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HeadRoom Amp: Which one?! - Page 6

post #76 of 87
Quote:
Originally Posted by bradman View Post
Hi folks. My order has finally been shipped! Audio nervana approaches. Fingers crossed for Tuesday next week. However, I have a question. Could someone who has the DPS tell me does it come with a US-terminated power cord or do you connect to the wall outlet via an IEC cable like the Astrodyne? I've looked through the downloadable manuals and it's just not clear to me. I need to know if I have to go out and pick up a computer power (IEC) cable or if I just need an adapter to convert the US pin configuration to the local one used here. It would be a shame for it to arrive and find that I'm missing the means to connect it to the mains.

Thanks.
IEC cable included.
post #77 of 87
Quote:
Originally Posted by Soundinista View Post
Back with my report on the wall-wart ("WW" for short) as alternative to the DPS for the Max+Max Desktop. ("Wall-wart" is actually a misnomer. This is a brick. But I adhere to HeadRoom's terminology.)
I do not know why they call them 'bricks', just because they're vaguely a similar shape, because they're nowhere near being the same size?

My external HDD is much more brick-like, but its not a brick. The only other thing thats called a 'brick', is a brick.
post #78 of 87
Thread Starter 
Quote:
Originally Posted by Soundinista View Post
IEC cable included.
Thanks Soundinista. Fantastic! In that case I'm set. Spare adapters I have.
post #79 of 87
Bradman,
Don't forget, we want pictures, pictures and pictures. Ohh, before I forget, did I tell you we want pictures?
post #80 of 87
Quote:
Originally Posted by riverlethe View Post
Why has no one compared the Astrodyne vs. the DPS yet?
x
post #81 of 87
Quote:
Originally Posted by riverlethe View Post
Why has no one compared the Astrodyne vs. the DPS yet?
I believe feifan has sort of concluded that the DPS is superior here at
http://www.head-fi.org/forums/showpo...5&postcount=34

I know it wasn't an exhaustive comparative between both supplys but merely a quick or 'forced' response.
post #82 of 87
Thread Starter 

Comments on the Stepped Attenuator

Quote:
Originally Posted by Cecala View Post
What is heard when changing between steps from the headphones, does the sound quickly turn from on to off back to on?
Also going by my deduction, the displacements on the HR total 24 steps. Now the gain switch has 3 positions, so 3x24=72 actions. This would in theory give the ability to fine tune the sound.
Sorry about the delay in giving you some feedback on the stepped attenuator. I finally got the amp. I was under the impression that Fedex would move it through customs and dispatch it to me, but it seems that they are not set up to provide such civilised service. Anyway, I finally got my hands on the beasty last Friday. Let me make a few comments about the stepped attenuator for you.

As I turn the volume knob, it makes a physical click that I can feel. This thing is impossible to bump accidentally. In addition, with no source playing, I hear a pop through the headphones, much like the amp's turn-on thunk. The volume of this thunk seems to be related to the actual volume. With music playing, it is inaudible at low levels. there is never any break in sound from the source, just the little pop. I'm not worried in the least by this behaviour. I would think it is the nature of the beast as when changing from one discrete pair of resistors to another, you have to switch contacts at some point.

As for the step sizes, I don't believe you have anything to worry about. When I'm using the HD650's, I set the gain selector to medium (down) and I have had no difficulty finding a suitable listening level. When using the DAC as source, I find that a comfortable listening level is between 8 and 12 clicks (depending on the recording) from the lowest volume level. When listening to an analogue source, I have to go an extra 6 clicks or so to obtain the same level.

The low gain setting is not enough for the HD650's, but works well with my HD555's, HD25-SP's and even KSC-75's. These phones have impedances in the range 55-85 ohms (my 555's are the newer 55 ohm model).

the high gain setting is utterly unsuitable for any of the cans I have. With the HD650's I can turn the dial 4 clicks clockwise from the minimal setting and that's probably beyond where i'd want to be listening for any length of time. Moreover, with each step it jumps a huge amount. I was under the impression that the HD650's were no walk in the park for amps to drive, but there must exist some phones that are significantly more difficult to drive.

In summary, I believe that you should be able to find a gain selection that will appropriately match the step sizes of the stepped attenuator to just about any headphones you care to use with the amp so that you will have no difficulty selecting a desired volume level.

I hope my comments are useful.
post #83 of 87
Thanks Bradman for clearing up my indecision regarding the stepped Attenuator.
I look forward to the the rest of the review though with great want.
post #84 of 87
Bump. Any more news on a concrete Astrodyne vs DPS shootout? I'm really interested in getting a Desktop with Max module and Home DAC and would like to know what the final verdict is. At any rate, at least I'll get a preview of the Max/Max combo at the Vancouver meet this Sunday!
post #85 of 87
Bump. Bradman, its time you posted your impressions on your 'Desktop' setup.
post #86 of 87
Quote:
Originally Posted by Cecala View Post
On the DPS page no internal image is shown for this product, why?
From what I have read elsewhere the DPS is a simple E-Core transformer coupled to a bridge rectifier then passed on to a series of smoothing caps, very ordinary(Of course confirmation is needed here). I still can't get over the power outputs as stated by Max Dudio's review. If I could get an image of the internals of both the Astrodyne and DPS, I am willing to bet that the latter has large caps and this is why it is supposedly more 'refined' as stated by Max Dudio. If confirmed than it is a simple case of getting the Astrodyne and adding large capacitors in it, albeit in a larger case. As it stands though I am convinced that the Astro variant will suffice for Max+Max.
did you ever confirm what is inside this $400 DPS?

does anyone know for sure what is inside this DPS?

did you ever find a picture of the inside of the DPS? how about the Astrodyne?

is there anyone here at Head-Fi willing to take a picture of the inside of the DPS so we can all see? Feifan? Bradman? please, someone? q:O)
post #87 of 87
Noseallinit, check your inbox. I have PM you.
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