[grizzlybeast]

  I am still looking for a all around amp, and have been following this one. I would like to see a little more information on how it handles hard to
drive phones ? I guess I am a little thick, I cannot wrap my brain around the power output rating and what was said early on in this thread !
I have no way to test one, and I am not into making a order just to test a product and to send it back. So I will take my time and watch for info.

what headphones do you have. I had the Omni and I was only at 1 oclock on the dial it is harder to power than the HE560. It was just that the amp is not fast enough for that pairing because the Omni needs extra speed for because it's bass isnt that fast. Something like an he560 would make your ears bleed before you maxed out. 

 

[jasonl]

Some US dealers (Audio Advisors, sonicunity.com and perhaps others) allow you to return the product within 30 days for a full refund.  If you return the item in like new condition (this is easy to do, just don't trash the item, accessory or packaging box), you get a full refund. As far as I know, despite of the warning about restocking fee (this is for legal protection to charge this people who abuse the item), nobody has been charge a restocking fee. When I was running Nuforce for almost 8 years, not once did we charge a restocking fee, even when the packaging box was slightly damage. 
It is to the best interest of the retailer that customers feel comfortable to try it at home.
 
The return shipping cost (by FedEx ground) is less than $25.  Technology is hard to understand.  Reviews give you a reason to try.  So, what are you waiting for?  The only way is to try it and hear for yourself how good it is. 

 

[JChrisG]

Are headphone outputs and preamp outputs active at the same time, or does plugging headphones in mute preamp outs?

 

[grizzlybeast]

When you select the preamp function it only serves as a preamp. This is actually the way just about every amp with a preamp function works. I have heard clear sound come through but the volume is only adjustable on the preamp section, not the headphone outputs. This is because it is quite impossible for the Pot to control all of the inputs at once. Each input has to be selected individually. 

 

[JChrisG]

I can't see where pre-amp function is selectable. My Emotiva DC-1 is intelligent about this, but I was surprised to see that the Schiit Mjolnr 2 has headphone section and pre-amp section active at the same time. 

 

[grizzlybeast]

Not sure here. 

 

[grizzlybeast]

Update with the Hifiman HE-5le... 
 
I thought it wasn't going to be able to power it. That is one of the very hard to power headphones and this thing is cranking em beyond sanity without distortion. 
 
Very impressed with this pairing. Also my Pavane with is an amazing DAC pairs very well with the Nuprime. 

 

[recca]

Can anyone comment on its performance as a preamp?  This is how I would be using it.

 

[jasonl]

It is a very high end preamp. It uses switched resistor network circuit (implemented in FPGA) for its preamp. 
For other technical details, please refer to the product page.
You can use HPA-9 with STA-9 for bi-amping or tri-amping. With two sets of RCA outputs, you could configure two STA-9 in mono (290W@8Ohm) for the woofers and STA-9 in stereo for the mid and high.

 

[recca]

Thanks for the reply.  I see a lot of description about the headphone stage begin Class-A.  Is the Preamp stage as well?  I'm assuming it is an active preamp and not just a passive volume control for preamp.

 

[jasonl]

HPA-8 uses transistors in Class A design. The goal of a preamp is not to add sonic characteristic to the sound, and perform with low distortion regardless of volume.
In the past, the design technique and parts that we used are typically found in very expensive preamp costing thousands of $. 
For example the HITACHI 2SA872 and 2SC1775 transistors are highly sort after (look at the prices on e-Bay).
Switched resistor network preamp design is also very expensive. 

 

[recca]

I do not doubt the quality of the amp at all. Just wanted to know if it's an active or passive preamp. I assumed it was active but I'm not sure as most of the literature speaks of the Class A headphone amp and output stage using the Hitachi's. Again, I'd just like to know as someone who will be using one.

Thanks for taking the time to reply.

David

 

[desik]

  I completely overlooked the fact that this has a phono stage. I am desiring to get into vinyl and was shopping for a turntable so I guess that means I need to keep it if I do not like it more than the Liquid Carbon. Chances are I will end up selling the liquid carbon regardless and keeping this one even if it is not better. 
 
maybe someone can compare it to the schiit mani one day.

How did it compare to Liquid Carbon?

 

[Sethivict]

I glanced at FFT plot JasonL posted and must admit I got curious. I contacted a seller here in Denmark and he was sure I would love this amp. I will borrow it for a few days to see how it will pair with my gear. I will mainly test it on Marantz DAC with Fostex TH900 and Sennheiser HD650 and will report back. He will send it Monday or Thusday. I am sceptical but if the info is correct then we might get a big surprise. More info to follow

 

[jasonl]

I glanced at FFT plot JasonL posted and must admit I got curious. I contacted a seller here in Denmark and he was sure I would love this amp. I will borrow it for a few days to see how it will pair with my gear. I will mainly test it on Marantz DAC with Fostex TH900 and Sennheiser HD650 and will report back. He will send it Monday or Thusday. I am sceptical but if the info is correct then we might get a big surprise. More info to follow

Why would you be skeptical ? The parts and circuit design we explained are just facts, it is not like some marketing statement with fuzzy terminology. We took a high end design and just implemented it and sell it at DIY price. As a result of this approach, we don't do much marketing. Users would have to "discover" HPA-9 by word of mouth.