---
product_id: 70667571
title: "ST-4B 4-Channel 65 Watts x 4 RMS Full Range Class AB Amplifier"
brand: "zapco"
price: "$419.70"
currency: USD
in_stock: true
category: "Zapco"
url: https://www.desertcart.us/products/70667571-st-4b-4-channel-65-watts-x-4-rms-full
store_origin: US
region: United States of America
---

# Class-AB high current output 65W x 4 RMS power Stable 2Ω stereo & 4Ω bridged load ST-4B 4-Channel 65 Watts x 4 RMS Full Range Class AB Amplifier

**Brand:** zapco
**Price:** $419.70
**Availability:** ✅ In Stock

## Summary

> 🎶 Elevate your drive — sound that’s as sharp as your hustle.

## Quick Answers

- **What is this?** ST-4B 4-Channel 65 Watts x 4 RMS Full Range Class AB Amplifier by zapco
- **How much does it cost?** $419.70 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/70667571-st-4b-4-channel-65-watts-x-4-rms-full)

## Best For

- zapco enthusiasts

## Why This Product

- Trusted zapco brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Pro-Level Sound Control:** Includes built-in crossovers, bass boost, and variable gain inputs for tailored audio perfection.
- • **Versatile Load Handling:** Stable operation down to 2 ohms stereo or 4 ohms bridged, ensuring compatibility with diverse speaker setups.
- • **Compact Yet Robust Design:** Sleek extruded aluminum chassis fits modern compact cars without sacrificing durability.
- • **Power Your Ride with Precision:** Delivers 65 watts RMS per channel for crystal-clear, full-range sound that commands attention.
- • **Cutting-Edge MOSFET Power Supply:** Efficient and reliable power delivery for consistent performance and longevity.

## Overview

The Zapco ST-4B is a 4-channel Class-AB amplifier delivering 65 watts RMS per channel with exceptional clarity and low distortion (<0.03% THD+N). Its compact aluminum chassis fits modern vehicles, while MOSFET power supply and stable operation at 2Ω stereo or 4Ω bridged loads ensure versatile, reliable performance. Featuring built-in crossovers, bass boost, and variable gain control, it’s engineered for audiophiles who demand professional-grade sound on the go.

## Description

The zapco ST-4B 4-channel bridgeable 2 to 6 channels, amp brings the sound quality and reliability that built the zapco legend; and an amplifier that everyone can afford. The extruded aluminum chassis is compact to fit today's smaller cars. The feature set provides versatility including built in crossovers, bass boost and preamp outputs. The ST-4B amplifier is misfit powered, uses class nab designed hi current bi-polar outputs, pass through preamp outs, and high voltage speaker level inputs. Th.D. + noise: 82Db, stereo separation: >45Db.

## Features

- 4-Channel, Class-AB Full Range Amplifier
- Stable into 4 ohms bridged or 2 ohms stereo load
- MOSFET power supply
- RCA and OEM speaker level input
- Variable Inputs Gain Control

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B01MQ6A92Y |
| Best Sellers Rank | #280,116 in Electronics ( See Top 100 in Electronics ) #634 in Car Multichannel Amplifiers |
| Brand Name | Zapco |
| Customer Reviews | 5.0 5.0 out of 5 stars (2) |
| Included Components | Mounting ScrewsOwner's Manual, Mounting Screws, Owner's Manual, ST-4B 4 Channels Class AB Amplifier |
| Item Dimensions | 12.2 x 2.05 x 7.17 inches |
| Item Type Name | ST-4B |
| Manufacturer | Zapco |
| Maximum Output Power | 260 watts |
| Model | ST-4B |
| Mounting Type | Surface Mount |
| Number of Channels | 4 |
| Number of Items | 1 |
| Number of Packs | 1 |
| Output Power | 65 watts |
| Part Number | ST-4B |
| Specification Met | Unspecified Technical Specifications |
| Unit Count | 1 Count |
| Warranty Description | 1 Year Warranty |

## Product Details

- **Brand:** Zapco
- **Item dimensions L x W x H:** 12.2 x 2.05 x 7.17 inches
- **Manufacturer:** Zapco
- **Mounting Type:** Surface Mount
- **Number of Channels:** 4

## Images

![ST-4B 4-Channel 65 Watts x 4 RMS Full Range Class AB Amplifier - Image 1](https://m.media-amazon.com/images/I/51qGYjJpDeL.jpg)

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-09-10*