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SIQ Amplifier
Discover our SIQ amplifiers: a blend of Hi-Fi class A/B & D backed by 25+ years of audiophile expertise. Boasting top-tier components for crystal-clear sound, we offer these gems directly to you for exceptional value. Experience pristine power, from SIQ 75.4 to the robust SIQ 3000 D.
Description
Hi-Fi class A/B and class D amplifiers are back with our SIQ amplifiers. Full bandwidth, zero filters, discrete gain knob per channel, zero crossovers, zero EQ. Purity at its finest. Being avid audiophiles for over 25 years we have always appreciated the finer performing amplifiers in mobile audio and with our growing presence in the mobile audio industry, we have been able to team up with talented amplifier engineers and finally produce our own hi-fi amplifiers. Audiophile components were used throughout construction and engineering to bring our amplifiers to fruition. And because we are a direct company (no dealers) the cost savings are passed directly to you, our customers.
All of our SIQ class A/B amplifiers utilize audiophile-grade T0-3 output transistors, clean board layouts, thick extruded aluminum chassis, copper anodized shielded transformer covers, and a large plexiglass viewing window. Coming inward we use UPC4570 op-amps followed by IRFPO64N power supply transistors, sand cast resistors, surface mount parts to save board space, and Tiffany-style RCA connections. All of the above FR and power graphs are from Audio Precision measurements.
SIQ 75.4 (Class A/B) Specifications
| Rated RMS power output into all 4 channels at 4 Ohm | 75 watts | Rated RMS power output into all 4 channels at 2 Ohms | 120 watts | Bridged RMS power into 2 channels at 4 Ohms | 250 watts | THD | 0.03% | S/N ratio | 90 dB | Idle current draw | 1.2 A | Maximum current draw | 66 A | Frequency bandwidth | 5 Hz to 150,000 Hz | Dimensions | 14″ x 8″ x 2″ (WxDxH) | RCA input maximum | 16 Volts |
SIQ 125.4 (Class A/B) Specifications
| Rated RMS power output into all 4 channels at 4 Ohm | 125 watts | Rated RMS power output into all 4 channels at 2 Ohms | 200 watts | Bridged RMS power into 2 channels at 4 Ohms | 400 watts | THD | 0.01% | S/N ratio | 91 dB | Idle current draw | 1.6 A | Maximum current draw | 98 A | Frequency bandwidth | 5 Hz to 150,000 Hz | Dimensions | 16.5″ x 8″ x 2″ (WxDxH) | RCA input maximum | 16 Volts |
SIQ 200.2 (Class A/B) Specifications
| Rated RMS power output into 2 channels at 4 Ohms | 200 watts | Rated RMS power output into 2 channels at 2 Ohms | 400 watts | Bridged RMS power into 1 channel at 4 Ohms | 800 watts | THD | 0.03% | S/N ratio | 92 dB | Idle current draw | 1.3 A | Maximum current draw | 85.6 A | Frequency bandwidth | 5 Hz to 150,000 Hz | Dimensions | 14″ x 8″ x 2″ (WxDxH) | RCA input maximum | 16 Volts |
SIQ 200.4 (Class A/B) Specifications
| Rated RMS power output into all 4 channels at 4 Ohms | 200 watts | Rated RMS power output into all 4 channels at 2 Ohms | 425 watts | Bridged RMS power into 2 channels at 4 Ohms | 875 watts | THD | 0.03% | S/N ratio | 91 dB | Idle current draw | 2.6 A | Maximum current draw | 176 A | Frequency bandwidth | 5 Hz to 150,000 Hz | Dimensions | 27.25″ x 8″ x 2″ (WxDxH) | RCA input maximum | 16 Volts |
SIQ 1500 D (Class D) Specifications
| Rated RMS power into 1 Ohm | 1500 watts | Rated RMS power into 2 Ohms | 900 watts | Rated RMS power into 4 Ohms | 600 watts | THD | 0.15% | S/N ratio | 85 dB | Idle current draw | 1.3 A | Maximum current draw | 173 A | Frequency bandwidth | 5 Hz to 200 Hz | Dimensions | 16.5″ x 8″ x 2″ (WxDxH) | RCA input maximum | 16 Volts |
SIQ 3000 D (Class D) Specifications
| Rated RMS power into 1 Ohm | 3000 watts | Rated RMS power into 2 Ohms | 2500 watts | Rated RMS power into 4 Ohms | 1500 watts | THD | 0.18% | S/N ratio | 84 dB | Idle current draw | 2.6 A | Maximum current draw | 354 A | Frequency bandwidth | 5 Hz to 200 Hz | Dimensions | 24.25″ x 8″ x 2″ (WxDxH) | RCA input maximum | 16 Volts |
Bill –
I have 3 of these bad boys. The 75.4, the 125.4 and the 1500d and am impressed beyond words how amazing they are. Tonally transparent, very powerful, supremely clean, very small power consumption and they are just beautiful pieces. Everyone that has seen them has said the same thing “Those are beautiful!” I replaced my Helix amps with them and it was the best move I could have made. They are every bit as clean and powerful as my old Mosconi Zeros and Sinfoni amps but for 1/4 the price (or less). I have 2 more cars to upgrade and there is no doubt they will be getting SIQ amplifiers as well. I have never tested and amp so powerful and clean at this price point much less one thats 10x more that I liked better. You simply cant go wrong if you just want clean and pure amplification.
Aaron –
I’m running a 3 way component set using passive crossovers.{In a pickup truck} I had them on a Rockford Fosgate 125 x 2 at 4ohms, no issues with the amp it’s just getting old. I came across a youtube video from Williston audio labs, he tested the 200.4 and was pleased. So I decided to replace my Rockford with a 200.2. I set the gains to deliver 180 watts at full power, I can’t even get to full volume it’s SO LOUD and absolutely crystal clear and my truck sounds so much better than it ever has. I’m blown away and extremely happy with my purchase. THANK YOU Stereo Integrity and THANK YOU Williston audio labs.
Ian –
I recently replaced an Alpine PDX-F4 and PDX-V9 with a trio of the SIQ amplifiers – A 75.4 for tweeters and midrange, another 75.4 bridged to a pair of SI TM65 and a 1500.1 powering an SQL-12 in a sealed enclosure. I had zero complaints with the PDX amplifiers, but the SIQ amplifiers have taken my system to another level, there is that little extra detail that was lacking before. Plenty of power, all the volume I could ever need, the price point is excellent for what you are getting and once you peel that protective layer off the window…. they look phenomenal. Don’t hesitate to buy one if you are considering it, you won’t be disappointed at all.
Tom kirby –
Had the opportunity to hear these connected to a SI 26″ sub. Played down to 8 Hertz and it did not disappoint!
MIrageB. –
So far I have only purchased the SIQ-75.4, but I plan to build my next front 3-way setup plus a subwoofer on SI components, in general, everything on SI components except the DSP.
What can I say about SIQ-75.4? This is a great-sounding amplifier that can accurately and reliably amplify a signal without introducing any distortion or embellishment to the sound. Built on audiophile components and with competent circuit design. Made from thick aluminum alloy, which means cooling should be fine, although it is always better to use additional cooling depending on the installation. Great looks. Probably the best price/quality ratio in terms of sound quality out of many car amplifiers I have listened to.
I highly recommend it to those who value sound quality.