Item(s) for Sale: ZAPCO ST-4X SQ SOUND QUALITY AMP 4-CHANNEL 420W RMS CLASS AB CAR AMPLIFIER
Item(s) Description/Condition: Mint. Purchased from an authorized dealer. Warranty can be maintained.
Price: $125 shipped / No Trades
Shipping and Miscellaneous Item Information: Lower 48 states only.
Purchased from an authorized dealer. Warranty can be maintained. Amp has less than 30 minutes of playing time. Had it in a project car, but letting the car go.
This is the SQ (Sound Quality) version. Upgrades include more Power, better Op-Amps, Caps, etc. and Tiffany Style Panel Mount RCA's (all compared to the ST-4X II).
Features and Functions
Specifications
The ST-4X SQ Amplifier from Zapco was designed specifically for today’s car audio market. The ST-4X SQ amplifier is the smaller lighter amp you need for today’s smaller lighter cars. But with the Zapco ST-4X SQ amp, smaller doesn’t mean weaker or softer. With the ST-4X SQ amp you get all the power and sound quality you expect from Zapco. The ST-4X SQ’s compact chassis makes it an easy fit in any car truck or suv. The square, low profile chassis also means it will be easy to trim out for a great looking installation so your system will look as awesome as it sounds.
Speaking of sound…This is a Zapco amplifier and sound is what it’s all about. The Class A/B Zapco ST-4X SQ amplifier is the best solution for your mids and highs. When comes to quality no one comes even close to the high quality caps, 5532 op-amps,and bi-polar outputs that made the C2K and Reference series amps the industry standard for sound quality.
Reliability? Zapco defines reliability. It’s not at all unusual to see Zapco amps moved from car to car and from generation to generation. Zapco Amps produced in the ’90 are still being traded and bought on the internet by sound quality fans world wide. The ST-4X SQ will be no different. This amp is built to last.






Item Pictures:
(List pictures in this section, 1st picture should be your username/date if you have less than 10 positive feedbacks with the i-Trader system or less than 10 references that you have sold to in the past. (These must be listed in your signature, or a link provided to a feedback thread listing these references)).
Item(s) Description/Condition: Mint. Purchased from an authorized dealer. Warranty can be maintained.
Price: $125 shipped / No Trades
Shipping and Miscellaneous Item Information: Lower 48 states only.
Purchased from an authorized dealer. Warranty can be maintained. Amp has less than 30 minutes of playing time. Had it in a project car, but letting the car go.
This is the SQ (Sound Quality) version. Upgrades include more Power, better Op-Amps, Caps, etc. and Tiffany Style Panel Mount RCA's (all compared to the ST-4X II).
Features and Functions
- 4-Channel, Full Range, Class A/B
- SQ Upgrades: Op-amps, Caps, Etc.
- Tiffany style Panel Mount RCA’s
- RCA and Speaker Level Inputs
- Variable input gain control
- Variable electronic crossover
- Auto-on with Speaker level inputs
- Compact chassis
Specifications
- Power @ 4Ω: 4 x 70 watts
- THD @ Rated Power
- Power @ 2Ω: 4 x 105 watts
- Power Bridged @ 4Ω: 2 x 210W RMS
- Signal to Noise Ratio > 90dB
- THD + Noise
- Channel Separation >60dB
- Frequency Response 15Hz to 30KHz ±1dB
- Input Sensitivity .25v to 5v
- Dimensions in mm: 160(W) x 52(H) x 320(L) or 6.4″W x 11.1″L x 1.8″H
The ST-4X SQ Amplifier from Zapco was designed specifically for today’s car audio market. The ST-4X SQ amplifier is the smaller lighter amp you need for today’s smaller lighter cars. But with the Zapco ST-4X SQ amp, smaller doesn’t mean weaker or softer. With the ST-4X SQ amp you get all the power and sound quality you expect from Zapco. The ST-4X SQ’s compact chassis makes it an easy fit in any car truck or suv. The square, low profile chassis also means it will be easy to trim out for a great looking installation so your system will look as awesome as it sounds.
Speaking of sound…This is a Zapco amplifier and sound is what it’s all about. The Class A/B Zapco ST-4X SQ amplifier is the best solution for your mids and highs. When comes to quality no one comes even close to the high quality caps, 5532 op-amps,and bi-polar outputs that made the C2K and Reference series amps the industry standard for sound quality.
Reliability? Zapco defines reliability. It’s not at all unusual to see Zapco amps moved from car to car and from generation to generation. Zapco Amps produced in the ’90 are still being traded and bought on the internet by sound quality fans world wide. The ST-4X SQ will be no different. This amp is built to last.






Item Pictures:
(List pictures in this section, 1st picture should be your username/date if you have less than 10 positive feedbacks with the i-Trader system or less than 10 references that you have sold to in the past. (These must be listed in your signature, or a link provided to a feedback thread listing these references)).