+ Reply to Thread
Results 1 to 2 of 2

Reload Thread: Ways to feed audio signal to car stereo volume controller?

  1. #1
    Gagong's Avatar
    Gagong is offline Junior Member



    Join Date
    May 2017
    Location
    Hong Kong
    Posts
    1
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Ways to feed audio signal to car stereo volume controller?

    I'm trying to hack AUX input into car stereo with tape mechanic. I managed to identify the most important circuits. The idea was to use tape mode to amplify custom audio input.

    The original wiring was something like this.

    tape head -> preamp -> volume controller -> amplifier

    So I removed the preamp and soldered my signal wires to pre-amps output. I also added a switch which makes stereo to think the tape is inserted. So I can also use a radio receiver.

    And it works. But the there are to things which bother me. The signal level of my input is lower then output of radio receiver. So I have to adapt the volume when switching between radio and AUX.

    The next thing is that sound is actually a little bit distorted. Maybe some frequencies are missing or something. So I guess my wiring is not right.

    I also noticed that there are some empty holes and unused labels on PCB. Probably for actual AUX input. I identified the circuit and it should look something like this (if it was there).



    Indeed I don't know values since the parts are not actually present on the PCB.

    So I thought I should use something similar to feed my signal to the tape input of the volume controller.

    Can someone help me to understand what is the purpose of parts in the circuit? And what values to use?

    I guess C1 should filter DC component? There are some capacitors in similar positions and have values of 2.2u so could I use the same?

    And the R1, R2 acts just as voltage divider? So it's for adjustment of signal level? So something in kOhms?

    And the C2 is mystery to me.

    link to the of volume controller:
    LC75421M-TLM-E - SANYO - IC Chips - Kynix Semiconductor







  2. #2
    Jeffdachef's Avatar
    Jeffdachef is online now Gunz That Turn on Nunz



    Join Date
    Feb 2013
    Location
    South Coast Metro, CA
    Posts
    12,773
    Post Thanks / Like
    Images
    1
    Mentioned
    118 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    5763 Post(s)

    Re: Ways to feed audio signal to car stereo volume controller?

    just too many things in the signal line and too weak of a signal to start with. The fewer things in the signal line, the better. I would definitely use some OEM integration or get a proper head unit with RCA output. Makes the biggest difference or else you'll just have pure garbage sound quality no matter how you try to make it work.



    09 Sienna Subs : Four Team Ascendant 18s......Sub amp: Two Taramps 15k
    Headunit: Pioneer 80PRS................................Mids/Highs amp: CT 500.2, ppi 600.2, ppi 900.4 bridged
    Front stage: Two PWX 10s per door midbass only....... PRV 6MR500 midrange....... Massive CT 2 german tweeters.
    320 amp Singer alt....... 1 group 34 under the hood 6 group31 agms in the back 560 amp hours total.

+ Reply to Thread

User Tag List

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may post attachments
  • You may edit your posts
1e2 Forum