[mizuvo]

Hey guys,

I am very impressed with the reviews of the HD650s. Affordable(HF sense) and seems to hold its own compared to almost everything else.

My question is in regards to impedence. I just received my Ibasso D3 Python and love it when used with my SE530. I have read that the Senns require a much stronger amp because of its high impedence. D3s spec sheets says that its recommended for headphones with impedence of 8-300. The Shures are at 36 so no problem there. However the Senns full size headphones are at 300. Would my D3 still be able to power it or do I have to invest in a desktop amp? I will eventually get one but is it absolutely required?

Another questions.. I know there are long answers but a quick one would suffice - Whats the difference between Closed and Openn headphones? Any one better than the other?

Thanks guys!!


Calvin

 

[wnmnkh]

Impedance is not that important enough to match.

Most portable amps usually have trouble with high-demanding cans like HD650 due to limited power (remember portable amps are powered from a mere battery.) This means a lot of limitations (i.e class-A amplification is just not practical/possible)


Now, the real question is whether desktop amp is 'absolutely' required..... Well, HD650s scale really well..... this means the more money you invest, the better HD650s are.

That's all I could say.

 

[pp312]

Do the spec sheets say the amp is suitable for 299 ohms or 300 ohms? If the latter, you should be OK. I'm being sarcastic, of course, but you see my point.

The difference between open and closed phones is, not surprisingly, that one is open at the back and the other closed, which means the open radiates its sound out through the back and the closed has to deal with internal reflections. Thus open phones tend to sound better but annoy everyone around you. A good closed phone can sound as good as an open; however they're usually expensive (i.e. Denon D5000).

 

[mizuvo]

I see.

So the main thing that does not allow the portable amp to work with full size headphones is the lack of power it generates from the batteries. Are there any headphones that could be powered by a portable amp?

As for closed or open, if open sounds better for less money, then I think im going to go the open route.

Thanks guys

Calvin

 

[jpscool4u]

afaik, the Little-Dot MKI is good enough to power the HD 650.

that's what i'm planning on buying, so I hope so

I was considering the iBasso D2 Boa, but i don't trust it'll sound as good

 

[Nocturnal310]

Quote:

Originally Posted by wnmnkh /img/forum/go_quote.gif Impedance is not that important enough to match. Most portable amps usually have trouble with high-demanding cans like HD650 due to limited power (remember portable amps are powered from a mere battery.) This means a lot of limitations (i.e class-A amplification is just not practical/possible) Now, the real question is whether desktop amp is 'absolutely' required..... Well, HD650s scale really well..... this means the more money you invest, the better HD650s are. That's all I could say.

I tried running HD650 with GoVibe Magnum & o22 amp...both failed miserably.

i didnt enjoy my HD650 experience with portable amps.

 

[Uncle Erik]

Impedance tells you about the power transfer from an amp to headphones.

The closer the output impedance of the amp matches the impedance of the headphones, the more efficiently power will transfer. There is a formula that you can use to show power loss from an impedance mismatch.

Once you know how much power transfers from the amp (using the amp's output power and calculating for loss due to possible impedance mismatch) you can use the headphone's sensitivity (measured in dB) to find how loud theywill get.

There are other factors, but this should get the concept across.

In my opinion, portable amps do not have enough power to drive the HD-650. You can get sound, but nowhere near what the HD-650 is capable of. You really need wall current or maybe a car battery to give enough power. Also, class A devices tend to run hot. Even if you have a power source, a class A amp in a portable case would probably be too hot to carry. And the heat in a small case would probably cook off the caps and resistors inside of a year.

If you want full-sized cans for portable use, try Grado. They are efficient and I like them straight from an iPod - no portable amp necessary. Some say Audio-Technica cans are efficient, but I'm not familiar with their line. I've only got one of their old electret models.

 

[Nocturnal310]

^^ ..i am using HD555.. it works well with iPod...

But seriously... there is no Portable Amp in the market which can drive HD600?

i am getting it at an affordable price... could buy it few months later.