thanks for the musikding circuit, seems pretty simple (great!) - but would it work also for a single rail 5V supply, resp. what would be the implications?
I would vote against this - as you stated yourself the actual need for this is pretty low and threads like the current one provide plenty of information for those who have an interest in this (and after all this information could go into a wiki article).
But most of all instead of cramming feature after feature into Zynthian imho there should be a much greater focus on usability and workflow - there are several examples of open source projects which benefited very much from restraining feature overflow and concentrated instead more on UX and interface design, e.g. Blender or Musescore as recent examples. /rantOff
I use a Behringer UMC202HD as preamp only (the Zynthian audio interface is a Hifiberry DAC+ ADC), it also works without a computer (you have to push the Direct monitor button). Iām experimenting with process guitar and vocal simultaneously. One channel act as a cheap microphone preamp with XLR input and gain control, the other act as a Hi-Z guitar input, with gain control and pad, and you have a headphones monitor output with volume control. No need to put it all inside the Zynthianā¦
I have not a single clueā¦ my wireless system seem to take car of that, I have a good level of input with my guitar, bass, electroacoustic ukulele bass, ukulele, kazoo
For my microphone with xlr to jack adapter , it work only with jack-wire.
Yes it should be fine with 5V supply. It is designed to connect directly to a guitar which tends to have peak output less that 1V so plenty of headroom.
Running a simple transistor buffer that has been designed for 9V on 5V runs the risk of distorting the signal, either because the signal hits the rails or because of the misbiasing. Moreover, these simple circuits are designed to run on clean power either from a battery or a well filtered and regulated linear power supply. Running them on a switching power supply is likely to introduce noise. Worse, running these analog curcuits from the same power supply as a digital device will likely introduce more issues. Here are a few suggestions ordered from the simplest:
Use any pedal that has a buffered bypass. All Boss pedals (in)famously feature a buffered bypass. If you donāt want to bust the bank spending 100 EUR for something that you will mostly use as a buffer, you can get one of these Behringer clones. You can find those for as little as 10 EUR second-hand.
Use any other device that provides buffering for a guitar input, with a direct out, such as a portable recorder, an audio interface, a preamp, etc. Again, Behringer has these little tube preamps that you can find for as little as 25 EUR second hand.
Build a simple JFET buffer with a 9V battery supply. JFETs are getting more difficult to find these days, but since this is a boost, you can use any JFET that is reasonably priced (e.g. 20c). Alternatively, you can build a buffer using an op amp.
If you must run the buffer on the same 5V supply as the Zynthian, I would recommend using a charge pump (e.g. ICL7660/MAX1673) to get from 5V to 9V, and add some power filtering and/or regulation.
I personally use 1 and 2 for both guitar and bass, and I have built 3, but I did not find it too practical. 4 could work but I havenāt tried.
