Can I assume from the fact that you are using 7.4V batteries instead of higher voltage Li-Ion batteries (8.4V) that, at least in the desktop portable, you are doubling up the current to run the + and - rails at 14.8V instead of 7.4V, i.e. perfectly in line with your usual PSU voltages?
For the Portable Micro, are you using a rail splitter or something more elaborate to get the + and -, and from the single battery are the electronics +/-7.4V, or is it a single rail supply?
I see that you've put a 'preamp out' on the back of both the new units, however isn't that in reality just a further headphone jack on exactly the same circuit as the front outputs? That's not a criticism - I know they work very well that way as preamp outputs - just a detail.
Member of the Trade: HeadRoom Corp.: Product Manager
Quote:
Originally Posted by TheSloth
Can I assume from the fact that you are using 7.4V batteries instead of higher voltage Li-Ion batteries (8.4V) that, at least in the desktop portable, you are doubling up the current to run the + and - rails at 14.8V instead of 7.4V, i.e. perfectly in line with your usual PSU voltages?
For the Portable Micro, are you using a rail splitter or something more elaborate to get the + and -, and from the single battery are the electronics +/-7.4V, or is it a single rail supply?
I see that you've put a 'preamp out' on the back of both the new units, however isn't that in reality just a further headphone jack on exactly the same circuit as the front outputs? That's not a criticism - I know they work very well that way as preamp outputs - just a detail.
I hate not knowing all the little details!
There are two dual cell 7.4V batteries in the Portable Desktop that each generate the + and - supplies.
The Portable Micro uses a custom battery with a center tap so we do not need any rail splitter or similarly functioning circuitry.
A very good preamp is able to deliver the signal from multiple sources with authority to whatever load is presented. The load presented from a headphone is much worse than what is potentially presented by any power amp. I'm not sure how a 'preamp' is really any different except that it could be simpler. It could be as simple as a passive switch depending on your system. This thing has the potential to deliver much more with the addition of the DAC. Feel free to elaborate on this as I don't know how I would make the preamp outputs any different. Maybe I'm not understanding the point?
Thanks for your comments and questions. I'm sure most of them will be answered when your package arrives. :evil: Don't hold your breath though...
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Great sound starts with great musicians.
There are two dual cell 7.4V batteries in the Portable Desktop that each generate the + and - supplies.
The Portable Micro uses a custom battery with a center tap so we do not need any rail splitter or similarly functioning circuitry.
A very good preamp is able to deliver the signal from multiple sources with authority to whatever load is presented. The load presented from a headphone is much worse than what is potentially presented by any power amp. I'm not sure how a 'preamp' is really any different except that it could be simpler. It could be as simple as a passive switch depending on your system. This thing has the potential to deliver much more with the addition of the DAC. Feel free to elaborate on this as I don't know how I would make the preamp outputs any different. Maybe I'm not understanding the point?
Thanks for your comments and questions. I'm sure most of them will be answered when your package arrives. :evil: Don't hold your breath though...
I completely agree about the preamp. It's just a nomenclature thing. I was just wanting to clarify that there is nothing different about the signal path to the 'preamp' socket on the back then there is in the signal path to the 'headphone' socket on the front, and that they are in parallel and thus what is connected to one effects the other by altering the load on the circuit - is that right?
I'm still not quite with you on the PSU - by dual cell, do you mean that each cell is running at 7.4V and then run in series with its neighbour to make 14.8V per battery? And for the portable micro, does that mean it is running at +/-7.4V?
If that's right, I'd be very interested to hear how this battery arrangement compares to your DPS/internal PSU's with the same electronics. Experience tells me it might actually be better...
When are you expecting to post info on the rest of the new Micro line?
Member of the Trade: HeadRoom Corp.: Product Manager
If you take a look at the Portable Desktop page, you'll see two green batteries mounted on the circuit board. They are both 7.4 batteries, one for the + and one for the - supply. In the Portable Micro, there is only one of those batteries but it is a little different in that it has a center tap (actually there's two cells inside) which essentially provides +/- 3.7V.
The rest of the Micro Line info will be posted in about a month, maybe sooner.
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Great sound starts with great musicians.
I hope I haven't misunderstood the Sloth; I believe the two new units he mentions are the 2007 Micro Portable and the 2007 Desktop Portable.
Does the 2007 Desktop Portable have a pre amp out? No mention is made of this on the product page. Perhaps it shows up in the photo, but I'm not really good at seeing photos. It'll be great once HR get around to putting up the instruction manuals for the new products. Anyhow, I just want to confirm that the Desktop Portable does indeed have a pre amp out. Also, what kind of connectors does it use (RCA or mini?) and is it a fixed level line out or volume controlled level?
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Rig: (notebook -> USB A to mini b) or Iriver (H340 -> 6" Cardas mini to mini) -> Headroom Total Bithead Clear 2006 -> (Grado 1/8 to 1/4 cable -> Senn. HD555) or Senn. HD25-SP
The Desktop Portable does havea preamp out (as does the new Portable Micro). They are 1/8" outputs. Given that they are a preamp (as opposed to a line level output) out they are variable, dependent on the volume knob. That's what I see and based upon my experience with equipment that's what I would assume to be the case.
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TOGA RIG: Headamp Pico --> AKG K701/ Grado HF-1/Sennheiser HD580(EA Senn cable)/AKG K1000
SLUG RIG: Sony D368 -> Mini Cubed/Headamp Pico -> JVC HA-D990/Sennheiser HD580
I hope I haven't misunderstood the Sloth; I believe the two new units he mentions are the 2007 Micro Portable and the 2007 Desktop Portable.
Does the 2007 Desktop Portable have a pre amp out? No mention is made of this on the product page. Perhaps it shows up in the photo, but I'm not really good at seeing photos. It'll be great once HR get around to putting up the instruction manuals for the new products. Anyhow, I just want to confirm that the Desktop Portable does indeed have a pre amp out. Also, what kind of connectors does it use (RCA or mini?) and is it a fixed level line out or volume controlled level?
Yes, they both have preamp out (minijacks) on the rear panel. These are on the exact same circuit as the headphone outputs and therefore controlled by the volume control and source selection in exactly the same way.
The new Micro with "Home" circuitry sounds faboo, but I don't have a fancy CD player; I do 100% of my listening through my iPod. I love, love, love what my current Micro with Desktop circuitry does for my listening, and am intrigued by the new Micro. But would the new Micro be overkill for my humble setup, and not provide any sort of upgrade in sound that I could appreciate through an iPod?
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Robin Michael
iPod 5.5g 80 gig w/256k tracks > HeadRoom Micro with Desktop upgrade > Grado GS-1000s > A nice chianti
The new Micro with "Home" circuitry sounds faboo, but I don't have a fancy CD player; I do 100% of my listening through my iPod. I love, love, love what my current Micro with Desktop circuitry does for my listening, and am intrigued by the new Micro. But would the new Micro be overkill for my humble setup, and not provide any sort of upgrade in sound that I could appreciate through an iPod?
Hi there,
Provided that you use the line out from your iPod and a reasonable cable (the relatively inexpensive Cardas mini is just fine), the SQ will scale with the amp electronics, even with your iPod as source. Run the iPod off its internal batteries whilst plaing for best SQ as well. That assumes you are prepared to up the quality of your files to lossless or equiv. It isn't really worth it otherwise.
Also, as you do already have a Micro with DM (what year, 05 or 06 module?), the improvement is unlikely to justify the cost difference unless you have an older module.
Just to make sure you aren't confused, the Micro with the 'home' electronics will not be battery powered, and will only run connected to AC power. So you would be giving up that portability - overall, I'd either go for the Micro Extreme with Max electronics, or keep what you have already.
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