Speaker amps for headphones
Apr 27, 2014 at 8:15 PM Post #2,552 of 3,873
Quoting a post I made three months ago:
  Having learned, with some math tutelage from Armaegis, that the resistor network built by Jan Plummer for my TBI Millenia MG3 reduces the power output by 15.8 dB (from 5.1W into 50 Ohms to 133mW into 50 Ohms), I no longer use the attenuated, Class BD MG3 with my LCD-2, due to the loss of dynamics and bass control had with only 133mW.  Of course, the real reason for using a resistor network with the MG3 is to silence the hiss inherent to its excessive gain - a hiss that can be easily heard with transducers that are far more sensitive than the typical 8-Ohm loudspeakers for which it was designed.  
 
But, as FlySweep later convinced me, that MG3 + 10/2 resistor network sounds freaking awesome with the HD600 that I purchased at his recommendation. He has since gone on to say that his more recently acquired HD650 are even better with the MG3 + resistor network. The good news is that the story ends well, after silencing the MG3's hiss, by using headphones that don't need more than 133mW into 50 Ohms (or 23.4mW into 300 Ohms).  I'm also blown away by how wonderful the attenuated MG3 sounds with my HD800 (at least with recordings that don't have a lot of bass - a weakness of the HD800 that the relatively neutral MG3 can't compensate).  Overall, the HD600 is a much better match to the MG3 + resistor network (as is, the HD650, per FlySweep, who started out with the HD800 on his attenuated MG3).
 
So why should anyone buy an over-powered speaker amp for use with headphones - especially if you have to attenuate the output?  Because the amp itself might bring something to the table that you're not able to get from any other amp you've heard.
 
Seriously, it's surely not the 110W into 8 Ohms that Gary is exploiting when he listens to his Odyssey Audio Cyclops Extreme - fed directly into his LCD-3.  He's using a tiny fraction of that power.  No... He must just be attracted to those same qualities that make the amp so popular with HiFi enthusiasts - the amp's sound!
 
Mike

 
For about two months now, I've been using my TBI Audio MG3 to power my near field monitors, exclusively - having abandoned all thoughts of using it as a headphone amp - due to the 15.8 dB attenuation required to silence the hiss caused by excessive gain.
 
Today, a revelation:  For the first time ever, it occurred to me to try the OPPO PM-1 on the MG3 amp.  I broke out the TBI resistor network and connected the OPPO PM-1 with balanced cables to the MG-3.  No hiss (thanks to the attenuation), but there's no evidence of a lack of power either, thanks to the PM-1's efficiency!  Sweet! 
 
The resistor network is knocking the MG3's output down to only 208 mW rms per channel, but I'm hearing everything I love about the MG3's signature, with an almost undetectable loss of dynamics and bass control (nothing like that suffered with the much less efficient LCD-2 on the MG3 with resistor box.)  
 
At this moment, I'm running the exact battery-powered rig seen in this video I made a couple of months ago - having replaced the HD800 with the PM-1, but everything else is the same:
 

 
/img/vimeo_logo.png
 
 
The overall sound is very "musical" - I hate using that word, but it's so appropriate - a sweet, natural, organic sound, with no lack of detail, LCD-2 like bass energy, with not quite the same tightness, full-bodied, transparent mids, and plenty of sparkle for my taste (like the HD650, not the HD800).  The attenuated MG3 for sure offers more and better-controlled bass than the Bushmaster Mk-II's headphone out. 
 
Everything I enjoy about the Beresford Bushmaster MkII and the TBI Audio MG3 are coming together into a headphone that's not only efficient enough to tolerate the resistor box's 15.8 dB attenuation, but also capable of delivering all of the esoteric goodness that's embodied in the DAC and amp.
 
This may end up being nothing more than my "rig of the month," but I'm really enjoying it - and very glad that I had a reason to hang onto the MG3 (for use with speakers), when I would have sold it otherwise.
 
biggrin.gif
 
 
Updated a few hours later:  Forget I said all of the above - dynamics are still an issue on the MG3 with resistor box - even with the very efficient PM-1.  Listening to many different tracks has awaken me to the facts.  The PM-1 wants more power than the 208mW coming from the attenuated MG3.  Switching to other amps has proven it, and I just can't live without the slap and punch - even though I love what the MG3 does, otherwise.
 
Apr 27, 2014 at 11:23 PM Post #2,554 of 3,873
Haha!   Classic Gary humor!  I love it!  LOL
 
Guess why I came to this thread just now!  I came here to retract my praise for what will NOT be the rig of the month!  In fact, it didn't even last the day!  
 
Hahaha!
 
See my last post - edits applied.
 
I'm laughing my head off, here. 
 
When will I learn that I should wait at least a few hours before posting my impressions?
 
redface.gif
 
 
Apr 27, 2014 at 11:43 PM Post #2,555 of 3,873
And here all this time I thought you just wrote down the names of your components on a spinning dartboart and picked a new combo each morning...
 
Apr 27, 2014 at 11:52 PM Post #2,556 of 3,873
And speaking of stuff I already owned...
 
I was at my elderly parents' place last weekend, and my mother asked me if I could take a box up to the attic.  While I was up there, I did a little lookin' 'round, and found my old Nikko NA-890 integrated amp from the late 1970s that I had given them to use in the 1980s or early 1990s along with a pair of my old speakers so that they could listen to music at bridge games or whatever.  In any case, they were clearly no longer using it (my mother was never really into it and my father is almost 87, mostly deaf... too many years playing bass too close to the drummer... that's his story, he's sticking to it...) so I figured I'd take it home with me and try it as a headamp.  I mean, that's what we do on this thread right?
 
A little about the amp:  it is solid state, rated at 70 wpc into 8 ohms, .04% THD 20 to 20K, blah, blah.  Specs on a ~35-year-old amp are pretty meaningless, they designed/tested mostly by ear in those days.  Nikko was never a big player in the audio business, they mostly did big industrial electronics (circuit breakers, etc.) but they did a lot of contract audio work, and sold amps and tuners under their own name on the East and West coasts.  In the East they were pretty much the store brand of Tech HiFi, one of the stores I used to haunt back then (haunt being the operative and appropriate term... I think they performed several exorcisms to keep me away, but it didn't work).  This particular amp was not a top-of-the-line unit, but it was what I could afford as a teenager and at that time it was a big step up.
 
So I finally got around to playing with it Friday night.  First I looked at the connections in the rear... certainly no 5-ways back there.  In fact, the posts were tiny, so that I couldn't even fit spades in there.  Crap, no way to directly connect the speaker tap without undoing the tap's connectors, and I wasn't going to do that. 
 
I was tired, so I just decided to try the HP jack in the front.  Connected the Yulong DA-8 to the Aux inputs, jacked in, powered on and... staticky noise.  Lots of it.  First in the left ear, then when I adjusted the volume, the noise came and went, sometimes on the left, sometimes on the right.  But when the static wasn't there it sounded okay.  A bit congested, though rich and full-bodied.  .  But that noise was not acceptable.  Oh well, it was worth a try right?  I gave up and went to bed.
 
ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
 
As usual, I do my best thinking while I'm asleep
redface.gif
biggrin.gif
evil_smiley.gif
.  I woke up yesterday realizing that I had the solution to the rear connections... a resistor box.  I cut a couple of ~1-foot hunks of 12-gauge speaker wire that just barely fits in those posts, and connected up my spare box (the one with the Mills resistors).  Connected the speaker tap and then the LCDs.  Power on.  JRiver open.  Click on a test tune...
 
 
 
 
 
 
BWAHAHAHAHAHAHAHAHAHHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA
 
This sucker kicks arse!!!!
 
It isn't the equal of the Odyssey, but it is more than a match for the Millenia MG-3.  No noise -- hiss, static or other -- through the box.  Clean, tight, punchy.  Decent soundstage (much better than the Millenia).  Dynamics?  Craploads.  Edgier than the Odyssey in the treble, with a tiny bit of harshness up there, so some of you might actually like it better
deadhorse.gif
.   
 
I don't like it better than the Odyssey, but I like it just fine as a backup amp.  I wouldn't pair it with the HD800, but it is pretty damned nice with the LCD-3s and even the HD650s.  None of the other amps I tried last summer, including the MJ and Soloist, are in this league.  And it was free.  Well, it wasn't free when I bought it in the 1970s, particularly given my economic situation at the time (poor student), but I think I can depreciate that purchase price enough now that for all intents and purposes it's free.
 
So if you happen to see a vintage but functional Nikko amp anywhere on eBay, Audiogon or at a yard sale or thrift shop, you might want to risk that $5 or even $85 (that was the asking price on a couple of old eBay ads I saw).  I think you will be pleasantly surprised by how well it can drive a pair of cans from the speaker outs.
 
As for me, I already got my hidden treasure.  I feel like somebody on one of those PBS or cable shows who brings an old piece of junk in and finds out it's worth a fortune. 
 
Damn I love free stuff that works great!!!
 
On the other hand, now I have too many headamps... I guess I need a 3-output pre-amp and another pair of cans so I can have 3 easy choices for my daily listening.  Hmmm, maybe this thing ain't quite as free as I thought!!!
 
 
 
 
 
Apr 28, 2014 at 7:31 AM Post #2,557 of 3,873
  And here all this time I thought you just wrote down the names of your components on a spinning dartboart and picked a new combo each morning...

 
I could fare better doing that!  LOL
 
This morning I've gone back to yet another all battery-powered rig:  Laptop USB > Resonessence Concero SPIDF > Beresford Bushmaster MkII > 15V Meier Stepdance > PM-2  (a solid contender for portable rig of the month).   The PM-1 is getting lots of highly detailed, transparent, and neutral power from the Stepdance's OPA1611s on 15V supply (almost 30V swing).
 
The MG3 has been put back into service as a speaker amp - for good this time.  Am I sure?  Yes, I'm sure!  
 
I'm going to turn my TBI resistor box into a $100 trailer hitch cap!  
 
Wait a minute... maybe what it needs is some uber-efficient IEMs.  Yeah... that's the ticket!
 
biggrin.gif

 
Apr 28, 2014 at 8:07 AM Post #2,558 of 3,873
  And speaking of stuff I already owned...
 
[snip]
 
so I figured I'd take it home with me and try it as a headamp.  I mean, that's what we do on this thread right?
 
[snip]
 
In the East they were pretty much the store brand of Tech HiFi, one of the stores I used to haunt back then (haunt being the operative and appropriate term... I think they performed several exorcisms to keep me away, but it didn't work).
 
[snip]
 
 
BWAHAHAHAHAHAHAHAHAHHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA
 
This sucker kicks arse!!!!
 
It isn't the equal of the Odyssey, but it is more than a match for the Millenia MG-3.  No noise -- hiss, static or other -- through the box.  Clean, tight, punchy.  Decent soundstage (much better than the Millenia).  Dynamics?  Craploads.  Edgier than the Odyssey in the treble, with a tiny bit of harshness up there, so some of you might actually like it better
deadhorse.gif
.   
 
I don't like it better than the Odyssey, but I like it just fine as a backup amp.  I wouldn't pair it with the HD800, but it is pretty damned nice with the LCD-3s and even the HD650s.  None of the other amps I tried last summer, including the MJ and Soloist, are in this league.  And it was free.  Well, it wasn't free when I bought it in the 1970s, particularly given my economic situation at the time (poor student), but I think I can depreciate that purchase price enough now that for all intents and purposes it's free.
 
So if you happen to see a vintage but functional Nikko amp anywhere on eBay, Audiogon or at a yard sale or thrift shop, you might want to risk that $5 or even $85 (that was the asking price on a couple of old eBay ads I saw).  I think you will be pleasantly surprised by how well it can drive a pair of cans from the speaker outs.
 
As for me, I already got my hidden treasure.  I feel like somebody on one of those PBS or cable shows who brings an old piece of junk in and finds out it's worth a fortune. 
 
Damn I love free stuff that works great!!!
 
On the other hand, now I have too many headamps... I guess I need a 3-output pre-amp and another pair of cans so I can have 3 easy choices for my daily listening.  Hmmm, maybe this thing ain't quite as free as I thought!!!
 
 
 
 

 
Good laughs with which to start the day - thanks for being you, Gary!  
 
And that's got to be one of the best spoilers I've ever opened. You snuck up on us!  
 
Back in the late 70's, when I was a student, I sold Nikko gear (and a lot of other stuff) on the west coast - in Pasadena, CA, working for a chain that years later became Circuit City: Custom HiFi, based in Louisiana.  We had some regulars that needed exorcising, too.  Kids my age, who came into the store almost every day, just to play with gear and talk about gear and leave puddles of drool on the floor - seldom buying anything. And being the youngest salesman there, I was expected to entertain them - and had the low commissions to prove that I was doing a fine job of keeping them out of everyone else's hair.
 
The Federated Group was our nemesis:
 

 
Mike
 
Apr 28, 2014 at 8:58 AM Post #2,559 of 3,873
Mike:
 
I believe Custom Hifi stores were called Dixie Hifi in the South. I irritated the folks in a couple of their stores lots when I was in college.  Then they changed the name to Circuit City and now... RIP Hifi stores...
 
Apr 28, 2014 at 6:21 PM Post #2,561 of 3,873
Brack Electronics, Toronto.
I think I irritated a few salesmen there with my lust for JBL L300 loudspeakers!
 
Apr 29, 2014 at 11:25 AM Post #2,563 of 3,873
And speaking of stuff I already owned...

I was at my elderly parents' place last weekend, and my mother asked me if I could take a box up to the attic.  While I was up there, I did a little lookin' 'round, and found my old Nikko NA-890 integrated amp from the late 1970s that I had given them to use in the 1980s or early 1990s along with a pair of my old speakers so that they could listen to music at bridge games or whatever.  In any case, they were clearly no longer using it (my mother was never really into it and my father is almost 87, mostly deaf... too many years playing bass too close to the drummer... that's his story, he's sticking to it...) so I figured I'd take it home with me and try it as a headamp.  I mean, that's what we do on this thread right?

A little about the amp:  it is solid state, rated at 70 wpc into 8 ohms, .04% THD 20 to 20K, blah, blah.  Specs on a ~35-year-old amp are pretty meaningless, they designed/tested mostly by ear in those days.  Nikko was never a big player in the audio business, they mostly did big industrial electronics (circuit breakers, etc.) but they did a lot of contract audio work, and sold amps and tuners under their own name on the East and West coasts.  In the East they were pretty much the store brand of Tech HiFi, one of the stores I used to haunt back then (haunt being the operative and appropriate term... I think they performed several exorcisms to keep me away, but it didn't work).  This particular amp was not a top-of-the-line unit, but it was what I could afford as a teenager and at that time it was a big step up.

So I finally got around to playing with it Friday night.  First I looked at the connections in the rear... certainly no 5-ways back there.  In fact, the posts were tiny, so that I couldn't even fit spades in there.  Crap, no way to directly connect the speaker tap without undoing the tap's connectors, and I wasn't going to do that. 

I was tired, so I just decided to try the HP jack in the front.  Connected the Yulong DA-8 to the Aux inputs, jacked in, powered on and... staticky noise.  Lots of it.  First in the left ear, then when I adjusted the volume, the noise came and went, sometimes on the left, sometimes on the right.  But when the static wasn't there it sounded okay.  A bit congested, though rich and full-bodied.  .  But that noise was not acceptable.  Oh well, it was worth a try right?  I gave up and went to bed.

ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ

As usual, I do my best thinking while I'm asleep :xf_eek: :D :evil: .  I woke up yesterday realizing that I had the solution to the rear connections... a resistor box.  I cut a couple of ~1-foot hunks of 12-gauge speaker wire that just barely fits in those posts, and connected up my spare box (the one with the Mills resistors).  Connected the speaker tap and then the LCDs.  Power on.  JRiver open.  Click on a test tune...





BWAHAHAHAHAHAHAHAHAHHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA

This sucker kicks arse!!!!

It isn't the equal of the Odyssey, but it is more than a match for the Millenia MG-3.  No noise -- hiss, static or other -- through the box.  Clean, tight, punchy.  Decent soundstage (much better than the Millenia).  Dynamics?  Craploads.  Edgier than the Odyssey in the treble, with a tiny bit of harshness up there, so some of you might actually like it better :deadhorse: .   

I don't like it better than the Odyssey, but I like it just fine as a backup amp.  I wouldn't pair it with the HD800, but it is pretty damned nice with the LCD-3s and even the HD650s.  None of the other amps I tried last summer, including the MJ and Soloist, are in this league.  And it was free.  Well, it wasn't free when I bought it in the 1970s, particularly given my economic situation at the time (poor student), but I think I can depreciate that purchase price enough now that for all intents and purposes it's free.

So if you happen to see a vintage but functional Nikko amp anywhere on eBay, Audiogon or at a yard sale or thrift shop, you might want to risk that $5 or even $85 (that was the asking price on a couple of old eBay ads I saw).  I think you will be pleasantly surprised by how well it can drive a pair of cans from the speaker outs.

As for me, I already got my hidden treasure.  I feel like somebody on one of those PBS or cable shows who brings an old piece of junk in and finds out it's worth a fortune. 

Damn I love free stuff that works great!!!

On the other hand, now I have too many headamps... I guess I need a 3-output pre-amp and another pair of cans so I can have 3 easy choices for my daily listening.  Hmmm, maybe this thing ain't quite as free as I thought!!!
This is the thrill I had when I got my HE-6 and found all the headphone amps I tried to be underperforming. A pair of Rotel RMB-100s at 125w are running my HE-6. I've heard better amps but for free, I'm a happy camper.
 
May 3, 2014 at 12:30 PM Post #2,564 of 3,873
Think I'll join this thread. Was briefly considering the XTZ A-100 D3 as replacement for my emotiva mini-x. It's a 50 watt class A with the option to switch to class AB (180 watt). Sounds good, right? Well, until I looked up the specs:
 
SNR Ratio >100dB (A Weighted, 100W, 8ohm) 
 
Voltage gain 42dB 
 
Damn, that gain and SNR!
 
May 3, 2014 at 3:19 PM Post #2,565 of 3,873
The chances of hearing noise with that much gain are somewhat high...
 

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