Hi all.
Starting off modding my Audiolab transport to see what more I can get out of it, its great.
Some questions please going into the Project?
Not a lot online about it,
but saw a German site with before and after pics, going along these lines.
STOCK
MODDED
Usual Cap improvements,
but Note the 2 4pin rectifier chips that have been relaced by a Shottkey diode bridge below the AC input cable.
My (limited) understanding is that you'd normally put a smoothing cap in there to avoid ripple and keep DC to board level?
Couple of guys have replicated this mod exactly, and report only improvements in the sound.
One guy used 1A, 100V the other used 1A 1000V
Higher voltage rating better to handle potential AC voltage spikes?
Seems a viable way to do things, but whats the story with the lack of Smoothing Cap?
Is this a full Shottkey Bridge, or just a Wave rectifier, that doesnt seem to need a smoothing cap?
Also,
in this application, are superfast switching diodes better, in the nS rather than pS range?
Thanks for any feedback Chaps. 🙂
Starting off modding my Audiolab transport to see what more I can get out of it, its great.
Some questions please going into the Project?
Not a lot online about it,
but saw a German site with before and after pics, going along these lines.
STOCK
MODDED
Usual Cap improvements,
but Note the 2 4pin rectifier chips that have been relaced by a Shottkey diode bridge below the AC input cable.
My (limited) understanding is that you'd normally put a smoothing cap in there to avoid ripple and keep DC to board level?
Couple of guys have replicated this mod exactly, and report only improvements in the sound.
One guy used 1A, 100V the other used 1A 1000V
Higher voltage rating better to handle potential AC voltage spikes?
Seems a viable way to do things, but whats the story with the lack of Smoothing Cap?
Is this a full Shottkey Bridge, or just a Wave rectifier, that doesnt seem to need a smoothing cap?
Also,
in this application, are superfast switching diodes better, in the nS rather than pS range?
Thanks for any feedback Chaps. 🙂
I don't understand this fixation of replacing components that are doing its labour perfectly.
Although it's just hanging there, I'm not going to touch that one, as it smells like a trap.
But aren't C102 and C107 the caps you're searching for?
Attachments
Why would you need to add more capacitors than the original rectifier circuit had,
when changing the diodes?
And the 1000V diode is actually inferior to the lower voltage diodes of the same series.
when changing the diodes?
And the 1000V diode is actually inferior to the lower voltage diodes of the same series.
It is a full Graetz bridge replicated by separate diodes. C102 and C107 are the smoothing caps. AFAIK Schottky bridges exist in the exact same format so one better picks such a replacement if really necessary. This mod comes from a known German audio tuner and is therefor copied blindly with all the usual speculation. It probably is a bit blown up. Apparently there was not much else to change easily 🙂 If you feel the need to make such a rats nest go ahead but you can also pick the CS50D by Diotec and have a nice looking and performing mod. Please make sure to leave 1..2 mm space between PCB and bridge. Of course you should first know what AC voltage is connected to the Graetz bridge as some just pick some part without looking at the maximum ratings...and others copy that...
Of the Audiolab products I have seen the electrolytic caps are the ones hat really fail (not replacing just for the sake of it) after a while so please pay attention to those. Look at brand and series and look them up to check of they are known for failure.
Of the Audiolab products I have seen the electrolytic caps are the ones hat really fail (not replacing just for the sake of it) after a while so please pay attention to those. Look at brand and series and look them up to check of they are known for failure.
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The round diodes shown are super fast soft recovery. Only the long cylindrical ones pictured (mine) are Schottky's. A Schottky rectifier package was either discontinued or only available as a large bulk order at the time. Perhaps status has changed since then. Either way a very inexpensive mod. I have all the replacement caps on hand but unfortunately still sitting in a box like many other DIY mods I hope to eventually get at. Will post an update then but likely won't be for a few months. Had the parts for almost 2 years. (Sheesh.) Glad to say the player has served me well since the original purchase new back in 2019. (Diode mod done in 2021.)