[wushuliu]

Nice, I love those RCA's.

Your amp probably sounds better than mine now.

After these mods...oh man.

[wushuliu]

I told my wive that it was also an ash box, so when she cremates me, she can take the batteries out and put my ashes in it. But she came back with, "I will just leave the batteries in it and when I think you need a charge, I will just plug it into the wall and turn it on."

 

[DaveC113]

After these mods...oh man.

Did you do the binding posts and RCA jacks at the same time? I am looking at copper RCA jacks and they are pricey! Those DH labs jacks look like a decent value, just wondering how much of a difference you think they make?

[wushuliu]

Ok, post mod update:

                                                               



oh and treble thingy? gone.

thanks to OzarkTom for bringing this amp to light.

[wushuliu]

Did you do the binding posts and RCA jacks at the same time? I am looking at copper RCA jacks and they are pricey! Those DH labs jacks look like a decent value, just wondering how much of a difference you think they make?

Yes all were done at the same time. I have used the jacks on and off for several years with months in between as I jump from project to project. They always improve performance. Always. I have tried to be skeptical cause I have a lot of shiny cheap ones from HK that I use too but I hear the difference every time. So I gave in and now use wherever possible.

[DaveC113]

Yes all were done at the same time. I have used the jacks on and off for several years with months in between as I jump from project to project. They always improve performance. Always. I have tried to be skeptical cause I have a lot of shiny cheap ones from HK that I use too but I hear the difference every time. So I gave in and now use wherever possible.

Thanks. For $30/pair they seem like a great value, and partsconnexion is having a 20% off sale right now, so $24/pair... I may cave in and buy 3 pair for my DAC and preamp. I have the Vampire copper jacks in my amp but never compared them to brass RCAs...

[JLM]

Could we separate the mods/battery discussion from the tour related posts before this thread gets really long?  (I give up on long threads and this is approaching my limit.)

thank you

[wushuliu]

Could we separate the mods/battery discussion from the tour related posts before this thread gets really long?  (I give up on long threads and this is approaching my limit.)

thank you

That's why I said I would stop discussing it.

In other news, I guess I can claim fanboy status: I emailed the reviewer at TNTAudio who did the 3 amp mini comparison last year between the TBI, Ampino, and Trends. Basically asking why no effort was made to actually *review* the Ampino and TBI (there was a previous review for the Trends). The Ampino is award-winning and has gotten accolades. It was also the first 'review' of the TBI. All he does is compare a few tracks and says 'this one has better bass', 'this one has better highs', then a small paragraph where says the TBI sounded best and that's it. So you have an amp that you know is better than one of the current lauded budget audiophile amps which you don't even bother to discuss in any detail, and all you can do is a little 'good on you buddy' and call it a day?

His reply to my email (which was very polite) was as pithy as the 'review' itself - basically 'I said all that needed to be said'. Good thing Positive Feedback gave it a chance.

[OzarkTom]

In other news, I guess I can claim fanboy status: I emailed the reviewer at TNTAudio who did the 3 amp mini comparison last year between the TBI, Ampino, and Trends. Basically asking why no effort was made to actually *review* the Ampino and TBI (there was a previous review for the Trends). The Ampino is award-winning and has gotten accolades. It was also the first 'review' of the TBI. All he does is compare a few tracks and says 'this one has better bass', 'this one has better highs', then a small paragraph where says the TBI sounded best and that's it. So you have an amp that you know is better than one of the current lauded budget audiophile amps which you don't even bother to discuss in any detail, and all you can do is a little 'good on you buddy' and call it a day?

His reply to my email (which was very polite) was as pithy as the 'review' itself - basically 'I said all that needed to be said'. Good thing Positive Feedback gave it a chance.

I feel he was being fairly accurate on the review. He was only using a stock unit and it was edging out the Ampino on AC power. It was because of his review, I had to try the TBI. I had an Ampino in my system when I read it, and was impressed with the Ampino at the time.

And I am thankful for the Positive Feedback review, since it delved deeper into the design and sound quality than the TNT review.

[Freo-1]

Well, it’s time to write up a more detailed review of the TBI Millenia MG3 amplifier.  The take away is that this is truly one impressive sounding device, and a remarkable achievement of engineering at its price point.  One could spend FAR more cash and not achieve anywhere near the same level of quality sound.
 
First off, let me state this amp is not for everyone.  It has limitations one needs to be aware of:
1) At a maximum of 32 WPC into an 8 ohm load, the amp is suited primarily to systems configured to get the most out of a low wattage amp.  This amp can and does play loud for 32 watts, and seems to have a bit more gain than the standard 26 db or so. 
2) The speakers should be greater than 87db/w in order to get optimal performance.  The website for the amp also states that the speaker’s minimum impedance should not dip below 3 ohms.
3) The amp comes with an AC power supply that looks just like a laptop power supply.  The sound from that power supply is rather pedestrian at best.  In order to get the amp to perform to its potential, need to employ an external battery power supply.  I would recommend a 24 set up that are at least 7.5 or 10 amp hours.
 
The equipment used for review was as follows:
1) Modwright Oppo BDP-95 (Tube), with NOS Sylvania Mil-Spec 6SN7 and 5AR4
2) Pass Labs X.2.5 Preamp
3) Cary Silver Oak Model One Speakers (88db/w at 6 ohms) (SEAS Excel Drivers)
4) Genesis G 928 Subwoofer
5) Ran the amp as a power amp, with the TBI volume control all the way up

Now, onto the review:
After replacing my restored Threshold SA/3 with the TBI, I settled in for some listening.  First, I listened to the amp with the supplied AC power source.  The sound was clean, but un-remarkable.  The music sounded 2D, a bit flat and etched, with a treble that very much reminded me of my past Class D amps I’ve owned in the past.  After about an hour, switched the AC power source out, and did not go back to it.
 
Next, I connected the SLA battery to the TBI.  Honestly, I thought the amp might sound a little better, but was not expecting anything dramatic.  I was wrong.  From the fist note I heard after with the TBI, I heard a very pleasant and engaging performance.  Whoa!  I was not expecting this.  The SLA power supply transformed the amp from middle of the road to a high end source in a significant fashion.  OK, time to pay attention and try to capture what is going on here:
1) First up was an imported CD of Jethro Tull This Was.  I’m very familiar with this recording, so I thought this would be a good start.  Listening to the CD on the TBI was like finding a first generation master tape of the performance.  The clarity and detail was truly remarkable, low level detail was among the best I’ve ever heard from any system.  No doubt the TBI is a great match for the Cary speakers, as the Cary’s were designed to work with low powered SET tube amps.  Still, I was taken aback by the sound, and had to wonder on more than one occasion: “This is Class D?”.
2) The next CD was a import Keely Smith from here Capitol years.  My, this was a treat!  Keely sounded like I could reach out and touch her.  One felt like you were in the studio.  Horns and strings (two of the hardest instruments to reproduce accurately) sounded like horns and strings.  Very impressive.
3) Next was onto classical.  Several items from Rachmaninoff were played (Symphony #2, Piano Sonata #2 and #3).  The symphony sounded outstanding.  The loud passages were reproduced with excellent clarity.  It was not quite as concussive as playback via the SA/3, but that is somewhat to be expected given the wattage/headroom deltas.  None the less, it was very clean, with no signs of congestion.  The piano sonatas were reproduced with a sense of realism that I was again surprised to hear.  A Debussy SACD recording of La Mer was a joy to listen to with this setup.
4) Tried some Count Basie next, and the old recordings came to life.  Miles Davis was up next (So What on DVD), along with Miles Ahead and Round About Midnight.  All sounded great, with accuracy and clarity that I have not experienced before. 
 
After listening critically to the above, I concluded that this amp with the Cary’s and Genesis Sub was a standout combination.  I went and pulled out old recordings that I have not listened to in years (Beatles Let It Be, The Smithereens, Hot Tuna, Jefferson Airplane, Johnny Hartman, Oscar Lopez, etc.).  When a new piece of gear motivates one to get out old recordings and listen to them again, you know you have something.
 
I am very impressed with amp on the SLA battery power supply.  It has a lot of strengths, and just a few limitations (mostly associated with its lower power out).  I would highly recommend anyone who has a low wattage system to audition this amp to see how it integrates into your given system. 
 
Compared to the SA/3, (a 50 WPC Class A Bipolar design) it’s difficult to summarize, but will try:
1) The TBI provided a bit more detail and clarity with the SLA connected to the Cary speakers. The sound from the SA/3 was a bit more rounded, where the TBI seemed a bit sharper.
2) The SA/3 is more concussive, but use of the Genesis G 928 subwoofer almost rendered this a moot point
3) Both amps provided excellent 3D rendering.  The TBI might be seen as sitting a few rows closer in the hall, whereas the SA/3 seems to present the performance towards the rear third of the hall.
 
So, while I’m not about to sell my SA/3, I will be getting a TBI to provide a different perspective when the mood strikes.  Also, will be getting a pair of tube 1625 mono blocks in the house for when the tube amp bug strikes.  Since all audio gear deviates from live, it’s nice to have different flavors available.
 
The TBI provides a very satisfying musical performance its owners will go to again and again with pleasure.  Highly recommended. 
 
 

[OzarkTom]

That was a great review.

Freo-1, PM me for the special for AC members on the modified TBI Miillenia amp.

[kbuzz3]

not to hijack but has anyone heard the new tbi subwoofer amp -xover?  Im thinking about upgrading from the basic tbi box amp

[Freo-1]

Some last minute impressions before the amp is forwarded to the next person in the tour:
 
It was suggested to listen to the amp directly from the digital source, bypassing the preamp altogether.  So, connected the output of the Modwright Oppo BDP 95 directly to the TBI, and settled in for some listening.
 
Overall, (in this system), the presentation improved, with low level detail and soundstage more precise sounding.  There was a perceived 1 db or drop in the bass registers, which comes across as slightly less concussive.  The Modwright Oppo has a sufficient voltage/current output to drive the TBI quite nicely.  The 6SN7 output connected to the TBI is a excellent sounding combination.
 
The downside to this setup is only one source is available and no remote control of source or volume is available.  The Modwright Oppo does have a digital volume control, but generally should be set to max out to minimize sound degradation. 
I would encourage trying the TBI with and without the preamp to see what works best in your system.  I was mildly surprised that direct connection from the Oppo to TBI provided an improvement in overall presentation with this system. 
 
For vinyl lovers, or those with a solid state digital playback setup and a tubed preamp, using the TBI as a power amp may very well be a better option.

[wushuliu]

Some last minute impressions before the amp is forwarded to the next person in the tour:
 
It was suggested to listen to the amp directly from the digital source, bypassing the preamp altogether.  So, connected the output of the Modwright Oppo BDP 95 directly to the TBI, and settled in for some listening.
 
Overall, (in this system), the presentation improved, with low level detail and soundstage more precise sounding.  There was a perceived 1 db or drop in the bass registers, which comes across as slightly less concussive.  The Modwright Oppo has a sufficient voltage/current output to drive the TBI quite nicely.  The 6SN7 output connected to the TBI is a excellent sounding combination.
 
The downside to this setup is only one source is available and no remote control of source or volume is available.  The Modwright Oppo does have a digital volume control, but generally should be set to max out to minimize sound degradation. 
I would encourage trying the TBI with and without the preamp to see what works best in your system.  I was mildly surprised that direct connection from the Oppo to TBI provided an improvement in overall presentation with this system. 
 
For vinyl lovers, or those with a solid state digital playback setup and a tubed preamp, using the TBI as a power amp may very well be a better option.

Great review. I will add that the binding posts, wire and rca mods are of great benefit to this amp - essential really. It's also impressive how much you get out of the 32 watts.

[Mister Pig]

It was pretty interesting to come across this thread, and to see how far you guys have taken this neat amplifier.

I wrote the PFO review for the TBI amplifier. I have been a member of AA, AC, AK, and a couple of other groups for a long time, but these days I spend most of my time just browsing the boards. I will say that the Millenia is a great product, and a piece that can bring high quality music back to a sane price point.

There were some last minute technical changes to that piece that created some issues in the body of the writing. If you look close enough, the fractures in the article can be found. Sorry about that, but time constraints would not allow for a complete rewrite. It ended up being what it was.

Couple of things though. Jan does say that the stock power supply is a linear one, not a switching unit. But with a total selling price of $500, its going to be a basic power supply no matter how you look at it. One thing I did discover is that the linear power supply benefited greatly from being run through my Mini Reference power conditioner. Doing this closed the gap considerably between the PS and the battery modes.

Now as far as not running it in 24 volt mode. Well, if I was sent a 24V battery power supply, I certainly would have done so. But I wasn't going to run out and build one just for the review, as I would have no use for it afterwards. This is just one of the constraints of having to do a piece this way. Besides, it gives potential owners an understanding of what the unit will do in stock form.

The mods you guys have given it are really cool. I wouldn't mind hearing this one with the upgraded jacks! I know of a couple of other owners who have used upgraded internal fuses in theirs, including the liquid Audio Magic ones. I also have heard of one owner filling the battery cavity with ESR paper, and reports positive results. I certainly would love to hear one tricked out, and be able to have a stock unit on hand to make a comparison with.

I hope your guys tour of this amp works out. For $500 its a budget buster that allows a person to allocate funds into different parts of a system, and therefore gets serious value for the money they have to spend. In my minds eye, I could see the Millenia driving a pair of Danny Ritchie's Neo 2X, and being fed by a computer system with the Musical Fidelity VDAC II. Quite a lot of sound available there for some short green.

EDIT: What I would really like to hear is two or three of the Millenia used in an actively amplified speaker system. Place a Marchand electronic crossover in front, or even a DSP/Crossover processor, and see what comes about. It could be crazy good.

Regards
Mister Pig

[OzarkTom]

Mister Pig, your PFO review was great and right on the money. What is so amazing about this $500 amp is that any little improvement tweak that you make in your system and this amp will immediately tell you.

One of the last reviewers on the tour owns Danny Ritchie's Super V's, so that will be a very interesting review.

[Mister Pig]

As an update, the power supply is a switching unit, not a linear one. Actually as far as a switching unit goes, it looks to be far more substantial than the ones that often comes at this price point. However, if past experience is any indicator, it is not going to equal a good linear power supply.

Perhaps some day in the future a modified Millenia article could be in the works. I would certainly be interested in hearing what a hot-rodded version would be capable of. If it could be the equal or even better than my SET that would be interesting indeed.

A short word about the Electra Print amplifier I use. This is not a typical SET amplifier. Jack Elliano designed this one as a trial bed for using op-amps as a pre driver stage for his A2 circuit. The op-amp is an excellent pre driver stage, and sidesteps many of the issues with traditional signal tube circuits. Noise floor and distortion levels are quite low, which is unusual for a SET. In certain aspects it shares a certain sound quality with the Millenia.

As an example, this amp is dead quiet, with a very low noise floor. Took it over to a friends house once who has custom built Altec 604 speakers. Hooked the amp. up, and flipped the switch on. There is no power indicator light. He is standing next to the speaker, and asks "Is it on?" I say yes, and he says I cannot hear the amplifier at all, its perfectly quiet. This SET is a pretty decent one capable of wide bandwidth and low noise floor.

One more point to discuss. Has anyone with high efficiency speakers made a comparison of 12 versus 24 volt battery configuration. I know of one person who claims to prefer the 12 volt arrangement in his system. He doesn't need the full 32 watts of power in his application. Running it in both modes, he claims the 12 volt arrangement is a tad sweeter. Just thought I would throw that out there as another avenue of exploration.

Regards
Mister Pig

[Freo-1]

It was pretty interesting to come across this thread, and to see how far you guys have taken this neat amplifier.

I wrote the PFO review for the TBI amplifier. I have been a member of AA, AC, AK, and a couple of other groups for a long time, but these days I spend most of my time just browsing the boards. I will say that the Millenia is a great product, and a piece that can bring high quality music back to a sane price point.

There were some last minute technical changes to that piece that created some issues in the body of the writing. If you look close enough, the fractures in the article can be found. Sorry about that, but time constraints would not allow for a complete rewrite. It ended up being what it was.

Couple of things though. Jan does say that the stock power supply is a linear one, not a switching unit. But with a total selling price of $500, its going to be a basic power supply no matter how you look at it. One thing I did discover is that the linear power supply benefited greatly from being run through my Mini Reference power conditioner. Doing this closed the gap considerably between the PS and the battery modes.

Now as far as not running it in 24 volt mode. Well, if I was sent a 24V battery power supply, I certainly would have done so. But I wasn't going to run out and build one just for the review, as I would have no use for it afterwards. This is just one of the constraints of having to do a piece this way. Besides, it gives potential owners an understanding of what the unit will do in stock form.

The mods you guys have given it are really cool. I wouldn't mind hearing this one with the upgraded jacks! I know of a couple of other owners who have used upgraded internal fuses in theirs, including the liquid Audio Magic ones. I also have heard of one owner filling the battery cavity with ESR paper, and reports positive results. I certainly would love to hear one tricked out, and be able to have a stock unit on hand to make a comparison with.

I hope your guys tour of this amp works out. For $500 its a budget buster that allows a person to allocate funds into different parts of a system, and therefore gets serious value for the money they have to spend. In my minds eye, I could see the Millenia driving a pair of Danny Ritchie's Neo 2X, and being fed by a computer system with the Musical Fidelity VDAC II. Quite a lot of sound available there for some short green.

EDIT: What I would really like to hear is two or three of the Millenia used in an actively amplified speaker system. Place a Marchand electronic crossover in front, or even a DSP/Crossover processor, and see what comes about. It could be crazy good.

Regards
Mister Pig

 
Thanks for sharing your insight.  I think one of the major reasons this amp sounds so good is what you penned as follows:
 
“Class D amplification holds a great deal of promise, for it has elegant solutions to many of the issues with traditional Class A/B amplifier topology. A conventional Class D circuit is designed to switch the output devices on and off to amplify each ½ of the signal waveform, however it is fundamentally different than a Class A/B amplifier that also switches its output devices. In a Class D circuit the bias point is non-existent, and there is a moment where both output chips are switched off. This leads to a switching distortion, that has to be dealt with in the circuit. The methods of how to eliminate the effects of this phenomenon are closely guarded trade secrets, and is one of the main reasons that Class D amplifiers sound different from each other. The Millenia amplifier uses an unusual output stage configuration that is essentially a Class BD arrangement, which is different than the more widely used Class D topology. The output of the amplifier is generated differentially between the + and – speaker terminals, and is capable of extremely fast response times. The Class BD circuit used by TBI has quicker transition times, and therefore has fewer switching errors to deal with.  Which means that only a minimal degree of filtration and correction needs to be applied to the output of the amplifier, and has negligible effects on sound quality.
The preamp stage of the Millenia amplifier is not a gain stage, for its primary purpose is to provide impedance matching with the source component. Impedance mismatches between amplifier input stages and source components is an area where sound quality can be severely compromised, and the solution implemented in the TBI is an effective means to solve this issue. A newly developed Burr Brown op is used in this circuit, and has a low current and high slew rate characteristic.
This allows for low distortion rates that are consistent at either high or low output levels. In essence, any non-linearities introduced by input signal swings are dealt with consistently at any volume level, which is the intended purpose of a pre-amp stage. The input voltage range of the amplifier is .1V to 4V, and can be driven by traditional audio components, or even portable music devices. Input impedance is 75K Ohms on both the RCA jacks and the 3.5mm input on the front panel. "
 
 
I think Mr. Plummer is a pretty smart designer, which means this amp holds its own compared to other amps out there.  When connected to a battery power supply, this amp really sings.  I hope you get a chance to listen to this amp with the battery power supply.  It’s much better on the battery.
 
Regarding the comment of 12 volt vs. 24 volt, the issue to me is the speakers.  Although this a bit of an oversimplification, the more sensitive/efficient a speaker is, the more difficult it is to get it to perform with a flat manner.  Personally, I found the Cary Silver Oaks at 88db/w with this amp (and a subwoofer) was both dynamic and linear.  The limitation is that a battery with 10 to 12 amp hour is needed with this setup.
 

[Mister Pig]

 
Thanks for sharing your insight.  I think one of the major reasons this amp sounds so good is what you penned as follows:
 
“Class D amplification holds a great deal of promise, for it has elegant solutions to many of the issues with traditional Class A/B amplifier topology. A conventional Class D circuit is designed to switch the output devices on and off to amplify each ½ of the signal waveform, however it is fundamentally different than a Class A/B amplifier that also switches its output devices. In a Class D circuit the bias point is non-existent, and there is a moment where both output chips are switched off. This leads to a switching distortion, that has to be dealt with in the circuit. The methods of how to eliminate the effects of this phenomenon are closely guarded trade secrets, and is one of the main reasons that Class D amplifiers sound different from each other. The Millenia amplifier uses an unusual output stage configuration that is essentially a Class BD arrangement, which is different than the more widely used Class D topology. The output of the amplifier is generated differentially between the + and – speaker terminals, and is capable of extremely fast response times. The Class BD circuit used by TBI has quicker transition times, and therefore has fewer switching errors to deal with.  Which means that only a minimal degree of filtration and correction needs to be applied to the output of the amplifier, and has negligible effects on sound quality.
The preamp stage of the Millenia amplifier is not a gain stage, for its primary purpose is to provide impedance matching with the source component. Impedance mismatches between amplifier input stages and source components is an area where sound quality can be severely compromised, and the solution implemented in the TBI is an effective means to solve this issue. A newly developed Burr Brown op is used in this circuit, and has a low current and high slew rate characteristic.
This allows for low distortion rates that are consistent at either high or low output levels. In essence, any non-linearities introduced by input signal swings are dealt with consistently at any volume level, which is the intended purpose of a pre-amp stage. The input voltage range of the amplifier is .1V to 4V, and can be driven by traditional audio components, or even portable music devices. Input impedance is 75K Ohms on both the RCA jacks and the 3.5mm input on the front panel. "
 
 
I think Mr. Plummer is a pretty smart designer, which means this amp holds its own compared to other amps out there.  When connected to a battery power supply, this amp really sings.  I hope you get a chance to listen to this amp with the battery power supply.  It’s much better on the battery.
 
Regarding the comment of 12 volt vs. 24 volt, the issue to me is the speakers.  Although this a bit of an oversimplification, the more sensitive/efficient a speaker is, the more difficult it is to get it to perform with a flat manner.  Personally, I found the Cary Silver Oaks at 88db/w with this amp (and a subwoofer) was both dynamic and linear.  The limitation is that a battery with 10 to 12 amp hour is needed with this setup.

A portion of the listening sessions of the  review was written with the power supply in place, the other sections were with the battery power supply being used. Another section was dedicated to using it in portable mode with lithium batteries and a portable music player as a source. Since the amp has this capability, it makes sense to give it a look see.

There is an incremental, yet noticeable shift in the character of the Millenia amplifier when it is used in battery mode. For this evaluation I used an automotive jump pack for its battery and recharging capabilities. A cable had to be fabricated to fit the power port of the jump pack, but that was an easy task to accomplish. When being fed 12-volt power, the Millenia amplifier has increased micro detail, lower noise floor, and improved spatial presentation. The tonal balance of the amplifier undergoes a subtle shift, moving from a slightly warm and full character to one that is delicate and lighter in tone. In many respects the Millenia amplifier in battery mode is closer in sonics to my Electra Print 300B SET amplifier than it is any conventional solid-state piece. When revisiting the Lucia Hwong piece I found that high frequency notes had a longer decay pattern and had a greater degree of shimmer. The distinctive tone of the wood flute in the opening passage had gained a higher degree of realism. The vocal passages moved farther back in the sound stage and now floated in a space above the instruments, expressing the surrealistic feel of this composition. These gains in musical reproduction move the Millenia amplifier closer to what the Electra Print amplifier achieves, which happens to be a $4000 amp and preamp package. While the Millenia does not have the harmonic density, or the complete transparency of the SET amplifier, it comes shockingly close. Which is quite an accomplishment for a $500 integrated amplifier.

The differences between linear and battery power supplies continued to be apparent with all types of music. Returning to "The Fiddling Ladies" I found that the 12-volt option increased transparency and low level detail, just as previously noted. The opening drum passage gained clarity, with each drum strike being easier to hear with the decay trailing off in a natural manner. The violins in this song are quicker and there is greater separation between each instrument. The overall sound when operated on battery power is transparent and lively, which is certainly different than the character of the Millenia when used with the linear power supply. On this song I can appreciate the differences in presentation of both power supplies, although my personal preference is for the battery option.

I used a 12 volt power supply that is basically an automotive jump pack. It powers the motor on my Serac turntable, and happens to be fitted with the same diameter plug for the Millenia. This happens to be a cost effective way to experiment with battery power, provided you can live with the lower power output. For it gives you battery, charger, and case for a moderate price. With 98db efficient speakers, the 10 wpc provided in 12 volt mode was more than enough power. Now a discussion about the linearity of high efficiency speakers or single drivers, there certainly are strengths and limitations to these speaker types. There are fans and detractors to all speaker designs, its a subject many get enthusiastically involved. now back to batteries, it may be that there are performance gains left on the table with the 12 volt arrangement, its an avenue I need to make time to explore in the future.

While it is difficult to isolate the reasons why the Millenia sounds as good as it does, I would suspect that the pre-amp stage plays a significant role. In previous experiences with pre-amps with impedance matching or buffering circuits, there has always been a high level of performance. The TBI amp also seems to move along this pathway. But, its something that I can isolate and verify, it is just a personal hunch.

I will be curious to see what the other members on the tour think of the amp.

Regards
Mister Pig

[Freo-1]

A portion of the listening sessions of the  review was written with the power supply in place, the other sections were with the battery power supply being used. Another section was dedicated to using it in portable mode with lithium batteries and a portable music player as a source. Since the amp has this capability, it makes sense to give it a look see.

There is an incremental, yet noticeable shift in the character of the Millenia amplifier when it is used in battery mode. For this evaluation I used an automotive jump pack for its battery and recharging capabilities. A cable had to be fabricated to fit the power port of the jump pack, but that was an easy task to accomplish. When being fed 12-volt power, the Millenia amplifier has increased micro detail, lower noise floor, and improved spatial presentation. The tonal balance of the amplifier undergoes a subtle shift, moving from a slightly warm and full character to one that is delicate and lighter in tone. In many respects the Millenia amplifier in battery mode is closer in sonics to my Electra Print 300B SET amplifier than it is any conventional solid-state piece. When revisiting the Lucia Hwong piece I found that high frequency notes had a longer decay pattern and had a greater degree of shimmer. The distinctive tone of the wood flute in the opening passage had gained a higher degree of realism. The vocal passages moved farther back in the sound stage and now floated in a space above the instruments, expressing the surrealistic feel of this composition. These gains in musical reproduction move the Millenia amplifier closer to what the Electra Print amplifier achieves, which happens to be a $4000 amp and preamp package. While the Millenia does not have the harmonic density, or the complete transparency of the SET amplifier, it comes shockingly close. Which is quite an accomplishment for a $500 integrated amplifier.

The differences between linear and battery power supplies continued to be apparent with all types of music. Returning to "The Fiddling Ladies" I found that the 12-volt option increased transparency and low level detail, just as previously noted. The opening drum passage gained clarity, with each drum strike being easier to hear with the decay trailing off in a natural manner. The violins in this song are quicker and there is greater separation between each instrument. The overall sound when operated on battery power is transparent and lively, which is certainly different than the character of the Millenia when used with the linear power supply. On this song I can appreciate the differences in presentation of both power supplies, although my personal preference is for the battery option.

I used a 12 volt power supply that is basically an automotive jump pack. It powers the motor on my Serac turntable, and happens to be fitted with the same diameter plug for the Millenia. This happens to be a cost effective way to experiment with battery power, provided you can live with the lower power output. For it gives you battery, charger, and case for a moderate price. With 98db efficient speakers, the 10 wpc provided in 12 volt mode was more than enough power. Now a discussion about the linearity of high efficiency speakers or single drivers, there certainly are strengths and limitations to these speaker types. There are fans and detractors to all speaker designs, its a subject many get enthusiastically involved. now back to batteries, it may be that there are performance gains left on the table with the 12 volt arrangement, its an avenue I need to make time to explore in the future.

While it is difficult to isolate the reasons why the Millenia sounds as good as it does, I would suspect that the pre-amp stage plays a significant role. In previous experiences with pre-amps with impedance matching or buffering circuits, there has always been a high level of performance. The TBI amp also seems to move along this pathway. But, its something that I can isolate and verify, it is just a personal hunch.

I will be curious to see what the other members on the tour think of the amp.

Regards
Mister Pig

 
Thanks again for the additional clarification.   
 
I needed a 24 volt battery source to get good sound.  Your observations about the preamp and the output stages are my hunch as to why this amp sounds so good, and exceeds  expectations.

I am also curious to get other's impressions.  I would encourage SET bottleheads to audition this.
 
Well stated about the speaker debate.  The fact that the amp worked very well with 88db/w speakers at 6 ohms nominal speaks well of the amp’s ability to reproduce a musically satisfying experience.