Pro-Ject Phono Box MM, Phono preamplifier with metal case and special low-noise ICs

Product Information

In addition, the midband voltage gain of the input stage is adjusted at around 46dB. With that kind of a low input level, it is apparent that low noise transistors (such as the BC109C) are required to get excellent performance. If you’re in the market for a quality affordable phono stage, this little Award-winning box is well worth auditioning.

This is where the phono stage (or phono preamp) comes in. It has two jobs. Firstly, it has the reverse response built into it – one that boosts bass and flattens treble to exactly the right degree, which should result in a tonally even presentation for the audio signal. New Tubes: Whether you want to buy brand new or NOS, tube rolling is definitely the way to go if you want to fine tune to your specific tastes your system’s synergy.As much as wiring is concerned, that may be not an issue, however matching the high impedance of the guitar component with the low impedance of the line input of the mixing panel does becomes an issue. True clipping of the input signal is not going to take place until eventually significantly bigger levels above the minimum guitar specs are utilized. The circuit is powered by a 9-V (PP3) battery through which the circuit pulls a current just around 3 mA. 3) Stereo Preamplifier Using IC LM382 The higher amplitudes are processed normally and is reproduced with a potential that's approximately equal to the supply voltage, however for the lower misc amplitudes T2 is allowed to conduct at the higher ratio which is allowed to pass to its emitter. This is done to boost the gain of the circuit, which as explained earlier, needs to be about ten times higher for a low impedance microphone. Zero Noise Preamplifier Circuit Provided you keep it away from other mains-powered products and power cables, this phono stage will prove suitably quiet and hum-free. Features are basic but it's clear that Moon has focused on the bit that counts – sound quality.

I am not a total audiophile who demands ultra-low noise and distortion, but I would be wishing for this buffer to be more-or-less ‘transparent’. These usually provide an output signal level of about 0.2mV. R.M.S., which is about one tenth of that generated by a high impedance microphone.

The physical limitations of vinyl mean that the original audio signal has to be altered before it can be recorded onto its tiny grooves – low frequencies are reduced in level and the highs are boosted. The curve that governs this equalisation standard was set by the RIAA (Record Industry Association of America) in 1954. Detail is great, too, uncovering new layers of musicality and texture as it goes, especially with regard to vocals. From Beethoven to Bruce Springsteen, the Rega Fono MM is completely at home.

We've continuously been impressed with Rega's excellent (and rather affordable) Fono MM range, so it was something of a relief that the latest model, which featured a brand-spanking new look, didn't sacrifice style for sound. That same Rega DNA is still in there throughout the latest Fono MM Mk5 phono stage.

Sound quality is first-rate: fantastically detailed, with the upper register particularly impressive. It’s difficult to imagine a more detailed presentation from a phono stage for the money. There are rivals with an equally wide soundstage, but they perhaps don’t shine the spotlight so intensely on each instrumental strand. Detail is where it stands out, but the Gram Amp 2 is also a dab hand at dynamics and timing – although perhaps not with as much bite and punch compared with the Rega.

The prototype was found to work well with both 200 ohm and 600 ohm impedance dynamic microphones, but it should also work well with electret types which have a built-in FET buffer amplifier, but no step-up transformer. You can read more about how we test and review products on What Hi-Fi?here. Why do I need a phono stage? The required value of Rf is found by multiplying the required voltage gain by 560. Thus, a voltage gain of ten limes, for example, requires Rf to have a value of 5.6k. We have state-of-the-art testing facilities in Reading, London and Bath, where our team of experienced, in-house reviewers test the majority of hi-fi and AV kit that passes through our door – including phono preamps (or phono stages). So why do you need one? Your stereo amplifier or turntable may not have one, in which case you won't be able to play records without this crucial component. Or you might just want to upgrade its sound beyond what's possible with the built-in phono stage found in amplifiers or some record players.Please suggest me a good quality stereo audio small signal preamplifier circuit which can work from 5 or 6 volts single supply, that would not load the set top box, preferably using good low noise op-amp with detailed circuit and parts label. Another oldie but still a goodie, the Gram Amp 2 holds its own nearly a decade after first coming on the scene. And you can see why - simplicity is the name of the game here, an approach that ages remarkably well. It's a moving-magnet phono stage with one set of inputs, one output, no bells or whistles. The circuit described so far, are of course, only suitable for use with high impedance microphones, and provides insufficient gain for use with low impedance types.