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Voltage Regulators for Line Level Audio. Part VII : The k-multiplier

Posted 18th February 2014 at 12:55 AM by rjm
Updated 18th February 2014 at 01:08 AM by rjm

Part of a series.

This circuit is from this page by Kean Token, also referenced in his recent blog post.

Two versions are presented, one with all the protection diodes and a simplified version with extraneous components removed.

LTSpice simulation shows so-so performance into a light load, with about 70 dB of ripple rejection and a fairly high output impedance, but the drop out voltage is respectably low and we must factor in - coming directly from the Jung Super Regulator - that this is just a two transistor circuit, with no error amplifier to provide feedback.

As a frame of reference, it is quite similar in performance to the Z-reg we looked at back in part III.

The k-multipler is of a class of voltage regulators where the output is referred to the input voltage, rather than to ground. It provides "X volts less than the input", rather than the traditional regulator which provides "X volts above zero". There's a second, related class of k-multipler which provides "a fraction Y of the input" that we will look into shortly.
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Attached Files
File Type: asc voltageregulator-kmult.asc (2.9 KB, 272 views)
File Type: asc voltageregulator-kmult-simple.asc (2.1 KB, 263 views)
Total Comments 2


  1. Old Comment
    The performance of this circuit in simulation is slightly better that what is shown here (especially the output impedance).
    You should increase R1 since the load is "only" 1k in your sim and the k-multiplier is badly biased.
    Posted 19th September 2014 at 06:46 PM by Chris4 Chris4 is offline
  2. Old Comment
    rjm's Avatar
    Good point, it seems R1=220 ohms is a better value.
    Posted 3rd October 2014 at 12:17 PM by rjm rjm is offline

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