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DIY Stompboxes => Building your own stompbox => Topic started by: Freppo on April 10, 2015, 01:54:33 PM

Title: Green Currant Vibrato. A TDA5072A based percussive vibrato / tremolo
Post by: Freppo on April 10, 2015, 01:54:33 PM
Here is a new design I have been working on for alittle while

Soundclip:
https://soundcloud.com/fredrik-lyxz-n/green-currant-vibrato (https://soundcloud.com/fredrik-lyxz-n/green-currant-vibrato)
(Anyone know how to embed soundcloud code here?)

More info, schematic and vero layout can be found in my blog:
www.parasitstudio.se (http://www.parasitstudio.se)

Dual layer PCB layout for fabrication is already done and PCB's will be sold later through my webshop

I hope you like it :)
cheers / Fredrik
Title: Re: Green Currant Vibrato. A TDA5072A based percussive vibrato / tremolo
Post by: ~arph on April 11, 2015, 03:54:12 AM
Never thought about that you could not hook up a speaker and just use it as a vca. This ic has some potential  :) I have one on my breadboard all the time as a headphone amp.
Title: Re: Green Currant Vibrato. A TDA5072A based percussive vibrato / tremolo
Post by: samhay on April 11, 2015, 05:05:56 AM
>This ic has some potential
Seen it used in a compressor before, but hadn't thought about a trem - nicely done Freppo.
Title: Re: Green Currant Vibrato. A TDA5072A based percussive vibrato / tremolo
Post by: Freppo on April 11, 2015, 07:03:23 AM
Thanks! :)
Yes, it certainly has potential. I just love when I can avoid LDR's or transistor VCR's...
I kinda went alittle crazy and took every possible measure to avoid LFO ticking.
Even my vero layout is dead silent, so I think it was worth the extra trouble/components. :)
A more conventional tremolo would be even easier to do with less parts.
Title: Re: Green Currant Vibrato. A TDA5072A based percussive vibrato / tremolo
Post by: Freppo on June 07, 2015, 03:41:43 AM
PCB is now avaliable at www.parasitstudio.se (http://www.parasitstudio.se)  :)
Title: Re: Green Currant Vibrato. A TDA5072A based percussive vibrato / tremolo
Post by: armdnrdy on June 09, 2015, 11:10:27 PM
I was looking at the schematic while I was listening to the sound sample.

I heard quite a bit of the clean signal coming through...which is best for some things.

I feel that a "mix" control to vary the amount of clean verses tremolo would be a good addition for versatility.

What do you think?
Title: Re: Green Currant Vibrato. A TDA5072A based percussive vibrato / tremolo
Post by: Freppo on June 10, 2015, 04:22:24 AM
Thank you for the suggestion. :)

Yes, part of the lowend always stays clean. It's just so that even the choppiest sounds doesn't get too "thumpy".

I have tried to add a mix/depth control, but since this circuit uses phase cancellation as a part of it's sound, there is a small "sweetspot" when blending the two signal paths (to get the slightly phaser-ish sound I was going for). Changing the relationship of the signalpaths (that are 180 degrees out of phase) would change to sound too much for my liking, so I decided to not include it.

However, the range control kinda works as a mix pot in a sense, as it controls how much of the frequency range is effected by the modulation, and it can even dump all of the modulated signalpath to ground. It's just a highpass filter, so the blending of the two signal don't change too much. I like having that control insted of a usual depth/mix control, makes the circuit alittle bit more unique. :)

Cheers / Fredrik
Title: Re: Green Currant Vibrato. A TDA5072A based percussive vibrato / tremolo
Post by: Mark Hammer on June 10, 2015, 08:16:43 AM
Not to be picky, but the schematic indicates a TDA7052A (which the pinout corresponds to), NOT a TDA5072A (which I can only seem to get links for in Cyrillic).

The 7052A is an 8-pin dual power-amp chip, suitable for headphones; a bit like a JRC2073.
Title: Re: Green Currant Vibrato. A TDA7052A based percussive vibrato / tremolo
Post by: Freppo on June 10, 2015, 08:21:19 AM
Quote from: Mark Hammer on June 10, 2015, 08:16:43 AM
Not to be picky, but the schematic indicates a TDA7052A (which the pinout corresponds to), NOT a TDA5072A (which I can only seem to get links for in Cyrillic).

The 7052A is an 8-pin dual power-amp chip, suitable for headphones; a bit like a JRC2073.

Ops, you are right! The TDA7052A is indeed the correct chip. :)
Can't seem to update the name of the tread though.