Schematic Elements for Guitar and Effects: Synchronized LFO's and Harmonic Tremolo

[@blueduck577]

nice! I am an EE that originally got interested in the field from modding my guitar pedals all those years ago. your channel is so cool!

[@velvetsound]

Please keep up this schematic elements series, it’s really good. I’m totally loving each one. It’s the analog circuit side of what Phil’s Lab is for PCB and DSP design. Loving it!

[@velvetsound]

Great explanations. I build tube amps and this totally reminds me of parts of the Princeton and Tremolux topologies. It’s amazing how much tube amps from the Sixties and pedals from the Naughties have in common some times.

[@-______-______-]

Thanks so much for doing this video. It's very much appreciated!

[@JulioNusdeoIII]

thanks for this man! greettings from buenos aires argentina. i really apreciatte your schematic elements series! could you explain R7 in the low pass path? it's not present in high pass one. or yes it is but as part of the CR filter. also the large C3 which has not that big counterpart in the high pass. thanks!!

[@buildyourownclone]

To the point The Scientific Guitarist was making at the end of this video regarding designing your own circuits, while this circuit could be considered "original" in its entirety, all of the individual parts were taken or derived from parts of other circuits. The primary tremolo effect was heavily influenced by the Schaller Tremolo. If you examine the Schaller tremolo, you will see that the input signal passes through a voltage divide before entering the transistor amplifier. This is purely to reduce the amplitude of the input signal. It would not be apparent from simply looking at the schematic, but without this signal reduction, you get a thumping noise in the tremolo effect. In this circuit, signal is split into high and low frequencies. The passive high pass filter is enough to reduce the amplitude of the input signal to its respective amplifier. Low frequencies possess greater amplitude. The low pass filter alone was not enough to reduce the input signal to its respective amplifier. So that is the purpose of R7 - to further reduce the amplitude of the signal. With regards to C3, we don't want to lose any low frequencies in the low frequency path, so a large DC blocker is used. Perhaps 4u7 might be slight overkill. 1uF or even .47uF would likely work just as well, but 4u7 is already being used for electrolytics and the fewer values you have in a BOM the easier production is. C2 is pulling double duty as the DC blocker and high pass filter.

[@waynegram8907]

Do a lesson about the DOD Vibrothang because for the vibrato it only uses 3 phase shifting stages =270 degrees compared to the univibe vibrato mode uses 4 phase shifting stages = 360 degrees. Its a different vibrato phase shifting to do a deep dive lesson about it

[@-______-______-]

So how do we introduce syncronisation to the LFO?

[@thescientificguitarist4228]

The way it is done in this circuit is to buffer it and create and inverted version. Other ways that can be done are to use a digital LFO, or to have a central clock controlling multiple oscillators.

[@-______-______-]

Why did you title the video this way, and then not mention it at all? Plus, your answer here doesn't explain it. Might want to retitle the video to save further confusion.