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The LIVERPOOL  Tube Compressor inspires creativity and has a sound reminiscent of world famous Mu compressors used at major Studios. It is a modern design born from an original American Mu tube compressor modified by engineers in the 1960’s.  The Liverpool incorporates large custom wound transformers, new old stock tubes and high quality components throughout the audio path. The Liverpool Compressor is a combination of art and function.

Out of stock


Grove Hill Audio introduces the LIVERPOOL — a hand-assembled, all-tube feedback compressor.

Tube compressors were first introduced in the early 1930’s, and became widely used in the United States and Europe in the 60’s. An original American Mu tube compressor found its way to England where it was improved with several modifications; these units are still in use today. However, these rare custom configurations have never been commercially available. For years there’s been much curiosity surrounding the modifications made to these renowned compressors.  To differentiate the modified units,

The LIVERPOOL compressor is a distinct and unrivaled product, and NOT a clone of its predecessors. It is a fusion of the American compressor and the British-modified feedback compressor designs, with modern enhancements that were thoughtfully developed in the spirit of the original Mu tube compressor.

The designers of the LIVERPOOL compressor took well over a year to recreate the sonic character of the original units still in use at world famous recording studios. Custom-wound input and output transformers (Made in the USA), critical component choices and circuit layout make the LIVERPOOL compressor a reliable, creative tool for a wide variety of instruments, vocals and program sources. The LIVERPOOL power supply also provides low noise and exceptional stability even at high (30dB) gain reductions.

We are passionate about this remarkable compressor and are excited to offer it at an accessible price to the creative recording arts community. Because of the rare components used in the LIVERPOOL design, we are building the compressor in limited quantities.





Click For – Quick Start Guide

Audio Samples:




 Background Vocals


Full Kit with Mono Ribbon Compressed


Floor Tom – Flat then with Compression


Kick – Flat then with EQ and Compression



Type:                                                         Tube compressor, 2U rack mount design

Frequency Response:                                +/- 1.5dB, 10 Hz to 40,000Hz

Power Output:                                            +20 dBu

Total Harmonic Distortion:                          0.08% at 1 KHz with output at 0dB

Noise Level:                                                82 dBu below rated output

Source Impedance:                                      Any up to 15,000 Ohms

Load Impedance:                                         600 Ohms

Attenuation:                                                 30 dB in 5 dB steps – Constant impedance.

Maximum Compression:                             30dB

Attack Times (msec):                                  3*, 19*, 48*, 77*, 109*, 138*.

Recovery Times (*msec):                           127*, 447*, 917*, 1.9 sec., 3.4 sec., 6 sec.

Threshold:                                                   0dBm to +16dBm Output

Compression Ratios:                                   2:1 at 0dBm Threshold, 4:1 at +16dBm Threshold

Tube Complement:                                      6BC8/6BZ8, 6CG7, 6AL5

Circuit Design:                                            Variable transconductance compression circuit utilizing a medium Mu, semi-remote cutoff twin triode tube.



Additional Information

Weight 13 lbs
Dimensions 24 x 12 x 6 in
  1. :

    For an audio dinosaur like myself, the Liverpool is simply one of the most exciting pieces of gear I have ever run signal through. Ignoring its primary function as a compressor for a moment, the transformer coupled line amp heart of this machine is a true testimony to the hours of listening tests that have gone into this design. I have always been a fan of quality transformers in their ability to help audio maintain a visceral holographic quality, and the Liverpool does this at a level that was unmatched by any other device in the Robert Lang Studios arsenal. There is a presence and clarity which is comparable to the silverface 1176, which stands as my go to lead vocal comp, and the depth and body of the LA2A.
    No matter what material I fed it, bass, guitar, vocal, drums,… the Liverpool delivered back a sound that was just beautiful to listen to. Frequently, I found that found that instruments required no additional processing at all to sound “finished”, the harmonic balance of the transformers is just that nice – and that is a most superb trick.

  2. :

    The Liverpool compressor by Grove Hill is a wonderful piece. I tried it out for a few days and became very attached.
    On a male lead baritone vocal it immediately added extra classic colour with a consistent top end texture. The mids were buttery smooth, not harsh in any way, even with heavy gain reduction.
    On roomy backing vocals, the Liverpool was superb, grabbing them just right. Sitting perfectly in the mix without needing even a hint of EQ. The unruly note to note dynamics of the Mellotron were easily leveled too.
    The attack and release settings allow you to go from gentle averaging to aggressive shaping and the “hold” features add even further unique character.
    I wish I could have had the unit longer, but my impression is that it’s an extremely flexible, super musical compressor reminiscent of my trusty old Telefunken U73B tube compressor.

  3. :

    This is the gear that you want to run through to make everything sound better. If you want to hit a part really hard and give it a little more bite, the Liverpool is your best friend. My favorite setting is with the threshold all the way off, then run a vocal track through it and hit the input hard. It will make the vocal sparkle and jump out of the mix! The “hold” feature allows you to compress as much as you want, without hearing the compressor clamp down, or lift up at the tail. It’s one of the most fun pieces of outboard gear I’ve had in the studio.

  4. :

    As soon as I heard the Liverpool, I sold my vintage black-face 1176 and bought two. It’s not almost as good (like clones try to be). It’s actually better.

  5. :

    Just wanted to send you a message telling you how much I love the compressor. A friend of mind brought his Chandler RS124 over yesterday and we did some comparisons. I would say your unit held it’s own against the Chandler in just about every way. If anything, your unit was a little smoother and retained the bottom end on bass guitar a bit better. Yours was able to be a little quicker and I definitely felt yours was more flexible due to the separate input and threshold knobs. On yours, I’m generally always using the unit with the output set to -15 or -10, meaning I’ve always got a little extra juice on the end if I need it. With the Chandler, I definitely found myself running out of gain with output maxed. The only way to get more output is to turn up the input, which compresses more. … Your unit completely satisfies my desire for an RS124 type compressor.

  6. :

    Wonderfully transparent!

  7. :

    So far everything I’ve tried sounds better through this Grove Hill Audio Liverpool.

  8. :

    The analog sound is rising once more in our brave new digital world, and it’s good to know that there are still those who understand, and are committed to what sounds please the ear most. The Liverpool is the perfect mediator between my vocal mic and the hard drive. It softens the potholes and smooths the rough edges without sounding like a speed bump or something that got in the way. Congratulations guys.

  9. :

    I’ve been trying out this Grove Hill Liverpool compressor this week. It’s rocking!! Thanks to my good friend and gear guru PK for shipping some toys down to Santa Fe for me to play with. I’ve been using it on vocals and guitars this week, looking forward to trying it on drums next week.

  10. :

    It’s lovely and quiet – especially given its tube topology. Even when the compressor isn’t doing much, if any gain reduction, it seems to make things sound better, tighter, rounder.
    The lack of a bypass switch threw me at first, but after a few minutes use, the intermediate compressor off steps in the attack knob make perfect sense – and are actually easier / better than a separate bypass switch. More people should do this!
    It does both subtle and not very subtle compression really nicely – so often a box is good at one or the other and not both.
    Loved the hold function.
    All in all a sweet sounding box.

  11. :

    Oh!! I really like the Liverpool, I have been inserting it into the CL5 & it works amazing.

  12. :

    The Liverpool compressor sounded great on bass! When we a-b it with our trusty LA2a we chose the Liverpool for the vintage tones of the new Might Oaks album. It had a presence in the mids that fit right in the mix.

  13. :

    Man, this has been a fun find! The Liverpool is one of those rare units that just begs experimentation.
    And then pleasantly surprises you for your efforts. Gotta get a second unit!

  14. :

    Grove Hill Liverpool is a contemporary fusion of 1960s’ finest American and British compression technologies. This compressor sounds just like you like it – rich, wide and thick. Run acoustic guitars through it and you’ll hear them as clear as possible, yet with more full-bodied sound and soul. A great mid range healer it’ll add a desired smoothness to guitar leads, synths and vocals. When applied to bass you’ll achieve big and warm sound, push harder and you’ll add an edge without affecting clarity.

  15. :

    The Liverpool Institute for Performing Arts

    The Liverpool comes home…

    We took the opportunity of a small summer refit to install a Liverpool Compressor in our flagship room, the George Martin Studio. Opened in 1996, the Liverpool Institute for Performing Arts (LIPA) was founded in 1996 as a small specialist university that trains both performers (Actors, Musicians, Dancers) and those that make performance possible (Audio Engineers, Theatre Technicians and Designers, Managers). It seemed appropriate somehow, that a Liverpool should find a home here.

    After first being introduced to it by Steve Levine, it was obvious to me that the Liverpool had both such a unique sonic signature, and a wonderfully intuitive way of interacting with users, that we had to let our students have access to one. I love the way that it encourages you to listen to what it’s doing to the sound, rather than simply looking at settings. Having those bypass positions between the different attack settings is also really useful for encouraging students to really listen to the effect that this important parameter has. It’s lovely and quiet for a tube device, and even when there isn’t much gain reduction going on it seems to make things sound better, tighter and rounder. It segues seamlessly between subtle, transparent control and outright aggressive compression – it’s unusual to find a single box that’s equally happy both in a delicate vocal chain and strapped across a room mic for a drum kit.


    Jon Thornton, Head of Sound Technology

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