colin.hepburn wrote:OK so finally got my AK4396 DAC and going to get a pair of Toroidal transformers from rapid
So just want to check I have this right the regulators are 12 volt and 9 volt so
So for the 12 volt regs one 50VA 0-15-0-15 and one 50 VA 06-0-06 wired in series see link for TX wiring http://solderman.dapj.com/2005/09/trans ... allel.html
I would order 12 0 12 and 6 0 6 my little Talemas are that and no issues at all. Also 50 VA is overkill and will create problems of over voltage for you. A small toroid is given a 10% underwind of the primary to account for regulation. Regulation is the factor applied to take into account the iron and copper parasitic losses. So if you don't draw the full 50 watts your secondary voltage will be up to 10% too high. furthermore if it is wound for 230v your secondary would likely be high unl;ess you live in London in which case it will be low one minute and high the next.
colin.hepburn wrote:OK so finally got my AK4396 DAC and going to get a pair of Toroidal transformers from rapid
So just want to check I have this right the regulators are 12 volt and 9 volt so
So for the 12 volt regs one 50VA 0-15-0-15 and one 50 VA 06-0-06 wired in series see link for TX wiring http://solderman.dapj.com/2005/09/trans ... allel.html
I would order 12 0 12 and 6 0 6 my little Talemas are that and no issues at all. Also 50 VA is overkill and will create problems of over voltage for you. A small toroid is given a 10% underwind of the primary to account for regulation. Regulation is the factor applied to take into account the iron and copper parasitic losses. So if you don't draw the full 50 watts your secondary voltage will be up to 10% too high. furthermore if it is wound for 230v your secondary would likely be high unl;ess you live in London in which case it will be low one minute and high the next.
Right I was going by the print on the dac for 9 to 15volts and 13 to 15 volts and allowing for regulator drop out the VA Rating is me I always use bigger than is needed well in solid-state Amp so thought it was ok for the dac as well my Main Voltage is always a good 241 volts
I was just going by what i read somewhere about regulator Drop out think thats why the 3 volts over came in
Plus I reminder reading on the other WD forum about this some have had this problem with dropout on the WAD phono so must depend on your main voltage if it drop off
Ali Tait wrote:Nick, I wonder if that's the problem with mine? What's the mains voltage at your place?
235v normally.
Not that I'm questioning your thoroughness, but if you measured how it was doing with that voltage, I wonder if the slightly higher voltage I have here would be enough to upset the reg? Normally runs at 240-243 here. I haven't checked the secondary voltages yet, I can do so tomorrow. Whaddaya reckon?
Everything is possible. I still suspect damaged the dac or it was naff to start with. But hard to say. Having said that you found it was running hot. I found it warm, but not hot, so maybe thats part of it.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
I suspect you are correct also, but it sounds bloody good when it's behaving itself. I think I'll order another built one to compare with the other I'll build with boteek bits. It'll.serve to see if I've wasted money on better components if nothing else.
The board had arrived, so when I got home earlier I fitted it. Distortion seems to be gone I think, the only problem is it now sounds pants compared to how it did before, and I seem to catch a little glimpse now and again of a little distortion, but it may be it's just sounding glassy as it needs to run in. Again!
I have fitted 100R padding resistors as you suggested Nick, and the voltage at the terminals is just over 15v. I will go to Maplin tomorrow and get a higher value so as to get it under the 15 mark.