5.6 uf or 6.8uf 800vdc 425vac, but the question is it it safe? I think they are not ac cap.Will place it across the ac inlet inside the cdp.
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That's fine and safe for AC (well its fine for UK 240vac). Don't worry if you hear a buzzing noise they all do it.
Brent
Brent
Brent, just to sure the resistor & cap to be parallel across live & neutral?
Yes that's right. The resistor is to bleed the voltage off the capacitor when power is removed.
Brent
Brent
No, this is NOT safe! Although the voltage rating seems o.k., the capacitor must have self-healing properties if you want to connect it across mains permanently. You need to use an MKP class-X suppression cap that is suited for this purpose. A large motor-start cap is also an option. Otherwise there's a serious fire-risk in case something goes wrong and the cap causes a short
. It will burn itself up.Ray
Absolutely right, Ray. Well said.
And adding really large caps usually makes local mains noise worse, not better; this is quite easily and repeatably demonstrated ( eg acoustica.org.uk: shocking! - see 'Dont try this at home')
Oh, and if the internal regulation in the equipment is any good, such nonsense is totally unnecessary also.
And adding really large caps usually makes local mains noise worse, not better; this is quite easily and repeatably demonstrated ( eg acoustica.org.uk: shocking! - see 'Dont try this at home')
Oh, and if the internal regulation in the equipment is any good, such nonsense is totally unnecessary also.
And another serious objection:
A 1/2W , 100K resistor is nowhere near enough to guarantee safe discharge. 100K across 240VAC disspates 0.6W; the reistor will burn out. 1W absolute minimum.
And this needs to be substantially increased for larger uF values if you insist on using them. 100K/10uF is a time constant of a second. Pull the plug on that and terminal voltages are very likely remain dangerous for 3-5seconds thereafter. You need to move the resistor down to the 10-20K range as a maximum, and this will dissipate 3W on its own. Safe and appropriate parts ratings and mountings left as a research project...
A 1/2W , 100K resistor is nowhere near enough to guarantee safe discharge. 100K across 240VAC disspates 0.6W; the reistor will burn out. 1W absolute minimum.
And this needs to be substantially increased for larger uF values if you insist on using them. 100K/10uF is a time constant of a second. Pull the plug on that and terminal voltages are very likely remain dangerous for 3-5seconds thereafter. You need to move the resistor down to the 10-20K range as a maximum, and this will dissipate 3W on its own. Safe and appropriate parts ratings and mountings left as a research project...
Finally
Noise means something (an internal layer winding) is moving. It WILL fail.
NO. appropriately-rated parts do not do this.
Noise means something (an internal layer winding) is moving. It WILL fail.
Hmm, I thought even some X-class caps did this, and they are rated appropriately for Europe.
X2 caps do buzz! You try a 4.7uF Epcos etc.
Give Mundorf a ring and they will tell you the caps do self heal, they just don't market them for this purpose.
1/2 watt is fine and so is 100K. A 60uF filter such as the Russ Andrews uses Kimber kaps, 100K 1/2 watt parts and hes been selling these for 10 years. I too have tested all these parts for our own filters without problems. They have even been checked for safety and pass the CE criteria.
In terms of the filter working or not working i'll not get into that as its the same argument as do mains cables work etc etc
Brent
Give Mundorf a ring and they will tell you the caps do self heal, they just don't market them for this purpose.
1/2 watt is fine and so is 100K. A 60uF filter such as the Russ Andrews uses Kimber kaps, 100K 1/2 watt parts and hes been selling these for 10 years. I too have tested all these parts for our own filters without problems. They have even been checked for safety and pass the CE criteria.
In terms of the filter working or not working i'll not get into that as its the same argument as do mains cables work etc etc
Brent
I admit, it was an easy target 😀.
But the essence still stands, you'd better use good old theory as a starting point. 240VAC across 100k is still > 0.5W.
I use resistor ratings 2x the actual dissipation in practice, with 1.5x as a minimum.
Ray
But the essence still stands, you'd better use good old theory as a starting point. 240VAC across 100k is still > 0.5W.
I use resistor ratings 2x the actual dissipation in practice, with 1.5x as a minimum.
Ray
My point is really this: that when advice is given it must be solid - especially when it comes to fundamental safety issues like playing with mains voltages.
Brent explaining and justifying his choices like that is good. Possibly leaving the impression that any old crossover cap and resistor is appropriate definitely was not.
Brent explaining and justifying his choices like that is good. Possibly leaving the impression that any old crossover cap and resistor is appropriate definitely was not.
To the ones survived their mains, IIRC the transformers in these players have a color strip, all my players were green. I bought a "hard to read disc when player is cold" CD63 SE and wonder if its tx will be not-green and better sounding.
Hi, does anyone have some tips to improve the bass?
Since the last post I did some more cheap mods on my cd63 and put in a few black gates from an old rotel cdplayer. So much more detail now!! Mids and highs are really great. Only the bass still isn't that good. It improved a bit after these clock mods:
http://www.grønholdt.dk/diyelectronics/marantz CD63MKII/marantz.html
Did most of these mods and some others like the diodes, bypass caps, damping material, spikes, but the bass still isn't how I'd like it. It sounds a bit thin and not very controlled and detailled. What would be the best cheap and easy (I don't know too much about electronics...) mods to do to improve this?
Would it be a lot better to upgrade all the Elna Silmic to Panasonic/Rubycons?
Btw: I'm using the bb2604 now, maybe I'll try the LM4562NA later...
Tnks!
Since the last post I did some more cheap mods on my cd63 and put in a few black gates from an old rotel cdplayer. So much more detail now!! Mids and highs are really great. Only the bass still isn't that good. It improved a bit after these clock mods:
http://www.grønholdt.dk/diyelectronics/marantz CD63MKII/marantz.html
Did most of these mods and some others like the diodes, bypass caps, damping material, spikes, but the bass still isn't how I'd like it. It sounds a bit thin and not very controlled and detailled. What would be the best cheap and easy (I don't know too much about electronics...) mods to do to improve this?
Would it be a lot better to upgrade all the Elna Silmic to Panasonic/Rubycons?
Btw: I'm using the bb2604 now, maybe I'll try the LM4562NA later...
Tnks!
The op-amps will help but really what you need to do is regulate the servo driver chips. There are three of these and you can usually use 3 x 7808/7909 soldered directly to the board. This mod transforms the bass.