DAC build TDA1541A/SAA7220P/B *will take som time*

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Sorry I've come in late to this thread, been off the forum for a while due to ill health. I have these you could have had...

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.


All the TDA 1541A's are original, sourced from Philips many years ago for my now defunct Cambridge CD2...don't know where the 4th chipset is, or the upgraded SAA7220.

These are the CD2 originals....

An externally hosted image should be here but it was not working when we last tested it.


Ian
 
So, bigger isn't always better!?! :eek:

Bigger may well be better, but 18V is not bigger than 20V.


Common toroidal mains transformers in particular may be on the edge of saturation if not sufficiently loaded. Certainly they'll tend to produce more odd-order mains harmonics because they'll be pushed into the wriggly part of the relationship between flux and current.

As a rule, don't use transformers with higher voltages than intended on any winding. Over-voltage eats low frequencies.


Generally, if you compare equally well-specified transformers with materials of equal quality, bigger will be better. That's one big reason why good stuff is heavy, and most valve amps can be dismissed at a glance.

Ian
 
I think the comment quoted above was ment for VA, not V.
And it was also ment as an attempt at humor. I honestly thought that a 200VA toroidal was atleast as good as a 20VA provided Voltages were the same. I've never built dac's before but several amps, and when it came to PS went as big I could afford.
 
Mayday, МБГОs are not exactly PIO, but PIW (Paper in Wax). You can open one from it's metal casing and take a look. I can recommend getting rid of the steel casing anyway and put an organic (paper, wax, wood) case, fill it with wax and seal it with resin. The sound really does improve with these cheap babies, I use them for power supplies.
 
Mayday, МБГОs are not exactly PIO, but PIW (Paper in Wax). You can open one from it's metal casing and take a look. I can recommend getting rid of the steel casing anyway and put an organic (paper, wax, wood) case, fill it with wax and seal it with resin. The sound really does improve with these cheap babies, I use them for power supplies.

Really? They were sold as PIO...
 
The problem is, many people mistake them for PIO, even I did. They are very good for the price I think, but you really should get them out from the metal casing. I use a dremel to cut it. The terminals are a little PITA, they eat the cutting discs pretty fast, because they're made of glass.

I get them for real cheap and I get use to replace the electrolytics in a PSU :)

My advice is - listen first with their metal casing on, then try to remove it and listen again.
 
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A great for the price russian PIO is К40-У9. I'm not sure if you can find it in big capacities though. It's in a metal casing and I remove it as well, then I put it in heat shrink tubing and seal both ends with sillicone. It sounds awesome for the money.

K40-U9

http://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l2736&_nkw=K40U9

Removing the casing of these is a piece of cake. I can give you details if you need.
 
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Soldered the 47R/47nF-filters to the I/V-resistors.
Also soldered the wire that'll go to signalgnd, left to do is solder wire from TDA1541A out to I/V-resistors and from I/V-resistors to Grid(with gridstopper between).
An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.
 
Got some more work done on the tube output.
Soldered both supplies to one 4-pin connector and soldered connectors to the I/V-resistors.
An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.
 
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