Introduction:
This is another little helper module for my modular, a bank of 8 small mono amplifier stages which increase a signal or voltage 10 times / by factor 10 (electrically spoken, afaik +20db, but I do not know the computation really).
The 8 stages work independently from each other. But if you plug the output of one stage into the input of another, the amplification multiplies of course. This enables you to pimp up weaker signals as well.
The stages are dc coupled, so you can amplify dc voltages as well, but the inverting amplification has to be considered (see circuit).
Why do you need this? Well, I need this to be able to integrate weak-chested instruments in my modular during jam sessions, and I don't want to run a separate mixer unit in my gear. When a friend came for a session and brought some synths I realized that some battery driven boxes do whisper and don't play music!
Of course one can use this module as technical helper unit like an instrumental amplifier (not musically spoken) as well.
Circuit:
Schema: Clicking the schema means accepting the disclaimer on page bottom!
As already mentioned, a group of independent simple inverting dc coupled amplifier stages. Each individual stage amplifies by factor 10, or more precise Uout = -10 x Uin, as a result of the relationship between input resistor 10k and feedback resistor 100k. If you cascade two stages, the resistor relationship is changed by the 1k output resistor of the previous stage which has to be added to the input resistor of the next stage, and the amplification of that stage lowers to -9,09 * Uin.
Frontend:
The front panel consists of 8 rows, left input, right output. Each row forms an amplification stage.
TAMP Board
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