[Sonic Defender]

My A18 is stuck in customs and I am so sick of waiting that I have had time to discover and consider the Can Opener http://www.vinylflat.com/canopener.html and just turn around and sell my A18 when it finally arrives here. Before I even purchased a headphone amp I was looking for just such a device to add headphone capability to my NAD M3.
 
Assuming the device doesn't represent much of a load to the amplifier, which I suspect it doesn't my concern is whether or not the approach of simply sticking large numbers of resistors to buffer the headphone can degrade sound quality. I am not sure why it would, but I am not at all well versed in electrical circuit design so for all I know this is a terrible idea. Any thoughts or opinions are greatly welcomed.

 

[Sir Tmotts III]

It works wonders with my NAD 3020, It has better decay, and is great with low impedance headphones (most receivers have a pretty high output impedance for their jacks), among many other things. I highly recommend it. 

 

[Sonic Defender]

  It works wonders with my NAD 3020, It has better decay, and is great with low impedance headphones (most receivers have a pretty high output impedance for their jacks), among many other things. I highly recommend it. 

Thanks for the vote of confidence in the Can Opener. I might still go this route, but I am leaning toward making speaker taps and just going right from my M3. Glad to hear you are enjoying it, and I had a 3020 myself for a few years (that is from the classic power envelope line isn't it?) I think mine was actually a 3040, but I am unsure as it has been a number of years since I sold it. It was a great integrated, very poised and very musical. NAD puts out some questionable gear sometimes, but they have produced many gems over the years as well. Cheers.

 

[mrscotchguy]

I may have been one of the first Headfiers to pickup the Can Opener... And I was met with both excitement and skepticism from both sides.

I think it's handy, but no end-all-be-all device. For anyone looking to drive traditional headphones, it works wonders with an old integrated or modern receiver. Just note that many old vintage integrated amps use basically this same technology (resistors connected to a 1/4" jack) on the front panel.

I warn against the limitations that some amps do not like having their separate grounds joined. This he case with my T-amp, and can be the same with many integrated tube options. Be sure to contact the manufacture to prevent damage to your device.

A similar device is Hifiman's balanced version of the Can Opener... http://head-direct.com/Products/?act=detail&id=104

By separating the grounds, there should be very little chance of damage (to your amp) but Hifiman cautions against using this setup with anything too sensitive.

I experienced decent sound paired with a cheap Onkyo receiver, but improvement showed with better equipment. If you have a high quality integrated amp not in use or a good receiver with a set of free "B" zones not in use, this could be a great budget alternative to investing in a high end dedicated headphone amp. At said, those devices we never designed to run headphones, so refinement and microdetails are usually lost to a warmer, more euphonic sound.

As for speaker taps... Those afraid of blowing their speakers may consider getting this to prevent damage to the headphone if the amp supports crossed ground.

 

[Sonic Defender]

Thank you for the extensive and thoughtful reply. As an aside my families heritage is Scottish as well. Love to spend some time in Scotland. I think your point that the sonic signatures of non-headphone gear is likely in comparison to headphones amps, to sound less detailed and euphonic. In some headphone pairings this might be ideal (HD 800) and quite the opposite with warmer headphones. I have e-mailed NAD technical support as asking if the ground are tied as at this point I think I am leaning toward having speaker taps made. My M3 allows me to select the speakers, and speaker B is completely unused now so that is a good candidate. I will post in this thread when I actually get this done (about a month I figure). Cheers.

 

[mrscotchguy]

Thank you for the extensive and thoughtful reply. As an aside my families heritage is Scottish as well. Love to spend some time in Scotland. I think your point that the sonic signatures of non-headphone gear is likely in comparison to headphones amps, to sound less detailed and euphonic. In some headphone pairings this might be ideal (HD 800) and quite the opposite with warmer headphones. I have e-mailed NAD technical support as asking if the ground are tied as at this point I think I am leaning toward having speaker taps made. My M3 allows me to select the speakers, and speaker B is completely unused now so that is a good candidate. I will post in this thread when I actually get this done (about a month I figure). Cheers.

I would recommend the hifiman option to prevent any accidental damage to your hd800. Speaker taps were highly discouraged by the hifi dealer I work next to. (Even if they sound great). My girlfriend has no idea how to work a remote and could easily fry a headphone left plugged in (main receiver).

That said, if you want to pursue the Can Opener direction. I could probably be convinced to sell mine for a reasonable amount if you'd like to take it to PM. I would still recommend the hifiman option...

 

[guitargonaut]

I own two Can Openers, one for work and one for my bedroom setup.  Definitely cheaper than a quality dedicated headphone amp.  I enjoy both.  The work reciever has a resistor coupled headphone out but doesn't compare to the Can Opener as far as detail and soundstage.  The same can be said for my bedroom setup as well.
 
I've had several different headphone amps over the years; more than I care to mention.  I can't say the Can Opener is the best sounding out of all I've tried but I can say it ranks very high, especially when paired with the Denon AD H5000.  I love the sound I get out of my Sennheiser collection as well.