Music First Audio LP103 LCR phono preamp
I first got wind that Music First Audio (MFA)was working on its first phono stage a couple of years ago. I made sure I kept tags on progress until finally I got word in July that the new LP103 LCR was ready for production. The eagerly-anticipated first review sample found its way into my hands a couple of months ago.
I was particularly keen to listen to it as I had previously had good experiences with MFA’s Reference SUT moving coil step-up transformer and their Baby Reference V2 transformer-based preamp. Both were excellent, unsurprising perhaps as Music First Audio is a true transformer specialist, tracing its roots back to transformer winding company Stevens & Billington, co-founded in 1963 by owner Jonathan Billington’s father. Jonathan took it over in 1990. Many of its transformers were used in microphones.
The new LP103 LCR phono amplifier, retailing at £8,760, is a no-holds-barred design combining the experience and talents of Stevens & Billington in transformer manufacturing and the active stage design skills of collaborator and design consultant Thorsten Loesch, the man behind the early iFi creations.
Fully featured
Its main features include: constant impedance 600 ohm LCR RIAA equalisation; Class A fully discrete J-FET and bipolar transistor active amplification based on classic studio equipment; adjustable resistive and capacitive loading; dual mono design; single-ended and balanced input/output; dual mono external power supplies; high-grade passive components including Nichicon Muse KZ and ES capacitors, WIMA FKP and MKP film capacitors. It’s probably worth noting that LCR stands for inductor capacitor resistor network; a means of eliminating feedback from the RIAA equalisation circuitry.
I remember being mightily impressed by MFA’s Reference SUT MC step-up transformer (£5,040) and the LP103 LCR uses the same transformer, but with only three secondary taps (for three gain options) as opposed to four. It has the same large bobbin and Jonathan told me that because it has fewer copper windings, he could allow a larger air gap between them. The large EI format core uses laminations made from mu-metal that is 80% nickel and 20% iron. These laminations are heat treated and Jonathan says he uses as much paper interleaving between them as he can. All of this is said to reduce saturation and eliminate eddy currents that would degrade sound quality.
Three taps are taken off the secondary winding, giving gain options of 14dB, 20dB and 26dB over and above the nominal 40dB of the active gain stage, which should be enough for any moving coil cartridge.
Rotary controls on the front panel allow adjustment of capacitive and resistive loading. Capacitance can be adjusted between 1.175nf and 188nF for MC cartridges and 47pf to 470pF for moving magnets. While I myself have never found capacitive loading to be super-critical for moving coils, resistive certainly is.
Loading table
The knob that selects the resistive load has settings for 10kΩ, 20kΩ, 30kΩ, 50kΩ, 70kΩ, and 100kΩ, which correspond with the actual load for an MM cartridge. However, the actual load for an MC cartridge depends on the gain used (and therefore transformer tap). MFA provide a table in the manual to show users what the actual load is. For example, when the knob is set to 10kΩ, the resultant load is 25Ω when using the 26dB input, 100Ω for the 20dB input and 400Ω for the 14dB input. This sounds more confusing than it really is. Just follow the table and you’ll be fine. In any case, you should only need to set it once.
On the rear panel, as standard there are XLR balanced outputs to the far left and right and in the middle a row of RCAs for 14dB, 20dB and 26dB MC gain and one set for the MM input. If the user wants balanced XLR inputs, these will be fitted by request (note: our pics show only the standard RCA inputs). As well as the load selectors, there is also an overall gain trim control that provides ±10dB in 2dB steps. Three toggle switches give you a 12dB mute, full mute and, rather usefully, a mono switch.
The active stage
The output from the transformer in the MC circuit is then fed to the main active gain stage. Moving magnets feed straight in. I talked to Thorsten Loesch at length about his active stage design. He told me that he chose J-FETs for the first stage as he feels they “are more tube-like in their electrical parameters than bipolar transistors”. They also need less bias current than bipolars, which he said allowed him to be use a smaller value coupling capacitor, which in turn meant he could select the “highest possible quality capacitor”.
He added that while it is possible to dispense with the coupling capacitor with a J-FET, this normally means you need a replacement capacitor somewhere else that is not in an obvious signal path. He concluded that this new circuitry would add more noise and distortion than the coupling capacitor itself would have, so he left it in. That said, he pointed out that bipolar transistors outperform J-FETs in many other areas, which is why he chose them for the later stages.
In the RIAA EQ stage, the LP103 LCR uses custom-wound inductors made in-house by Stevens & Billington. Loesch explains that the kind of inductors he needed were not available off-the-shelf, as he needed around 1.8 Henry and 45mH for a constant 600 ohm impedance circuit. Air cores, he said, were not possible, so those used are wire-wound. He also said that he preferred the sound of discrete inductors, capacitors and resistors in the RIAA EQ circuit to using an IC or op-amp. The active stage offers a gain control on the front panel, with a range from -10dB to +10dB, to suit all applications.
Proof of the pudding
Now you know all about what’s inside the LP103 LCR, but how does it sound? To find out, I tried it with two different cartridges. On the one hand, the new Hana Umami Black and on the other the Audio Note Io1. The Hana has an output of 0.3mV, but the Audio Note’s output is around one tenth of that, at 0.04mV, which would be a good test for the MFA. They were both fitted to an Audio Note TT3/PSU3/Arm Two turntable combo, through a Viva Solista integrated valve amp and Fyne Audio Vintage 10 speakers with Supertrax super-tweeter. The mains cable and block were from Musicworks. I also had a well-respected phono stage standing by, priced around £6,000, to serve as a benchmark.
I listened initially using the Hana Umami Black, fed into the +20dB input with resistive loading set, after comparing various settings, to 200 ohms. It is always best to try various settings for yourself, as you may prefer a different one to that recommended by the manufacturer.
First track I played was No One Emotion from George Benson’s superb 20/20 album. Right from the off, it was clear that the LP103 LCR is in a different league to my chosen benchmark. Bass was tighter and moved better, vocals were cleaner and more articulate and I could separate the different strands of this lavish production better and listen into what all the instruments were doing. The track’s driving, staccato rhythm was well conveyed and Michael Sembello’s blistering guitar solo had much more bite, presence and inner detail.
Next up was the It’s Your Thing from bass player Christian McBride’s Conversations album. This features vocals from Dee Dee Bridgewater and her voice was full of character, with all the sassiness and exuberance she puts into it, while McBride’s bass was fluid, agile and tight. The benchmark product by comparison was a little congested on vocals, woolly on bass and failed to convey the energy and fun of the track. On the LP103 LCR, you could really hear how McBride played and shaped each note, while on the benchmark the lower notes of his bass line seemed to blur together.
Next is what I think is one of the best recorded albums in my collection, from the MCA Master Series, namely Discoveryfrom guitarist Larry Carlton. On his reworking of The Doobies’ Minute by Minute, the LP103 LCR really conveyed the insistent, driving rhythm of the track and its deep, sinuous bass line, which I have to say waffled a bit on the benchmark phono stage. The LP103 LCR gave me better insights into Carlton’s guitar playing, separated the backing vocals and subtle percussion lines much better, and gave Kirk Whalum’s sax more bite and incisiveness. But it was in terms of that driving rhythm and superb bass line that the MFA left my benchmark for dead.
When I was chatting with MFA owner Jonathan Billington, he mentioned that I should try the Hana into the +26dB gain input. I plugged it into that, adjusted the loading switch to ‘50k’ (equal to 125 ohms) and lo and behold, as he had predicted, it definitely sounded better, with greater definition and separation of vocals, tighter and more solid bass guitar lines, better leading edge bite and body on sax and greater delicacy and detail on complex cymbal, snare and percussion lines.
I also tried the Audio Note Io1 into the +26dB gain input with 25 ohm loading (10k on the selector switch), and the results were excellent, with the Io1 sounding superb. The MFA coped easily with its very low input with not a hint of noise, leading me to conclude that the LP103 LCR should cope with absolutely any cartridge you throw at it.
Effortless excellence
The Music First LP103 LCR turned in a superb performance. Its sound was detailed, full of life, musically compelling and as persuasive on the subtlest drum or percussion play as it was on the deepest and fastest-moving of bass lines. Vocals were clear and articulate, while guitar and saxophone were sharply defined, full of inner detail and charged with emotion. I was extremely impressed by the MFA LP103 LCR and have no hesitation in giving it my enthusiastic recommendation. Worth the money? You bet!