Review: Bob's Devices MC StepUp Transformer 1131 Blue SUT Tube preamp

Category: Preamps

A Letter to Bob:

Hello Bob,

Thank you for the quick shipment of the 1131 Blue MC Step-Up Transformer and your beautifully designed IC Cable (both of which are impressive in build-quality). As you know, my intention is to upgrade the MC phono stage in my beloved VAC Standard LE tube preamp.

I trust I didn't offend you with my skepticism as to whether this will be worth the money, since I believe my analogue set-up is pretty great sounding already. I asked how long the new SUT would take to burn in so I could make a good comparison, your instructions were clear: "If you don't hear a difference right away, just send it back to me and I'll refund your money." Fair enough.

So here's what I did the same day I received your SUT:

I prepared my system, warming up the amps for two hours, picking out tracks and sides of albums from my reference collection that I know very, very well, then playing some cuts to make sure the system was ready. As always, before any A/B comparisons, to fix in my aural memory the sound I'm starting with, I listened closely to the familiar tone, depth and speed of my system, which is my audio benchmark. And lastly, made sure I could move the new component in and out of the chain quickly and easily.

I did hear a difference right away, but I was not terribly impressed. The gain of your SUT was much higher than my preamp's built in MC stage, so I spent time equalizing the SPL for a more valid comparison, and listened again. Yes, the unit was much quieter than my VAC's built-in MC stage, which is somewhat important to me, but not worth the cost alone. Here's what I found in three hours of A/B testing:

1. The bass was definitely more pronounced, but loose and unfocused compared to my reference. On Ray Brown's solo on LA4's "Just Friends," I couldn't locate his instrument clearly in the soundstage... he was everywhere.

2. On Ennio Morricone's The Mission soundtrack, the upper mid-range sounded distorted, with some glare in the soprano choral voices. I paused here to clean the album and cartridge again because it sounded like a dirty stylus that caused some mis-tracking. I played it again... still there... took the SUT out of the chain and thankfully, I was relieved to be back to the familiar lush sound of my VAC (this amazing album is long out of print and I was concerned it was getting worn out).

3. After over two hours of A/B-ing, the little SUT did improve, but not enough to come close to my VAC. I was ready to pack it up and send it back to you, but it was getting late, so I figured I would do it in the morning and write you this letter of explanation. Before calling it quits, I decided to put on one of my favorite album sides, Dexter Gordon's Tanya from the LP "One Flight Up" on a wonderful Blue Note test pressing. OK, so something definitely happened about halfway through this remarkable 20 minute jam... It was startling. I got up to check, and yes, the SUT was in the chain and nothing had moved. I could barely believe my ears, and had to A/B this track three times to grasp the transformation.

Somehow, quite suddenly and without any really encouraging improvement that lead up to this, your SUT came to life! Everything was now better than my reference! The soundstage blew open and focused the instruments in space with so much air around them it felt like if I got too close to the tenor sax I might get sprayed with some spittle! Bass reproduction also took a quantum leap, getting richer, tighter and more musical. The mid-range glare not only disappeared, but left in its place an easy, natural sparkle that made my system without the SUT seem veiled and dull in comparison (this was hard to come to terms with since I love my VAC). I spent the next half hour doing more A/B and trying not to wake up my wife and dragging her into the listening room just so I could have someone, anyone to share this incredible experience with (would have been a serious infraction of the WAF code)!

Bob, when you said the 1131 Blue won't change much over time, you should know that least in my system, the SUT most definitely broke in very, very significantly over the course of 2-3 hours of continual use. And It's hard to imagine that it won't get even better as it ages in my analogue chain.

This test was a very moving experience of "You don't know what you don't know until you know it" – when the joy of an audio upgrade reveals itself to us in one impossible musical epiphany that is so exciting, well, at least to us hopeless audiophiles (I'm certain had I interrupted my wife's beauty sleep, I would be getting that look right about now), that we want to shout "Yes! Yes! Yes!" in celebration of our obsession with sound and gear.

Anyway, it's now the morning after and I'm experimenting with albums that haven't gotten much airplay on my revealing rig, which would trash what I had deemed "bad" recordings... one such album is Ekseption, the remarkable Dutch classical-jazz fusion LP from the 1970s. It has always been shrill and strident on all my previous systems. I'm listening to it as I write and I can't believe what I'm hearing. I won't bore you with audiophile expletives, just know that your humble device has put a wide smile on my face.

Thank you for helping me reclaim 100s of LPs from the "unlistenable on my system" file.


Associated gear
Click to view my Virtual System
OK, I know a SUT is not a tube preamp... for some reason the system inserted that at the end of my review title.
Great review... although it almost sounds like a dry solder joint making good!!
Great review... although it almost sounds like a dry solder joint making good!!