Description
The ST-ACR2 is a compact line-level audio controlled relay module designed to switch audio sources based on signal presence. It uses adjustable sensitivity to detect line-level signals and drives a DPDT relay for external switching. The unit is optimized for installations that require silence-sensing control and a configurable release delay.
The module includes two multiturn trimmers for precise setup – a SENS control for input sensitivity and a DELAY control for relay release time. A front-panel threshold LED provides visual feedback to set the trigger point between -30 dBu and 0 dBu. The DPDT contacts and an open-collector SLAVE output expand the device’s control options.
Performance specifications include a 25 ms activation response time and a 250 ms retrigger delay for stable switching behavior. Relay switching ratings are 60 W or 125 VA maximum and 2 A maximum current, with maximum switching voltages of 220 Vdc and 250 Vac. The relay release delay is adjustable from 5 seconds to 50 seconds to accommodate different hold times.
Connectivity supports balanced or unbalanced connections and a 10 kO balanced bridging audio input. Control outputs include an open-collector SLAVE output rated at 25 mA for driving indicators or a slave relay. Power is ground-referenced 24 Vdc at 50 mA assuming typical SLAVE loads, enabling simple integration with existing control power systems.
Typical applications include cue-controlled switching, silence-sensing mute control, and automated source switching in broadcast or installed-audio systems. The ST-ACR2 is suitable for rack or equipment-room installations where line-level sensing and reliable relay control are required. It provides consistent performance for live sound, broadcast, and signage control tasks.
Installation is straightforward using the STICK-ON series form factor and standard wiring practices. The unit operates from 0 C to 55 C and ships in a compact cardboard box for convenient handling. Its compact footprint and clear front-panel controls make setup and maintenance quick and predictable for technicians.
Free Ground Shipping
We offer free ground shipping on every purchase of $300 and more for US and US territory. Please choose "Free Ground Shipping (UPS/USPS)" option at checkout.
UPS Ground
UPS provides up-to-date tracking information. Ground service takes anywhere from 2-7 working days for delivery depending on destinations. UPS Ground does not deliver on Saturdays, Sundays or Holidays.
USPS Priority Mail/USPS Express Mail
For all shipments shipped via USPS, we offer 'DELIVERY CONFIRMATION' number with each package. Difference between tracking number provided by UPS vs USPS Delivery Confirmation number is: Delivery Confirmation status is updated when the delivery has been made or when the package has made it through major USPS stations.
Air Shipment
Air shipments, Overnight, 2nd day and 3 day select methods offer guaranteed delivery time for your shipment. If you are in hurry or in need for the items on schedule, select one of these methods. Up-to-date tracking information is provided with each Air Shipment. AVProSupply has the right to choose between Air shipments to meet or reduce delivery time. For guaranteed delivery of multiple items with expedited shipping, please contact our customer service representative for personalized assistance to get your items delivered to you when you need them.
International Customers
We offer shipping via USPS/UPS for our international customers. You can find different shipping options during checkout.
Most items ordered from AVProSupply will be shipped out from our California Warehouse. Will-Calls are only allowed with Appointment Only - Please call Customer Service to set one up between the hours of 9am to 6pm PST.
We Offer A 30-Day Money Back Guarantee:
Our main goal is to ensure your complete satisfaction with our service and products. If, for any reason, you are not 100% satisfied with your purchase, you can return it within 30 days of the purchase date for a full refund. Our 30-day money back guarantee applies to all of the products we sell, except for: TVs and monitors 20" and larger, Special Order merchandise, or any item indicated as non-returnable. Shipping is not refundable. Prior to returning your purchase, a Return Merchandise Authorization (RMA) number will be provided to you.
Refunds:
Refunds on returned items will be issued in the same payment form as received from the customer at the time of purchase. Once we receive the product and it passes inspection, we will credit your account. Please allow 3 - 6 business days for a credit to appear on your account.
Exchanges:
If the item was sent back to us for an exchange, please allow 3 - 5 business days for the replacement to be processed.
No Returns/Exchanges on the following:
- TVs and monitors 20" and larger
- Special Order merchandise
- Any item indicated on the website as non-returnable
For more information see our official Return Policy
