HLabs CS169

Having studied the sturdy Studer 169 console, French company HLabs decided its classy combination of mic pre and EQ deserved a place in modern studios.

In the world of pro audio hardware, the classic analogue circuits of yesteryear continue to hold appeal, and it seems barely a month goes by where one recreation or another isn’t announced. But while countless products inspired by revered classics have made their way to me for review, I don’t think that I’d ever seen one based on the Studer 169 until HLabs’ latest creation arrived in my studio toward the end of last year. Having used it for a couple of months now, I have to say that I have no idea why that should be the case — because this CS169 is a very appealing and classy sounding device, and one that offers a different character from the various Neve‑ and API‑inspired designs that seem to have dominated this market in recent years.

Overview

The CS169 is based on the preamp and EQ section of the 169 console, made by the now‑legendary Swiss manufacturers Studer. First made in 1976, the 169 mixer was more compact and portable than the large‑format x89 consoles that had come before it, and it was an incredibly robust design. Reportedly, several thousand units were sold, and it saw use right around the world for location, broadcast and post‑production sound. In music production circles it soon gained a strong reputation for its open and detailed sound, and smooth, ‘musical’ EQ section, and that meant it found a home in many a small‑but‑serious studio.

HLabs’ interpretation of the 169 input channel is housed in a 1U rackmount chassis, with a white‑painted front panel providing the backdrop to dark‑blue, black and yellow legends and controls. On the rear, you’ll find four XLR sockets, with an input and output each for the preamp and EQ sections, and both those outputs have their own ground‑lift button. A short XLR patch cable joins the two sections but can be removed should you wish to access them separately or insert another device between them. The only other feature on the rear is the ubiquitous IEC C14 mains power inlet that accepts 10‑240 Volts and 50/60 Hz AC.

The preamp and EQ sections each have their own balanced XLR I/O and, as shipped, the preamp’s output is routed to the EQ’s input through a short patch cable.

On the left of the front panel, you’ll find controls for the transformer‑balanced preamp section; the input transformer is a Neutrik NTM‑4 and the output one a Carnhill VT24499. These controls comprise a large‑ish continuous gain control that’s marked with two gain ranges, switched using an adjacent Hi button. The ranges are given as +18 to +42 dB, and +40 to +65 dB, respectively, though HLabs say there’s actually a touch over 67dB available. There’s also a smaller output attenuator knob (‑30 to 0 dB) that allows you choose whether you want a cleaner sound (low gain, high output) or to drive the preamp hard in search of transformer coloration, and then back off the levels feeding the EQ or next device in the signal chain (higher gain, lower output). Next up we have buttons for the usual +48V phantom power, polarity inversion and a 33dB pad (making the total gain range a whopping 82dB), before a second‑order (12dB/oct) high‑pass filter with an in/bypass button. Since this filter can be set anywhere from 20 to 315 Hz it could be just as useful for taming proximity effect or pulling some low mids out of the way of another instrument as it can be for filtering out bumps and rumbles. All in all, then, there’s ample gain and both functional and sonic versatility here, whatever mic you’re working with.

To the right of all these controls is a high‑impedance (>1MΩ) TS jack input, for electric guitars, basses and the like, which feeds the same input transformer. A simple circuit, but one that should make most players happy, given those transformers. Speaking of impedances, the mic preamp input impedance is given as 1.2kΩ (not vast but ample), and the mic preamp output impedance is under 20Ω.

In the middle of the front panel is the three‑band EQ section, which comprises four knobs and an on/bypass button. Behind the faceplate, this is treated as an entirely separate device and the EQ has a transformerless input and output — having developed the 500‑series versions of each circuit, they’ve effectively put these PCBs in the same box with a dedicated PSU and reworked the front panel. It works well, even if I can’t help wondering what it might sound like using the EQ to shape the sound being fed into that Carnhill transformer! The EQ’s outer two bands are shelving filters and the knob controls the gain (marked simply from ‑4 to +4) and, somewhat counterintuitively, the band on the left is the high shelf and that on the right is the low shelf — it’s an arrangement that would make sense if the strip were arranged vertically, as on a console, but it initially threw me, given the horizontal orientation. Again, I gather that this is a byproduct of using the same design as their 500‑series versions, since this orientation of the boards makes sense internally. The mid band, Presence, has the same markings for the gain knob and is joined by a frequency selector pot that ranges continuously from 100Hz to 7kHz, which seems suitably generous for a general‑purpose recording EQ.

On the right, we have an output level meter and a large power toggle switch. The moving‑coil meter is a horizontal type where the needle moves across the edge of a protruding 3D curve. It’s nicely illuminated, the needle is visible from above, and anything above +4dBu is denoted by a thick red stripe so it’s easy to see if you have a healthy level coming in. Cleverly, the backlighting also turns red just before clipping. I approve of front‑panel power switches generally (who wants every device to be always on today?), and this particular switch is flanked by Studer‑esque protective cheeks.

There was plenty of gain on hand, and it accommodated sensitive mics used on loud snare hits without problem.

On Test

I’ve recorded through a Studer 169 only once before but I recall being impressed by its (for a vintage console) open and detailed sound that also benefited from a pleasing ‘smoothness’, which I mentally attributed at the time to the transformers. That experience was many years ago now, so I can’t claim to have made a direct comparison, but in subjective terms the CS169’s mic preamp and EQ stages certainly chimed with those memories, and I’d use the same subjective terms to describe it. I tried the usual sources — various dynamic and capacitor mics (including a ribbon) on vocals, acoustic guitar, miked electric guitar amp and percussion (a kick, a snare and a tambourine) and I was always very happy with the result. There was plenty of gain on hand, and it accommodated sensitive mics used on loud snare hits without problem. I found the instrument input a pleasant bonus, again lending a subtle coloration to the signal that’s comparable with that of the better transformer DI boxes I have at my disposal — it usually increased the appeal of the instruments that I played through it, and the front‑panel access could increase its attraction in a project studio setting.

On the face of it, the EQ section might not appear particularly remarkable in terms of functionality: there are no transformers, and there are just two shelves and a swept mid here (OK, if you’re using the preamp stage, there’s the high‑pass filter too, which can be used to shape the LF shelf to some extent), and there’s no control over the bandwidth or anything like that. But really, that’s precisely what you want in a recording channel — something that’s as easy in use as it is easy on the ear, with enough range in the gain controls (those markings on the gain knobs turn out to give you about ±15dB for the shelves and ±11dB for the Presence band) and the mid frequency to let you nudge most sources in whatever tonal direction you want, without the risk of causing carnage.

I know it’s fashionable to do EQ’ing after you’ve recorded these days, but I much prefer to get things sounding as close to the way I want on the way in, and if you don’t have a vast mic collection or the time available to audition and reposition mics, a good EQ is not just a perfectly legitimate tool — it can be incredibly useful. The sound of this one is oh‑so smooth. ‘Buttery’, if you like, yet for a vintage‑inspired design it certainly sounds pretty clean and open, especially at the top end. Other than during my initial confusion over the placement of those low and high bands, I found it nigh impossible to screw things up. There are plenty of other EQs that can do a similar thing in terms of the frequency response, but it does sound like there’s a bit more going on here than that, even when used without the preamp. Enough so that I sometimes found myself deciding to run signals out of the DAW and through it while mixing. In that role, I was marginally frustrated at the lack of post‑EQ output control, but that’s not really an issue when using the preamp as intended.

Verdict

HLabs’ CS169 is a classy transformer‑balanced recording channel, and could be a great option for anyone looking for a single, versatile, high‑quality front end, whether for mics or instruments. At this price, it’s competing in a crowded marketplace, with plenty of appealing channel strips available, some with different sounds and others boasting more functionality. But the CS169 is beautifully constructed, offers some thoughtful touches, and while these things are subtle in the grand scheme of things, the tonality is different from that of the many other ‘vintage’ recreations available today. So I’d say it’s well worth auditioning — in fact, if I had to record everything through this strip for the rest of my music‑making days, it certainly wouldn’t be the worst thing in the world!