MP573 - Mic Pre 500 series, Neve style - DIY Analog Pro Audio
  • MP573 - Mic Pre 500 series, Neve style - DIY Analog Pro Audio
  • MP573 - Mic Pre 500 series, Neve style - DIY Analog Pro Audio

MP573 Microphone preamplifier for the 500 series

$378.07 VAT incl.
$378.07 VAT excl.

The MP573 is a two stages, single ended class A preamp, based on the design that was originally used in the Neve 1290/1073 modules, that has been adapted to the 500 series of API.

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The MP573 is a two stages, single ended class A preamp, based on the design that was originally used in the Neve 1290/1073 modules, that has been adapted to the 500 series of API.

Just install it in your API* compatible LunchboxTM rack and start recording.

The sound of the MP573, like its model is full, silky, detailed and musical, slightly larger than life, very complimentary to a digital recording environment.

The MP573 is great on vocals, acoustic instruments and generally all close miked sources that need to be pushed forward in the mix.


    • Single ended class A design
    • Carnhill/St. Ives transformers on input and output
    • 0 to 70 dB of gain
    • Switchable 300 & 1200 Ohms and line level input impedance
    • The output stage is biased in a rich Class A with 70mA of iddle current
    • Fet DI input, relay switched, the signal passes through the input transformer
    • Signal/Clip LED monitors clipping in both stages
    • 24V supply built from the +/-16V with a linear regulator
    • Controlled inrush current for lunchboxes with sensitive power supply
    • Golden contacts on relays and switches
    • High quality Grayhill gain switch
    • Tantalum capacitors in the audio path (as in original)
    • High grade components throughout
    • High grade double sided PCB with plated holes
    • Easy build, dense but straightforward
    • Available assembled or as a full kit (everything included)

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1 Output level: Potentiometer that sets the signal level to the output stage.

2 Signal/Clip LED: Flashes green when a signal is present and turns red 3 dB before clipping.

3 Gain switch: In combination with the level potentiometer the overall gain can be set between 0 and +70dB. The 10 and 20 positions entirely bypass the input stage.

4 Input impedance: Center is the standard 1200 Ohms input impedance. Left sets a 300 Ohms low impedance, useful for ribbon mics that also adds 6 dB of gain. Right sets a 10 kOhm impedance input pad for line levels.

5 Polarity Sets the polarity (phase) of the output signal.

6 Sends phantom power to the microphone.

7 High impedance input (> 1 megohm) for instruments. The instrument signal goes through both transformers.

What's in the kit?

Absolutely everything!

  • Passive components (resistors, capacitors),
  • 2 Carnhill transformers
  • Active components (diodes, transistors, LED, ...),
  • Front panel elements (switches, potentiometers, knobs),
  • Connectors, relay,
  • PCB's,
  • Front panel and side panel,
  • All hardware

You bring the solder (use good quality solder, 1mm diameter max) and the Lunchbox.

Difficulty level

The MP573 kit is an easy build in spite of a rather large number of components.
The only setup is adjusting the bias current in the output stage. It requires a standard DC voltmeter.


Specific References

Technical specifications

Measure Conditions Value
Iddle supply current No input signal

V+ : +92mA
V- : -92mA

Input impedance f=1kHz 300Ω, 1200Ω and 10kΩ
Maximum input level Line input unlimited
Maximum output level before clip f=1kHz +27dBu
Minimum gain   0dB
Maximum gain   +70dB (+76dB in 300 Ohms)
EIN Zin=0Ω
Frequency response Gain=+40dB
Deviation < 1dB
THD f=1kHz
< 0.008%
DI input impedance   > 1MΩ
DI gain range   -22dB to +48dB
DI max input level   +15dBu

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Excellent Product, super parts, great price

I haven't tested the MP573 extensively, so I'm mainly focusing on the build process and the parts. Although there is a high parts density, it's great fun to solder and build this preamp. The selected parts including the Carnhill transformers as well as the Grayhill rotary switch are state of the art. Fully assembled this thing weighs a ton. Setup process is easy. Luckily I did not f* up and got no mistakes so I could enjoy the MP573 right away. My first listening tests indicated a low-noise preamp with lots of gain and great functionality. Now I have to do extensive tests with different material and A/B testing with my other preamps. I'll keep you updated.

Chuck V

Great sound, great kit

I've had it for about 5 years now and it sounds great on everything. Great clarity and tone. I particularly love the DI bass sound. Granted, I don't have day to day access to an original Neve to compare the sound, but it sounds great. The build was pretty easy, with good documentation.

Paul Tietze

Wonderful Preamp!

I bought it already assembled via Reverb. Comes very close to the original. The quality is actually on the same level soundwise. Warm, punchy, yet wich great resolution and depth. It does have the "magic" in the midrange that one would expect. The DI works exceptionally well for Bass. A fantastic preamp, I want another one!


Great preamp with small part inconsistencies

Just went through the build process of this preamp, no major complaints other than two things:

1. My kit did not have the SIL2.54 13-pin 90° headers, but I received straight headers instead - I tried bending them to 90° with catastrophic consequences, but luckily I was able to McGyver my way out by dremel'ing out similar parts from my own stash of random SIL 2.54 connectors.
2. One of the output tranny screws was bent a little bit and had no threads on it (!). Local hardware stores didn't have an exact replacement so I had to go full DIY here also and cut the threads to the screw myself.

Without the issues mentioned above I'd definitely give this kit the full 5 stars. Nevertheless the preamp works & sounds great, and overall I felt it was an easy build. I didn't really mind that much about the extra steps mentioned above, in the end they just added a bit more DIY to the build.

I definitely recommend this kit even with the small issues I had!

Stefan Dinkel

5 stars is not enough!!!

Just finished my second MP 573...i really love this characterful has all the classic vintage characzer, i was looking for...full sounding and handy bottom end, silky highs...extactly this "larger than life" i was reaching for...not a neutral, modern preamp, but still detailed, airy and very, very musical...5 stars is not enough!!!

Clergeot Michael

Parfait pour les voix, guitare acoustique, overhead

Je l'utilise sur des voix, guitare acoustique, overhead batterie (j'ai enfin un beau et vrai son de cymbale !).
Il est assez doux et enrichi délicatement le son.

Udo Terlisten

Another great piece of gear

I must say this is a very good preamp when it comes to that „bigger than life“-sounds on vocals.It was very easy to build,same as all the other kits I built from Soundskulptor so far.Very well prepared,no missing parts,superfast shipping to germany.Another great addition to my arsenal,congrats Jean-Pierre!

Best regards and keep it going,


Pierre B

ready to go preamp!

Preamp terriblement efficace et conforme à la description: si vous avez quelque chose à mettre en valeur dans le mix c'est bien ce preamp qu'il faut choisir!

Le kit est complet, très bien documenté. Attention cependant à bien lire la doc et à ne pas aller trop vite sur le montage même si vous avez l'habitude du DIY.

Et si vous avez un problème, le SAV répond très rapidement. J'ai eut un problème d'inversion de composant et avec la DI, et Jean-Pierre du support a su m'indiquer rapidement ce que je devais modifier.

J'ai pu faire une comparaison A/B avec un 710 universal audio sur une basse électrique, Synthé et voix. Résultat le MP573 remporte le match. Un très beau medium, du bas à revendre mais équilibré (j'ai pensé avoir oublié le low cut sur le 710 au début...), les aigus sont là.

L'avantage du kit: on sait ce qu'il y a dedans et c'est de la qualité! On peut éventuellement corriger soit meme une panne dans le temps. Qualité audio largement supérieur à ce que l'on peut trouver dans le commerce pour le même prix!

Bref Soundskulptor tape fort, le MP573 est devenu mon "ready to go", aussi bien en home studio qu'en live!

JG Teheux

Fabulous "1073"-inspired 500 Series preamp

Fantastic "1073"-style preamp kit for the money! Does everything you could hope this type of pre would do, with the bonus of a great integrated DI, all in the very popular 500 Series format with its many benefits (and no disadvantage, provided you use a good rack with a proper PSU).
The reason I chose SSK over the other popular options (AML, Don Classics, Heritage, AMS Neve, Golden Age Project, Warm Audio...) were :
- fantastic value for the money (partly thanks to the kit form) : for the price of an entry-level clone (GAP...) you get a top notch one (similar in sound quality to other listed above except Warm Audio which I found inferior although better than GAP).
- ease of build, great documentation, all components included in one single order (not the case with Don Classics)
- easily replacable, discrete components (not the case with AMS which has lots of SMD)
- can form a complete "1073" channel strip when combined with the SSK EQ573 module, or used independently : depending on the task at end you can quickly put or remove the EQ from your 500 Series rack (not the case with AML, Don Classics, or Heritage whose EQ doubles up on transformers so less flexible).
- formidable, unparalleled after-sale service by Jean-Pierre of SSK (should you run into any trouble)
The only two things I wish it had on top of that would be an output trim pot providing full attenuation or at least 20dB) and some sort of HPF (as on the Heritage HA-73jr), but these are more small details than real quibbles regarding what you get for the money which I think is unbeatable!
Thanks SSK and JPK for the fantastic kit and support!

Philipp Wilfinger

Great Sound

Have 4 573s:
Great Preamps!!
Had fun building, Great support as always,
They sound fantastic!


Best DIY 1073 Clone out there

If you are like me and were trying to decide between this and the AML EZ 1073 for your studio, I've got good news: you came to the right place.
I haven't personally tried the Ez1073 but from others I've heard that the MP573 sounds fatter and phat it sounds.
Additionally, the MP573 has a DI input which is very useful, and it accepts line level input with a flick of a switch- amazing!.
I can't think of a negative thing really, except the output knob could be a bit sturdier as it wobbles slightly, but that doesn't change the sound or the quality of the other parts.
Just phenomenal! I hope Jean-Pierre will make more kits. Merci!

Karl J


Hello. I just wanted to throw you some feedback (of the good kind). Now that I've had my 573 pre in use for over 1.5 year, I gotta say it's GREAT! I have some other Neve clones and legit API 512c pres and the 573 hangs right with them. In fact, the DI is so huge it's become my go to for Bass guitar. The 573 has also been doing the main vocal tracks on my current project, as well as having some duties recording guitars through Marshall amp.

I'm tracking drums for my project in two weeks and plan on using the 573 with a tube mic for "front of kit" duties and I know it will sound HUGE!

All said, it is a great kit at a reasonable price. It arrived quickly! And JPK is great at answering the tech questions.

I still have a slot left in my lunchbox and am curious about the MP566. But another MP573 is very likely. I can't recommend it enough!



For the record, I had never soldered before I bought my first Sound Skulptor kit (CP5176). I love this pre! I use it for everything, but it's especially cool on vocals. It may be taboo, but I even use it on acoustic guitar. The build is easy and straightforward. The sound is great from crisp cleans to colorful harmonic overdrive (I like this on some vocals and bass).




The MP573 was the very first DIY preamp I’ve ever built. Even with very little soldering experience building it was a breeze – thanks to the detailed assembly guide. By now, I own five different outboard preamps, but the MP573 is still my favourite for male vocals, acoustic and electric guitars as well as bass.

I’ve never had a Neve 1073 in my studio, so I can’t really say how close the MP573 is to the original, but I do know that it is a solid piece of gear with high quality components and an excellent warm and rich sound.

One thing I sometimes miss is a trim knob that can attenuate the signal by more than the currently available 10 dB. If I want to drive the input transformer really hot for a fat distorted sound, it’s sometimes difficult to bring down the volume of the preamp to a level that does not distort my audio interface. I found a workaround for that, but having the option in the module would be helpful.

Other than that, the MP573 is a wonderful preamp which I highly recommend. Thanks to Sound Skulptor for this kit!

Write your review

MP573 Microphone preamplifier for the 500 series

The MP573 is a two stages, single ended class A preamp, based on the design that was originally used in the Neve 1290/1073 modules, that has been adapted to the 500 series of API.

Write your review