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Below is from the Grado website. We recommend you choose usps priority mail with this order for maximum shipping protection.
THE GRADO PHONO PRE-AMPLIFIERGrado's New Proprietary Phono Equalization"The Best of Both Worlds"
Our new Grado Phono Preamp, model PH-1, represents the most successful solution to one of the most complex technical challenges in the field of audio that Grado Labs has ever tackled. It can be compared to the undertaking of designing our highly acclaimed phono cartridges, headphones and our world renowned RA-1 headphone amplifier over the past several years. Our design goals were for a truly superb sounding phono preamp to work equally well with both low and high output cartridges with negligible noise. We wanted a phono preamp with ultra wide band pass, high overload, virtually perfect RIAA amplitude and phase coherency, and very low output impedance. This was the challenge set forth! This we have accomplished!
We realized immediately that a challenge like this was not going to be met by using either of the time-honored methods of passive or active equalization circuits. The relative advantages and disadvantages of these old methods are very well known: the passive preamp approach is characterized by problems of first stage headroom and second stage noise. This is due to the 40dB high frequency insertion-loss of the passive network itself. Phono stage gain is frequency dependent with the result of too little feedback at the low end and too much at the high end. Of course, both extremes are sonically non-optimum and unacceptable.
The more commonly used active equalization stage provides solutions to the classic passive circuit problems, but it also comes with a whole new set of its own problems. These difficulties arise out of the subtle ramifications of the classic negative feedback theory. The RIAA characteristic requires that the amplifier's closed-loop gain needs to change by a hundred to one (40dB) over the entire audio range. This means too little feedback-closure at low frequencies and too much at high frequencies. Too little causes inadequate suppression of simple distortions, and too much causes the generation of complex distortions (high-order).
The new Grado phono preamp circuit design now has all of the advantages of the old methods, yet none of its antiquated disadvantages! The challenge was met! The processing problem has been split into two separate parts: a forward propagating signal current and a back propagating error voltage. We have indeed eliminated all of the past methods. Our new phono equalization technique is a derivative of the principals that we used in our highly regarded RA-1 headphone amplifier. In this design, feedback closure ratio does not change with frequency, but the total output gain does. Virtually all latter stage noise disappears! The output impedance is very low, with the EQ stage opened-loop and the closed-loop gain being the same. The best of both worlds!
What is so significant about these new innovations is the fact that the technical superiority claims absolutely correlate to an unprecedented improvement in openness, greater depth of field and increased definition to the sound of each musical instrument. The PH-1 offers a true freedom from past sonic problems along with Grado's usual warm, smooth, full bodied, non-fatiguing and rich sound qualities that everyone has embraced.
If your turntable is driven with a Grado cartridge then you deserve to go the final step with the new PH-1 phono preamp.
GRADO'S PH-1 PHONO AMP
PART I
Todd Green"The Vinyl Junkie"
Sales Manager
HeadRoom Corp.
I feel very fortunate to be a part of the preliminary listening group for the new Grado Phono Stage. The wooden box that houses the electronics looked very familiar - it is the same as the box for the RA-1 headphone amp. Not one to care about looks as much as sound; the PH-1 in its pre-production form has all the possibilities of being a good-looking unit. More importantly it sounds fantastic. It has 2 gain settings; the lower of the two fit my Rega Planar 11 with a Grado Reference Sonata cartridge best. The first thing I noticed was how relaxed yet detailed the sound was. Instruments were alive and full - sounding convincingly real. Soundstage was full and accurate. It did not hide flaws but allowed those albums that were produced better to stand out. Each instrument had its place and yet the whole sound remained coherent. Detail was very good with tight deep bass complimenting the sweet mids and smooth highs. It reminded me of why I kept my vinyl and own a turntable - they can sound every bit as good as digital reproduction yet have a natural sound that digital sometimes misses. This is the sound I grew up with and love.
The Grado PH-1 had plenty of gain and when I switched it to high gain it was far too much for my setup. Thus it spent 98% of its time in my rig with it set at low gain. I hope to audition it further with one of the new ...
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