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Summit Audio Everest ECS 410

Analogue Channel Strip
By Bob Thomas

Summit Audio Everest

Featuring a built-in push-button patchbay, it seems that this channel strip is scaling new heights...

Summit Audio's TLA100, launched in the '80s, combined the traditional feel of older compressor-limiters with Summit's unique approach to compression. This debut product felt 'right' from the start and is the longest-running continuously produced piece of audio outboard equipment. Summit have gone on to develop a range of compressors, equalisers and preamps, all of which are built in house in the USA, and the latest of which is the Everest ECS 410 Channel Strip.

Base Camp

This unique device combines four independent all-analogue building blocks in one 2U rackmount enclosure: the Mz2 mic preamp, FE1 passive three-band EQ, Dc1 compressor and Db2 output stage. Each can be accessed individually and the unique relay-switched TouchPatch routing system links them in series, via a total of 10 different preset configurations. I haven't seen this degree of physical configurability in a single unit before, and it makes the Everest extremely flexible in use.

An attractive, angular topography divides the light-grey, solid-metal front panel into separate areas, each containing one of the five operational functions. On the rear panel, four delineated areas carry the I/O on both balanced XLR and TRS quarter-inch jack. In the manual, Summit suggest connecting the I/O to a balanced patchbay, and unless you're simply going to use the Everest as a semi-configurable channel strip, this is a good idea.


The Mz2 mic preamp carries a front-panel Hi-Z quarter-inch jack input, a 10-segment LED meter, the TouchPatch LED, a rotary gain control and a bank of five switches, three of which select the mic input's -20dB pad, 48v phantom power and 60Hz high-pass filter. Of the remaining switches, one inverts the signal polarity and the other selects the tube or solid-state outputs.

Before hitting the Jensen line-level inter-stage transformer, the mic signal passes through a discrete solid-state preamp. In contrast, the mono Hi-Z jack input (which also switches out the XLR) runs into a 12AX7A valve preamp stage before reaching the same point. After the transformer, the signal passes through the polarity switch, the gain control and insert point, followed by either the valve or solid-state amplifier stage, the feed to the internal TouchPatch bus and, finally, the balanced buffer amp for the +4dB XLR and the -10dB TRS rear-panel jack outputs.

One nice thing is that you can start colouring the sound at this point, with a choice of valve warmth or solid-state purity. Having two parallel outputs available also means that you could, for example, record a dry signal direct and, at the same time, drive another device. Alternatively, you could record a safety track direct while routing the Mz2 on the internal TouchPatch bus and still have available both the TRS jack and a 'sniff' from the insert point.

The preamp's +60dB of gain (there's a further +20dB available via the Db2 output stage), coupled with a quoted solid-state output frequency bandwidth of 15Hz to 200kHz +0.5dB (15Hz–70kHz through the valve amp) means that the Mz2 will be more than able to handle any microphone or other source.

Three-band EQ

The Fe1 three-band passive EQ is a classic inductor-based LC circuit. If you haven't come across a passive LC equaliser before and you're interested in what makes them so special, there are several excellent papers, and you can find a good, maths-free starting point at

Fed from either its external input or the TouchPatch bus, the Fe1 provides +12dB of EQ over six separate switched frequencies on each of the three bands. The 500Hz to 3.3kHz midrange band is a peak filter, whereas the 33 to 390 Hz low-frequency and 5 to 16 kHz bands can be switched between peak or shelf responses. On all three bands the bandwidth (Q) of the peak response at the selected frequencies is two octaves, andthe shelving response cuts or boosts at 6dB per octave above or below the chosen points.

An In/Bypass switch allows you to compare the effect of your EQ settings with the unaffected signal and next to that sits the TouchPatch indicator LED. Two balanced +4dB XLR sockets make up the rear-panel I/O as, unlike the other sections, the Fe1 does not have any additional TRS quarter-inch jack sockets.

The Fe1 also has a wide frequency bandwidth, its +0.5dB points being at 5Hz and 100kHz. As with the Mz2 this level of performance is not going to place any constraints on the source material being fed into it. In a perfect world, I'd like to have seen a subsonic high-pass filter in the Fe1 to prevent the build-up of too much energy in the low bass frequencies, but you can't have everything.

Dual-mode Dynamics

The Dc1 compressor utilises a proprietary Summit design. This allows you to select between their smooth-sounding classic implementation of programme-dependent compression, at an approximate ratio of 3:1, and a tighter, faster and harder 10:1 manually controllable compressor with continuously variable threshold, attack (4 to 100 ms) and release (50ms to 1s).

In addition, a 10-segment LED ladder calibrated in 1.5dB steps to 15dB shows the amount of gain reduction being applied. A three-position switch next to the LED routing indicator can either switch the Dc1 in and out of circuit, or link two Everests together to form a stereo compressor.

On the Dc1 rear-panel area, the XLR I/O sits next to the Link socket and the TRS external side-chain socket. Here, you can route an external trigger via the ring of the TRS jack plus also you have the option of taking a sniff output. The Dc1 +0.5dB frequency bandwidth is again a superb 5Hz to 136kHz.

One omission on the Everest that surprised me is that there's no way to insert the Fe1 EQ into the Dc1 side-chain to assist in de-essing, other than via an external physical connection. Granted, Summit do recommend the connection of a patchbay to the Everest but, from my personal point of view, a TouchPatch insert routing facility for this would have been useful.

Drive Stage & Master Output

The concept of a drive stage coupled with a master volume control first surfaced on guitar amps some 45 years ago. The Everest's final stage, the Db2, features two selectable gain stages — Tube (valve) and Solid State — both of which can be overdriven in order to increase the harmonic content of the output, adding a subjective richness and warmth to the sound.

In the Db2, the smaller Drive control sits underneath both the three-position switch that selects between the two gain stages and Bypass, and the two LEDs that monitor the TouchPatch bus for any unwanted distortion (red) and indicate that the gain stages are being overdriven (yellow). A nicely retro-looking VU meter sitting above the much larger Output gain control completes the control complement.

Both the high-voltage, transistor-based solid-state gain stage and the twin 12AX7A, triple-triode, zero-feedback valve stage run in Class A and are designed to deliver both clean and saturated sounds. For ultimate fidelity, bypassing the gain stages removes them entirely from the signal path. The +0.5dB bandwidth with the solid-state drive stage in circuit is 5Hz to 200kHz, and with the valve stage in that reduces to a more mundane (but still respectable) 5Hz to 25kHz. Once again, the back-panel I/O are on two balanced +4dB XLR sockets plus a balanced TRS jack at -10dB.

TouchPatch Routing System

If there's one thing that endears the Everest to me more than anything else, it's the TouchPatch routing system. Ten buttons route the four sections to the Drive bus in various combinations. Nine of the preset configurations end with the DriveBus output, while the tenth configuration is the 'nothing routed' preset in which the sections are entirely separated. Five of the nine routed presets have the Mz1 routed to the DriveBus with or without the Fe1 and Dc1, and the remaining four are configurations of Fe1, Dc1 and DriveBus.

With nothing routed, each section's rear-panel external input and outputs are available for connecting to whatever source and destination you have to hand — so you could, for example, insert the Everest's compressor into a channel of your mixer, and the EQ into another, route a recorded vocal through the DriveBus, and so on.

Most stages of this channel strip feature multiple output options.Most stages of this channel strip feature multiple output options.

When the input of one section has the output of another routed into it via TouchPatch, although its external input is disabled both sections' outputs remain active. This enables you to route, for example, the Dc1 into the Fe1 into the DriveBus and insert the Dc1/Fe1 combination into a mixer channel, whilst still having the Dc1 and DriveBus outputs available separately.

Extending that concept, using the TouchPatch system and the Everest's XLR and TRS outputs, it's possible to get six simultaneous outputs from one source: you have the main XLR outputs from the four processing stages plus the Mz2 and DriveBus TRS outputs available. That gives you multiple choices of recording clean or processed sources, including six completely clean feeds with the DC1 and Fe1 bypassed.

Climbing The Mountain

The Everest is an intuitive pleasure in use. Setting up a mic in the preamp is simply a case of adjusting the gain and choosing between valve or solid-state output. For ultimate transparency and fidelity, use the transistor stage and take the output straight from the Mz2 rear panel or, if you need the gain control, from the DriveBus with the Drive section bypassed. If you want a more coloured sound, the tube stage coupled with either the solid-state or valve drive stages gives you a seemingly infinite range of thicker,warmed-up sounds. For electric guitar and bass, the Everest is probably the finest 12AX7-based guitar input stage that you'll ever come across — it's also the most expensive way I know of feeding three 12AX7 valves into a guitar amp.

Adding EQ and/or compression takes a simple TouchPatch button press and careful use of your ears. The Everest EQ doesn't really do surgical cuts or boosts, it's much more adept at the broader function of tonal shaping and sculpting, and this ability allowed me to develop real tonal character in my sounds. The compressor is another intuitive joy. The Classic setting is absolutely perfect for vocals and bass guitar and I loved the Tight mode for its ability to deliver that snap and pop so loved by country guitarists or to grab a snare-drum transient and nail it down.

Then there's the DriveBus to play with, and it's here that the Everest really comes alive for me. I could easily spend a very happy hour or two with the Everest inserted in a track return tweaking the other sections and the DriveBus looking for exactly the sound character I want. Of course you can get great sounds out of it much more quickly than that, but there are those occasions when only perfection will do!

Then there's the Everest's overall sound — the clear and highly detailed direct output from the Mz2 preamp at one extreme, but becoming warmer and richer as the DriveBus comes into play at the other. The ability of the Fe1 equaliser to add both air and depth to a source meant it was a real joy to work with, as was the smooth sound and action of the Dc1 compressor in its Classic mode. There's a character and an air of sheer quality in the sound of the Everest that I just can't replicate in my own setup, and that I'm really going to miss after this review is over.

Summit Special?

The Summit Everest ECS 410 Channel Strip is a very special device. It sounds wonderful, it has a character all of its own, it offers great flexibility in configuration and using it is a completely intuitive experience where your ears are the one and only arbiter of sound. There's no recall, no programmability, no automation — nothing but the facilities necessary to help you find the sound that you want in a source. I happen to like making decisions as I go along about how a track will sound in the final mix, but if you prefer to delay those decisions, you'll love the facility in the Everest to record multiple simultaneous clean feeds to which you can add EQ, compression and drive later.

Certainly the Everest is expensive, certainly it has a character of its own and certainly there will be times when you'll feel that another preamp, compressor or EQ suits a particular voice or instrument slightly better. However, that choice will be down to your personal preferences rather than to the performance of the Everest.

I could say that the Everest ECS 410 Channel Strip is the peak of the Summit Audio range, the high point of 25 years of experience — but instead, I'll give up on these mountainous metaphors and simply recommend that you audition one at your earliest opportunity.  


There are no direct equivalents, but in the Everest's price bracket you'll find similar offerings from the likes of Tube-Tech, Manley, Rupert Neve, Millenia and Empirical Labs. SPL's Frontliner takes a similarly modular approach but lacks the onboard patching. You could also look at building your own bespoke combination of 500-series rack units.

In this price bracket, differences in performance are more down to differences in design philosophy and implementation and equipment choice becomes more a matter of personal taste and workflow preferences than anything else.


  • Wonderful, all-analogue sound.
  • Four independent sections.
  • TouchPatch routing configuration.
  • Unique DriveBus output saturation.
  • Hand-crafted in the USA.
  • Expensive, but great value for what it delivers.


  • None — unless the cost is outside your budget.


The Summit Audio Everest ECS 410 is a unique embodiment of the ubiquitous channel strip, combining the exemplary audio performance of its four sections with push-button configurability. Unique drive circuitry can add saturation from solid-state or valve gain stages to add warmth and harmonic complexity to the final output. Expensive to buy, but low cost for the sound that it delivers. If the Everest's level of performance is within budget, then auditioning it is a must.


£3349 including VAT.

Summit Audio +1 775 782 8838


Summit Audio +1 775 782 8838

Published January 2014