Making a comparison between different products is always a nerve racking experience, the variables at stake are many, and opinions are influenced both by one’s personal taste and by previous experiences with similar devices. When, as in this case, the test is involving a solid state power Pre and a valve one, it gets even harder, you end up dealing with two different schools of thought, regardless from any type of applied source. Will there ever be a winner between two products which, although they are “genetically” heterogeneous, they still belong to the same manufacturer and at the same price range? Arm yourself with a popcorn sack, a good drink and let’s face together this jungle of different opinions.
The preamplification subject is indeed considerably important. The preamplifier holds by definition the second link in the audio chain, but no less important than microphone for that, its role is decisive, in fact it’s the one in charge of the delicate work of giving substance and volume to the signal of any kind of source, be it a microphonic or a line one; this processing result then feeds your devices, mixers, recording systems (both analogic and digital) or rather final amplifiers. It’s good to remind that the term “preamplifier” is not correct for it is an amplifier, to all intents and purposes and for all its functions already described. The convenient “PRE” suffix is there only to make a difference, not to confuse a potential final amplification phase. So, for this very delicate and sensible job through the audio chain, one should not skimp on buying a preamplifier. It’s justifiable to make timbre research, interfacing various kinds of microphones with specific preamplifiers, in order to achieve a specific sound “nature”, but anyways we’ll have to be dealing with “serious” equipment; serious does not necessarily mean extremely expensive, but the thing is that the timbre we can use should be pleasant, that the sound should not depart from our own way of listening and producing music. The products we have been testing are from the new SOLO series by Universal Audio, the 110 and the 610 model.
What better time to try out the two Universal Audio’s little sons and have them baptized by tv fiction production?
I used two computers for this test: The first one is a 2 Gb ram DDR Toshiba M40-232 laptop, intel chipset, 80Gb HD, supplied an additional external 300 Gb H.D. with 16 mb cache; the laptop in question is controlled by Cubase SX 3 which is hosting the Kore hardware. As for the second PC, it’s a Mate M1 Daw (Pentium 4 CPU, 3.4 Ghz and 2Gb Ram) on which a MOTU 896 HD soundcard is installed. The test has been made by connecting the sound sources through a Klotz cable directly to the two amplifiers, then the signal has been sent to an analogic input of the audio soundcard on call; everything through two couples of monitors, such as the Dynaudio BM6A and the Yamaha NS 10M monitors. The list of available microphones inside the studio was remarkable, but anyway I preferred to go for high quality models: Neumann U 87 and TLM 103, Akg C414 and so on… As for the string and percussion instruments there’s no need to make a list, I used everything that the studio had to offer; whenever a different timbre instrument performer came across, he was always asked to lend himself to a recording test.
Description SOLO 610
The Preamplifier is made by a small and solid travel suitcase showing a very well designed look and heavy with a handle on top of it (Pic.1). On the front panel there are two big knobs (GAIN and LEVEL) separated by two leds (Power and Signal). On the lower side, from right to left, we find five position switches, the first one is the input MIC/DI selector followed by the input LO-Z/HI-Z impedance selector, in the middle there is the switch to enable and disable the 48V phantom power (+48V/OFF), then the low cut filtering switch (LO CUT/FLAT) offering the flat option, and lastly the phase reverse impedance switch for both Mic and DI inputs (OUT/IN). For the guitar and bass players who enjoy passive pickups, or for those who love to play the Fender piano like me and wish to taste it in all its splendor, the lower side features a DI monophonic line and a THRU output which is not affected by the signal process.
On the back side (Pic.2) there is POWER IN input, the ON/OFF switch, an XLR output between the two LIFT/GND and MIC LINE switches and an XLR audio output; It is important to note that all the connections boast the Neutrik brand; these little details show the high quality design for the instrument.
Male voice SOLO 610
The voice for this test is in native language (Italian), with a singer-songwriter appeal and with blues influences featuring a slightly raw timbre which alternates to the smooth one, moving through a baritone to a tenor register area. After a few takes just to set the input levels properly, we start to record setting the big input knob on an intermediate position (remember that the gain control is in charge of the valve harmonics, turning it clockwise, the signal results richer, on the contrary, anticlockwise, a more linearity is kept). The overall signal is very clean, giving back an inspiring as well as rich and open timbre at the same time; as a result, from 1500 to 2500 Hz on the middle range, the frequencies aren’t troublesome at all, so perfectly balanced that it is not worth equalizing (Amazing!). Lastly, by setting the GAIN heavily and controlling the output through the LEVEL Knob, we can immediately notice a timbre fiber growth around the lower-mid frequencies, to be more precise, from 120 to 400 Hz. As for the upper-mid, from 3000 to 5000 Hz, they become excessively rich. Dealing with a warm voice like this, what you get is an extremely rich sound in terms of timbre, the voice results too much emphasized, risking in losing intelligibility and effectiveness within the mix. This is not said in order to belittle the quality of the product but only to highlight the fact that this setting will be very useful for thin, week or conventional female voices. Lastly let’s analyze the LO CUT filter behaviour set by default on 100Hz. One thing I ought to say is that, in this case, using the above-mentioned filter has been crucial; as the microphone used is a Neumann TLM 103, with no low-pass, all the convenient anti-pop filters (I fastened the microphone upside down with the center of the membrane facing the nose tip in order to take advantage of the proximity effect) were not enough, with this kind of voice the bumps caused by the consonants were still audible (Pic.3). By using the filter of the 610 the problem is finally settled with no general timbre loss, not wasting any natural timbre smoothness.
Cello SOLO 610
For this test, it was my pleasure to record a very good musician; unfortunately he didn’t have an excellent instrument for the occasion. The microphone involved is a Neumann KM 184 (condenser) (Pic.4) placed at a 40 cm distance from the cello bridge. The sound, through the 610, gains a lot of “warmth”, a term that we engineers use when we get a good feeling from a nice sound, a balanced mix in dynamics, presence and truthfulness about the sound. I believe that only a professional device can get this kind of results without making you feel the sound engineer’s work as too much “manipulated”. It often happens to work on an instrument with a built-in preamplification outboard, and realize that the sound you’re getting is similar to a plug-in or, even worse, to a good keyboard’s preset one. It’s usually the outboard’s fault and its lack of “human” content or rather for the engineer’s never-ending search for something that the instrument does not offer. In my opinion, the 610 is very “alive”, almost “human”. It is able to pick out all the beauty there is inside a sound signal avoiding a plastic and man-maid result.
Violin and Viola SOLO 610
As for the violin and the viola recording (Pic.5), instruments dealing with an almost similar register area, I used a AKG C414 omnidirectional microphone, in order to see how the pre would behave within environmental recordings. Placed at a 70/80 cm distance from the bridge, also in this case I got a nice result. Playing with the GAIN and LEVEL switch I was able to reproduce the sound of these two amazing instruments, without twisting or emphasizing the original signal. For this particular test (the rule is applicable for general acoustic instrument recordings), to get a good recording, I had to choose a proper environment first and then place the microphone in the exact point where the ear could get all the nicest timbre nuances.
Pic.4 – Neumann KM 184 microphone
Classical and spanish guitar SOLO 610
Dealing with a classical guitar sound has always been very hard for me, because, the guitarist on duty is, by definition, always overtaken by doubts, In this case the guitarist had a very nice hand-made classical guitar at hand, I would have preferred to choose a microphonic technique through AKG 414 ULS placed in the usual way, one on the right and the other one on the left of the guitar, but having just one pre, I went for one NEUMANN TLM 103 microphone. The performance has been in classical style with a pleasant final result, though not so excellent, with slightly unclean phases where harmonics had come in. I did the same thing for a Spanish guitar, equally balancing the GAIN section through the OUTOUT, I managed to get a rather good timbre even for the arpeggio parts (Pic.6); when increasing the performance speed (as for the solo during Queen’s Innuendo, for example) the signal gave the impression to be lacking in definition and intelligibility due to an excessive harmonic enrichment, therefore I had to reduce the GAIN section to set the appropriate balance back again.
Hand-made penny whistle SOLO 610
One of the tests has involved a hand-made penny whistle, one from the past, which have been built by the calabrian sheperds. The beautiful and unique sound of this instrument, however rural and genuine, gave a rather undetectable result in terms of dynamic: really low. To record this instrument I chose the AKG 414 microphone.
Unfortunately i didn’t get the result i expected, average presence but the sound was a little bit distort. This is not the right preamplifier when we are facing too weak signals which need a higher and clearer amplification capacity.
Over Head SOLO610
The use of this little treat as a microphonic preamplifier for drums has been a really interesting experience. I had to make do with a mono recording despite of a stereo one for this test. The drum player is a jazz one this time, and he kindly spared some time to play just cymbals, both in a very stripped-down standard jazz and in fusion style. In order to capture the cymbal sound properly, I placed the AKG 414 microphone right in the middle at a 50 cm distance from the cymbals (Pic.7): the result was very interesting. I must say that the SOLO 610 did its job flawlessly, in a way that only a few preamplifiers can do. Its work on the signal was really respectable, without distorting the attack, which is a typical valve device benefit, and with no loss at all on the higher range; Only when the drum player started to play harder and faster, the signal started to lose a bit its temporary sharpness, there was no use in changing the way the microphone was placed.
Conclusions SOLO 610
To sum it up, we can say that we are in the mere presence of a professional outboard, perfect for those who don’t have high budget at their disposal. The preamplifier circuitry is extremely neat, the noise is nonexistent, you don’t hear any type of background noise or breath, both when you manage to go hard on the preamplification and when you try to make a too weak signal stronger. The device is very simple and intuitive, easy to use even by a not-so-expert sound engineer, making his first steps with a professional instrument. I have been struck by the sound quality, honestly i was expecting something different, a “dirtier” sonority, which is something that mostly amazes the ears of an uneducated audience; a very rich-in-harmonics sound, but very distort, is what deceives listeners with little experience, in fact a very rich sound, especially on the mid and low frequencies, helps shaping weak or “empty” voices too. I must admit that the 610 sounds amazingly good, a perfect combination between dynamics, “warmth”, “background cleanliness”, moreover it does its job dexterously and it’s got the skill to bring also the “weakest in levels” candidates to an acceptable result. It gave me the impression to be a kind device, rather undemanding and easy-fitting to almost every kind of instruments, when it’s asked, it can pull out a strong and determined temper, but never overdoing it. It sounds really nice, I can affirm that it’s one of the few valve devices I know which is able to offer a good fast transient response as for example a drum cymbal or metal percussion sounds in general. The strong point about this model is in the ability to emphasize and tie the low and medium frequencies fairly without losing in sound intelligibility, you can hear a silky grain on the higher spectrum side with no content loss, even between the 8000 and 10000 Hz. It’s something that usually only high-priced devices own. The benefit stands, as I said, that it’s often unnecessary to use the equalizer. The “super knobs”, vintage looking, are very sensitive to any little movement, even the LO CUT switch acts discreetly without creating a whole on the low frequencies, let’s say that it softens them instead of cutting them, letting the sound stay warm and rich in harmonics. All told, let’s not forget of all the benefits that musicians who work with direct signals -without having them pass through a microphone- (Pic.8) can take advantage of. If I had to suggest the SOLO 610 to a specific target range, I am thinking to anyone who has got a troublesome voice, both in the case of weakness and “emptiness” about expressivity, instead, for those who wish to give “substance” to their works, my advice is not to combine this pre, being it a valve one, a valve microphone too, it would create a raw and thick signal. The first part of comparing preamplifiers has come to the end, what should we expect for the next month? On one side of the ring we’ve met and learnt to appreciate a big champion whose name is yet a threat “SOLO 610” and on the other side we have his little skinny brother “SOLO 110”. What would be the latter’s strong points?Which strategy will it carry out to defeat and knock out his opponent?
Until next time…
Italian to English translation: Umberto del Giudice