sound without a patch cable, with shared Treble, Middle, Bass and Presence beside the high-mid gain switch and three-position bright switch. PRS notes the power supply and filament design keep hum and hiss very low.
There is no master volume, since amps of that era often had to double as a PA, and PRS recommends an attenuator. The HDRX 4x12 Cabinet is our pick to go under it. If 100 watts is more than your rooms need, the HDRX 50 Head is built to sit close to it.
SPECIFICATIONS
AMPLIFIER
Country of Origin: USA
Available Configurations: Head Only
Wattage: 100
Output Transformer: Straight Edge 100 Watt Output
TUBES
Power Tubes: (4) EL34
Preamp Tubes: (3) 12AX7 / ECC83
V1: Input
V2: Cathode Follower
V3: Phase Inverter
CONTROLS
Global Controls: Treble, High Mid Gain Switch (on/off), Middle, Bass, Presence
Front Panel Controls: Channel 1 Controls - Bass Volume Channel 2 Controls - Treble Volume, Bright Switch (Off, Bright 1, Bright 2) (Channels 1 and 2 are internally bridged)
CONNECTIONS
Inlet: Fused Power Inlet (IEC)
Extension Speaker Jacks: 5
Ohm Switching: (2) 4 ohm & (2) 8 ohm parallel, (1) 16 ohm
Bias: Adjustable with Monitoring Jacks
HARDWARE
Covering: Black Tolex
Piping: Black
DIMENSIONS
Amp Width: 21.5" (54.61 cm)
Amp Depth: 10" (25.4 cm)
Amp Height: 10" (25.4 cm)
Amp Weight: 40 lbs (18.14 kg)



