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Manley Labs ELOP+

Dual-channel Compressor By Matt Houghton
Published June 2020

Manley Labs ELOP+

Manley's well-liked optical compressor gets a makeover in time for its 30th birthday!

One of Manley Labs' first products, the ELOP compressor/limiter has proved enduringly popular. It hit the market in the very early '90s, having been conceived before Manley Labs even existed, and remained pretty much unchanged through almost three decades. Like all Manley gear, the ELOP uses vacuum-tube electronics, but in this case, only for the amplification stages — the gain reduction is courtesy of an electro-optical cell. If that sounds a lot like the famous Teletronix LA‑2A, it's no coincidence; Manley make no secret of the fact that the LA‑2A was the inspiration for the ELOP. Construction techniques have evolved over the last few decades, and Manley decided it was high time the ELOP design was refreshed. The result is the ELOP+.

In With The New

The first thing to say, from a user point of view, is that there are more similarities with the original ELOP than differences. It remains a classy-sounding processor that's capable of a lovely, clean, relaxed-sounding compression. It can be 'driven' a bit to coax some flavour out of the tube stages, but the aim is for clean, unobtrusive dynamic control, and to that end, the tube amp stages have bags of headroom. There are still two channels, which can be dual mono or stereo-linked. And general operation is the same: you juggle a peak Reduction knob, which is a threshold control, and a make-up Gain pot. All the knobs have a good feel, with a smooth action. A characteristic of this type of compression is that the ratio and attack/release times are dependent on how much gain reduction is applied, but hold that thought...

The front panel has been restyled to bring it in line with Manley's wider range, and it looks as classy as it sounds. Most of the switched functions are unchanged, but the original's metal toggle switches have been replaced by bright-but-diffused white backlit latching buttons, which provide a tastefully discreet yet clear indication of the status. The screen-printed brand name has moved to the middle, but the model name is CNC-milled into the brushed-metal front panel. The other labels and markings are cleanly printed and easy to read.

While both channels still have switchable side-chain filters and an in/bypass switch, and the metering remains switchable between gain reduction and output level, there are some small changes. For instance, where the original's side-chain filter switch offered 100 and 200 Hz options (as well as off), that of the the ELOP+ is an on/off type. This filter is factory set to 80Hz, but an internal jumper can be used to set it instead to 150Hz — so you do have options, just not from the front panel. And whereas the original had separate switches for each meter, a single switch now controls both channels together. This 'lost' functionality is not something I missed in use, and I suspect the design aim was to keep the front panel minimal and uncluttered while incorporating a headline new feature: one button per channel that switches from the normal (broadly 10:1 ratio) 'limiting' to a new compression (broadly 3:1) mode. This facility, another nod to the LA‑2A, doesn't only allow you to choose whether to compress or limit a signal. As it's a dual-channel design, you can treat two sources differently (a vocal and acoustic guitar, say), or both compress and limit one mono source. This makes it really useful in a vocal or bass recording chain, for example.

Other significant changes aren't visible from the front. The original's inputs and outputs were unbalanced, but handwound 'Manley Iron' transformers now balance the ELOP+'s inputs, and the outputs are impedance-balanced. The PSU has been updated with the 90-254 Volts AC switch-mode model used in the rest of Manley's range — this helps to lower the noise floor, and obviously makes manufacturing and maintenance more efficient. The internal construction is tidier and more modern-looking, but I was pleased to see that through-hole components are still used.

One of several improvements to the original ELOP design is the provision of balanced I/O. The inputs use Manley's own hand-wound transformers, while the outputs are impedance balanced.One of several improvements to the original ELOP design is the provision of balanced I/O. The inputs use Manley's own hand-wound transformers, while the outputs are impedance balanced.

Reduction Made Easy

I said 'broadly' when describing the ratio settings, because in either mode the ratio isn't constant, and neither are the attack and release times. It's a characteristic of optical compressors like this that the gain reduction becomes more assertive the more the signal exceeds the threshold. As the optical cell's light source (in this case an LED) becomes more intense, so the ratio increases until the LED is fully illuminated at around 20dB of gain reduction.

Attack and release both get faster as the signal level rises, and back off again as the gain reduction reduces. In practical terms, this behaviour means the compressor can act swiftly enough to take care of, for example, loud consonants, while acting more gently on lower-level sounds. It's why optical compressors like this can, despite the small number of controls, deliver gentle, natural-sounding vocal compression, pin down a bass part with lashings of gain reduction, or smash the bejeezus out of a drum bus.

One quirk of Manley's design is that the meter ballistics stop being anything like accurate once you reach about -20dB. It's not that Manley are unaware of this, but that they chose to focus on getting the ballistics right in the useful range, and I reckon it's the right decision. I mean, if you're applying that much gain reduction, you're into effect territory where the ear rules absolutely, and the meters are redundant.

You genuinely have to work really hard to make the ELOP+ sound bad and this, combined with the dual channels, means it excels as a tracking compressor.

Over the course of a few recordings and mixes, I used the ELOP+ on a range of different sources and it quietly got on with the job in the most unfussy way: fast enough to take care of peaks and natural performance dynamics, yet also relaxed and graceful. The overall character is fairly transparent but there's a subtle je ne sais quoi that must be from the tube stages, since it doesn't go away when the gain reduction is bypassed.

You genuinely have to work really hard to make the ELOP+ sound bad, and this means it excels as a tracking compressor. Some say there's no point recording with compression, given the headroom of 24- and 32-bit recording and the capability of plug‑ins, but I'm of a different view. If you know that you're going to compress something and can do even half the job while tracking, you might as well get on with it; it's much nicer to pull up the faders if your recording sounds half mixed already! It was wonderful in this role on vocals in particular.

What's Not To Like?

As a reviewer, I find it really hard to be critical of the ELOP+, which says a lot. I considered whether Manley might have missed a trick in not including a wet/dry blend knob, since I love to use this sort of compressor in parallel, and quite often I'll run a signal through a parallel compressor, to bring up details, and then into another to tackle wayward peaks. But that would add to the cost and complexity, and I tend to EQ the compressed sound; 'instant parallel compression' wet/dry knobs can make me a little lazy! Some users might prefer a couple more controls. The ability to change the side-chain filter frequency from the front panel rather than using an internal jumper could be handy, for example, as would a switch to route the output of channel 1 into channel 2's input, removing the need for repatching for the compress-then-limit trick. But the simplicity of the ELOP+ is a big selling point, and such additions could easily erode that; you have to draw the line somewhere and I think Manley have struck a decent balance.

Sound-wise, I have absolutely no complaints, and so I have to give the ELOP+ a big thumbs up. Enough has changed to make it more useful in a modern studio than its predecessor (lower noise, ratio switch, better visual feedback and balanced I/O) but in essence, it's the same, intuitive, great-sounding processor that gets a sound where you want it very quickly, and allows you to focus on the music rather than the gear. You pay for such luxury, of course, but while the ELOP+ is priced with professional users in mind, it's a versatile device that should see a lot of use in any setup, and it's more competitive on a price-per-channel basis than some rivals of comparable quality.


Tube optical compressors are available from Universal Audio, Tube-Tech, Buzz Audio, IGS Audio and Gyraf Audio. LA‑2A clones from Golden Age Project, Warm Audio, Stam Audio and Klark Teknik might also be worth considering — but you'd need two of them.


  • Two channels of idiot-proof, effortless-sounding gain reduction.
  • New 3:1 ratio mode extends versatility.
  • Adds the balanced I/O that the original ELOP lacked.
  • Lower noise floor.
  • Bypass makes it a lovely line amp.


  • 150Hz HPF option only via a jumper.


The original ELOP was well liked and this overhaul will do nothing to dent its popularity. The addition of a gentler ratio increases versatility, but the general selling point remains the same: classy-sounding level control that's utterly foolproof.


£2499 including VAT.


Manley Labs +1 909 627 4256.