#Led clipping detector update#
#Led clipping detector series#

While you can also use expensive high-performance opamps, there is no reason to do so - the circuit only lights an LED. The circuit diagram is shown in Figure 1, and although shown with an LM358 opamp, you can use TL072, 1458, 4558 or any other common (cheap) dual opamp.

#Led clipping detector series#

For example, with ±5V supplies, you might reduce the LED series resistor to around 820Ω. Only the LED series limiting resistor will need to be changed in order to maintain a useable current at reduced voltage. The detection thresholds are set from the supply rails, and the ratios remain the same regardless of supply voltage. An overload indicator that creates distortion in the source circuit is hardly useful.Īlthough shown here using ☑5V supplies, these circuits will all work fine with other supply voltages. This is especially true with high impedance circuits, because any non-linearity in the detector is directly reflected back to the source. This is not really a good idea, because many (most) audio signals are asymmetrical, and detecting only one polarity could mean that some signals could be clipping without you realising that it's happening.Īnother requirement is that the circuit can be connected to high or low impedance circuits without creating a non-linear load that causes distortion. The aim of the circuit is to detect both positive and negative peaks - a great many peak/ overload detectors only work with one polarity. While it could have been made faster by limiting the opamp output swing with more diodes, doing so would increase complexity and introduce switching noise onto the input line. The circuit is shown below - it's very simple, but works well even with the most basic opamps.

#Led clipping detector update#

An update has changed the switching so the LED is switched between the supply rails and doesn't include the system ground. There are also two additional circuits, both intended where you need a single overload detector for multiple points in a circuit (or to indicate an overload on either of two channels in a stereo system). The modifications are primarily to allow the detection threshold to be adjusted to suit different applications. Since this is something that people seem to need (especially with mic preamps and the like), the circuit has been modified, physically tested, and is presented here. The ESP website does have a couple of circuit for high performance overload detectors, but one is buried within the Project 30 mixer pages and is easily missed, and the other is in the Project 152 bass amp project. Please Note: PCBs will be available for this project depending upon demand.