I have made guitar amplifier with few schematics i found online. I use torus transformer, J201 fets. I haven't solder part for delay, just all the transistors, tone control and power (you can follow on schematic from input to output). When i turn on the preamplifier part you can hear the buzzing. I tried to short circuit the input on TDA (not on schematic) and the buzz is gone. I have grounded the ground on preamplifier circuit, TDAs ground is connected via flat cable to preamp (you can see that also on one of the picture) so it is also grounded, and i grounded the metal part on which pots are attached. When i turn the volume all the way down the gate of the last fet is connected to ground but you can hear the buzz (not so loud). If i turn the volume up, buzzing volume also increases. When i connect the guitar it sounds really nice, but the buzz sound i about 1/3rd of volume of guitar. Any ideas what i should try to eliminate buzzing?
Here is the link for pictures of electronics taken out from cabinet and schematic of preamplifier.
Here is the link for pictures of electronics taken out from cabinet and schematic of preamplifier.
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are the green cable your input lines ?
you need shielded cable from your guitar to the preamp input.
you need shielded cable from your guitar to the preamp input.
Yes, i will change that, and i got shielded cable from the guitar to that input, but even without guitar, when input is connected to ground there is noise and it doesn't got worse when i plug in guitar. You can see maybe on picture that there is one small cable that connects two of the pins of inputs so without cable input is connected to ground. Disregard that i got buzz when volume is all the way down and I explained that than the last transistor is connected to ground, and the input doesn't play any role than. You can look in schematic for master volume control to see what i mean. Still don't know what is the problem.
The cable joining the tip and sleeve looks to be on the wrong side of your switching jack. (We are talking that thin copper wire right?)
The signal and ground should only be connected when no cable is plugged in.
Like this: https://www.midikits.net/foot_pedal/mono_skt_wiring.JPG
The signal and ground should only be connected when no cable is plugged in.
Like this: https://www.midikits.net/foot_pedal/mono_skt_wiring.JPG
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