ECM
100+ Head-Fier
- Joined
- Jan 9, 2004
- Posts
- 175
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- 23
after reading much about the toshiba DVD players and how good they sound i decided to try some mods on my old sony dvd unit.
the first thing i did was to remove the opamp (njr4558) and replace it with an opa2227. the old opamp was fairly difficult to remove because it had been tacked in place with some red glue. but fortunately, no lifted traces. i had never soldered a soic chip, but the new one went in without any problems.
instead of jumpering the muting transistors, i just removed the ouput caps right after the opamp and installed two 5.1uf solen caps left over from another project. these were wired direct to the the rca jacks. i cut and desoldered the metal part of the rca jack that goes to the PCB to isolate them and soldered the wires to the backside of the stock rca jacks.
i fired it up and it was like night and day. lower, more controlled bass and open highs. i really liked the sound.
not being able to leave things alone, i came back the next day and replaced some of the power supply and audio board caps with higher values and/or voltage rating. i bypassed all the big caps too.
using two jfets i biased the opamp to class "A." i used 2n5484 and 2n5486 as suggested in tangent's website. minimal damping to the mechanism was also added.
this mod really refined the sound of the player. the highs are smoother and the bass really slams. i use grado 125's and a szekeres mosfet buffer so smooth highs and defined bass mate well with my setup.
i'll post pictures later today. /Pictures Posted/
the first thing i did was to remove the opamp (njr4558) and replace it with an opa2227. the old opamp was fairly difficult to remove because it had been tacked in place with some red glue. but fortunately, no lifted traces. i had never soldered a soic chip, but the new one went in without any problems.
instead of jumpering the muting transistors, i just removed the ouput caps right after the opamp and installed two 5.1uf solen caps left over from another project. these were wired direct to the the rca jacks. i cut and desoldered the metal part of the rca jack that goes to the PCB to isolate them and soldered the wires to the backside of the stock rca jacks.
i fired it up and it was like night and day. lower, more controlled bass and open highs. i really liked the sound.
not being able to leave things alone, i came back the next day and replaced some of the power supply and audio board caps with higher values and/or voltage rating. i bypassed all the big caps too.
using two jfets i biased the opamp to class "A." i used 2n5484 and 2n5486 as suggested in tangent's website. minimal damping to the mechanism was also added.
this mod really refined the sound of the player. the highs are smoother and the bass really slams. i use grado 125's and a szekeres mosfet buffer so smooth highs and defined bass mate well with my setup.
i'll post pictures later today. /Pictures Posted/
