
Stam Audio Engineering builds high-end studio tools by hand about 75 miles outside Santiago, Chile. Dig around in online forums and you can find numerous mentions of Stam Audio. Some users express concerns about quoted lead times for popular items but Stam builds each model in small batches and does not always keep pace with growing demand.
While I have never used an SSL G-series stereo-bus compressor, I briefly used a very similar one designed by a former employee of SSL. Earlier this year, I happily bought another popular clone of the SSL stereo-bus compressor. Even though I had results that clients were quite happy with, something about the SA4000 MK2 from Stam intrigued me enough to secure a review unit.
When I unboxed the SA4000 MK2, I was impressed by how solid the chassis was overall. I didn’t find any loose or uneven sides as I have on other, more expensive gear. The machining was nice on every surface and edge. The larger top vents offered me a glimpse of the beautifully designed interior. The buttons as well as the stepped attenuators and potentiometers under the traditional knobs also felt reassuringly solid.

The first thing you notice on the front panel is the gain-reduction meter. Who doesn’t love the black dial and illuminated markers and needle? It looks sharp and is visible from a distance. The controls are mostly standard in terms of threshold, ratio, attack, release and makeup gain. Worth noting is the addition of 1.5:1 and 3:1 ratios not found on the original version of the SA4000. A five-position sidechain filter control is also a nice touch.
The back panel is neatly arranged with a pair of XLR inputs, a pair of XLR outputs and a single XLR sidechain input. Near the IEC power input socket is a small, recessed switch to select an input voltage of either 115VAC or 230VAC. There was no included power cord but since the SA4000 MK2 has an internal transformer, it requires only a standard IEC type. You should have no trouble finding a power cord for the wall receptacle type used in your country.

The SA4000 MK2 offers two more indispensable features: a wet/dry mix blend control for parallel processing and a push-button switch to select an external sidechain control signal. The latter can also be used in conjunction with the sidechain high-pass filter switch for greater flexibility in defining the compressor’s response to source material.
One more distinctive feature of the SA4000 MK2 is the transformer button which allows the user who paid for one of the two upgrade options to route the output through either a pair of Carnhill transformers (like that used in a Neve 1073) or a pair of unspecified transformers coupled with Stam’s version of the API 2520 op-amp. I did not request either upgrade option when I ordered the review unit, so I focused on its fundamental operation and performance.
I ran a recently-approved mix for my flagship client through the SA4000 MK2 with the settings closely matched to what I had on my compressor, then sent it to the client who was immediately blown away by the improvements. We agreed that the SA4000 MK2 sounded amazing. It has more character, weight and a slightly darker tone than my compressor yet somehow glued the mix together and retained more detail and depth of the stereo field.
I also ran some other experiments with new demos and unfinished mixes of pop tracks and singer/songwriter tracks through the SA4000 MK2, which revealed more of the same changes in tone and overall improvements to each mix. Rather than having a slicker, smoothed-over sound like my compressor, the SA4000 MK2 allowed natural textures and subtle dynamics to come through.
My compressor feels a bit cheaply made and sounds somewhat thin and synthetic relative to the SA4000 MK2, perhaps because it is made with lower quality surface-mount components. In contrast, Stam delivers superior quality for less money with premium and custom parts, hand-matched and hand-soldered to each board. That sort of focus on quality is rare and likely why the SA4000 MK2 walks all over the mass-produced competition.
My only criticism of the SA4000 MK2 is that while the control knobs for threshold, ratio, attack, release, sidechain HPF, gain and mix are quite nice, the position indicators are only visual and not tactile. The gain-reduction meter is quite usable in low light but the knobs are not at all, so I might suggest a new variation of the same knobs with raised position markers on each cap. That’s the best complaint I could come up with.
In summary, the SA4000 MK2 is a lively, versatile, huge-sounding compressor that offers the usual benefits of a quality VCA-based compressor but with some nice harmonic coloration and character, quite unlike the boring, glassy sounding alternatives on the market. I initially thought this compressor would only work well for pop and rock songs. After continued use, I think it works extremely well for any musical genre.
Many thanks to Josh and everyone at Stam Audio for making this happen. For more details on the SA4000 MK2, please visit: