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Edit Disregard my questions . It helps if I remember what people are doing in this thread
Oops...I see you are using transformers.
I'm going to get one of these kits when I have the spare cash, and do the transformer output mod. This chip has potential from what I gathered last time I played with it....and killed it...a couple actually *sighs* I'll have better luck with this kit as I won't end up over heating the chip
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For those of you that want to go completely over the top:
Feastrex FINEMET Premium Transformers for AK4399 DAC | eBay
I especially love the part about the "magic" performed by Mr Teramoto..
Oh, and the Shipping is Free..
Feastrex FINEMET Premium Transformers for AK4399 DAC | eBay
I especially love the part about the "magic" performed by Mr Teramoto..
Oh, and the Shipping is Free..
For those of you that want to go completely over the top:
Feastrex FINEMET Premium Transformers for AK4399 DAC | eBay
I especially love the part about the "magic" performed by Mr Teramoto..
Oh, and the Shipping is Free..
It should be shame that if winding is made of plain copper.
National's metal can LME49720 must have been tried at output before this kind of attempts. It bothers me when i think idea of committing precious signal electrons to a magnetic field.
I like the 80% nickel Cinamag quadfilers in my CS4398 dac, but some may prefer 50% nickel ones, It's a personal and system dependent thing.
Jensen have good transformers too JENSEN TRANSFORMERS, INC. - LINE OUTPUT TRANSFORMERS
The JT-11-BMCF looks good but are a little pricey at over $100, if budget is a concern maybe the 50% nickel JT-11-ELCF is listed at about $50 each.
The higher nickel transformers are more transparent/resolving, but for some peoples tastes and systems the 50% ones may suit better, and may sound kind of warmer.
I haven't used these, I'm just posting a couple of possibilities, at the end of the day in transformers you get what you pay for, in general that is
There are also some NOS transformers like the UTC A-20 that show up on the bay, but other retail brands like Lundahl are a definite option.
Those Feastrex ones are mad crazy priced!
Jensen have good transformers too JENSEN TRANSFORMERS, INC. - LINE OUTPUT TRANSFORMERS
The JT-11-BMCF looks good but are a little pricey at over $100, if budget is a concern maybe the 50% nickel JT-11-ELCF is listed at about $50 each.
The higher nickel transformers are more transparent/resolving, but for some peoples tastes and systems the 50% ones may suit better, and may sound kind of warmer.
I haven't used these, I'm just posting a couple of possibilities, at the end of the day in transformers you get what you pay for, in general that is
There are also some NOS transformers like the UTC A-20 that show up on the bay, but other retail brands like Lundahl are a definite option.
Those Feastrex ones are mad crazy priced!
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Small signal transformers can't have DC current as they become magnetized because of that and then they perform awfully. This is very old and common information but it seems transformers and the knowledge of them are something of the past since switching PSU's have become common goods now. I use Neutrik and Haufe signal types that can't even be measured with a DMM (in the resistance setting) as then core will be become magnetized.
A transformer is not meant to block DC, it is originally meant to transform an AC voltage/current up or down in a ratio. DAC's with symmetrical outputs have 0 Volt between the + and - outputs. They have a voltage with respect to GND but the transformer won't have a problem with that as long as you don't connect the center tap to GND ! So connect the primary winding to + and - outputs of the DAC and you won't have a problem.
Some mV between the + and - output is acceptable ( ALWAYS measure first !), the less the better of course. If you would use a symmetrical input amp I would use caps instead of a transformer. My primary goal is to load the DAC chip symmetrically and convert the symmetrical output signal to asymmetrical otherwise i would not bother to choose the most expensive solution.
A transformer is not meant to block DC, it is originally meant to transform an AC voltage/current up or down in a ratio. DAC's with symmetrical outputs have 0 Volt between the + and - outputs. They have a voltage with respect to GND but the transformer won't have a problem with that as long as you don't connect the center tap to GND ! So connect the primary winding to + and - outputs of the DAC and you won't have a problem.
Some mV between the + and - output is acceptable ( ALWAYS measure first !), the less the better of course. If you would use a symmetrical input amp I would use caps instead of a transformer. My primary goal is to load the DAC chip symmetrically and convert the symmetrical output signal to asymmetrical otherwise i would not bother to choose the most expensive solution.
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I see, there is no DC between the balanced outputs to worry about.
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Hang on a bit...
In another thread someone states there is 2v DC on the DAC outputs, and this would follow as these are voltage out DACs.
http://www.diyaudio.com/forums/digital-line-level/194748-capacitor-voltage-dac-output.html
This is getting confusing
With that Jensen transformer JT-11-EM it states "Driving
signals should be free of DC and source impedance kept as low as possible."
But with the few other ones listed that I looked at, it reads "For best performance, driving
signals should be free of DC and source impedance kept as low as possible." So it looks like the JT-11-EM needs to be avoided for this application, as far as I can see.
Looks as though I linked the wrong page to begin with.
Best to look at these ones http://www.jensen-transformers.com/ln_in.html
In another thread someone states there is 2v DC on the DAC outputs, and this would follow as these are voltage out DACs.
http://www.diyaudio.com/forums/digital-line-level/194748-capacitor-voltage-dac-output.html
This is getting confusing
With that Jensen transformer JT-11-EM it states "Driving
signals should be free of DC and source impedance kept as low as possible."
But with the few other ones listed that I looked at, it reads "For best performance, driving
signals should be free of DC and source impedance kept as low as possible." So it looks like the JT-11-EM needs to be avoided for this application, as far as I can see.
Looks as though I linked the wrong page to begin with.
Best to look at these ones http://www.jensen-transformers.com/ln_in.html
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Regulator Voltages
Hi guys,
Finally got my DAC up and running. Im a little concerned and am hopping someone can help. My kit shows a pair or 15v regulators on the screen printing. however the kit contained 12v regulators. I have seen versions of the PCB with 7812 12v regulators screen printed on the board. Does anyone know if the kit was revised? If so what else changed and what version is better? These two regulators are running VERY hot i have had to add a large heat sink to keep them cool. Im powering with a 15-0-15 vac maybe to high for these regulators. I have had a good look around but have not found this discussed anywhere. Would be great full if someone know about this?
Russell
Hi guys,
Finally got my DAC up and running. Im a little concerned and am hopping someone can help. My kit shows a pair or 15v regulators on the screen printing. however the kit contained 12v regulators. I have seen versions of the PCB with 7812 12v regulators screen printed on the board. Does anyone know if the kit was revised? If so what else changed and what version is better? These two regulators are running VERY hot i have had to add a large heat sink to keep them cool. Im powering with a 15-0-15 vac maybe to high for these regulators. I have had a good look around but have not found this discussed anywhere. Would be great full if someone know about this?
Russell
