Our Mastering Series is designed for the most demanding tasks in sound processing, routing, converting, recording and monitoring.

All devices work with our 120V technology. Their designs are matching and available in three colour variations.



Convert your audio files with up to 768kHz and 32 bits.


Improve your masterings with M/S processing.


Route your mastering processors in any order with a flip of a button.


Expand the channel count for surround monitoring to 16 channels.


Discover the revolutionary centerpiece for your mastering studio.


Classic tube compression meets modernity.


Parametric equalization in perfection.


Classic passive equalization and shaping.
Dan D’Ascenzo
Dan D’Ascenzo Mastering
Dave Reitzas
Darcy Proper
Paul Schal
Alexandre Charnier
Capitaine Mastering
Yasumichi Aikawa
Luca Petrolesi
Studio DMI
Riccardo Mazza
Experimental Studios
Michael Romanowski
Coast Mastering
Javier CC
Deep Wide Mastering
Galaxy Mastering
Marcin Bocinski
Bob Ludwig
Gateway Mastering & DVD
Christoph Stickel
CS Mastering
Howie Weinberg
HWM Mastering
Adrian Sauvaget
Gentry Studer
Epicenter Mastering
Simon Heyworth
Super Sound Mastering
Play Video

This video introduces you to the entire mastering series.

Mastering ...

… is a no-compromise discipline. It is expected that mastering improves the mix. This implies that the gear a mastering engineer chooses outperforms what is used in mixing.

Besides being about gear, mastering is probably even more about art. The mastering engineer and his artistic approach is what sets him apart. And like any artist the mastering engineer needs tools that realize the artistic vision. 

Future-proof investment is the other vital aspect. The ever changing digital world is costing a fortune when trying to keep up with the latest while analog remains backward compatible and can operate for decades.

To make analog technology future-proof and even better than the best digital formats, we developed the 120V DC Audio Rail technology. Based on proprietary operational amplifiers, analog audio is superior to all known and foreseeable audio formats. All products of the Mastering Series operate on this unequalled high-voltage audio rail.

Designing mastering equipment has a long tradition at SPL. Along with the invention of the first SUPRA 120V rail op-amps, we designed the MMC1 Mastering Console for Galaxy Studios back in 2000. Soon followed by the PQ, the ”King of Parametric Equalizers“.

We improved the SUPRA op-amps year after year. We made them smaller, less expensive, better spec’ed, and even more reliable. Today we produce them in their 5th generation.

The 120V Technology

What exactly is that?

And what does it do?

Good questions need good answers. And that’s what the 120V video gives you.

Play Video


Due to Covid19 there are no events scheduled at this time.

What does it actually mean …

In Stock!

The product is in stock in our warehouse in Niederkrüchten, Germany, and will be shipped the same or next working day.

We process the orders after receipt of the order and update the stock in the online shop regularly. If the product is no longer available at short notice due to high order volume, you naturally have the right to withdraw from the purchase (see Right of Withdrawal).

In any case, you will receive an e-mail with details of the delivery and the estimated delivery time.

Available soon!

The product is not in stock in our warehouse in Niederkrüchten, Germany. Usually it will be available again within 5 working days.

In any case, you will receive an e-mail with the details of the delivery and the estimated delivery time.

Of course you have the right to withdraw from your purchase (see Right of Withdrawal).

Product Condition


Brand-new product from the current product portfolio.


Demo, exhibit or return item.
In original packaging, incl. manuals and full warranty.
Only slight to no signs of use.


Demo, exhibit or return item.
In original packaging, incl. manuals and legal warranty.
In some cases clear signs of use, which are documented in photos.


"New Old Stock"
After discontinuation of a product still available new products with full warranty.