Leema Acoustics Essentials phono preamplifier Measurements

Sidebar 3: Measurements

I measured the Leema Acoustics Essentials phono preamplifier (serial number ES140704B) using my Audio Precision SYS2722 system (see www.ap.com, and the January 2008 "As We See It"). As always with phono stages, I experimented with the grounding between the Essentials and the Audio Precision system to get the lowest level of noise.

The voltage gain at 1kHz was 35.7dB with the Leema set to MM (moving-magnet), and 61.2dB when set to MC (moving-coil). Both values are very close to their specifications, and the preamp preserved absolute polarity (ie, was non-inverting) at both settings. The input impedances for both the MM and MC settings were also very close to spec. The MM impedance was 46k ohms at 20Hz and 1kHz, dropping inconsequentially to 40k ohms at 20kHz; the MC impedance was 92 ohms at all audio frequencies. The output impedance at 20kHz and 1kHz was very low, at 60 ohms, rising to a still low 432 ohms at 20Hz due to the presence of a coupling capacitor.

The Leema's RIAA equalization (fig.1) was well matched between the channels, and flat from 30Hz to 1kHz. Above 1kHz the response sloped gently up, reaching +0.25dB left and +0.4dB right at 20kHz. This should not be audible. At the other end of the audioband, the output was down by 1dB at 10Hz without the Bass Cut switched into circuit (blue and red traces), –1dB at 43Hz and –3dB at 22Hz with Bass Cut active (cyan, magenta).

Fig.1 Leema Acoustics Essentials, response with RIAA correction (left channel blue, right red) (1dB/vertical div.).

The Leema's channel separation was very good, at 80dB in both directions above 1kHz. The Essentials was very quiet, its wideband, unweighted, MM signal/noise ratio (ref. 1kHz at 5mV, taken with the input shorted) measuring 70dB, and improving to 81dB when A-weighted. The MC ratios (ref. 500µV at 1kHz) were almost as good, at 66dB and 76dBA.

With its lower-than-usual gain in MM mode, it came as no surprise to find that the Essentials had a superb overload margin: about 25dB throughout the audioband. It was almost as good in MC mode, at 22dB across the band.

With low RIAA error, noise, and crosstalk, the Leema's distortion was also low. Fig.2 shows the spectrum of the Essentials in MM mode, driving a 1kHz tone at 1V into 100k ohms (equivalent to an input level of 17mV). The only harmonics visible above the noise floor are the second, at –76dB (0.015%), and the third, at –99dB (0.001%). The picture wasn't significantly different in MC mode. While reducing the analyzer's load impedance to a very low 600 ohms raised the level of the second harmonic, it still lay at –60dB (0.1%), which, given the innocuous nature of second-harmonic distortion, is low enough. The Essentials also had low intermodulation distortion (fig.3), the second-order difference product resulting from an equal mix of 19 and 20kHz tones lying at –81dB (0.01%). However, there is a peculiar rise in the noise floor visible in this graph between 25kHz and 30kHz.

Fig.2 Leema Acoustics Essentials, spectrum of 1kHz sinewave, DC–10kHz, at 1V into 100k ohms (linear frequency scale).

Fig.3 Leema Acoustics Essentials, HF intermodulation spectrum, DC–30kHz, 19+20kHz at 1V peak into 100k ohms (linear frequency scale).

It was a pleasure to measure a product as well sorted as Leema's Essentials phono preamplifier, especially considering that it sells for less than $1000.—John Atkinson

Leema Acoustics Ltd.
US distributor: Bluebird Music Ltd.
271 Woodward Avenue
Buffalo, NY 14217
(416) 638-8207

fetuso's picture

Mr. Dudley, I get your point about the relativity involved in the price of goods. One thing to remember, however, is that in the 1970's ' there were no monthly expenses on cable/internet, cell phones, streaming services, and numerous other expenses with associated with the "good life." I'm 42, make a six figure income, and I have a mortgage and a young family. No way on God's Green Earth am I spending $749 on a phone preamp. I just bought an $800 integrated and I thought that was plenty.

hifiman1978's picture

Totally agree agree with you. The prices are completely over the top when it comes to this hobby. And then you hear everyone talk about how to engage the younger generation in this hobby. Well they can start by making things affordable first. But I have to add the asking price of $749 is nothing compared to what we usuall see in Hifi magazines. These inflated prices are mainly due to the few people who are willing to pay 10x more for a phono stage. Take leema acoustics top of the line phono stage Agena that costs roughly $5500. How can anyone in their serious mind think of upgrading from a $750 phono to a $5500?. Hence there is no upgrade paths it's just buy what you can afford. Due to the resurgence of Vinyl these companies are just trying to take advantage. The resurgence in Vinyl is mainly because of the 30's something who mainly are in the hobby for its novelty factor. Believe me these people are listening to vinyl on project or rega turntables costing no more than $300-$400 I can't see them buying a leema phono stage. Message to these companies if you want to engage with a younger audience you need to set realistic pricing. Otherwise this fledgling market is going to collapse.

ChrisS's picture

Starting on p.75, there are 5 pages of recommended phono stages... At the end of this list there's the NAD PP4 for $199 and the Bozak Madisson CLK-PH2 for $19.95!!

Go hang out at a record shop to see who's actually buying vinyl.

Also read Michael Fremer's column and website http://www.analogplanet.com/home

You'll have a much better understanding of what's happening with vinyl.

hifiman1978's picture

Just visited the analog planet website. And the first article has Michael Fremer review on a $1600 phone stage that he describes as "Moderately priced".

ChrisS's picture

It's a matter of perspective...

Click on "Reviews" and "Phono Preamps" and you'll find reviews like this http://www.analogplanet.com/content/four-phono-preamps-reviewed#xf6LCSVl7OvPZG0t.97

There's a phono preamp for every budget level.

Do your research.

fetuso's picture

I would like to clarify that I wasn't suggesting that this particular item, or any of the items you mentioned, aren't worth the asking price. My point was that I don't think college students are buying $750 phono amps. They're buying Schiit phonos for $150. Or they're buying the U-Turn Pluto for $89. Stuff like that.

volvic's picture

You say that now but in a few years you may look to upgrade.

fetuso's picture

I'm sure you're right. This hobby is as much about the equipment as it is the music, if not more. I love reading about the gear, and of course I'd like to buy some of it.

volvic's picture

I swore after I sold my Linn and got my VPI and SME IV combo that I was done, yet here I am with a TD-124 now without a tonearm yet (can't decide) and I am already thinking of a third turntable in a few years time. Yes just as much about the gear as the music. It's fun though.

Johnny2Bad's picture

" ... The product category didn't even exist until the mid-1980s ..."

Maybe for some, but I remember owning or auditioning in my home Phono Preamps during the late 1970's, probably '78~79. I remember I had a PS Audio Phono Pre and a battery-powered unit built by Peter Moncrief, both which were available at the local HiFi Store for a few hundred bucks.