[ting.mike]

I've never used an amp with my MSPRO before.. this afternoon I tried my father's ADCOM amp, with a source out of an iPod shuffle. Now I know it's not the best combination, but what I was surprised was how much difference in the sound there was, and this was with a regular amp.
The amp didn't really change the sound character, but the sound gets fuller and just better.
Now I'm curious, if a regular amp does so well, why do we need special headphone amps. (Please don't answer "it'll be even better"). And what exactly is the difference in a regular amp and a headphone amp design?

Thanks.

 

[tfarney]

It'll be even better.

Just kidding. If it sounds that good, it would seem that Adcom put some care and resources into the design of the headphone section. Which means there will probaby be dedicated headphone amps that are better and plenty that aren't as good.

Tim

 

[Navyblue]

Most (if not all) headphone jack found in speaker amplifier are added as an after thought or "throw in" kind of feature. While dedicated headphone amp are designed for that very purpose.

As Tim mentioned, I'm sure some dedicated amp are better than the headphone jacks found on speaker amplifier, while others are worse.

If you browse a bit here you'd find that there is a thread recently that talks about this.

 

[derekbmn]

I'm assuming that you infact used an Adcom preamp. The Adcom preamps do have dedicated headphone amps in them and several models (GTP-400 is one) have what are basically a Grado RA-1 circut in them. Same opamps etc.

 

[ting.mike]

thanks for the replies, guys.

I thought there should be other threads with a similar question, I'm trying to look for them now.. I actually like Tim's idea of getting 70s integrated amps. I've seen them around local pawnshops, silver coloured, but not that cheap.. probably $30 to $80. Still, much2 cheaper than many dedicated amp.

derekbmn: yes, it's a preamp, and I'll try to find out the model number.

 

[senns&nonsense]

It is very hit/miss....

Miss = the hp jack is noisy or sharp sounding or otherwise suffering from the age of the unit.

Hit = You stumble into the best possible value in the headphone world, imo, by spending around $70 and getting a great old amp/preamp/receiver that happens to have a hp jack that is the equal of one on a dedicated headphone unit that costs several hundred dollars.

I believe this happens (the "hits") far more frequently than is suspected by some. Because of the great (possible) values I have bought quite a few over the past year and have had many very nice "surprises".

In terms of bettering your odds, I would suggest preamps over other components and would try to find the following names (though hits can also be had elsewhere) NAD, Adcom, Marantz, Nikko, Denon, and Harman Kardon.

Again, a generalization, but this also works better it seems if you are using higher imp cans. I am currently using my Doge for my Ultrasones, but using the hp jack on my Nikko Beta50 Pre for my K501s.

 

[scompton]

Take your headphones to thrift stores. I found a NAD 3155 at Goodwill that has a great heaphone jack. It's from the 80s and in perfect shape. Cost me $15. I've not compared it to dedicated headphone amps, except portables, which it blows away. I feel no need to get a dedicated headphone amp since I need a speaker amp to drive my Stax anyway.

 

[Uncle Erik]

Yes, some of the older preamps and receivers are terrific with headphones. The problem is that there are probably over a thousand varieties and there's no list of what's good and what isn't. If you want to go this route, take your headphones and a portable source so you can listen before buying.

As for the difference between a regular amp and a headphone amp, there are several. First, a speaker amp is for driving speakers. Speakers are bigger and require more energy to physically move the drivers. Headphones don't need much energy to drive them. If you put a lot of power through headphones, you can overheat or fry the voice coils. It's a little like lighting candles with a blowtorch. You can do it if you're careful, but it really isn't the best approach.

It gets more technical from there. First, keep in mind that headphones are right up against your ears. That means you're going to hear subtleties that don't show up with speakers - which is why a lot of us love them. That means that designers can get away with lesser designs and cheaper components.

One example is running an amp in class AB or even B. It's difficult to run in pure class A without making the amp expensive, hot and big. Because headphones don't need as much power, you can build a (relatively) inexpensive class A amp. And since you hear so much detail, class A pays off.

Another benefit is that you can run tubes (and chips, I suppose) that are awesome, but would never cut it for speakers. Lately, I've taken a liking to the 417A and 832, neither of which could drive my speakers.

Anyhow, I recommend buying or building a proper headphone amp. If you enjoy listening, sell some stuff or put it on the card. The vast majority of owners love them and get years of enjoyment from them. If you're unsure, get a used one here. You can usually sell a used one for about what you paid for it.

 

[ting.mike]

thanks! I find all the replies very helpful.

I think I will give the old preamp route a try.. I've been reading around headphone amps for a long time, and I think if I finally get one, it would be something in the above $500 range, and unfortunately I don't want to spend that money now, nor try to build one.

good thing the pawnshops normally let you try things on.. so I'll take my portable source and listen on the spot.

 

[ting.mike]

The ADCOM is a GFP-565, which some reviews at audioreviews says to be very warm. The headphone out, though may not be as good as the speaker out, does sound nice and warm..

Now here is another question (may be stupid): there is another unused Clase Audio 5L preamp which is also nice. It has balanced XLR out plugs. What will happen if I connect my headphones to those? (I'd have to convert my phones to balanced first)

 

[Navyblue]

I might have misunderstood your question, but you can't power a headphone with the line out of a preamp, line level signal has to be amplified (which is what the amplifier is doing). What others are saying is you can use the preamp if it has a headphone outlet (i.e. built in headphone amp).

 

[DocHamm]

A few of the Adcom preamps have good headphone sectons. Some to note are the GFP/GTP-400 and GFP/GTP-500 series. I have had one from both and prefer the latter. The GCD-575 was rated one of the best CD players of it's class and it also has an incorported headphone section, however it does struggle a bit with depth at higher impedance, like my MBQ-55x's, but it still sounds great and I love it!

 

[krmathis]

A couple of reasons:
* Portability (the ADCOM is hard to lug around in your pocket).
* The money are put into designing the actual headphone amplifier, and not in designing a speaker amplifier (then add output for dynamic headphones at the end).
* Eliminate an energizer when using an electrostatic headphone.
* ...

 

[ting.mike]

Quote:

Originally Posted by Navyblue /img/forum/go_quote.gif I might have misunderstood your question, but you can't power a headphone with the line out of a preamp, line level signal has to be amplified (which is what the amplifier is doing). What others are saying is you can use the preamp if it has a headphone outlet (i.e. built in headphone amp).

Hi. No you didn't misunderstood it.. I know it may sound crazy, but I was looking at the back of the pre-amp (and I know it's a good pre amp, probably much more expensive than anything I can afford today), and noticed XLR outs, so I thought "what would happen if I connected the headphones to those outs?" After all, the pre amp does have a volume knob, so the output may not a line level output, but controllable through the volume knob..

of course I am not really an electrical engineer, so there might be something I'm missing.

-edit-
I should take a picture of the back panel.. maybe that'll clear things up..

 

[Navyblue]

Quote:

Originally Posted by ting.mike /img/forum/go_quote.gif After all, the pre amp does have a volume knob, so the output may not a line level output, but controllable through the volume knob..

Often the case, a pre amp sole function is to add a volume knob between your source and the power amplifier, or else your volume would be permanently fixed at 100%.

A pre amplifier is meant to output a line level signal to feed a power amplifier which then drives the transducers. If it outputs anything stronger than a line level signal, then it probably can't be considered a pre amplifier.