[Navyblue]

Quote:

Originally Posted by wae5 /img/forum/go_quote.gif If what you say is true, why can I use the volume control on the MKIV SE to control the volume of the portable amp?

Think of it like a water tap, water flows out of the tap when you open the tap, but it doesn't mean that the tap pushes the water out. In fact the tap is preventing the water from flowing out when it is closed (volume at 0%).

 

[worldman]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Yes, there are exceptions and some devices are designed to be both a pre and a headphone amp. But they were engineered that way.

One of the preamps that qualifies as an exception is the April Music Stello DP-200 that I am currently using. It is actually a D/A converter (same as Stello DA-220) + Preamplifier (same as Stello P-200) + all discrete (no opamp) headphone amplifier combined into one neat package.

Although the headphone amp on the DP-200 is of very high quality, I have recently purchased an LD MKV connected to it via its unbalanced ouput for the sake of trying out this headphone amp. Although I can bypass the preamp part and just feed the signal straight from the D/A converter part to the headphone amp, I am using the signal from the preamp because (1) the sound quality between the D/A converter and preamp does not differ and match each other extremely well and (2) I can use the volume control (attenuator) of the preamp part using its remote control (60-step digitally controlled). That way, I can change the volume of the sound through my headphone by way of the remote control while the volume knob on the MKV stays at the 12 o'clock position.

The headphone amp of the DP-200 is very good with pitch black silence (absolutely no hum) even when used with the most sensitive headphones. The DP-200 is one equipment I would wholeheartedly recommend to anyone.

 

[wae5]

Quote:

Originally Posted by Navyblue /img/forum/go_quote.gif Think of it like a water tap, water flows out of the tap when you open the tap, but it doesn't mean that the tap pushes the water out. In fact the tap is preventing the water from flowing out when it is closed (volume at 0%).

However, I like thinking my MKIV actually boosts the signal rather than just opens up and closes down the signal like an electronic faucet.

 

[Tiemen]

Quote:

Originally Posted by vcoheda /img/forum/go_quote.gif another question is whether there is any good reason - any real benefit - to use a preamp with a headphone amp. what is there to be gained by using CDP >> Preamp >> Headphone Amp >> HP over just CDP >> Headphone Amp >> HP

If you have only a CDP, you don't need one.
But I use, besides my CDP, a cassette-deck, MD-deck, computer soundcart and a recordplayer.
In that case it's cheaper to connect all those gear to a pre-amp, and from that amp a line to the headphone amp. Otherwise I would have to buy a headphone amp for all those players.

 

[KonstantinT]

Quote:

Originally Posted by TX33 /img/forum/go_quote.gif Hello everyone! This is my first post! I've been reading head-fi for some time, but never posted anything. I'm was never really into writing anything online (ie. myspace, facebook...), but being so into audio I am compelled to write. I have a couple of questions. First, what is the whole purpose of a preamp and is it necessary? I've been using the rca output from my cdp to my headphone amp for some time and it sounds fine. If I get a preamp, will this alter the sound in any way or have any overall benefits to my system? Currently, I am using a philips dvd963sa cdp to a basic MPX3, driving a Sennheiser HD600. Any help would be greatly appreciated, thanks!

Hi, TX33! This is my second post.
A quality preamp should not alter the sound in any way (except boosting volume), but no amp is perfect. Sound altering is not intended, but in the real world you can´t avoid it. If the preamp has a tone control (bass, treble), you CAN alter the sound if you want to.

 

[KonstantinT]

Quote:

Originally Posted by tom hankins /img/forum/go_quote.gif I have run my HD650 with balanced cable out of the balanced outputs of two preamps with good results. Also out of the balanced outputs of my Audio Aero DAC (which had volume control)

Hi, Tom! Did you run your headphones out of the balanced LINE outputs? Does ithe impedance match?

 

[66645]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Preamps and headphone amps are not interchangeable. Passive pres would be totally ineffective and most active ones don't have the power to drive full sized headphones. Headphone amps, generally, are not designed to work as a pre.

I have ROTEL RC-970BX (10 years old middleweight model) preamp which I use to drive my K701. Also I have Zero 24 bit (low end dac+headamp combo). When I switch between them, I can not tell which is better, which means that they are on the same level more or less. Sound signature is different however.

Regarding power - K701 are known to be very power hungry, but rotel drives them easily, with knob between first quarter and half. It has plenty of power.

Frankly, I don't understand why "Preamps and headphone amps are not interchangeable". What the difference between feeding poweramp and headphone? Impedance? Why it should be dedicated?