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Speaker amps for headphones - Page 60

post #886 of 2933

Hey Stew,

 

With all our talk of music and speakers, we're derailing this thread, but anyone who has an MG3 should really go get themselves some efficient monitors for near-field listening - in addition to using the MG3 with headphones, of course!   Gary has a pair of Jan Plummer's Diamond speakers for use at his PC, which is essentially what I'm doing with the laptop in the dining room (my audio workbench), but my "real" PC is in a spare-bedroom-turned-into-my-office, upstairs, where a sound card and self-powered el-cheapo speakers are all that's happening.

 

I just finished reading Kent Johnson's review of the Sjofn Hifi "The Clue" loudspeakers, in Positive Feedback #53.  Wow.  I'm impressed by his being so impressed!  

 

They're about the same size as my Def Tech SM45s, but in another league, for sure, not just going by the $1500/pair price tag, but by what he says about them.  The review is a fun read for anyone interested in such things (here at Head-Fi).  I was about to quote some highlights, but I'll restrain myself.  (Wrong venue.)

 

I have to ask Stew, and I realize it will be kind of an apples and oranges question (difficult to compare), but which do you enjoy more on the MG3, the Paradox or The Clue?  redface.gif

 

I have some trepidation about receiving the impedance match (some time next week, maybe?), because I'm so very enchanted by my current near-field setup (MG3 > SM45) that I fear both the impedance match and my (formerly) beloved LCD-2 will end up on a shelf somewhere gathering dust.  This is sacrilege for a Head-Fi thread, I know, but guys, having the stage out in front of you instead of on both sides of your head and in between your ears, is simply wonderful with the MG3.  

 

Coincidentally, both the Kent Johnson review of Stew's "The Clue" speakers and Chris Martens' (TAS) review of the Def Tech SM45s, write of how their respective speakers-under-review can "vanish" when you're head is in the sweet spot.  My headphones never "vanish." 

 

I'm even thinking about getting a rolling hard case that's large enough for the MG3, my laptop and DACmini CX (or maybe just an HM-801, expected to arrive Wednesday), LiPo batteries and charger, PLUS my SM45s - as my new travel rig!  (Just a thought, but it's not likely to happen.) 

 

 

OK, I got that off my chest, so I'll try to stay on-topic from now on - speaker amps for headphones!   When Jan's impedance match arrives, I could very well become smitten by the LCD-2 all over again.  biggrin.gif 

 

Mike

post #887 of 2933

Oh Brunk,  I can't solder worth a hoot!  redface.gif

 

I'm sure I could learn to solder, with the right gear, and with someone showing me what is certainly just a handful of do's and don'ts, but I'm a klutz with a soldering iron - especially embarrassing given that I hold an Amateur Extra Class (ham radio) license.  I feel like an impostor when I talk to some heavy-duty DIY hams that are out there.

 

I had never heard of the Lightspeed Attenuator.  That thing is seriously fascinating - light-modulated resistance - no way!  I remember reading somewhere that Jan Plummer doesn't recommend removing or replacing the MG3's volume pot.  He instead suggests that you run it all the way up, or just shy of all the way, when using an external attenuator.  Is that what you plan to do?

 

I love your plan to go "transportable" with it.  Batteries for everything!  That seems to be my motto. tongue_smile.gif

 

So do let us know when/where that thread is when you document your project!  

 

Mike

 

Brunk's awesome idea... (Click to show)

 

Quote:
Originally Posted by brunk View Post

Hey Zilch, check out what I'll be building hopefully next weekend. Ever heard of the Lightspeed Attenuator? It's a Stereophile Class "B" component. Anyways, there's a recently released DIY version from Tortuga Audio, called the LDR3X. It's still on it's promo sale. You can currently do 1in/1out RCA or XLR with matching slave board. It even comes with a remote, and next to no soldering needed! Total cost for the board, chassis, jacks, wall wart etc. came out to $250 shipped. Incredible. In the future, Tortuga Audio will also be releasing add-on cards for additional I/O, rotary encoders, and discrete buttons if you desire.

 

Anyways, the reason i bring it to your attention is that what would be a good battery solution that is small as possible. It can accept either 5VDC (trigger-out disabled)or 12VDC. I suppose going with 5VDC (regulated) would be more practical. The black steel case I bought for it has dimensions of 7"(178mm) L x 5"(127mm) W x 2"(51mm) H. The LDR3X has dimensions o2.5 inches wide by 4.7 inches long, so it will be a pretty tight fit. I just think it would be awesome if i could have this transportable since it's so small. I'll start a thread on it once i get the parts in the DIY section.

 

 

 

 

You enjoy a challenge right? tongue.gif

 

 

 

post #888 of 2933
Quote:
Originally Posted by zilch0md View Post

Hey Stew,

 

With all our talk of music and speakers, we're derailing this thread, but anyone who has an MG3 should really go get themselves some efficient monitors for near-field listening - in addition to using the MG3 with headphones, of course!   Gary has a pair of Jan Plummer's Diamond speakers for use at his PC, which is essentially what I'm doing with the laptop in the dining room (my audio workbench), but my "real" PC is in a spare-bedroom-turned-into-my-office, upstairs, where a sound card and self-powered el-cheapo speakers are all that's happening.

 

I just finished reading Kent Johnson's review of the Sjofn Hifi "The Clue" loudspeakers, in Positive Feedback #53.  Wow.  I'm impressed by his being so impressed!  

 

They're about the same size as my Def Tech SM45s, but in another league, for sure, not just going by the $1500/pair price tag, but by what he says about them.  The review is a fun read for anyone interested in such things (here at Head-Fi).  I was about to quote some highlights, but I'll restrain myself.  (Wrong venue.)

 

I have to ask Stew, and I realize it will be kind of an apples and oranges question (difficult to compare), but which do you enjoy more on the MG3, the Paradox or The Clue?  redface.gif

 

I have some trepidation about receiving the impedance match (some time next week, maybe?), because I'm so very enchanted by my current near-field setup (MG3 > SM45) that I fear both the impedance match and my (formerly) beloved LCD-2 will end up on a shelf somewhere gathering dust.  This is sacrilege for a Head-Fi thread, I know, but guys, having the stage out in front of you instead of on both sides of your head and in between your ears, is simply wonderful with the MG3.  

 

Coincidentally, both the Kent Johnson review of Stew's "The Clue" speakers and Chris Martens' (TAS) review of the Def Tech SM45s, write of how their respective speakers-under-review can "vanish" when you're head is in the sweet spot.  My headphones never "vanish." 

 

I'm even thinking about getting a rolling hard case that's large enough for the MG3, my laptop and DACmini CX (or maybe just an HM-801, expected to arrive Wednesday), LiPo batteries and charger, PLUS my SM45s - as my new travel rig!  (Just a thought, but it's not likely to happen.) 

 

 

OK, I got that off my chest, so I'll try to stay on-topic from now on - speaker amps for headphones!   When Jan's impedance match arrives, I could very well become smitten by the LCD-2 all over again.  biggrin.gif 

 

Mike

Just to respond to your post, and then back to the thread topic:

 

First off, the speakers are $1000, available directly from Sjofn in USA. They are designed to go right up against the wall, but sound best with some rather affordable and nice looking sound panels behind them. Placement makes them ideal in a living room situation such as ours.

 

Funny you should ask about the Paradox vs The Clue, because I just got done listening to my hi fi. It's no contest, the Clues and my hi fi rig sounds best. They replace of pair of the legendary LS3/5A speakers I was using on and off for many years; those are now up for sale. Those require a more dedicated space than I can presently give them.  The Clue speakers pretty much disappear (as did the LS3/5As). The Audeze LCD2s I auditioned are closer to what I am getting with my hi fi, tonally and with voices and instruments having a 'real' quality to them. But I would still say the Clue wins out in that comparison as well. If I lived in a home that was not an open floor plan and could easily listen to my hi fi without impacting my wife, the hi fi with speakers would be my first choice. But the reason I have gotten somewhat taken with these better headphones and trying to get the most out of headphone listening is because of our present living situation. And just to say, even though the Clue speakers have a great low end, I also use a small REL subwoofer, turned down quite low......of course that adds a dimension that no headphone can match. Even without the sub though, my speaker set up bests the headphone experience.

post #889 of 2933
Quote:
Originally Posted by khaine1711 View Post

The Tortuga is quite overpriced imo, so are most other commercial LDR stuffs.

 

If you're going with DIY, 2 pairs of matched LDRs cost 35 bucks - the rest of the component is cheap. Especially when you want battery instead of a toroidal transformer. 

 

Why do you need one anyway - replacing the pot of the Crack? I see no power amp in your profile blink.gif

I'm not too sure about being overpriced because it has a micro-processor that stores all the calibration data between the LDRs for perfect channel balance and smooth attenuation. LDRs are highly non-linear, so there's no way you're getting optimal results by just using a standard pot to control them. Not to mention the addition of slave cards for XLR and additional I/O in the future. I'll be using a $6 wall wart to power the LEDs tongue.gif Let's not forget the remote control that is included too, bringing more value.

 

I'm building one because I do want to bypass the pot in the Crack, and see how it fares against the preamp inside my integrated. If all goes well, I may let my Yammy go in favor of a traditional power amp.


Edited by brunk - 8/31/13 at 8:52am
post #890 of 2933

Hey Michael,

 

I love the way your commentary is so dense with information - you get right to the point, not pedantic, like me. biggrin.gif

 

 

potterma's first impressions of the MG3 (Click to show)

 

Quote:
Originally Posted by potterma View Post

So.......... I received my Millenia MG3 amp from Jan today.

 

First thing I did was hook up my vintage Yamaha HP-1 headphones... Initial impression with female vocals (SHEL) VERY positive.  The HP-1 in stock form tend to be dark, or at least lean toward the dark side (Luke...  Oh, never mind).  These are my go-to headphone despite the fact that they are not the BEST headphone I own.  The HiFiMan HE-6 hold that honor.  

 

I listened to a couple of tracks and found myself continually dialing down the volume.  Too loud!  Turn it down!  So, what does it sound like against a couple of other amps on the shelf?

I went about the task of measuring and setting a set SPL level between the Millenia and an old-school Parasound HCA-1000A amplifier (John Curl design, you know!).

Pink noise has been my go-to for setting SPL level between amps, headphones, and such... Right off I discovered a dramatic difference in the perceived "loudness" with identical SPL levels between the MG3 and the Parasound (C weighted).  If I set the Parasound output to a decent listening level, swap to the MG3 and set identical SPL, the same track is much too loud!  Repeat, repeat repeat... yeah, same result....

 

OK, time to break out the Scientist in me.  Launch REW (RoomEquilizer) and take some measurements.  Sure enough, no matter what I do to ensure the set up is as close to identical as possible between the Millenia and the Parasound, from 2 kHz and above the Millenia measures between 3 and >10 dB higher than the Parasound.

 

I think to myself, Self, maybe the problem is with them old Yammis!  Try those fancy HE-6's!  To my dismay, dern near same result.  Much enhanced 2k+ frequency range on the Millenia over the Parasound.  OK, maybe the Parasound is the problem!  Squelching the high frequencies!  Lets compare to the First Watt F1!  OK... Same problem.  Frequency response measurements of the Parasound HCA-1000A and the First Watt F1 with the HE-6's very nearly overlap (within experimental error).

 

Being bothered by the inequity of perceived loudness and SPL measurements, I investigated other noise forms.  Violet, blue, blah, blah, blah.... gray... there it is... Gray Noise.  If I set SPL equivalent between MG3 and other amps, PERCEIVED loudness is much closer to "the same"....   Boy is this an inexact science!  Gray noise seems to help, though.

 

Progress...

 

Need to go back and do some A/B listening with the Gray Noise technique.

 

Next, I went to some favorite test tracks that especially emphasize bass response: The Dead Weather: 60 Feet Tall and Hang You From The Heavens.  Holy CRAP!  What is that I hear!?!?!?  Bass clipping!?!?!?  Quick comparo to F1... Yup... F1 sounds like it should... Bass clipping in the MG3....  Need sleep and further investigation...

 

Back to SHEL, HP-1, MG3.... Heaven...  (SHEL is amazing, by the way, if you are not familiar with them).

 

Config notes:  Signal path is flac played via Foobar2k->Schiit Gungnir->MG3 on 24 VDC wall plug (no battery or capacitor bank operation yet, sorry)

or 

 flac played via Foobar2k->Schiit Gungnir-> First Watt B1 preamp -> Parasound HCA-1000A or First Watt F1.

SPL measurement duties: Radio Shack SPL meter.

Bass clipping observations through my resistor box driving HE-6's.  Bass clipping not observed with Yamaha HP-1's and resistor box.

 

I plan to run the HE-6's direct to the MG3 to see if the resistor box is forcing the drive level too high, causing the clipping behavior.

 

MG3 Hiss... Its there, but pretty minimal with both the HE-6 and HP-1's.  Apparent enough that the resistor box was definitely helpful.  It may be that tuning the resistor values will allow the elimination of hiss and not induce clipping.  Time and experimentation will tell.

 

Edit to add I've noticed clipping on The Dead Weather, 3 Birds with the MG3... Gotta look at the resistor box and see what I need to do to reduce the resistor divider.  Bass extension is not nearly as good on this track with the MG3 as it is with the B1/F1 combo... Expecting too much?  Gary set my expectations very high... I blame it on him!  (j/k Gary :) )

-michael

 

 

 

Regarding the bass clipping problem, here are some ideas that come to mind...  

 

Is there any way you can reduce the voltage of the input signal from your DAC?  (Or have you tried a different source - one that puts out something less than 2V rms ?)

 

Have you tried reducing the power supply voltage (12V instead of 24V, for example)?

 

Do you get bass clipping with 8-Ohm speakers?

 

For the record, I went to Spotify and listened to The Dead Weather's Hang You From The Heavens, and did not hear any bass clipping (2Vrms into MG3 > 8-Ohm speakers), but the compression Spotify uses could be taking out the lowest bass content, so you might want to take that with a grain of salt.

I have to say, it seems you not only have a lot of nice gear, but you also seem to know what your're doing - and then some!  L3000.gif

 

Mike

post #891 of 2933
Quote:
Originally Posted by zilch0md View Post

Oh Brunk,  I can't solder worth a hoot!  redface.gif

 

I'm sure I could learn to solder, with the right gear, and with someone showing me what is certainly just a handful of do's and don'ts, but I'm a klutz with a soldering iron - especially embarrassing given that I hold an Amateur Extra Class (ham radio) license.  I feel like an impostor when I talk to some heavy-duty DIY hams that are out there.

 

I had never heard of the Lightspeed Attenuator.  That thing is seriously fascinating - light-modulated resistance - no way!  I remember reading somewhere that Jan Plummer doesn't recommend removing or replacing the MG3's volume pot.  He instead suggests that you run it all the way up, or just shy of all the way, when using an external attenuator.  Is that what you plan to do?

 

I love your plan to go "transportable" with it.  Batteries for everything!  That seems to be my motto. tongue_smile.gif

 

So do let us know when/where that thread is when you document your project!  

 

Mike

 

Yeah it is very interesting isn't it. I'm planning on getting the Millenia and possibly selling my Yammy. I'm looking for a way to not only be "off-grid", but also smaller, more efficient, and frankly less complicated with all the gear i currently have without losing SQ. I'll definitely link my thread here when I have it up!

post #892 of 2933

Stew,

 

I'm just acknowledging your most recent post, here.  Thanks! 

 

On the subject of headphones, you had earlier asked how it is the LCD-2 can suppress some of the annoying treble artifact heard in some recordings - The LCD-2 has a "shelved" treble response.  It doesn't so much roll off in the treble region, as it simply steps down a couple of dB, starting at something like 10kHz (if I remember correctly).  Look for FR curves and you'll see what I mean.  

 

Some people feel the LCD-2 doesn't have enough sparkle. I like them just the way they are (with a neutral source and amp.)

 

Mike

post #893 of 2933
Quote:
Originally Posted by brunk View Post

I'm not too sure about being overpriced because it has a micro-processor that stores all the calibration data between the LDRs for perfect channel balance and smooth attenuation. LDRs are highly non-linear, so there's no way you're getting optimal results by just using a standard pot to control them. Not to mention the addition of slave cards for XLR and additional I/O in the future. I'll be using a $6 wall wart to power the LEDs tongue.gif Let's not forget the remote control that is included too, bringing more value.

 

I'm building one because I do want to bypass the pot in the Crack, and see how it fares against the preamp inside my integrated. If all goes well, I may let my Yammy go in favor of a traditional power amp.

You're slightly mistaken on how the LDR preamp works. If the pairs of LDRs aren't matched, no micro processor can "calibrate" them. They're similar to FETs, you can buy a bunch and sort them yourself - or buy a matched pairs. Nothing you can do about unmatched pair except buying a new pair =p.

 

The Tortuga is like every other LDR preamp out there, using 2 matched pair of LDRs. The only LDR pre that guarantee 4 matched LDR is one from Geogre himself (and at a heavy cost).

 

Due to the way LDR works, standard pot is fine. There's no difference for LDR between a 10 bucks pots and a RK50. You can even use button if you wanted tongue_smile.gif

 

 

Looking back it isn't THAT overpriced. But I'm the kind of cheapo that wants a functional LDR pre that cost 60 bucks mounted on a cardboard bigsmile_face.gif


Edited by khaine1711 - 8/31/13 at 9:30am
post #894 of 2933

Maybe we misunderstood each other. The matched pairs of LDRs were put through their entire usable attenuation and the data was logged for each one, then it's stored and used to control them in a precise manner. This is taken from the LDR3X manual to see the benefits. 

 

The set of 4 LDRs in each LDR3x are custom matched in a rigorous two step testing program. First, individual LDRs are tested to determine their individual current vs. resistance curve. This test data goes into a master LDR database. When each LDR3x board is built, the LDR database (typically with data from 100+ LDRs) is sorted to yield the 4 next most closely matched LDRs (8 in the case of a Master & Slave set of boards). 
 
After a board has been built using a matched set of 4 LDRs, the default software is loaded into the board’s microcontroller. Next, the board goes through an integrated attenuation test where the attenuation of the left and right channels are each measured and logged. The results of the integration test are then used to produce attenuation correction curves. These custom  correction curves are  then programmed into the final version of the software. 
 
The attenuation correction curves ensure precisely matched attenuation of both channels and is a unique feature of Tortuga Audio’s digitally controlled LDR product line. While we use automated data logging and proprietary computer programs to achieve the precision matching described above, the overall process remains fairly labor intensive. We continue to work on that in an effort to bring down costs.

 

The LDR3x emulates a 100k-125k ohm, 2 channel,  LPad voltage divider with an effective attenuation range of -60 to 0 dB in 70 steps as shown in the figure below. The first 55 steps are approximately 1 dB each. The remaining 15 steps cover the final 5 dB. This feature smoothes out the incremental volume increases as you approach max volume where even a 1 dB steps can result in very noticeable increases in sound pressure levels.
 
Lol I like to save money where possible too, but this was too good to pass up IMO.
 
Best,
Brunk
Quote:
Originally Posted by khaine1711 View Post

Warning: Spoiler! (Click to show)

 

You're slightly mistaken on how the LDR preamp works. If the pairs of LDRs aren't matched, no micro processor can "calibrate" them. They're similar to FETs, you can buy a bunch and sort them yourself - or buy a matched pairs. Nothing you can do about unmatched pair except buying a new pair =p.

 

The Tortuga is like every other LDR preamp out there, using 2 matched pair of LDRs. The only LDR pre that guarantee 4 matched LDR is one from Geogre himself (and at a heavy cost).

 

Due to the way LDR works, standard pot is fine. There's no difference for LDR between a 10 bucks pots and a RK50. You can even use button if you wanted tongue_smile.gif

 

 

Looking back it isn't THAT overpriced. But I'm the kind of cheapo that wants a functional LDR pre that cost 60 bucks mounted on a cardboard bigsmile_face.gif

 

 


Edited by brunk - 8/31/13 at 9:54am
post #895 of 2933
Quote:
Originally Posted by zilch0md View Post

Stew,

 

I'm just acknowledging your most recent post, here.  Thanks! 

 

On the subject of headphones, you had earlier asked how it is the LCD-2 can suppress some of the annoying treble artifact heard in some recordings - The LCD-2 has a "shelved" treble response.  It doesn't so much roll off in the treble region, as it simply steps down a couple of dB, starting at something like 10kHz (if I remember correctly).  Look for FR curves and you'll see what I mean.  

 

Some people feel the LCD-2 doesn't have enough sparkle. I like them just the way they are (with a neutral source and amp.)

 

Mike

I like them just the way the are too (sound wise). I am not big on 'treble sparkle' anyway. Whatever they are doing helps make listening to them more similar to listening to my speakers, because the speakers are not accentuating the treble region either (excess hash). And yet I don't  feel like I am missing anything music-wise with the Audeze. I guess I can just say their sound signature, etc., is to my liking, it's what I prefer. Being that the drivers are so close to the ears with headphones, for my tastes it helps to have the treble shelved down. 

post #896 of 2933
Quote:
Originally Posted by zilch0md View Post

Hey Michael,

 

I love the way your commentary is so dense with information - you get right to the point, not pedantic, like me. biggrin.gif

 

 

Regarding the bass clipping problem, here are some ideas that come to mind...  

 

Is there any way you can reduce the voltage of the input signal from your DAC?  (Or have you tried a different source - one that puts out something less than 2V rms ?)

 

Have you tried reducing the power supply voltage (12V instead of 24V, for example)?

 

Do you get bass clipping with 8-Ohm speakers?

 

For the record, I went to Spotify and listened to The Dead Weather's Hang You From The Heavens, and did not hear any bass clipping (2Vrms into MG3 > 8-Ohm speakers), but the compression Spotify uses could be taking out the lowest bass content, so you might want to take that with a grain of salt.

I have to say, it seems you not only have a lot of nice gear, but you also seem to know what your're doing - and then some!  L3000.gif

 

Mike

Mike... Thanks and thanks for the suggestions...  Haven't tried playing with input voltage yet, but that is on the schedule.  No 8 ohm speakers... Only speakers currently in the house are a set of ancient Bose AM-5's and a set of mini-Maggies, both 4 ohm.  

 

I took time this morning to look at the resistor box and threw the numbers into my headphone drive spreadsheet.  Even though the voltage divider is only a factor of 4 (about -12 dB, hiss is gone) its demanding too much current from the MG3, hence the clipping.  Box was configured for the HPA-1000A

Discovered I had an extra female inline 4 pin XLR on hand, so I made up a second pigtail to go directly to the speaker taps on the MG3.  Clipping is now gone with both the HP-1's and the HE-6's.... Phew!

 

Think I'm going to let the amp burn in a bit before doing too much more critical listening.  Maybe those highs will tone down and the bass will fill out.  We'll see.

 

- michael

post #897 of 2933
Quote:
Originally Posted by potterma View Post

Mike... Thanks and thanks for the suggestions...  Haven't tried playing with input voltage yet, but that is on the schedule.  No 8 ohm speakers... Only speakers currently in the house are a set of ancient Bose AM-5's and a set of mini-Maggies, both 4 ohm.  

 

I took time this morning to look at the resistor box and threw the numbers into my headphone drive spreadsheet.  Even though the voltage divider is only a factor of 4 (about -12 dB, hiss is gone) its demanding too much current from the MG3, hence the clipping.  Box was configured for the HPA-1000A

Discovered I had an extra female inline 4 pin XLR on hand, so I made up a second pigtail to go directly to the speaker taps on the MG3.  Clipping is now gone with both the HP-1's and the HE-6's.... Phew!

 

Think I'm going to let the amp burn in a bit before doing too much more critical listening.  Maybe those highs will tone down and the bass will fill out.  We'll see.

 

- michael

This is what I was wanting to hear (no resistor box) about the HE-6 and hopefully the HD-800. I'm still waiting for word on the HD-800/MG3 before I hop off the fence. popcorn.gif

post #898 of 2933

Michael (Potterma):

 

Just to be clear, you actually like the Millenia with your Yamahas and your resistor box, right?  So I'm not totally out of line with my appreciation of the TBI amp? redface.gif

 

I'm not the technical expert that most of the folks around here are, but as others have started to point out, and you have started to figure out, you appear to have a mismatch in components on both sides of the MG3 when using the Gungnir and your resistor box with the HE-6s.  I went to a meet today with the MIllenia and hooked it up to a source that was outputting too much voltage, and the MG3 hated it.  Bass got all boomy and mid-range got loud and distorted.  Hooked up a lower voltage input and ahhhh, back to normal.  The clue to me was your comment about the "too loud" volume, which probably indicates too much voltage going in, which the amp clearly is not designed to handle.  Have you tried pushing lower voltage to the Millenia yet?

 

On the output side of the Millenia, Jan has been very clear that the resistor box has to be tailored to the headphones used... so if your resistor box was set up for a higher impedance headphone or one that was much more efficient than the HE-6s (and that would be everything except the AKG-1000s, right?), you are obviously getting too much power attenuation.  I have never heard clipping with the LCD-3s.  I also have never had the amp above ~11 o'clock on the dial, and I'm normally using it at ~9 o'clock.  Where is the volume control set for normal listening with your resistor box using the HE-6s? 

 

It is entirely possible that you are going to have to have separate resistor boxes for each of your cans if you want to use them with the Millenia.  That's what you get for choosing cans with such different specs tongue.gif.  Or if there is no appreciable hiss using the HE-6s straight out of the amp, you can do that. 

 

In the end, it could be that you and your HE-6s are a candidate for an Odyssey amp... No resistor box needed (no hiss), probably doesn't care about input voltage, and at 110 wpc (and I'm guessing a very conservative 110 wpc) into 8 ohms, there isn't much chance of the HE-6s clipping the amp before your head explodes.

post #899 of 2933

Taking this from the TBI MG3 page: "The gold plated inputs of the MILLENIA amplifier can handle input source voltages from less than .1V to 4 volts"

 

 I don't "think" it would be a voltage issue, but rather a gain and possibly output impedance issue with the source. Reading further, it appears the MG3 has a rather high input impedance of 75k ohms which is good. The only three possibilities that would leave why it "hated" the hotter source is because A: It was over 4v. B: The source's output impedance is too high (600ohm+) or C: There's simply too much gain from the source's OP-amps and MG3.

 

What was the source in question?

 

EDIT: Looking at the Gungnir, the highest voltage it has is 4v from the balanced, and 2v from the RCA. It also has a nice low impedance of 75 ohms. This would leave me to believe its a gain issue.

Quote:
Originally Posted by Gary in MD View Post

Michael (Potterma):

 

Just to be clear, you actually like the Millenia with your Yamahas and your resistor box, right?  So I'm not totally out of line with my appreciation of the TBI amp? redface.gif

 

I'm not the technical expert that most of the folks around here are, but as others have started to point out, and you have started to figure out, you appear to have a mismatch in components on both sides of the MG3 when using the Gungnir and your resistor box with the HE-6s.  I went to a meet today with the MIllenia and hooked it up to a source that was outputting too much voltage, and the MG3 hated it.  Bass got all boomy and mid-range got loud and distorted.  Hooked up a lower voltage input and ahhhh, back to normal.  The clue to me was your comment about the "too loud" volume, which probably indicates too much voltage going in, which the amp clearly is not designed to handle.  Have you tried pushing lower voltage to the Millenia yet?

Warning: Spoiler! (Click to show)

 

 

On the output side of the Millenia, Jan has been very clear that the resistor box has to be tailored to the headphones used... so if your resistor box was set up for a higher impedance headphone or one that was much more efficient than the HE-6s (and that would be everything except the AKG-1000s, right?), you are obviously getting too much power attenuation.  I have never heard clipping with the LCD-3s.  I also have never had the amp above ~11 o'clock on the dial, and I'm normally using it at ~9 o'clock.  Where is the volume control set for normal listening with your resistor box using the HE-6s? 

 

It is entirely possible that you are going to have to have separate resistor boxes for each of your cans if you want to use them with the Millenia.  That's what you get for choosing cans with such different specs tongue.gif.  Or if there is no appreciable hiss using the HE-6s straight out of the amp, you can do that. 

 

In the end, it could be that you and your HE-6s are a candidate for an Odyssey amp... No resistor box needed (no hiss), probably doesn't care about input voltage, and at 110 wpc (and I'm guessing a very conservative 110 wpc) into 8 ohms, there isn't much chance of the HE-6s clipping the amp before your head explodes.

 

 


Edited by brunk - 8/31/13 at 5:37pm
post #900 of 2933

Brunk:

 

It was a custom tube set-up.  He had 2 outputs and let me use one, since I hadn't brought a source.  It was about 10 feet away and he just brought the RCAs over and we hooked them up.  I just wasn't paying  that much attention (yeah, I know, I should have been).  We turned it on, tried it for a couple of minutes (not even one song), it was bad and I asked how many volts the amp was seeing, he said something like "oh, yeah, use this other one instead."  Voila, back to good sound.  Now that I think about it, I'm not sure I ever really heard him say anything about what the actual voltage was, I just assumed it was high.  In any case, I guess the lesson with the Millenia is that it is pretty sensitive to what you feed it.

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