hi all,
i check in internect say that by pass the muting transistor can give a more real sound anybody had try it? the best is replace the transistor with relay.
CD-player modification
Below are part of the article:
The first ......The best : costs $0.00
After the D/A converter you can find components for filtering, (to reduce ultrasonic garbage), buffering (to obtain low enough (typical 100-2k) output impedance) and muting. In almost any budget CD_player (below fl.1500 (~$900)) muting is performed with bipolar transistors. THIS REALLY SUCKS !!! More expensive players use relays for this job. Manufacturers apply muting to prevent "plopping sounds" while switching on/off. The audio circuit is temporarily short-circuited during on/off switching. When just playing music they do nothing at all! Nothing ?............., NO WAY, it alters the perceived sound. Why ? I remembered this explanation : a transistor has a small paricitic capacitance. The value is depending of the voltage from collector to emitter, i.e. your audio signal. The result : a signal dependent high-cut filter in your CD player. (ironic) Thank you so much : Marantz, Philips, Technics, Denon, Harman Kardon, Pioneer, Sony, Teac etc etc. Have they ever actually listened to their budget stuff ?! I can't imagine. Maybe they do apply muting transistors to give their more expansive one's a bigger lead and better sales. This would really suck !! (in my humble opinion)
I am not satisfied with this explanation : If you actually calculate the parasitic capacitance it is too small to hvae effect in the audio band. I hope to find a better more detalied explanation soon !
Check Audio en techniek for the source of this tweak.
The more expensive models use relays, so the manufactures are aware, but fail to pass the benefits to you.
I own a Marantz CD 52 MK2. After removing the muting transistors I noticed (warning : vague audiophile terms appear here) , a more fluently sound, less stress and more clarity, especially in female voices. Yes there are some plops to detect while switching on/off. This doesn't hurt my amp or speakers. (Unless : very high volume setting.). I am very pleased with this tweak. It is the best I ever encountered. It kept me from spending (too much) cash on audio en have left me more for music.
There has been some discusion on this bit in some newsgroups.
Goto : Deja News
and search with the keywords : muting transistors
or the keywords : CD Improvement Worked
click old
the : view thread is very usefull |