[mbliss]

Hello, first let me say thanks for taking the time to read and/or answer my questions.

Let me say right now that I am a little new to the audiophile scene so please forgive any "noob" questions I might have. Anyways let me get down to it. I just purchased a headroom micro amp and dac last night to go along with my new Ultrasone HFI-780. Currently I use a very old pair of Sennheiser 555 and wanted something with alot more boom in the lower end. Will probly continue to use the sennheiser's for classical. Anyways I just plug them straight into the s/pdif dual port in the laptop (asus g2s-b2).

Incoming questions: Would it be best to use USB to the dac, or s/pdif? Using either s/pdif or usb would I need to set up ASIO4ALL or wasapi (i use vista)? I've had problems with asio4all in the past only accepting sound from foobar and erroring when other programs want to send sound out. What is the best way to go from dac to amp? A simple 1/8th to 1/8th cable or stick with s/pdif? Last questions... is there a good resource here or anywhere that can explain crossover, gain, and all the other functions found on such amps/dacs?

Thank you again for helping a newcomer out!

 

[kboe]

First things first, Sorry about your wallet!
I have the same Micro Amp and DAC. I personally use a Kimber USB cable from headroom and am pleased with the results over basic USB, coax, and optical. I cant say anything about Foobar as I have never used it but it gets decent praise around here. The only way to get the analogue signal from the DAC to the Amp is to use a mini-mini cable, my results with a standard one were ok at best, but upgrading to any of the nicer ones provided by headroom will render a sizable difference in clarity, detail, and soundstage.

Crossfeed, which is what I think you meant by crossover, is a system that bleeds a little of one channel over to the other at a slight time delay and reduced volume to give a sense of soundstage and to reduce listening fatigue. Its subtle, but thats the way it should be.

As far as gain is concered, at 50 ohms your 555s would use the low or medium gain to get the most range out of your volume knob.
If you have other questions, this is the right place to ask, were all willing to help.
Kevin

 

[kboe]

I forgot to mention that in Headroom's website they have a paper explaining crossfeed that is easy to understand. copy and paste

Products - HeadRoom - Right Between Your Ears

and enjoy.

 

[mbliss]

Yes I think I just entered into a new hobby my wallet will not enjoy!

Thank you for your quick and thoughtful response. So basically I would not need to use anything like asio4all or wasapi when using USB? Does it just completely bypass windows mixer sort of like kernel streaming?

Now with the Ultrasone HFI-780 being 35 ohm would a low setting on gain be the appropiate choice or am I getting ohm and gain settings confused?

Thank you!

 

[kboe]

I have a mac, but I bet your PC should still recognize the DAC as a sound output device. You should only be able to control volume from the Amp.

Ohm and gain settings are directly related to each-other. As I understand it Ohms for the headphone deals with how hard it is to drive. The higher the ohm the harder it is to drive properly. For example, I have IEM that are between 20-30 ohms, and the Sennheiser HD650s which are 300 ohms. Your Ultras and HD555s will use the low gain setting. If we pretend I know what I'm talking about, the gain switch places resistors in the signal path either before or after the volume knob. So if you place the switch on low, the volume knob will now give the best dynamic range for your phones.
Kevin

 

[moogoob]

Quote:

Originally Posted by mbliss /img/forum/go_quote.gif Yes I think I just entered into a new hobby my wallet will not enjoy! Thank you for your quick and thoughtful response. So basically I would not need to use anything like asio4all or wasapi when using USB? Does it just completely bypass windows mixer sort of like kernel streaming?

You might want to ask that in the Computer Audio subforum- mac users like myself don't have to play around with stuff like that.

 

[JMCIII]

Quote:

Originally Posted by mbliss /img/forum/go_quote.gif So basically I would not need to use anything like asio4all or wasapi when using USB?

No

Quote:

Originally Posted by mbliss /img/forum/go_quote.gif Does it just completely bypass windows mixer sort of like kernel streaming?

Windows should automatically recognise the amp/dac as your new sound card and reroute the audio signals to it. Volume will be controled by the amp not the laptop.

Quote:

Originally Posted by mbliss /img/forum/go_quote.gif Now with the Ultrasone HFI-780 being 35 ohm would a low setting on gain be the appropiate choice or am I getting ohm and gain settings confused? Thank you!

This is purely an "up to your ears" question. Try all three settings a nd see which allows you to have the volume at what you consider appropriate listening levels without turning the volume control over halfway. If you add too much gain, you'll have to keep the control low, which isn't optimum. Too little and you'll be possibly driving the amp into clipping (also not good). I have three different headphones in-house and all use different settings to make them come alive. So try each one and see which works best.


Oh, and while your wallet will complain about your new hobby, I think your ears will keep reminding it every time you listen to all you cool new gear that you made a wise investment. Welcome aboard and enjoy. You made some excellent choices.

 

[mbliss]

Was thinking about giving this issue that recently came up it's own thread but decided against it...

Anyways I keep getting some bad crackling, popping and clicks from the DAC. The amp is not causing it (tested with just using the amp). Only happens when the system is stressed, like when rendering video. Sounds fine when just music is playing. I have it plugged in through the USB right now and I am assuming its just interference from the video card or fans. I only have laptops to test with but it happens on both of them (Asus and Macbook Pro).

Can anyone verify this is just a problem with USB interference and a possible solution is using optical out?

Thanks!