iDSD micro Black Label. Tour details (page 147). Release info (page 153).
Apr 26, 2014 at 5:05 PM Post #406 of 4,252
Looking forward to some new iPurifier reviews!
 
Apr 26, 2014 at 10:45 PM Post #408 of 4,252
Couldn't believe I won...PM sent 
 
Thanks a million!!!!!!!! 
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Apr 28, 2014 at 3:09 AM Post #410 of 4,252
Designer's Diary (no. 2)
 
Okay, fun week.
 
After flying back from Shanghai I found the first cut circuit boards for the iDSD micro have come back, so I have to test them. Keeping Gaggia in business with an Espresso or ten stronmg enough to stand a spoon in and just jump right in.
 
All went well until we came to the amazing new power supply for the DAC and analogue.

Clearly a 4.2V battery is not going to cut it where you need +/-8V, so we designed something really cutting-edge into the iDSD micro. It even works.
 
The only problem is that efficiency is way too low, everything gets too hot and the special step-up converter IC gets way hot and shuts down as soon as a bit of current is drawn. Trying different parts etc. got nowhere, there seems something that just does not work in this particular case.
 
Adding an improvised heat-sink to the IC allowed to complete testing, but still that one is definitely FUBAR. 
 
Excluding the power-supply that cannot deliver enough current for the Headphone Amp to drive any load, it all tests really well. So we can make the few small corrections and get the next bunch of PCB’s made up, except for the power management. With only 30% of the current taken in from the battery coming out at the other end of the converter, with the rest turned into heat there is no way we can use this in production, battery life would be a joke and the whole thing would run hotter than a Class A Amp.
 
So we will need to look for another solution.
 
Gulp!
 
Thorsten
 

 
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Apr 28, 2014 at 3:53 AM Post #411 of 4,252
That is terrible! I use a voltage doubler adapter for one of my vacuum tube amps that allows me to use a tube that requires 12v for the filament  but the power supply can only deliver 6v on the filament line otherwise the tube is the same except for the voltage on the filament. Sorry that you need to find a workable solution for the battery. Like the carton picture!
 
Apr 28, 2014 at 8:29 AM Post #412 of 4,252
What is causing the problems, the high power rating of the headphone amp? Maybe lowering the power output for the headphone section will help. I find the micro iCan even powers my Sennheiser HD 650 to very loud levels at the 0dB gain setting, haven't used the 10 or 20dB gain in a while.  
 
Apr 28, 2014 at 2:22 PM Post #414 of 4,252
The way I read it is that Thorsten is trying to generate 8v from a 4.2 battery from a novel ideal. The efficiency is way too low. 70% of the battery energy is wasted in heat. Thorsten has to come up with another solution. Back to the drawing board for the next chapter from IFI!
 
Apr 28, 2014 at 4:32 PM Post #418 of 4,252
Please please please, just make a 100% desktop version :)
 
The portable aspect is really ambitious and I applaud it, but I will almost certainly buy this if it is desktop with balanced outputs :D
 
Apr 28, 2014 at 5:00 PM Post #419 of 4,252
  Please please please, just make a 100% desktop version :)
 
The portable aspect is really ambitious and I applaud it, but I will almost certainly buy this if it is desktop with balanced outputs :D

After the micro iDSD is in full production there is still the mini to come out the third DAC from IFI which will just be a 100% desktop version that will have balanced outputs as per my understanding. There is a separate thread for it.  Who knows that Thorsten may have more surprises in store.
 

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