1 (323) 278-0001 [email protected]

American made. Audiophile quality. Music and cinema controllers, amplifiers, pre-amplifiers, and transports.

Limitless Intimacy

The Citadel 1.5 is a monoblock power amplifier offering all the advantages of the knowledge, research and dedication that Theta Digital has brought to its other amplifiers, and then some.

The heart of the Citadel 1.5 contains fully-balanced differential, zero-feedback circuitry, and zealously selected solid-state devices throughout. We scrutinize the selection to optimize component parts in each and every stage, and for the performance of the amplifier as a whole. Custom-made capacitors, Vishay precision resistors, copper buss bars, Litz / Teflon wires and a custom-made output connector are just some of the components that combine to make the Citadel 1.5 an unprecedented technical statement.

Sonically, this quality is expressed as a new level of veracity and intimacy in the experience of music, and in the prospect of movie soundtrack performance that no commercial theater can hope to rival.

The Citadel 1.5’s power supply design is an exercise in delivering massive brute power with absolute integrity. We give its output stage a high-current Kilowatt power transformer itself, which feeds a unique dual-choke and capacitive filtering system. This technique is rarely applied because of the huge choke size necessary to avoid impeding high current demands. Its filtering system employs two massive chokes almost as large as the power transformer. These are fed from an ultra-fast / soft-recovery 35 Amp full bridge rectifier, which are then filtered by two capacitive banks totaling 80,000uF. The synergistic effect of this filtering system results in high-current power supply lines that are more than 8,000% cleaner than conventional supplies.

The sonic result of these super-clean supply lines to the output transistors has not previously been achieved at such a high power levels.

The mechanical housing for the Citadel 1.5 is no less specialized than its internal components. More than an aesthetic statement, its seamless housing, devoid of traditional fasteners on top, front, and sides, provides a strong, stable environment for the operation of the amplifier. The power supply resides in its base, isolated from the amplifier module above.

The Citadel 1.5 has been created to power the most demanding two channel and home theater systems, effortlessly recreating the vast spectrum of music and soundtracks with both silky finesse and authoritative control.

Contact your local representative for pricing.

General Specifications

Analog Input Section
1 Single-ended RCA jack.
1 Balanced (XLR) jack.

Input Impedance
60K. Single-Ended or Balanced, each phase.

Input sensitivity
(Single-Ended) 3.1V RMS input for 400W into 8 ohms.
(Balanced) 1.55V RMS input for 400W into 8 ohms.

(Single-Ended) 25dB (18x).
(Balanced) 31dB (36x).

(Single-Ended) Non-Inverting.
(Balanced) Pin-2 = Positive, Pin-3 = Negative for Non-Inverting Output.

Analog Audio Outputs
1 balanced output (Standard); optional second balanced output for bi-wiring.

I / O RS232
1 DB9 and 1 RJ45 connector.

Standby: Amplifier is muted and output bias is reduced to 20%.
Thermal: Channel has overheated; amp automatically switches to Standby.

Power Output
(8 ohms) 400 W (rated) 425 W (typical)
(4 ohms) 600 W (rated) 650 W (typical)
(2 ohms) 800 W (rated) 800 W (typical)

Frequency Response
(-3dB points @ full power) 0.2 Hz – 400 KHz.

<2% Signal to Noise Ratio (unweighted) >103dB

Power Requirements
117 VAC, 15A Slo Blo fuse for analog, 1A Slo blo fuse for digital; 230 VAC, 10A Slo Blo fuse for analog, 1A Slo Blo fuse for digital; 50-60 Hz.

Power Consumption
80W @ Standby; 120W @ idle;
800W @ full power into 8 ohms;
1350W @ 4 ohms, 2100W @ 2 ohms.

Trigger Input
5-12 VDC Pulse between 1 and 500mS.

8 13/16″ W x 19 5/8″ H x 23 5/8″ D (224 x 499 x 600 mm)

110 Lbs. Stand alone (41.05 Kg)
130 Lbs. Boxed with accessories (48.52 Kg)

Maxumium Operating Temperature
Internal: 176° F (80° C)
Room: 131° F (55° C)

Contact Us

Theta Digital
1749 Chapin Road
Montebello CA 90640

Phone: +1 (323) 278-0001