[OzarkTom]

I kept getting  don't put them on your Maggie's from Tom and I figured 35 watts wasn't going to be too exciting.

And I also said in an Email to you that the TBI should drive your Maggies as loud as the Virtue will, maybe you forgot?  If you never use your GR speakers and keep them in your closet, you must not think too highly of them as a monitor speaker. Any true monitor will beat the Maggies any day of the week.

And I said all along that the Ncores would win, especially with the type of music that you play. Any 200 watt amp would have won in your situation, it did not have to be Ncores.

As I said before, the reason I put the TBI amp in the low wattage section, it is a low wattage amp like SET amps are. For my use, I use a 12v battery when I use the battery side of it, that is only 15 wpc. The most power that I ever use is 1/2-1 watt out of my amp since I use 99db speakers. Any louder and I would be deaf.

While being in the Army 40 years ago, I learned on what loudness levels to play my system to keep from losing my hearing. I have carefully protected my hearing ever since, around my audio system and working every day with noisy machinery. Very few people, especially men, ever does that.

Maybe that is the reason that I am so keen on AC glare, I haven't lost any of my hearing. I complained about it 30 years ago, and on the Virtue threads 2-3 years ago. I guess rclark might have forgotten about that. I love my Virtue amp on battery, on AC it is definitely a no-go.

[cab]

Hearing loss is a natural part of aging and can happen regardless of how well you protect your ears from loud noise. You might want to have your hearing checked to confirm your claim that you have not lost any of your hearing.

[OzarkTom]

Hearing loss is a natural part of aging and can happen regardless of how well you protect your ears from loud noise. You might want to have your hearing checked to confirm your claim that you have not lost any of your hearing.

I had them checked last year, I check them every five years. My audio hobby is very important to me. . The Audioligist could not believe how good my hearing was at my age. If I had hearing loss, I would never complain about AC glare.

The main reason for hearing loss as you age is the noise pollution in the world. Protect your ears against that as you age and you will have none to very little loss.

The Army audiologist 40 years ago said that you will have temporary loss after just going to one live concert, that is the reason your ears ring. But if you go to a live concert every night for just one week, you will have a permanent hearing loss. There are no cures for permanent hearing loss if you are an audiophile.

[cab]

http://www.umm.edu/ency/article/001045.htm

Definition of Age-related hearing loss:

Age-related hearing loss, or presbycusis, is the slow loss of hearing that occurs as people get older.

Causes, incidence, and risk factors:

Tiny hairs inside your ear help you hear. They pick up sound waves and change them into the nerve signals that the brain interprets as sound. Hearing loss occurs when the tiny hairs inside the ear are damaged or die. The hair cells do not regrow, so most hearing loss is permanent.

There is no known single cause for age-related hearing loss. Most commonly, it is caused by changes in the inner ear that occur as you grow older. However, your genes and loud noises (such as from rock concerts or music headphones) may play a large role.

The following factors contribute to age-related hearing loss:

    * Family history (age-related hearing loss tends to run in families)
    * Repeated exposure to loud noises
    * Smoking (smokers are more likely to have such hearing loss than nonsmokers)

Certain medical conditions and medications also contribute to age-related hearing loss. About half of all people over age 75 have some amount of age-related hearing loss.

[rodge827]

Gents,

This is a thread about the TBI MG3 amplifier.
If you have any comments on your experience about the TBI please post them!
Postings about age related hearing loss are kinda informative, but don't belong here.
Start another thread on the subject and stop wasting space in this thread with these petty arguments...NOBODY CARES!

Tom is a decent guy who at his own expense and risk offered up his personal amp for this tour.
It would be nice to show him the respect he deserves, and stop all of this nonsensical bickering! 

Now back to the regular program....

[Mister Pig]

And I also said in an Email to you that the TBI should drive your Maggies as loud as the Virtue will, maybe you forgot?  If you never use your GR speakers and keep them in your closet, you must not think too highly of them as a monitor speaker. Any true monitor will beat the Maggies any day of the week.

And I said all along that the Ncores would win, especially with the type of music that you play. Any 200 watt amp would have won in your situation, it did not have to be Ncores.

As I said before, the reason I put the TBI amp in the low wattage section, it is a low wattage amp like SET amps are. For my use, I use a 12v battery when I use the battery side of it, that is only 15 wpc. The most power that I ever use is 1/2-1 watt out of my amp since I use 99db speakers. Any louder and I would be deaf.

While being in the Army 40 years ago, I learned on what loudness levels to play my system to keep from losing my hearing. I have carefully protected my hearing ever since, around my audio system and working every day with noisy machinery. Very few people, especially men, ever does that.

Maybe that is the reason that I am so keen on AC glare, I haven't lost any of my hearing. I complained about it 30 years ago, and on the Virtue threads 2-3 years ago. I guess rclark might have forgotten about that. I love my Virtue amp on battery, on AC it is definitely a no-go.

This is a good point in this post to expand upon. This is a low wattage forum, and its areas of interest are low wattage amps and associated speakers, namely fairly efficient ones. Now the TBI is more flexible in speaker selection than single digit power tube amps, but there must be some speakers it works well with, and some it does not. It also makes sense that more powerful amps have the possibility of doing bass and dynamics better than the TBI, ESPECIALLY if the speaker being used is marginal for use with lower powered tube amps. Monitors can be this way in regards to the bass department, it takes a lot of power to coax the maximum bass output from them.

I am going to say a couple of things that may or may not be taken well. I don't post on this site a lot, but do read it regularly, and have been a member for awhile. But no big loss if you don't like what I have to say.

These kind of threads are great for exposing people to new and unheard of gear, and that is a positive thing. But they also have the ability to turn into a love fest or group think kind of event. Where dissenting opinions or less than effusive praise is looking on as a thread crap, or some other socially unacceptable behaviour. Participants have to take care to make sure that rational and unbiased critical thinking and listening skills are employed, otherwise exaggerations and hyperbole creep in. That does the manufacturer or potential owners no good.

With that said, I want to say one more thing. I do believe that one member here was pretty biased against the TBI amp before any critical listening started. From what I see, there are outside factors besides sound quality that appears to affect his/her judgement of the product. Some people are just somewhat contrary, especially when a thread kind of goes into a love fest kind of path. Much of how he/she evaluated the TBI was improper in my opinion.....and it is just my opinion mind you. from what I saw, it looks like this member had their mind made up that it was going to be just OK before any listening really started.

But once again, I must reiterate that much of what is being discussed in this thread is about symbiotic matches between speakers and amplifier. System configurations have as much to do with how well this amp is liked, and what its strengths and limitations are. My point of it being somewhat less harmonically sense must be taken in context of my system. In my system I use a J-FET based phono stage, a multi bit solid state DAC, and passive pre-amp. My amp only has one pair of output tubes and op amps as the pre driver stage. So when I take the amp out there are no tubes in my system. Another member believes that a system needs at least one tube to have proper harmonic texture...ie tube magic, and that is done at the source level. Which means that system has some characteristics that address harmonic texture that mine does not. System synergy.

Regards
Mister Pig

None of my points are intended to demean anyone in this thread. I am just calling them like I see them.

[Quiet Earth]

Nice post Mr. Pig.

Three people have mentioned that this amp is a good value, but it ultimately didn't do it for them. They have been dismissed as people that didn't "get it". Instead, they should have been counted as people that saw a good value but chose something else. The giant killer thing made the thread devisive from the get go.

Not sure if anyone else caught this, but Rclark was driving the attenuator on the TBI with another passive  attenuator. Usually this is a bad idea. With the 1v nominal output of his CD player it is something that I would have avoided, although I don't know the nitty gritty on the optocoupler so maybe it didn't matter. I still value his review and count it as one of many. In other words, I can read what he did for myself and it is one of the experiences that will make the collective review.

Carry on men! 

[genjamon]

Good point, Quiet.  And as a result, I'm not sure if impedance matching might have been an issue with the lackluster bass performance Rclark was reporting (I think).  From what I recall, if output impedance or source isn't at least 10X lower than input impedance of amp, you can have bass roll-off.  And passive attenuators can have higher output impedances, meaning amp pairing often needs to employ fairly high input impedance amps.  With a passive attenuator on the TBI, the input impedance might not be that high...

[Rclark]

A) My cdp is 2volts nominal, 12 volts peak to peak, it has tons of drive. So that kinda shoots that down.

B) Tom, I have a lot of the same music you might have, just a lot of stuff you wouldn't as well. Last night I listened to Dire Straits. I don't listen to a "your kind of music" I listen to nearly everything.

C) And hearing loss? My usual listening levels are 70db tops, I've mentioned this several times since I've been hear. One of my favorite things about the ncore is full enchilada sound at low level.

D) Who's deaf? I have excellent hearing up to 18khz. You wish you had my ears 
   

Also, to your comment about power, and the Virtue. My virtue on linear supply here, and I don't have power conditioners, is damn near as good as battery.

[genjamon]

As far as I understand, the impedance matching issue is not a function of the amount of voltage output of your source.  I would be curious to know the output impedance of the cdp, the input and output impedances of the optocoupler, and the input impedance of the TBI.

[Rclark]

If it makes you happy, I'll find out that stuff later. Meanwhile, carry on to the next guy 

[genjamon]

It's only important if you want to understand whether equipment matching might have played a role in the performance in your system.

[srb]

If it makes you happy, I'll find out that stuff later. Meanwhile, carry on to the next guy

I don't think it's a matter of making genjamon "happy" but if someone is using a preamp or attenuator into the TBI rather than a directly connected source, it is obviously relevant and light-shedding information.  (Pardon the unintended pun that could relate to LDR attenuators.)
 
Steve

[DaveC113]

Good optocouplers usually have buffered outputs... it's probably not a passive device but may not have any gain.

[Rclark]

I have been told it's not passive, but provides no gain. I love the thing. I'm source, knob, amps.

[Mister Pig]

Good point, Quiet.  And as a result, I'm not sure if impedance matching might have been an issue with the lackluster bass performance Rclark was reporting (I think).  From what I recall, if output impedance or source isn't at least 10X lower than input impedance of amp, you can have bass roll-off.  And passive attenuators can have higher output impedances, meaning amp pairing often needs to employ fairly high input impedance amps.  With a passive attenuator on the TBI, the input impedance might not be that high...

Actually this is a point worth emphasising. One evening I did run the TBI in place of my power amp, and kept my transformer based Electra Print PVA pre-amp hooked up. The sound was not to my liking at all, very lacklustre. I ended up pulling the PVA out and hooking up source directly to the Millenia, and sound was significantly better. I understand another member has gotten excellent results with using a tube pre-amp in front of the Millenia, but my experience is that I achieved the best sound quality with source units going directly into the amp.

Regards
Mister Pig

[OzarkTom]

And another good reason to go direct, one less IC cable to take away from the sound.

[trackball02]

The amp has arrived safe and sound in Pasadena, CA and is settling in quite nicely. Charging the battery and running on AC right now. So far, a big thumbs up. I'm really liking it. Very remarkable for such a small light weight unit. More details later.

For those of you fellow ACers in the area, I'm thinking of having an open house this Saturday afternoon at my place if there is any interest. PM me for details.

[jtwrace]

I kept getting  don't put them on your Maggie's from Tom and I figured 35 watts wasn't going to be too exciting.

Why not see for yourself? 

Maybe you should try this: 
http://www.diyaudio.com/forums/multi-way/204857-test-how-much-voltage-power-do-your-speakers-need.html#post2869365

[abernardi]

So trackball2 and I got together today and put this amp through its paces.  He brought over the TBI and his similarly priced gainclone amp.  I had my Virtue Sensation 901 with the Dodd tube buffer standing by.  Now, as I've mentioned in many other posts, my system isn't completely dialed in, I still need to tamp down the room, its wood floors and big window make for a lot of strong reflections.  As a result the high end is a bit emphasized and can get a bit of glare.  Why is treating the room so much less sexy than buying the latest, greatest, thingamajig?     My speakers don't help.  As I've also mentioned, these are the best speakers I've been able to get into my system, but they have a Heil type AMT and they go way up there, so that doesn't help the room.

Currently we both are running tube amps in our systems and have become accustomed to that sound.  I am recently a proud owner of a Dodd battery tube amp and preamp.  We chose 3 songs, hires files from my mac mini server, and listened with the Dodd amps first, just to hear the system at its best. 

Next we put the gainclone in the system (first time I've heard one).  Trackball brought the gainclone because he thought that would be a good apples/apples comparison, solid state, similarly priced.  It was very, very good.  Smooth from top to bottom, very even, with a very forward soundstage, which encouraged foot tapping immediately.  The base was tight and full, the body had good weight.  If I could find anything to criticize it would be that it sounded a little dry. 

Then we tried the TBI. 

ACK!  Please standby, we're experiencing technical difficulties, the show you are watching will resume shortly... 

We started getting some hiccups, little dropouts, especially on attacks/quick transients.  Not to worry, it's not the amp.  I had another amp in my system that was doing the exact same thing and we just couldn't figure out why.  I'm starting another thread on that, maybe somebody has some ideas.  BTW, we decided to use the Dodd preamp to drive the TBI with the pot all the way open since we were driving the gainclone that way.  In hindsight I'm not sure that was the best idea because I now realize we never listened to the TBI without a preamp...  Anyway, we played some less demanding cuts and tried to not notice the dropouts.  What I heard immediately was more detail.  The low end sounded very similar.  But as we listened more, I began to notice that it had a lighter body.  I first noticed it on a piano solo and couldn't tell if it was a real piano or a sampled piano.  That wasn't good.  Then on female vocals I noticed a bit of harshness at certain frequencies, glare.  On male vocals it sounded better and quite engaging.  After a while I sensed that there seemed to be a little of the upper midrange missing, which I think gave it that light body.  Of course that benefited some parts as well, but overall, that would be my biggest complaint about this amp.  Otherwise it sounded very good, alive, exciting, pretty accurate and more detailed than the gainclone.

Then we put the Sensation into the loop and I was really surprised at how emphasized the high end was.  Now I know this amp well and love this amp.  But when I got these new speakers, I couldn't tame the high end.  It has always sounded great with my bookshelf speakers, but it doesn't seem to get along with the AMT's.  Synergy.  I need to do some more tube rolling to see if I can get it to play nice with these speakers.

We decided to focus on the gainclone vs. the TBI for the time being and swapped them out a few more times to comfirm what we were hearing.  I played a very revealing cut, a solo sax in a relatively small room.  The weight difference between the two amps was obvious.  The gainclone just sounded more real to my ears.

We then took the show over to trackball's house and put it into his system.  His system is completely different.  Centered around a good turntable with Zu full range speakers and subwoofer.  It took me a little while to adjust to the dramatic difference in character.  Here we were able to really listen critically to the TBI now that the dropouts were gone.  I brought my digital files with me, but we pretty quickly focused on records.  I noticed much the same things.  Specifically in an acoustic jazz selection with the gainclone the standup bass sounded natural.  With the TBI it sounded like it was made out of balsa wood.  I also noticed, while the gainclone was even, flat across the whole spectrum, the TBI was not.  It brought out certain aspects, like the congas, which sounded great, or brushes on a snare, but then sounded unnatural and light on the piano and horns.  On this system the TBI also sounded like there was a slight notch up in the 3-6K range which could account for it's apparent increase in detail.  I'm sure it's more complicated than that, I'm not an engineer and don't really understand how amps work.

A quick comparison to both our tube amps confirmed my guess that neither the gainclone or TBI could really compete.  To my ear, the tube amps were just more real and satisfying.

So in conclusion, I liked this amp.  Would I put it in my system?  Probably not.  But for the price I think it's well worth it.  Giant killer?  Sorry, I don't think so.  If anything, our little shootout may just have revealed that the real giant killer is the gainclone!