Headphone Amp --> Powered Speakers = Surprisingly Good Sound
Jul 13, 2007 at 2:25 AM Thread Starter Post #1 of 21

ounkchicago

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Quick Summary: Using a headphone amp with high quality amplified speakers can sound surprisingly good!

Background: I stumbled across an unexpectedly pleasant sounding combination at a relatively low cost. I currently use a Creek OBH-21SE headphone amp, being fed by a Cambridge Audio 640C(v2) CDP. This is a great combination, and works well with both my Grado SR-225 for guitar/rock music, and Beyerdynamic DT880 (old version) for more versatility. Typical head-fi experience here... nothing out of the ordinary.

Then I thought, "wouldn't it be nice to enjoy this wonderful CDP through some quality speakers, when I have guests over at my house?" But I didn't want to buy another amplifier and speakers.

The New Setup: Fortunately, I own a pair of self-powered Audioengine A5 speakers, pictured here:



These are self-amplified speakers that were designed to be used with digital audio players like the iPod. They have received high ratings from a number of reviewers for making compressed music sound better. They retail for $349 but I managed to snag a pair that was cosmetically damaged for $199 plus shipping.

The A5 speakers use a 1/8" male-to-male miniplug, so I used a 1/8" female to 1/4" male headphone extension cable ($9 for 20-ft., gold plated, from Radio Shack) to plug them into the Creek headphone amp. The extension cable also provides the length needed to connect the speakers to the amp.

When listening, I keep the Creek volume control low. Since the signal is being amplified twice, not much gain is needed from either the Creek or the A5, so the volume on the A5 is also very low. The sound is much clearer, very well balanced, far more detailed, and with much greater bass impact and bass quality than any portable digital audio player could put out from the headphone jack. All the benefits of using a high quality source and headphone amp are passed on to the self-powered speakers.

Conclusion: Many of us have a head-fi rig because it is less expensive, more compact, and less disturbing to neighbors than an audiophile quality speaker rig. For those occasions when you would like to use speakers, try using some inexpensive but high quality self-powered speakers (probably in the $100-$400 range) and plug them into your headphone amp using some extension cables with the correct adapter. My results were surprisingly good, and I'm really excited about this added versatility of my setup. Now, I'm more attempted to listen through my A5 speakers during the day, and I switch to headphones at night when the neighbors might be going to sleep.
 
Jul 13, 2007 at 2:38 AM Post #2 of 21

ounkchicago

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Some notes about the setup above:

I've searched this forum for some time, but haven't found much information about the Creek OBH-21SE. Fortunately, I have had the opportunity to compare the Creek OBH-21 with the Creek OBH-21SE. While the OBH-21 is an acceptable headphone amp, the OBH-21SE sounds far better. The difference is not slight... it's drastic. Far better bass and greater overall detail with the SE version.

If you are interested in these amps, I recommend you listen for yourself to compare them. However, if you are like me, you will like the SE so much more that you couldn't possibly settle for the regular version.

Unfortunately, I have not owned any other headphone amps, so I cannot comment on whether the Creeks are good compared to other brands. All I can say is that subjectively, the Creek sounds flat -- the sound is all cleaned up, and bass is tightened up, but there doesn't seem to be any coloration at all. All there seems to be is wire and gain. As such, they seem to be a good match for the Beyerdynamic DT880's for reproducing a very true, flat, detailed, uncolored sound. It does not seem to have any particular synergy with any of the headphones I own, but that is what I would expect from a relatively flat solid state amp.
 
Jul 13, 2007 at 2:58 AM Post #3 of 21

ldj325

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I thought of the same thing with a SS amp that I had that only has headphone outs. Your speakers may be designed for other than line level input (I really don't know about them). But many speakers/monitors or downstream equipment is designed for line level input. Headphone out jacks are not line level. There could be an impedance mis-match than could damage either your amp or whatever piece you are connecting into. So if someone is comtemplating this kind of set up, you might want to check with your manufacturors first. I was thinking of this type of set up with my RudiStor SS amp, but I was told by RudiStor tech support that there could be an issue that could lead to damage. This is why active pre amp outs (line level) on a headphone amp can be a very good idea.
 
Jul 13, 2007 at 3:07 AM Post #4 of 21

ounkchicago

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ldj325:

I couldn't agree with you more. Indeed, at first, I tried turning the gain on the headphone amp up, but the speakers didn't sound right, and I was getting clipping with some frequencies. My thoughts are that under these conditions, the signal going into the self-powered speakers are too high. On my speakers, as with most computer/discman/ipod type speakers, they accept a headphone-level input. This would explain why you would need to be careful not to turn the volume on the headphone amplifier too high.

It wasn't until I lowered the volume on the headphone amp that I hit the sweet spot. So if anyone else is trying this, I would heed ldj325's advice and begin with very very low gain on the headphone amplifier You do not need high gain on the headphone amplifier to realize the benefits of the headphone amp -- you are merely bumping up the line-out from the CDP to the level of a headphone out. It should be noted that an improper gain setting may damage your equipment, and caution should be taken.
 
Jul 13, 2007 at 6:17 PM Post #6 of 21

ldj325

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Quote:

Originally Posted by ounkchicago /img/forum/go_quote.gif
ldj325:

I couldn't agree with you more. Indeed, at first, I tried turning the gain on the headphone amp up, but the speakers didn't sound right, and I was getting clipping with some frequencies. My thoughts are that under these conditions, the signal going into the self-powered speakers are too high. On my speakers, as with most computer/discman/ipod type speakers, they accept a headphone-level input. This would explain why you would need to be careful not to turn the volume on the headphone amplifier too high.

It wasn't until I lowered the volume on the headphone amp that I hit the sweet spot. So if anyone else is trying this, I would heed ldj325's advice and begin with very very low gain on the headphone amplifier You do not need high gain on the headphone amplifier to realize the benefits of the headphone amp -- you are merely bumping up the line-out from the CDP to the level of a headphone out. It should be noted that an improper gain setting may damage your equipment, and caution should be taken.



I am no expert in impedance, but it seems that in my checking I was told that damage could occur independent of volume level. Perhaps someone who is more knowledgeable could clarify these questions. Good luck.
 
Jul 13, 2007 at 6:20 PM Post #7 of 21

tbonner1

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Powered speakers can sound very good. Some of the best small studio monitors have had built in bi-amped amplifiers for years.
 
Jul 13, 2007 at 8:16 PM Post #8 of 21

cotdt

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if you have efficient speakers, you can even use your headphone amp to power them. my little headphone amp can output 5W into 8ohm speakers, which is enough to drive them decently loud, and has much better sound quality and lower noise than those T-amps (which output roughly the same power). just make sure that the amp does not overheat.
 
Jul 13, 2007 at 11:02 PM Post #9 of 21

koto-in

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It's hard to believe that anything real is happening here. The original signal is merely being amplified twice. The speakers are designed to self-amplify line level and low-level amplified signals. Try plugging the CDP directly into the speakers. If it doesn't sound the same (or better) then that's not a good recommendation for the fidelity of the Creek.
 
Jul 14, 2007 at 7:43 AM Post #10 of 21

ounkchicago

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Thanks for the helpful comments so far.

I discovered that my Audioengine A5 self-powered speakers come with a interconnect that allows me to go directly from the CDP to the speakers, which is what some people in this thread were suggesting to begin with. So to summarize, there are two methods of rigging self-powered speakers, one using a headphone amp (bi-amping), or one going directly to the speakers themselves:

([size=small](1) Bi-Amped Setup[/size]

CDP --> RCA male to male --> Headphone Amp --> 1/4" headphone out to 1/8" headphone in --> Amplified speakers

[size=small](2) Traditional Setup[/size]

CDP --> RCA male-male --> RCA female to 1/8" headphone in --> Amplified speakers

So the main questions here are:
(Q1) Are there any benefits of bi-amping, when using inexpensive self-powered speakers (such as those used for computers, iPods, or discmans)?
(Q2) Are there any dangers of bi-amping, such as damaging equipment because of incorrect impedances, etc.
 
Jul 14, 2007 at 7:47 AM Post #11 of 21

ounkchicago

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Quote:

Originally Posted by koto-in /img/forum/go_quote.gif
It's hard to believe that anything real is happening here. The original signal is merely being amplified twice. The speakers are designed to self-amplify line level and low-level amplified signals. Try plugging the CDP directly into the speakers. If it doesn't sound the same (or better) then that's not a good recommendation for the fidelity of the Creek.


My thoughts exactly. My original intuition is that the Creek is a much higher quality amplifier than the amplifier in my self-powered speakers. So I wanted to transfer the amplifying duty to the Creek. But the fact that the original signal is being amplified twice makes it more complicated... it is not as if I am using the Headphone Amp to drive a set of passive speakers.

I'm going to do some listening comparisons between plugging the speakers directly into the CDP, or using the headphone amp in between. I'll report back in a week or so. =)
 
Jul 14, 2007 at 10:13 AM Post #12 of 21

koto-in

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Quote:

Originally Posted by ounkchicago /img/forum/go_quote.gif
Thanks for the helpful comments so far.

I discovered that my Audioengine A5 self-powered speakers come with a interconnect that allows me to go directly from the CDP to the speakers, which is what some people in this thread were suggesting to begin with. So to summarize, there are two methods of rigging self-powered speakers, one using a headphone amp (bi-amping), or one going directly to the speakers themselves:

([size=small](1) Bi-Amped Setup[/size]

CDP --> RCA male to male --> Headphone Amp --> 1/4" headphone out to 1/8" headphone in --> Amplified speakers

[size=small](2) Traditional Setup[/size]

CDP --> RCA male-male --> RCA female to 1/8" headphone in --> Amplified speakers

So the main questions here are:
(Q1) Are there any benefits of bi-amping, when using inexpensive self-powered speakers (such as those used for computers, iPods, or discmans)?
(Q2) Are there any dangers of bi-amping, such as damaging equipment because of incorrect impedances, etc.



This is not bi-amping. http://en.wikipedia.org/wiki/Bi-amping
 
Jul 14, 2007 at 6:48 PM Post #13 of 21

noseallinit

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koto-in is right, that is not bi-amping. it is not a good idea to be setting up your equipment this way. this is what I would do.

your CA 640c(v2) has only one line level output, correct?

your Creek OBH-21SE has a line level input as well as a line level output(loop out), correct?

feed your CA 640c(v2) signal from it's line level ouput into the Creek OBH-21SE line level input. then feed the signal from the Creek OBH-21SE line level output(loop out) into your Audioengine A5 speakers line level input.
 
Jul 14, 2007 at 11:10 PM Post #14 of 21

koto-in

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Quote:

Originally Posted by noseallinit /img/forum/go_quote.gif
koto-in is right, that is not bi-amping. it is not a good idea to be setting up your equipment this way. this is what I would do.

your CA 640c(v2) has only one line level output, correct?

your Creek OBH-21SE has a line level input as well as a line level output(loop out), correct?

feed your CA 640c(v2) signal from it's line level ouput into the Creek OBH-21SE line level input. then feed the signal from the Creek OBH-21SE line level output(loop out) into your Audioengine A5 speakers line level input.



The output of the Creek is a bypass circuit and will not affect the audio signal in any way.
 
Jul 15, 2007 at 2:21 AM Post #15 of 21

noseallinit

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Quote:

Originally Posted by koto-in /img/forum/go_quote.gif
The output of the Creek is a bypass circuit and will not affect the audio signal in any way.


I doubt the Creek OBH-21SE would even have to be turned on for the Audioengine A5 speakers to receive the signal in this setup. this will keep him from having to plug and unplug his interconnects to go between the Creek OBH-21SE and the Audioengine A5 speakers with only one ouput on his CA 640c(v2). and better than running the signal out of his headphone output. the Loop Out is intended to send the source signal to another amp, receiver, etc.. why not a set of active speakers.
 

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