SW1X Stepped Attenuator Volume Control Debut!

Over the past 15 years I have owned a number of pre-amplifiers utilizing sold-state and tube typologies and have always been curious about the sound quality of these volume potentiometer and Khozmo attenuators used in these designs. I have read numerous articles on the degradation that these controllers have on the overall impact of destroying dynamics, scale and contributing to thin/flat sound.

I have experienced these attributes of poor sounding Alps volume controllers/digital attenuators with a scratchy like sound or a clicking/popping noises every time the volume is increased or decreased. It always led me to think, why would a builder use such an inferior product if a better sounding alternative would sound better for reasonable cost to upgrade and if the upgrade would highlight that builders’ designs? I’m sure cost weighs heavily on the designer and possibly the availability of quality part selections.

I have searched many old threads on stepped attenuators and there was always a question if a reputable manufacturer was still producing them. I had been following my Dac designer/builder every month or so to see the progressions on his amp designs and discovered that he had built a reference level stepped attenuators and I knew from the moment I laid eyes on them that his device was going to replace my blue alps in my 2A3 DHT pre-amp.

Both Mono and Stereo models are offered in 5 versions:

1. Black Series, Black Fibre Boards, with Copper ground wire, non-magnetic 0.5W Carbon resistors in shunt, non-magnetic AB 2W resistors in series
2. Grey Series, Black Fibre/Brown Bakelite boards and Copper ground wire, non-magnetic 0.5W Carbon resistors in shunt, non-magnetic AN Copper 2W Tantalum resistors
3. Brown Series, with all Bakelite boards and fine Silver ground wire, non-magnetic 2W Carbon resistors in shunt and non-magnetic AN Copper 2W Niobium in series
4. Gold Series, no expense spared Series, with all Bakelite boards and fine Silver ground wire, non-magnetic 0.5W Copper Tantalum resistors in shunt, non-magnetic AN Copper Niobium resistors in series
5. Silver Series, no expense spared Series, with all Bakelite boards and fine Silver ground wire, non-magnetic 0.5W Silver Tantalum resistors in shunt, non-magnetic AN Silver Niobium resistors in series

The moment of truth arrived on Christmas Eve and I was excited to get the Pre-Amp hooked up to hear it for the first time with a reference level stepped attenuator in place of the previous Alps. The sound was absolutely wonderful and with zero burn-in and based upon general internet opinions, it really starts to show its potential at 100 + hours of use. With just over 10 hours of use, more clarity is beginning to immerge.

I have really been evaluating these volume controllers in my pre and tube amp which also has a volume controller that I used while my pre was being upgraded… The first thing I noticed was the volume was more linear and more representative of loudness based upon the hands on a clock. My Alps at the 9 O-Clock position would yield my normal 70 Db listening level but 10-11 O-Clock position would run you out of the room…

So, what did I hear; musicality, unbelievable transparency, bold and articulate presentation, more holographic, effortless layering, lower floor noise, more refinement in sound stage width and depth with images being more tangible with real-life scale.

All of these characteristics are just amazing but the one thing that blew me away was the sense of being in the recorded space; You are not just hearing a three-dimensional rendering but instruments have body and dimensionality that swells and projects beautiful resonate sound toward the listener; this is a phenomenon that has to be experienced and heard to explain but breathtaking…

SW1X Brown Series 24 Way Stepped Attenuator Volume Control built by a renown engineer has been a revelation in my sound system and has brought me even more listening enjoyment. If you are using an inferior volume controller or even a so-called quality attenuator, I Highly Recommend that you contact Dr. Slawa to discuss your needs and be prepared to hear the very essence of natural and realistic sound.


Images of the install can be viewed below:

SW1X Stepped Attenuator Volume Control Debut! (audiocircle.com)

Wig 😁


Looks good. I have been building and upgrading preamps with the Khozmo and Shallco stepped and shunt type attenuators. Looks very similar in build. Wondering how they can claim this one is far better? One can load the same resistors in a Khozmo or even a top flight Shallco. These also can come with pure silver contacts etc..,


I bet these are great, but I fail to see why they would be any better sounding than the ones I mentioned!

@ roxy54

The prices are listed in GBP in the attached link above.

@ grannyring

The build quality is like nothing I have ever seen and built like a tank with no PCB and top shelf parts. He is a man of tremendous research and test and evaluates many available devices and if they don't cut it for him, he makes his own...

He provides almost weekly updates on what's being built and the level of sophistication is just extraordinary...

SW1X Audio Design - Home | Facebook




I had the Khozmo as an upgrade on an ANK 300b integrated, and I thought that it was very good as well. 

I have a Shallco in my SMc preamp that sounds great, but it looks much bigger than the SW1X, which may physically fit in a wider range of situations/equipment. When I owned the Lamm LL2 Deluxe, it sort of bothered me that such an acclaimed preamp used Alps pots. It appears the SW1X may have easily fit in the Lamm preamp as a replacement for the Alps. I like that they use full-size resistors rather than SMD resistors as used by Goldpoint and DACT.

Regarding Khozmo, I currently own two of their preamps (a Khozmo and a Hattor) and both sound excellent. They can be constructed using a variety of resistors (so far I like the Amtrans AMRG carbon film resistors) and what sets them apart from most others is that their attenuators offer a remote control and easily seen display.