NEED A HEADPHONE AMP

[jasonhanjk 0]

Tropical know how to build one from of those bare board.

Try Pm him.

 

Edit: Not meeting him tomorrow.

Edited July 18, 2004 by jasonhanjk

[nakedtoes 0]

Hi, I'm pretty new to this audio stuff, but after reading about how much difference a headphone amp can make to sound, I'm tempted to get a (portable) CMoy amp for myself to hear the difference. I'm not trained in electronics, and I don't have my own equipment, so I probably have to get someone else to build it for me. Are there any grandmasters in DIY headphone amps I can consult?

 

p/s: I own a Beyerdynamic DT231 Galactic. Impedance is 32ohms, same as earbuds. Is a headphone amp necessary in the first place?

 

Thks!

maybe we can meet up and pay tropical a visit..?

[digi01 0]

Hi nakedtoes,sorry for my slow reply please check your PM.

 

[nakedtoes 0]

DIGI01: ABit out of my budget.. sorry

[bpribadi 0]

Hi Nakedtoes,

 

Last month I built a CMoy, also to try the difference a HeadAmp can give. I built it with OPA2134.

 

I use 2 PCDP, iRiver iMP-150 and Panasonic SL-CT810, with ATH-EW9 headphone. The sound different is quite evidence, my wife, my brother, and some friends all of them can tell the difference, that means it is not subjective.

 

OPA2134 has a good bass and midrange for it's price, but not enough soundstage and details for me. I ussually add some bass when connect my headphone directly to the PCDP, with OPA2134 it is not neccessary to add the bass anymore, I can play it flat, the bass is enough for me.

 

So my first CMoy has drove me to build a better amp. I suggest you try a simple CMoy and try the difference. Now I'm preparing to build PPA's like (without PPA board) headamp, and some other with LM6171.

 

 

Edited July 20, 2004 by bpribadi

[digi01 0]

DIGI01: ABit out of my budget.. sorry

no problem.

[digi01 0]

bpribadi,great works.what case are you using?looks very pretty

[bpribadi 0]

Thanks Digi! It is one of the standard Hammond die cast casing. You can get it from Farnell.

 

Actually I was about to ask you where you got those casings you used for your headamp. I saw some of your threats in head-fi, and all of your casings are very nice.

 

Bram

[N@Z 0]

Great shots, camera?

 

Noticed you don't have a volume pot so I assume you use it from headphone out rather than line out?

[bpribadi 0]

Canon G2.

 

Well, I use line out of the PCDP. My iRiver line out using the same volume as the headphone out. So this is only works with iRiver, other brands PCDP has no volume for the line out, only iRiver use volume for the line out.

 

With my Panasonic SL-CT-810, I have another small box with blue ALPS as the volume pot. This small box I use as the interconnect between the PCDP and the headamp line in.

 

Using the PCDP line out volume is actually not a good approach. The headamp will amplified the line out hiss. Since hiss sound of the line out is the same level regardless of the player volume, so I can hear hiss during silent, or low volume level. To solve this, I need pots for volume, and set the player volume to max, so the ratio of the music signal will be much higher than the hiss, and then use the pot as the secondary volume. This way the hiss level will be reduce when we reduce accordingly by the pots. To my case, no more audible hiss.

 

It just happened that I have that hammond casing for a very long time in my drawer, so I want to make use of it. And because of space constrain, no space for pot. But next time I won't build headamp without volume pot, I have learnt my lesson

[digi01 0]

bpribadi,The case that I usually use is processed by myself,of DIY. The material is aluminium and stainless steel. Or I finish drawing want to see the low processing factory of Beijing help me to make. The advantage is that my circuit part can be at will . If use the case in common, then you have to put up with its size.

Recently, the weather in Beijing is sultry I have not felt like touching it by oneself either. So choose the case of some OEM, though a little with high more costs,but they are pre-drill format

 

[bpribadi 0]

Hi Digi, you are very fortunate to be able to design your own casing

 

I wonder there is such a place in Singapore where I can order wy own casing with a reasonable price (SGD 20 to 50, depend on size).

[mukegile 0]

u could ask the metalworkshop to do the work , like the those who do the aluminium sign-board

but i dun think it will come cheap.

 

[Mackie 0]

Using the PCDP line out volume is actually not a good approach. The headamp will amplified the line out hiss. Since hiss sound of the line out is the same level regardless of the player volume, so I can hear hiss during silent, or low volume level.

 

I'm surprised for I own a Panasonic Sl-CT790 and connected to Porta Corda II via line/optical output but I detect no hiss at all. In fact, connection via headphone out results in lower gain, higher noise level and also a somewhat compressed sound - in terms of soundstaging dimensions.

[digi01 0]

bpribadi,maybe I can help you get the good case.

such as this OEM case,the size is 100x60x200mm,pre-drill vol+headphone out jack+ac power+input.