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Zapco ST-4XSQ Studio X Series 4 Channel SQ Amplifier

  • Sound Quality Components
  • Tiffany Style Panel Mount RCA Connectors
  • Upgraded Caps and Op-Amps

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Regular Price: $209.99

Now: $189.99


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Zapco ST-4XSQ

Studio X Series 4 Channel SQ Amplifier

Everyone wants great sound in their car, but not everyone wants to compete in sound-offs. In 2013 Zapco determined to put its 40+ years of experience to work and develop a line of amplifiers that everyone could afford, that would meet today’s need for a light weight, compact product, and at the same time, stay true to Zapco’s heritage of unsurpassed sound quality and solid reliability.

The new Studio-X amplifier is the result of that work and today the Studio-X line is complete.

Studio-X Class A/B Full Range Amplifiers

There are five full range amplifiers in the Studio-X series and all are Class A/B and all use bi-polar output devices for the smoothest possible sound. And, all are packed with all those features you want. Common features of the ST-X amplifiers include variable HP/LP/ Full Range electronic crossovers, variable bass boost, variable gain by channel pair, speaker level input (except the ST-5X), heavy duty positive lock terminal blocks and preamp outputs to daisy chain out to the next amp in your system without having to add more RCA cables. The ST5X also has an input function switch. And the most important feature shared by all the ST-X amps is the legendary Zapco sound quality, developed with over 40 years of experience.

We have created the ST-4XSQ for the customer who appreciates the finer points of the music and wants to invest a little extra for a more “live” sound. We did this by upgrading the caps and op-amps and making few other changes. The SQ version will have a more open sound and a more precise sound stage. We also used Tiffany style panel mount RCA connectors on the ST-4SQ for a solid signal transfer.


  • Class AB
  • RMS Power/ch. at 4 ohms 70W/Ch.
  • RMS Power/ch. at 2 ohms 105W/Ch.
  • RMS Power/ch. at 1 ohm No
  • RMS Power/ch. Bridged at 4 ohm 210w x 2
  • Frequency Response 15Hz - 30KHz
  • THD at rated power 0.02%
  • Signal to Noise 90dB
  • Channel Separation 60dB
  • Tested Voltage 14.4v
  • Recommended Fuse Rating 25A x 3 
  • Dimensions (mm) L/W/H 282 x 160 x 52
  • Dimensions inc. feet/terminals 320 x 160 x 52

Additional Info

Name Zapco ST-4XSQ Studio X Series 4 Channel SQ Amplifier
Manufacturer Zapco
Manufacture's Warranty 2 N/A
Manufacturer's Warranty 1 Year Manufacture's Warranty
upc 636644602302
Manufacturer Sku ST-4XSQ