Bob’s Devices CineMag Sky 20 Step Up Transformer





I recently reviewed Bob Device’s CineMag 1131 and Sky 30 Step Up Transformers and was extremely impressed by the life-like presence and detail that I encountered from both. So when Bob’s owner, Bob Sattin, offered to send me his latest CineMag SKY 20 trannie I did not hesitate to oblige, especially since Bob stated it has lower distortion, higher bandwidth and lower inductance than any step up he has previously built. Bob challenged me to compare it to any SUT in the world. I took the challenge and decided to compare the SKY 20 to my reference Art Audio Vinyl Reference (VR) with its built in Lundahl passive step up. 

As I learned during my prior review of Bob’s step ups, there are many external factors that impact the sound experienced when using a particular step-up. These include, among other things, how a step-up mates with your cartridge, cabling, and your phono stage, etc. So I decided for this review to compare Bob’s newest step up to the phono set up I was most familiar with: the excellent VR phono preamp with its built-in passive step up that has gain and resistance settings to tweak its MC section to your particular cartridge, etc. The VR provides an extremely high level of performance in my system, so it presents suitable competition for the SKY 20. I simply inserted the Sky 20 between the turntable and the VR using the VR’s moving magnet input rather than its moving coil input. I picked out LPs that I am intimately familiar with to distinguish between the two setups.

Description of Bob’s Devices SUT

SKY 20.jpg

I hate to repeat the description and set up procedures from my previous review, but rather than refer you to that review I decided include the basic description here to alleviate having to jump back and forth, so here goes again. The SKY 20 trannie, like others in Bob’s lineup, is a small rectangular shaped black glossy enclosure with two round transformers sticking through the top with round metal caps over the transformers. There is a pair of RCA inputs and outputs on one side of the housing with a grounding post in between the pairs of RCAs. On one of the short sides there are two toggle switches, one for the high and low output ratio settings (Bob offers different SUTs with different step up ratios depending on the needs of your setup), and the second to lift or engage the ground. The bottom of the SUT is supported by four small round feet and has a piece of black tape that contains the step up ratios for the high and low settings. The ratios were 1:10 and 1:20 for the SKY 20.

Bob’s website provides the following information regarding his Sky Transformers.

Ultra High quality laminations, lower inductance and superior sound. These transformers were especially designed and tested with several low-output moving coil cartridges. These are very difficult transformers to construct and require a precision manufacturing process that can only be done by David Geren at CineMag. The same construction techniques are used as in the 1131, except that the inductance of the SKY is even lower due to lower step up ratios. In addition, the bandwidth is extended a little further. 


Setup is Easy

Setup of an external SUT requires running an interconnect from your tonearm into the RCA inputs on the SUT, and another pair of interconnects from the SUT outputs into the moving magnet (MM) inputs of either a phono preamp or the MM phono section of a regular preamp, integrated amp or receiver, etc.

So What About the Sky 20 Makes It Different From Other Bob’s Devices Step Ups?

This was the $64,000 question I posed to Bob Sattin.  Bob was kind enough to provide the following insight:

Going from the 1131 to the SKY 30, CineMag was able to increase the wire size on the primary due to fewer windings. Similarly, the SKY 20 has fewer turns on the primary than the SKY 30, and by using fewer turns, CineMag has increased the wire size, further reducing the DC resistance over that of the SKY 30 and the 1131.  Additionally, the coil winding pattern on the secondary of the SKY 20 been changed from that of the SKY 30 and1131 to reduce the capacitance coupling between the windings. The bandwidth is increased because of lower inductance and lower DC resistance of the windings. The bandwidth is improved moving from the 1131 to the SKY 30 and further improved moving from the SKY 30 to the SKY 20. So, how does this translate to sound? 

Let the Listening Begin

norahjones.jpgOnce I had the SKY 20 properly set up with a short cable run (1/2 meter from SKY 20 to VR) I began listening pleasure with Acoustic Sounds’ excellent reissue of Nora Jones “Not Too Late” LP. I initially had the SKY 20 flipped to the 1:20 ratio setting but experienced a bit of distortion, which completely disappeared when I flicked the switch to 1:10, so I used that setting for the remainder of the review. I suspect that the higher setting was overloading my preamp, and had experienced a similar occurrence during my prior review. With the proper setting in place I dropped the needle on my favorite song on the “Not Too Late album, the first cut on side 2, Broken. I had just listened to the album using the VR’s built in step up, and was immediately taken aback by the added texture and weight of Nora’s voice once I had the SKY 20 in place. The vocals were to die for. I also noted subtle cues in the instrumentals that I didn’t notice before. The articulation of the bass and guitar strings made it sound more like the instruments were in the room. Moving to side one, song 1, Wish I Could, I immediately noticed Nora’s voice had way more presence. I could hear her breaths and more air around instruments, and strikes of piano keys were much more realistic. Song 2, Sinkin Soon, presented guitar notes that were more articulate and distinct instead of being in the background. I also found a prevalent theme of more texture to Nora’s voice and was able to discern subtle inflections in her vocals.

Basie.jpgI bought a collection of records a few years back and discovered a gem in the bunch, a 1962 stereo version of “Count Basie and Kansas City Seven” on Impulse. I have listened to this LP so many times, but upon dropping the needle on side 1 Basie and the KC Seven had more of an “in the room” sound than I had ever previously experienced. I was drawn into the music from the very first note of Side one, song one, Oh Lady, Be Good.   Basie begins on piano and I could clearly hear the strikes, sustain and decay of piano notes which were so realistic that I just closed my eyes and was drawn into the music.  The tenor sax enters with such a sweet warm tone, with lots of air around the instrument. Thad Jones enters the mix on trumpet with beautiful brassiness hanging in the air and then all the instruments blend in a beautiful tapestry, but with each instrument readily discernable. I stopped taking notes and just listened to the rest of the side, with one final note… REALISTIC…

Next up in the rotation, based on a request from the family, was some 1970s nostalgia, a Mobile Fidelity Sound Labs Original Master Recording reissue of Daryl Hall and John Oates, “Abandoned Lucheonettte,” When the Morning Comes was the first song, and had very clear musical presentation with distinguishable vocal harmonies. Song two, Had I known you Better Then, provided a beautiful blending of the duo’s vocal harmonies and the instrumentation was clear with a nice crispness from the drum kit. Throughout side one I heard many details that I never noticed on the numerous previous plays of this album.The music was so enjoyable that I again found myself not wanting to take any notes but just listen to the music. A good sign! But, I had to make a final note of how beautiful the voices and their blending and texture sounded on the last cut, I’m just a Kid (Don’t Make Me Feel Like a Man). So warm, smooth and yet detailed… very nice.   

Norahjonescome.jpgI decided to go back to a female vocalist album that is off the shelf rather than a high end re-mastered version. So I pulled out the original release of Nora Jones “Come Away With Me.” I was immediately struck by the weight and presence in Nora’s voice. Throughout my listening to Side 1, I heard a lot more details and nuances that I never noticed. There was also a greater depth to the music. I concluded that this was a clear improvement over the last time I listened to this album using my VR by itself. So much more musical and natural sounding.

I used several excellent vocal albums to test BD’s SKY 30 trannie, so I was curious to see how these records would sound using the SKY20. First up was Nat King Cole’s, After Midnight, not only a great male vocal record but with wonderful jazz instrumental from Nat’s Trio and the other players that joined on this record. I discovered a pristine copy of this album in a bunch of records I bought at an estate auction, and from the first time I listened, After Midnight has become one of my favorite go to records not only for listening pleasure but for testing equipment changes. This 1956 mono pressing is extremely well recorded and makes it easy to identify the impact of changes in a system. I noted in my prior review with the SKY 30 that this mono pressing had nice weight, texture, and warmth in the vocals with subtle inflections being mined out of each track, and the attack of the piano keys sounding like there was a piano in the room. Well folks, it was even better with the SKY 20, with a more musical engaging organic presentation that sounded more like live music. On side 1, track 2, Sweet Lorraine, I found that the bass was more robust with greater weight and roundness than I ever remembered hearing from this record. Nat’s voice was also more immediate and in the room sounding. The articulation of the piano, guitar and trumpet notes were more distinct across the board than my VR alone or than I remembered using the SKY 30. I had the ability to more easily hear the attack, sustain and decay of notes on these instruments. On the next track, Sometimes I’m happy, Nat’s voice was so beautiful and natural sounding , that it was as if he was singing in the room. Stuff Smith’s violin was also dead front and center and in the room sounding, just like Nat’s voice, and I could easily hear the attack of the lightest bow strikes.

So What is the Bottom Line?

The bottom line on BD’s SKY 20, like the other SUTs I reviewed from Bob’s lineup, is that it definitely seemed to transform music into a more lifelike musical presentation, with added presence and immediacy in vocals, but this SUT clearly allowed more subtle details to come through than other SUTs I have used, including the built-in SUT on my VR preamp.


I loved the SKY 20 step up transformer because it had the same attributes as the BD Cinemag 1131 and Sky 30 trannies I recently reviewed; great presence and the ability to reveal previously unnoticeable subtle nuances in most LPs, but in my opinion to an even greater extent than the other Bob Devices step ups. I subjectively found the SKY 20 a bit tighter/more focused and I was able to hear many details I never heard before, albeit in a very natural/organic presentation (i.e., more information that sounded more like live music). What more can you ask for?

Happy Listening!!!



CineMag Sky  20 

Weight 2.00 lbs

Our price: $1250.00




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