Monday, June 4, 2012
Using the Cinemag CMQEE-3440A step-up transformer
Ah, the moving-coil phono cartridge is famous for it's speed, detail, and audiophile street-cred. Ranging from the lowly Denon line, up to multi-kilobuck units, the low output moving-coil (LOMC) requires more gain than your average phono stage delivers. Since I recently bought a Quicksilver full-function preamplifier (review forthcoming), I needed a way to boost the lowly voltage of my Denon DL-103R before hitting the tubed phono section. I could continue to use my Audio Sector Phono Stage into a line input, but if you're going to run a tube preamp, what's the point of letting the phono section lay fallow?
Enter the Cinemag 3440A step-up transformers. Cinemag, once a division of the famed Altec-Lansing, has been making this inexpensive step-up transformer for some time. Word is, coupled to the Denon Cartridge, this step-up makes beautiful music. Since I already had an aluminum chassis, RCA jacks, switch, and ground post from a previous DIY project, this was an easy decision to make.
Here's a list of what you would need:
four RCA jacks
DPDT switch (optional)
wire cutter/stripper that can handle 26awg wire
a few nuts/bolts to hold down the transformers to the chassis
some sort of chassis, metal or plastic will work
a drill press
two Cinemag CMQEE-3440A transformers
Since I didn't want to wait the few weeks for Cinemag, I ordered at a slightly higher price from an Ebay seller. A few days later and I received a small package with two dinky transformers, two L brackets and two screws. With both transformers, I screwed on the L brackets, using the longest piece against the bottom of the transformer. The other end of the bracket was fastened to the chassis into some holes that I drilled with my press.
I put in new RCA jacks and a binding post. I was lucky enough to already have a DIY phono project that already had holes for these. If you're not steady with a drill, Front Panel Express or some other company can do the work with a professional fit and finish.
Now comes the wiring. I used Cinemag's wiring diagram:
To Position 1 of switch: Red and Green Wire
To Position 2 of switch: Orange and Blue Wire
From Switch, solder a single wire to the RCA ground lug
Output: Purple wire to RCA input lug
Black, White, and Great wire to RCA ground lug
Note: The switch is optional if you know you are going to just use one of the taps. With the the Denon DL-103R, the 37.5 ohm input seems to work the best. At least in my system. But having the switch does allow one to try both settings.
Another Note: This wire is thin and fragile. I use a GB-branded wire stripper from Home Depot. When stripping off the insulation, make sure not to pull hard on the wire. I use a needle-nose pliers to hold a section of wire downstream, giving some support. I would hate to yank a wire off from inside the transformer.
Okay, here comes the moment of truth: So how does the Cinemag/Quicksilver combination stack up against the Audio Sector Phono Stage? Well, I will save the nitty gritty for my review of the tubed Quicksliver, but for now I will say that I was pleasantly surprised by the Cinemag. My presumption was that running the small output of the Denon DL-103R through several lengths of wire would give less detail and dynamics. But the real world shows great performance: deep bass, good 'slam', extended treble and, as the transformer broke in, plenty of detail.
I may give the nod to the Audio Sector Phono Stage for hi-fi pyrotechnics - attributes like detail and speed. But the Cinemag/Quicksilver has a more relaxed presentation that makes it easier to enjoy music. Stay tuned!