Yes I assume its a trade as usual
Nice, do you find it beneficial in practice?
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I'm very very happy with the sound of the dac1101, several small improvements, although the biggest improvement compared to a dam1021 is the new output buffer / headphone amplifier, in my humble opinion it's kinda fantastic, can drive 4V RMS into 32 ohm from just +-6.5V, fully discrete, no nfb, high bias class AB, my Sennheiser HD650 have never sounded better.... I now need to upgrade my headphones, maybe the new HD800 S, good to have a company to pay
I'm considering making an add-on balanced output buffer / headphone amplifier for the dam1021 based on that amplifier design, any interest ?
I'll take a couple, however before you do, you might want to check the OPA1622, which was designed for headphone use and really does very well in that application, more info here:
http://www.diyaudio.com/forums/vendors-bazaar/283672-new-audio-op-amp-opa1622.html
Interesting headphone amplifier without feedback.I'm very very happy with the sound of the dac1101, several small improvements, although the biggest improvement compared to a dam1021 is the new output buffer / headphone amplifier, in my humble opinion it's kinda fantastic, can drive 4V RMS into 32 ohm from just +-6.5V, fully discrete, no nfb, high bias class AB, my Sennheiser HD650 have never sounded better.... I now need to upgrade my headphones, maybe the new HD800 S, good to have a company to pay
I'm considering making an add-on balanced output buffer / headphone amplifier for the dam1021 based on that amplifier design, any interest ?
What type power supply have, We can know the power supply out impedance?
Or is easy to add our own power supply?
Seen and discarded that one, against my pinciples and kinda useless in my opinion:
Too slow, GBW only 8 Mhz at G=1 ?
Too weak, can only drive 2V RMS into 32 ohm.
And I'm not looking to be doing just "very well", I'm targeting to be the best possible
I also want to use some of the parts I already have on whole reels, although I'm hoping that the dac1101 will take care of that by itself....
The dac1101 have a small DC-DC converter generating +-6.5V from USB power.
A new separate output buffer / headphone amplifier would take external power up to +-20V, could be directly from dam1021 PWR A+-....
Thinking about making it easy to adjust bias, maybe from 15 mA to 50 mA, although high voltage / current would require a small heatsink.
I'm very very happy with the sound of the dac1101, several small improvements, although the biggest improvement compared to a dam1021 is the new output buffer / headphone amplifier, in my humble opinion it's kinda fantastic, can drive 4V RMS into 32 ohm from just +-6.5V, fully discrete, no nfb, high bias class AB, my Sennheiser HD650 have never sounded better.... I now need to upgrade my headphones, maybe the new HD800 S, good to have a company to pay
I'm considering making an add-on balanced output buffer / headphone amplifier for the dam1021 based on that amplifier design, any interest ?
Yes - definitely interested in a discrete balanced output buffer.
Also, is the attached normal? Downloaded 1.05 full with no issues. Typed update and got the 'Incorrect image' you see in the attached. I then exited, powered down and, on powering back up got the '1.04 uManager and 1.05 FPGA'.
Attachments
Try "update" again, if still not working, try downloading and "update" again.
Both uManager and FPGA should be vers 1.05.
Sorted. It appears the issue was me having the 'Send line Ends with line feeds' and 'Append line feeds to incoming line ends' boxes checked in ASCII Setup (which I had set for another application) in HyperTerm.
As soon as I unchecked those boxes it updated as usual. One more for the knowledge base.
Thanks for the prompt reply, Soren. Appreciated.
Yes, it works. The XMOS core is clocked from another clock, audio clocks only drive the digital audio outputs. I have actually tested that with an XMOS development board. Could not really do full testing with DAM1021 because in V0.99 firmware the DAM MCLK OUT was fixed at 24 MHz, if I remember correctly. But it worked fine when XMOS audio was clocked from a function generator.
Of course, the audio clocks should not vary beyond the adaptability limits of USB audio channel. And there could be some wrinkles with the clock adjustment algorithm in DAM - if there are no sanity checks, it could hypothetically go into a runaway condition.
Using an XMOS USB controller would allow to implement a virtual serial port (or several) in the same device, which would be very convenient for controlling the DAM. I was even thinking of also implementing an IR receiver input for remote control.
Take my money, but please finally do something about the mess with shipping at the U.S. store.
Yes I'm aware you have little control over it, but at least suggest to them to allow more options than just UPS. Even the UPS driver was surprised at the $190 COD on brokerage fees and taxes for a little box that basically weighed nothing. (2x dam1021's) Not forgetting it was like $40USD just to ship to Canada...
If you want to sell more dac1101's then get that mess fixed please. I know you claim you have little say but you should have some influence.
The EU store would be happy to ship to Canada. Or you can talk with Jeff at the US store, he's in charge of shipping, I don't really know anything about shipping from US to Canada, just know it seems to be complicated.... But none of us can do anything about Canadian taxes...
Or you can start importing and distributing in Canada yourself, our long term plan is to have a sales channel in each major market....
Taxes I get, thats fine. Its the fact that UPS thinks its okay to charge $80+tax on that fee just to clear the package (before actual tax on the value is considered!) that is the main issue. Otherwise I would have paid no more than $80 in HST at the most.
Getting back on topic, that discrete headphone circuit looks killer.
Big interest here.
I'm currently using an Opc the wire BAL-BAL in SE-to-BAL configuration (opa1632 negative input grounded - Gain 1x) - using raw output of a DAM1021-02 rev1 (+ rcore +Diyinhk 12v TPS7A4700 PSU / Normundss v1 input board with amanero) .
Something looking like a Nelson Pass SuSy stage with a discrete class A Bjt/Mosfset output would be interesting
+1 for HD800s, it's really a revealing headphone, quite hard to pair, with a huge (sometimes called artificial) soundstage.
For testing, comparing & critical listening: this is a good thing.
My beloved Fostex TH-900 has somewhat a similar "issue" when the source lacks soundstage depth... And it's actually the case with my stock Dam1021 + Wire configuration. I guess I should try mods and other filters, but it may also be because of my headphone amp.
So please, don't neglect the soundstage aspect of performance when testing prototypes with headphones. it's one that, as far as I know, can't be measured or simulated, and one of the most important aspect of sound when it comes to high end headphones
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