i have tda 2050 stereo made by me—working fine no noise——i buyed–a–tone control board bass,mid,treb,vol–2 ic —–4558d—-
power supply separate is for tone board—
9-0-9 v ac after bridge rectify—-12-0-12 v dc power given to tone board—-in board written d c—-( + – gr)
actually amp trannsformer 22-0–22=44 v dc so i cannot use in preamp
--------https://ibb.co/bHm1pw----------
vol pot–47k, bass treble mid–100k
connections———–amp is grounded to amp transformer ————
signal grounded to tone board transformer——–tried grounding too amp transformer—-no result———in the pic———–+-g is supplied by 12-0-12 v dc from unregulated supply using transformer-bridge-caps———
input—–is given from pc out–input is grounded to gr of power—-output connected to amp input
observations—-
1——-when i connect tone board—sound ok but huge constant background noise also when pause song huge background noise when signal cable open——–noise stiill there —-noise decreases if vol is turned down-----
2———weird thing in tone board—vol increases if i turn anticlock direction, all other pots increase anticlock direction
3——–when i turn off power to tone board with amp on no noise
4—–in board power ground, input,output,vol pot same ground
5—–in input of tone board 150 k ohm there—output 10k
6————-tried star grouunding for amp,signal,tone—–noise there
7---------does preamp needs regulated or unregulated power
——–what should i try to resolve issue ?
———–thank you
power supply separate is for tone board—
9-0-9 v ac after bridge rectify—-12-0-12 v dc power given to tone board—-in board written d c—-( + – gr)
actually amp trannsformer 22-0–22=44 v dc so i cannot use in preamp
--------https://ibb.co/bHm1pw----------
vol pot–47k, bass treble mid–100k
connections———–amp is grounded to amp transformer ————
signal grounded to tone board transformer——–tried grounding too amp transformer—-no result———in the pic———–+-g is supplied by 12-0-12 v dc from unregulated supply using transformer-bridge-caps———
input—–is given from pc out–input is grounded to gr of power—-output connected to amp input
observations—-
1——-when i connect tone board—sound ok but huge constant background noise also when pause song huge background noise when signal cable open——–noise stiill there —-noise decreases if vol is turned down-----
2———weird thing in tone board—vol increases if i turn anticlock direction, all other pots increase anticlock direction
3——–when i turn off power to tone board with amp on no noise
4—–in board power ground, input,output,vol pot same ground
5—–in input of tone board 150 k ohm there—output 10k
6————-tried star grouunding for amp,signal,tone—–noise there
7---------does preamp needs regulated or unregulated power
——–what should i try to resolve issue ?
———–thank you
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