A brief chronology of the Orange Squeezer follows. The Hartman Compressor is based on a combination of components from the early pre-logo Armstrong (top row) and the Musitronics unit (second row):
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| Original pre-Musitronics logo Dan Armstrong Orange Squeezer. Single 4558 op-amp, unmarked Silicon diode. 2SK30A FETs. ~1975. | |||
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| Musitronics logo Dan Armstrong Orange Squeezer. 1/2 Dual 4558 op-amp, 1n100 Germanium diode. 2N4547 FETs. 1975-1979. | |||
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| WD reissue Orange Squeezer. LF351 op-amp, 1N4148 Silicon diode. 2N4547 FETs. ~1980-81 | |||
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| WD reissue Orange Squeezer. 741 op-amp, 1N4148 Silicon diode. 2N4547 FETs. 2007 | |||
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