Dx Precision, finally released... now debugged and better than HRII

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DxPrecision lite

How about DxPrecision lite?
:cannotbe:
 

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Nordic, Found what looks like a suitable, low priced Cornell Dubilier (CDE) 10,000uf 80 volt, snap in, 10mm lead spacing, small size ( they did not give dimensions), general purpose caps.
Digikey only quote 500 @ $7.14 each. They sell in smaller lots, but you need to enquire for pricing.

The cap may be suitable for all the Destroyer DX amp versions.
A group buy would make them even more affordable?
For the P1, using two of your DXHR11 P/S PCBs you'd need 8 caps and end up with 20,000 uf per stereo rail.

To view the caps, go to: www.digikey.com

and search digikey part number: LP103M080H9P3-ND

billabong.
 
63 Volts condensers are cheaper than 80V units

and 63 volts condensers can hold more voltage than specified, they can face the normal mains variations of voltage.... and you will spend less money.

Those last 47 years i am using 35 volts condensers into Dc voltages that goes from 35 to 42 volts. also i have used, several times and for long periods of time, 63 volts condensers with 70 volts DC.... i NEVER have a single one burned, with leakage, or exploded because over voltage.

Try to imagine if they can, factories, to make a condenser that will enter a short exactly into the voltage specified.... only if they install a zener inside!

I had units damaged and exploded because i have inverted them.

Also, your 64 volts supply will not offer you 64 volts all time long..under consumption your voltage will drop down to less voltage.... sometimes when you adjust bias to 100 miliamps and your voltage already goes down to 62 volts.

And the condenser factories, knowing in advance that mains supply have voltage variations, they construct condensers already with some extra voltage capacity, and this is not written into the case..... there, into the case, the guaranteed voltage, in the reality, in many cases, this voltage can be 20 percent higher than the written value.

Of course, better is to use higher voltage insulating condensers..better to go to 100 or more volts...but this costs a lot of money, as the condenser price increases because of insulating voltage and also because of capacitance.

regards,

Carlos
 
...better to go to 100 or more volts...

Why is it better to go to 100+ volt Power supply capacitors for a 64V DC supply, when you have shown that 63V capacitors will do the job?

Wouldn't 80v capacitors provide a sufficient margin of safety for the cautious among us, and also justify the extra cost?

It appears that 100V capacitors would be an un-necessary added expense, unless they can be purchased at the same price as the 80V caps.

billabong.
 
Because soon or latter you gonna try a bigger amplifier

The big insulating voltage condenser can be used by a very wide range of voltages till it's limits, and those limits can be even 20 percent bigger than the informed value... thiw way, you will already have huge condensers, that will work into several amplifiers....not needed to buy condensers to each one..as you will listen the amplifier one by one...good to have a multi output voltage supply and a single bank of huge condensers..and three wires going to amplifiers.

100 Volts condensers not needed for the Precision I, but will not be bad too.

In the reality, for 64 volts, the use of 63 volts units are fine.

I am still trying coaxial cables to run cable to a remote output, this way a very huge output can be plugged into many amplifiers... but this is under testings.... i felt it a little mufled...i have to compare to decide if this idea is good or not...now lazy and having not too much time for that purpose.

Imagine, how good can be to plug a huge output that can hold many amplifiers.

Also how good could be the same supply, switchable voltages, to feed several amplifiers.

I am already thinking into the Precision III

regards,

Carlos
 
I guess it can make sense to buy higher voltage capacitors than needed, if the intention is to reuse them in other diy projects in the future. In that case it may be better to get higher capacitance as well (we are talking about power supply capacitors).
I may use that method myself. I just discovered I can get 100V Mundorf M-Lytic High Current 47000uf caps overseas for the same price as the 80V caps in Australia. I would then have the option of using them in my Perreaux power amp. The P/S caps in it are over 20 years old and the extra capacitance may be beneficial.

billabong.
 
This is a very old trick i have used into the seventies while i was building

Electron tubes Radio Frequency Power Amplifiers..... Linear amplifiers to Radio Amateurs...and for CBers too (Citizen Band Radio).

I had not 300 volts condensers, but i had 150 volts units.... this way i have assembled this way (nothing new...i have not discovered that..this is very, very old) to work with my 315 Volts DC voltage to plate.

The resistances helps to discharge the units, to avoid humans to be killed by accident and also helps to equalize voltage, in such way both will have half voltage over it's extremes.

You loose capacitance,but you can double your insulating voltage..i have tested real life...more than double voltage, and i have made several times..works safely.

regards,

Carlos
 

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There are application notes with formulas for calculating the right equalisation resistors on almost every electrolytic capacitor manufacturers websites....

e.g.: Chapter 4 from EVOX RIFA paper

http://www.evoxrifa.com/electrolytic_cat/electrolytic_appguide.pdf



cheers

P.S.: instead of buying Mundorf Cap's I would suggest to take a look at EPCOS Sikorel.... They are more accepted in the industry than those (good, but too expensive) Mundorf caps.
 
This happened, at least once, in Brazil

Take a look.

The image will explain.... the condenser overvoltage capacity too.... the guy perceived and have opened, but have worked for monthes till he conclude filtering not good enougth.

He removed to replacement by others and felt the unit not heavy enougth and felt shacking could perceive something not fixed inside.... see the reason.

regards,

Carlos
 

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That's sickening. The result of a nation's people (any nation, not JUST China) and their government not respecting intellectual property or consumers in general. Peoples' 3rd-world attitudes have to change -- mature. When people grow up under a regime of corruption, they adopt the same disrespect for others as a survival measure. It's just sad, and so frustrating.

..Todd
 
Counterfiet parts

That is a perfect example of why I try to use only official distributors for parts, though that is still no guarantee.

Some of the "deals" I see on eBay, especially when they are being shipped from parts of the world where intellectual property isn't respected, are very suspect. I probably sound cynical, but I have a hard time even trusting that the eBay rating system isn't being gamed in some fashion.
 
I hate that stuff too.

And now we are beeing invaded by those things... we do not know if comes from China, if comes from Paraguai or if those things happens here.... all i know is that i hate those things.

I could perceive double evil on that...not only robbered people as the capacitance is smaller, but also installed a lower voltage ratio condenser...so...things made to explode.... very criminal those things.

Well... if exist people that can crash one airplane against a building...... two airplanes against two buildings....people that used poison into a village... anything more drives me surprised...those condensers and fake transistors are even very small harm compared with Treblinka, Auchwittz, Buchenwald and other "termination" camps.

Thinking about those things...i feel that we can smile about those fake things, because they seems to be childrens kiddings compared with things the "big boys" use to do.

regards,

Carlos
 
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