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PAR’s software editor finds the new MkII as desirable as his original ISA 428, and then some.

It is in our nature to be skeptical, for most of us anyway. So, after Focusrite announced that the update to the classic ISA 428 — the MkII — would be less expensive than the original, yet maintain the same signal path, how could I not initially question its quality? Being a happy owner of the original ISA 428, I wanted to give the new MkII a thorough, comparative runthrough.

There are a few reasons why I like the original ISA 428: It has four high-quality channels; VU and digital metering; variable impedance, Hi-Z 1/4-inch inputs on the front panel; variable high-pass filters; a digital I/O option; 1/4-inch inserts; and, most importantly, it sounds very good.


Breaking the new MkII out of its shipping box, I stacked it right on top of my original ISA 428. The first difference I noticed in the MkII is the lack of analog VU meters. Both units retain the LED meters, displaying levels before the A/D converters. The result is that there is more frontpanel real estate, so the MKII has much bigger knobs for Gain, Filter and Trim on each of the four channels.

The Soft Limiter has been removed, as well as the Bit Depth button. On the inside, the power supply has been switched from linear to a switched-mode supply. According to Focusrite, this allows it to be plugged into most mains power supplies around the world without changing a voltage selector or fuse. This not only reduces the weight of the MKII but also (thankfully), lowers the operating temp — as the original can run quite hot.

In Use

Certainly, the cosmetics of the unit are a bit different, but how about the sound? To test this, I took both ISA 428s to my good friend Vincent Miraglia’s studio. Miraglia, aside from being an electronic design engineer, is also a talented drummer who records a lot of TV cues with me.

Our first step was to install the optional digital card; this 192 kHz, 8-channel card features Burr-Brown pro audio amps, PCM4220 A/D converter chips, a 25-pin D-Sub connector (for DAW users, etc.), two ADAT Lightpipe outputs, choice of one- or two-wire and AES or S/PDIF buttons and Word Clock I/O.

Popping the top, we noticed the nice Lundahl LL1538 transformers staring up at us; the MkII uses the same Lundahl transformers and input signal path as the original. The design inside was clean and neat; the digital card install took just a few minutes. Holding down any front button on startup digitally initializes the unit; this only has to be done once.

Next, we set the ISA 428s together and plugged an optical cable into an Avid Pro Tools 9 rig. We began with the original ISA 428. For drum tracks, we ran a pair of omni Earthworks SRO mics into channels 1 and 2 as overheads. On channel 3, we placed a Shure Beta 52 on the kick; on channel 4, we placed a Miktek C7 as a mono room mic. We then ran through each of the impedances and recorded the same basic drum pattern. It was the clean, clear sound that I know so well.

Then we plugged in the MkII using the same mic configuration and recorded in the same sequence of impedances; High (6.8K), Med (2.4K), ISA 110 (1.4K) and Low (600). While this was non-scientific (as his playing would understandably change a bit with each pass), we both heard little, if any, difference between the two units. OK, Focusrite wasn’t lying: these units would sound the same to our ears.

We were more impressed with the different impedances and the effect they had on each mic. The High impedance had the most open sound, with additional top end and clarity. The Medium setting had slightly less top, and Low was almost muted (Low seems to work best with some ribbons). But the ISA 110 setting really knocked us both out. It was punchy and thick, almost like good analog tape.

Placing a UA 1176 across the room mic and going for the Bonham “thing” was just slamming (hear it on webclip 1). But on the high-impedance pass, the 1176 grabbed the extra top end of the hi-hats and cymbals and made it almost brittle. The ISA 110 setting came across much smoother and sat better in the mix. I find the MkII, like the original, to be transparent for the most part, but the various impedances can add color.

Regarding setting levels, on the first test with the original unit, I was glad to have the VU meters to get me in the ballpark. With the MkII, I thought I would miss them. Yet without a doubt, it was much easier and faster to set levels with the MkII simply because the knobs are so much bigger and laid out better. The original has very small knobs for Input Gain and Trim and is definitely harder to tweak. Also, I like to ride gain on sessions (especially with vocalists) but it was something I could not do with my original. With the MkII, that would no longer be a problem. However, I do feel that the knobs were “tighter” on the original; they don’t feel as “solid” on the MkIIs.

Taking the MkII back home to my studio, I used it on several acoustic sessions (hear webclips 2 and 3); the results were again what I expected (in a good way): crisp, clean sound with a responsive attack.

On guitarist/vocalist Dave Murphy, I used all four channels of the preamp, running a Miktek C7 (at medium impedance) on the body of his Martin 000-18NB; a beyer M120 ribbon (at low impedance) also on the body; and an Earthworks QTC1 (at high impedance) on the neck. From a K&K Pure Western mini pickup, I ran his Sarno Steel Guitar Black Box DI into the Hi-Z 1/4-inch input on the front of the MkII. Wow! The whole package sounded rich and full, pulling a lot of bass out of a small-bodied Martin. We overdubbed vocal with the C7, then sat back and enjoyed the sounds.


Just as I liked the original, I like the Focusrite ISA 428 MkII a lot. It features the same Lundahl transformers, is easier to use, sounds great, and delivers the goods as advertised. I do feel the digital option is very useful for DAW users, and to have this entire package with all the I/O for around 2k (street) is an excellent value. Oh, and I didn’t miss the VUs.

Price: $1,899 and $624, list (ISA 428 MkII and ISA 8CH A/D card, respectively)

Contact: Focusrite |
U.S. distributor: American Music & Sound | 800-431-2609 |

Rich Tozzoli is a composer, engineer/mixer and the software editor for Pro Audio Review.