Using the Destktop as a standalone DAC

I actually have this question into HeadRoom right now. I should get a reply back today. I know that you can use the volume controlled RCA outputs on the Desktop to feed an external amp. If my understanding of the electronics is correct, then the volume pot doesn't have any gain stages, and thus turning the volume all the way up would be the same as a +0db gain.

That's how my 0404 does it, and the Desktop should not introduce any (noticeable) loss to the signal. This should apply to the Ultra as well.

I will post back after I hear from HeadRoom.

That's good to now. I hadn't heard back from them yet. I am guessing they are busy after CanJam. Thanks for reporting back.

Quote:

Originally Posted by Paganini Alfredo 

Well I suppose I answered my own question by calling Headroom. And no, not a good idea to run an amp through the desktop since you can't just use the DAC exclusively with the ultra and another amp down the chain. Oh well, it was worth a shot at not having to buy a separate DAC!

what??  so what exactly is the pre-amp feature meant for?   it is PRE AMP after all...

I also recall headroom answering the same question but with a positive answer,or maybe i misunderstood your question.

Quote:

Originally Posted by plonter 

what??  so what exactly is the pre-amp feature meant for?   it is PRE AMP after all...

I also recall headroom answering the same question but with a positive answer,or maybe i misunderstood your question.

The preamp is for definitely for going to something like a receiver, a (speaker) amp, or active speakers. It *may* be also used for driving a different headphone amp, which is the real question here. Either way, I will get an answer for you next week (someone I know is getting a Desktop and already has a Micro). I will have them run some tests and give back some subjective results on what they hear.

I think it all depends on how the volume pot is wired into the output. I kind of feel that my analysis of it was right, but I'm not so arrogant to say that I am right and Headroom is wrong. I personally had a very hard time phrasing the question in a way that made sense, so it is possible that I asked the wrong question at the time.

I still never heard back, officially, on my (second) question about how the volume pot is wired into the circuit.

Quote:

Originally Posted by simreg 

Quote:

The preamp is for definitely for going to something like a receiver, a (speaker) amp, or active speakers. It *may* be also used for driving a different headphone amp, which is the real question here. Either way, I will get an answer for you next week (someone I know is getting a Desktop and already has a Micro). I will have them run some tests and give back some subjective results on what they hear.

 

I think it all depends on how the volume pot is wired into the output. I kind of feel that my analysis of it was right, but I'm not so arrogant to say that I am right and Headroom is wrong. I personally had a very hard time phrasing the question in a way that made sense, so it is possible that I asked the wrong question at the time.

 

I still never heard back, officially, on my (second) question about how the volume pot is wired into the circuit.

I really don't see the difference between routing the desktop to a reciever or a headphone amp.  should be no difference the way i see it,maybe i am wrong.
 

Quote:

Originally Posted by plonter 

I really don't see the difference between routing the desktop to a reciever or a headphone amp.  should be no difference the way i see it,maybe i am wrong.
 

This issue was queried in another thread.  Can't find it though. 

HeadRoom did endorse using the preamp out to connect to another HA.  They had even given advice on what gain and potentiometer settings to start with.  So no, the preamp out isn't disconnected from the volume control.
 

I found the thread, and the specific post I'm referring to is this one.

Quote:

Originally Posted by Paganini Alfredo 

Well, I called them and explained what I was wanting to do; hook up a separate tube amp and use the Ultra as a DAC. I can't remember what his specific reply was but he said it would technically work but the signal would be compromised somehow because of the amplification of two amps. You can't, he said, bypass the amp itself and use the Ultra as a standalone DAC.

 

Hope I'm wrong though, or that he was. But I'm not really thinking about it anymore cause the thought of another amp isn't in the cards. Plus I'll have a chance to check out a good tube amp at a meet later this summer.

i guess that when using the pre amp on the ultra will still degrade the SQ since you are still double amping..but i didn't managed to understand what is the difference between plugging a pre amp to a headphone amp (which is apperantely not recommended) and hooking it up to a power amp,speaker amp...whatever.   after all,they are all amping devices,no matter if the latter has a volume control or not,and a alot of people are using pre amps as dac's,volume control, and other functions that a pre amp can do.    can somebody explain this to me?

Quote:

Originally Posted by aimlink 

I found the thread, and the specific post I'm referring to is this one.

 

Thanks for the link. At some point there is a "no gain" level where the internal amp is not modifying the signal (much). I was debating the Desktop vs. the Micro stack for this reason and decided that it was a problem I would solve when I needed to, if at all.

I'm not really sure what the differences are either - I guess if it sounds good to your ears it's good enough, right? :)

Quote:

Originally Posted by simreg 

Thanks for the link. At some point there is a "no gain" level where the internal amp is not modifying the signal (much). I was debating the Desktop vs. the Micro stack for this reason and decided that it was a problem I would solve when I needed to, if at all.

 

I'm not really sure what the differences are either - I guess if it sounds good to your ears it's good enough, right? :)

Unfortunately, how a particular setup will sound to your ears has a lot to do with your preconceived notions about it.  If you're after excellence and you're told that the preamp out will not work so well, then your appreciation for a preamp out to external amp setup will already be on the backfoot.  You'll be wondering how much better it would sound if you just got a different DAC. 

I have the Ultra Micro Stack and can confirm that the line out is volume and gain controlled.  I use the line out with a set of external speakers at work.  Works fine for my needs.

Quote:

Originally Posted by aimlink 

Unfortunately, how a particular setup will sound to your ears has a lot to do with your preconceived notions about it.  If you're after excellence and you're told that the preamp out will not work so well, then your appreciation for a preamp out to external amp setup will already be on the backfoot.  You'll be wondering how much better it would sound if you just got a different DAC. 

 

I have the Ultra Micro Stack and can confirm that the line out is volume and gain controlled.  I use the line out with a set of external speakers at work.  Works fine for my needs.

I totally agree. We're going to be biased and keep second guessing ourselves. I would say we may even hear things that are not there or would be anyway, and we chalk them up as defects for our "less than ideal" setup. I understand that the line out is volume and gain controlled. I'm having a hard time putting into words what I'm thinking.

Someone asked a similar question (http://www.head-fi.org/forum/thread/447188/using-a-pico-amp-as-a-dac-for-a-ecss#post_6039514) about the pico dac/amp and was given this answer from Justin: 

 What I was referring to as +0db gain is the line out voltage. I think that should be near perfect with very little noise introduced by the volume / amp section. It may not be 100% perfect, but it should be good enough. I know, I know - we're not in the business of "good enough".

I will still report back with some test subjective results next week, even though this is pretty much a dead topic :)