Overview
The HD-PA35U is a single input audio amplifier for systems demanding the highest energy efficiency. It may be used as a single zone amplifier fed from a variety of RDL or OEM mixers. It is ideal for providing one or more additional zones to a mix originating from another RDL HD series mixer amplifier. The 35 watt power amplifier output is driven from a high-efficiency Class D amplifier stage. The amplifier normally shuts down (standby “sleep” mode) when audio is absent and automatically turns on when needed. The amplifier output level may be VCA controlled using various optional RDL remote controls, or by industry standard 0 to 10 Vdc or 0 to 10k ohm controls. The output drives 4 ohm or 8 ohm speakers. The output impedance is switch-selectable on the rear panel.
The HD-PA35U is engineered, tested and manufactured in the U.S.A. to strict energy conservation standards. The unit consumes less than 1 watt of mains power in standby mode, and meets power amplifier efficiency specifications with an analog-filtered Class-D digital output stage.
The HD-PA35U provides a front-panel control to set the input gain. An optional remote control connected to the rear-panel RJ45 jack provides for remote adjustment of the output level. The tone controls adjust the equalization at the amplifier output.
The presence of a signal at the input causes the HD-PA35U to fully turn on, activating the power amplifier and all associated equalization and compressor circuitry. When an input signal is absent, a delay timer is initiated. Rear-panel DIP switches are provided to set the power-down delay timer to a value between 10 minutes and 2 hours in 10 minute increments. After the time-out period, the HD-PA35U enters the sleep mode until an input signal is received. The switches may be set to disable the sleep mode for systems specifying continuous amplifier operation.
The amplifier includes an analog compressor/limiter for audio fidelity noticeably superior to conventional class D amplifiers with digital limiting. Increasing the input gain can substantially increase the average output power beyond that of a standard 35 watt amplifier. A red front-panel LED flashes when the compressor is preventing output clipping. Normal audio level signals remain unaffected by the compressor thereby preserving audio dynamics. The audio is compressed according to three dynamic time constants providing aural transparency while maintaining clean, unclipped amplified audio for input overloads of up to 20 dB. The HD-PA35U, with compression, is capable of producing average audio output levels and clarity normally expected from amplifiers with a much higher output power rating.
During power-up and power-down, the amplifier output is protected against clicks, pops and thumping by internal soft-start solid-state switches.
A blue POWER LED illuminates when the HD-PA35U is powered from its external 24 Vdc power supply (included). The power LED is dim when the amplifier is in the standby mode, and is bright when the amplifier is fully active. A front-panel pushbutton is provided to manually cycle between standby and active modes. The power amplifier is equipped with both thermal and output short-circuit protection. The high-efficiency Class D output stage produces minimal heat for all levels of expected voice or music modulation.
Features:
- One input with front-panel volume control
- Bass and Treble tone controls
- Designed as a single zone amplifier
- Master volume VCA controlled with remote adjustment capability
- Amplifier output on detachable terminal block
- Unbalanced summing inputs on RCA jacks
- Includes power supply
- Automatic sleep mode meets strictest energy saving standards
Specifications
Audio Input:
Unbalanced stereo summing input on RCA jacks
Maximum Input Level:
+ 5 dBV (+11 dBV, one input); (for 1% THD+N at output)
Input level:
-15 dBV (180 mV), (to cross compressor threshold equaling 23 W amplified output, both input jacks driven)
Noise:
<-75 dB (max gain)
THD+N:
< 0.5% (1 kHz at compressor threshold)
Compressor:
Threshold 2 dB below rated output, automatically adjusting attack and release times
Frequency Response:
± 1 dB (50 Hz to 20 kHz)
Tone Controls:
±10 dB @ 10 kHz, ±9 dB @ 100 Hz (front-panel) with center detent
Power Amplifier Output:
35 W RMS (4 Ohms), 32 W (8 Ohms) on detachable terminal block (switch-selectable 4 or 8 Ohm impedance); <1% THD+N
Indicators (3):
Front-panel: Signal present (green), Compressor activity (red), Power (bright=on, dim=standby, blue)
VCA:
Output level, 0 to 10 Vdc control, RJ45 (compatible with RDL VCA wall controls)
Front-panel controls (4):
Input, EQ (2, bass and treble), Power (momentary pushbutton, toggle on/standby)
Rear-panel controls (4):
Sleep (standby) mode delay (4 binary switches)
Efficiency Standard Used:
“Energy Star® Program Requirements for Audio/Video” Version 2.0
Sleep Mode Power Consumption:
< 1 W (amplifier and included power supply)
Sleep Mode Delay:
10 minutes to 2 hours (switch-selectable in 10 minute increments)
Sleep Mode Disable:
Selectable
Active Mode Delay:
2 seconds (nominal) after input audio detected
Audio Detector Threshold:
-42 dBV
Ambient Operating Environment:
0° C to 50° C Maximum; 20° C Recommended
Power Supply (included):
100 to 240 Vac, 50-60 Hz, 50 W; 24 Vdc output to amplifier chassis
Dimensions and Weight:
Height: 3.5 in.(8.89 cm); Width: 8.5 in.(21.6 cm); Depth: 10 in.(25.4 cm); Weight: 5.6 lb. (2.5 kg)
Package Type:
Cardboard Box
Package Dimensions:
17.75 x 9.125 x 3.9375 in.
Shipping Weight:
7.795 lbs.
Tariff code:
8518.50.0000
RDL Three-Year Limited Warranty
Installation of these products by the Purchaser shall constitute Purchaser’s acknowledgement and acceptance of the terms and
conditions for sale and of this warranty, and shall constitute the Purchaser’s determination of the suitability of this product for the
Purchaser’s intended application. Radio Design Labs, Inc., also referred to as RDL®, warrants to the Purchaser that products
manufactured by RDL are free from defects in material and workmanship. This warranty applies to the period of three years from the date
of shipment, except for component parts or products purchased from other sources and supplied by RDL. Such component parts or
products bear only the warranty of the manufacturer thereof in effect at the time of shipment to the Purchaser. RDL will, without charge,
and after written notice has been received and acknowledged by RDL, repair an RDL product if proved to be defective according to the
usage of the trade, when such equipment is received by RDL at the location it designates with shipment costs prepaid by the Purchaser.
RDL shall not be liable for any expense whether for repairs, replacements, material, service, or otherwise, incurred by the Purchaser or
modifications made by the Purchaser to the product. No equipment shall be deemed defective if it shall fail to operate in a normal or
proper manner due to exposure to excessive moisture in the atmosphere, excessive temperature extremes, improper environmental
cleanliness, or any other environment not consistent with the principles of good engineering practice. In no event shall RDL have any
liability for consequential damage or expense directly or indirectly arising from the use of the products, or any inability to use it either
separately or in combination with other equipment or materials, or from any other cause, whether used in accordance with instructions or
not. This warranty is void if equipment is altered in any way by other than RDL. RDL products are NOT intended for use in life support
appliances, devices, or systems. Use of RDL products in such applications is done solely at the liability of the reseller/installer and/or end
user. RDL reserves the right to change design parameters and specifications at any time without notice. The performance measurements
reflect the products at the time of printing. This warranty is in lieu of all others, either expressed or implied. No representative is authorized
to assume for RDL any other liability in connection with RDL products.
