Description
The STM-1 is a compact microphone preamplifier designed to raise mic-level signals into standard line-level ranges. It provides a fixed 50 dB nominal gain to ensure consistent level matching across inputs. The unit is suitable for commercial sound and broadcast environments where a small footprint and reliable gain are required.
Key features include selectable high or low impedance inputs and balanced or unbalanced outputs. The STM-1 accepts 24 Vdc supply and can provide phantom power where required – the input circuitry is RF filtered to minimize interference. The preamplifier maintains low distortion and low residual noise for clean signal amplification.
Technical performance includes a frequency response of 50 Hz to 30 kHz within ±1.5 dB and THD+N under 0.05%. Common-mode rejection is better than 50 dB across the audio band and residual noise is below -70 dB relative to +4 dBu with a 150 ohm source at 50 dB gain. Headroom exceeds 20 dB on a 24 Vdc supply and remains greater than 14 dB when powered at 12 Vdc.
Connectivity covers a 500 ohm balanced input or 5 kohm unbalanced input plus two outputs available as +4 dBu 150 ohm balanced or -10 dBV unbalanced. Phantom power is provided at 24 Vdc filtered to IEC 61938 guidance and the phantom input draws up to 10 mA. Outputs and inputs are RF-filtered to help prevent interference in broadcast and live environments.
Typical applications include broadcast talent microphones, intercom interface where speaker input operation is needed, and compact stage or field rigs requiring a small preamp. The fixed 50 dB gain simplifies system setup and provides predictable level control for downstream processors and mixers. The STM-1 is engineered to operate in ambient temperatures from 0 C to 55 C for reliable field performance.
Installation is straightforward using the STICK-ON convenience package or standard mounting in confined spaces – the cardboard package is compact at 2 x 2 x 4 in. The STM-1 is ground-referenced and draws 24 Vdc at 25 mA, keeping power needs minimal. Its build and RF-filtered I/O deliver a dependable, easy-to-integrate mic preamplifier for professional audio systems.
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
