preamp regulated or unregulated 4558d

[rahulrahullll]

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

[PRR]

The 4558 is not terribly fussy and can be fed unregulated power if it is well filtered.

Is "noise" hiss, hum, buzz, radio?

The backward volume knob action may be mis-wiring of the board or even a bad board.

[rahulrahullll]

noise i guess is hum---like--------goooooooooooo

[AndrewT]

Originally Posted by rahulrahullll

......................what should i try to resolve issue ?
.............

Post a schematic and some detailed pics of what you have built.

[rahulrahullll]

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