Matt circuit

9V battery operated add-on unit for moving magnet pick-ups Two-stage Series/Shunt feedback RIAA equalization This unit was designed for amateurs owning an old collection of vinyl recordings and wanting to have it digitally remastered into a personal computer. Or sometimes they would listen to an old, invaluable, LP collection through their modern High Fidelity chain, usually lacking a phono preamp stage: this is a circuit capable of satisfying their needs. The unit is powered by a 9V battery, allowing a quick and easy connection to all high-level input preamplifier stages and the very low current drawing of the circuit will guarantee a long battery life. Circuit diagram : Portable Phono Preamplifier Circuit Diagram Despite the low voltage supply, circuit performance with moving magnet pick-ups is quite good, featuring high input overload capability, very low distortion and accurate reproduction of the RIAA equalization curve, thanks to a two-stage op-amp circuitry in which the R...

While we have published a number of variations on a standard RIAA preamplifier for magnetic phono cartridges, we have not published a preamp stage for ceramic phono cartridges. Typically, these were supplied as turnover cartridges in record changers but there were higher quality versions such as the Decca Deram. These phono cartridges are piezoelectric devices which require a very high input impedance. Similarly, violin pick-ups made by Fishman, Barcus Berry and others are piezo devices. These two circuits have been requested for a violin pickup but could equally well suit a ceramic or crystal pickup. The op amp circuit uses a TL071 connected as a voltage-follower. It can run from a battery supply of ±9V. Circuit diagram: The alternative transistor circuit uses a BC549 connected as an emitter-follower but with bootstrapping of the input bias network to provide a high input impedance. Both circuits have input coupling capacitors but since the transducers are capacitive (ie, piezo) t...

High Quality Moving Magnet Pick-up module, Two-stage Series/Shunt feedback RIAA equalization . Any electronics amateur still in possess of a collection of vinyl recordings and aiming at a high quality reproduction should build this preamp and add it to the Modular Preamplifier chain. This circuit features a very high input overload capability, very low distortion and accurate reproduction of the RIAA equalization curve, thanks to a two-stage op-amp circuitry in which the RIAA equalization network was split in two halves: an input stage (IC1A) wired in a series feedback configuration, implementing the bass-boost part of the RIAA equalization curve and a second stage, implementing the treble-cut part of the curve by means of a second op-amp (IC2A) wired in the shunt feedback configuration.  . This module comprises also an independent dual rail power supply identical to that described in the Modular Preamplifier Control Center. As with the other modules of this series, each electronic...

In recent years, following CD's introduction, vinyl recordings are almost disappeared. Nevertheless, a phono preamplifier is still useful for listening old vinyl discs from a well preserved collection. This simple but efficient circuit devised for cheap moving-magnet cartridges, can be used in connection with the audio power amplifiers shown in these web pages, featuring low noise, good RIAA frequency response curve, low distortion and good high frequency transients behavior due to passive equalization in the 1 to 20 KHz range. Circuit Diagram: Parts: R1 = 47K R2 = 100R R2 = 6.8K R4 = 68K R5 = 2.7K-1/2W R6 = 2.7K-1/2W R7 = 2.2K R8 = 39K C1 = 100uF-25V C2 = 100uF-25V C3 = 100uF-25V C4 = 47nF-63V C5 = 47nF-63V D1 = BZX79C18 D2 = BZX79C18 Q1 = BC337 Q2 = BC327 J1 = RCA Jack IC1 = LM833, Opamp Notes: R2, R3, R4, R7, R8, C4 & C5 should be low tolerance types. Schematic shows left channel and power supply. For stereo operation R1, R2, R3, R4, R7, R8; J1; C1, C4 & C5 must be doubl...