Volumdropp på phaser

AC15 · Desember 15, 2008

Leste at jeg kan bytte to motstander for å fikse dette.

Er dette riktig motstand?

UNMATCHED VOLUME PROBLEM:

Many people have complained about a small volume loss when the Small

Stone is switched on. My Small Stone exhibits this behavior as well.

Here is a post from R.G. from Aron's Stompbox Forum on a possible

fix (modifications to the circuit) for this problem.

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From R.G. Keen

The loss of volume when engaged is correctable in the Issue J Small Stone

by changing the gain of the two-transistor preamp at the input of the circuit.

There are two 4.7K resistors at the emitters of the input transistors. One

(R7) goes to ground from the emitter of Q1, the second (R42) connects the

emitter of Q2 to the emitter of Q1. Those two resistors set the feedback gain

of the two-transistor compound.

Increase the 4.7K between the emitters (R42) to increase the gain. Start with

10K. Be aware that this will affect the stage biasing, so the headroom may

be affected; I don't think this will really be a problem.

The silly thing *ought* to have included a JFET buffer in front of it for

buffered bypass and a bit of gain in the first place.

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Dave Matelitz reported successfully fixing this problem by making these

part substitutions:

Changing R42 from a 4k7 resistor to a 10k resistor

Changing R11 from a 3k3 resistor to a 10k resistor

Tweak these two resistors until you get the volume right with no oscillation

in the signal.

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