[OzarkTom]

I disagree. I didn't find the TBI "better" by any stretch. Interesting is Genjamon's comments

"The bass wasn't nearly as controlled or articulate as the Ncore. Neither were the highs as refined as the Ncore. Ncore was more "breathy" with vocals, but not as weighty. In the highs, Ncore had more decay and spaciousness.  Soundstage wise, I found width pretty similar, surprisingly, but Ncore provided much greater depth of soundstage. It was more 3 dimensional. "

was similar to my experience as well. and also:

"And if you already have grat midrange with your other components and really want the best bass control and really good highs too, Ncore would be better"

- that if you have a system that already has a solid midrange, such as those with planar speakers, then the Ncores are a better match, because you don't need midrange emphasised. Probably why I enjoyed Ncores versus TBI by a large margin.

The TBI was a nice sounding amp though, but was clearly voiced to have a sweet sounding coloration. I rated it highly in a few areas, but it's no Ncore.

Have you heard the MKII version? No comparison from the MKi. Mr. Pig's review was right on.

[Rclark]

It would have to be a hugely significant redesign, IMO, to gain any ground. And more power. But I can see how it would be a very sweet sounding amp for very efficient speakers.

[OzarkTom]

My speakers are 84db Zellatons , and it plays these speakers loud enough for me.

I have another TBI on order, so that will play them too loud.

[Rclark]

My speakers are 84db Zellatons , and it plays these speakers loud enough for me.

I have another TBI on order, so that will play them too loud.

Oh yeah, a pair of them would be better.

I think I might end up buying a TBI as a headphone amp. Can't decide if I want to do that or get a Bottlehead tube set up next.

[OzarkTom]

It would have to be a hugely significant redesign, IMO, to gain any ground. And more power. But I can see how it would be a very sweet sounding amp for very efficient speakers.

Those new PPS caps did the trick. The original Class BD design was correct, those new caps just put it over the top.

[Rclark]

Oh, well, right on. Cap changes were significant in my Virtue amp too. Anyway, back to your regularly scheduled program. Sorry for the diversion.

[genjamon]

After re-reading those, I think I would agree with the more meat on the bones comparison, but I would not say the Ncore's image was more rock solid than the TBI. The TBI had easily more solid imaging. However, I perceived that as due to a combination of midrange warmth, body, and lucidity, but less midrange micro detail and nuance and soundstage depth. The Dude as preamp helped a good bit in adding some of that micro detail in midrange, adding a bit more high frequency air and vibrancy while also helping those highs to be smoother, and adding bass drive. But the Ncore really expanded on those properties while losing some of the midrange warmth/body.

I'm really not trying to bag on the TBI, so I hope my comments are not interpreted that way. I've had several amps in its price range, and it's the best I've heard at its price point. And it's midrange strengths are VERY desirable to me, enough to make me start looking around at possible amp next steps much more closely. It might be that running two as mono blocks would do the trick, and if there's any kind of trial-return policy, I might try that. Also, running with higher voltage power supply is something I would like to try.

One more thing I forgot to mention that is a bit problematic and I'd need to trouble shoot. The speaker level connection to my subs worked great when the amp was on, but when turned off there was really significant hum out of the subwoofers.  I'd have to solve this ground loop problem for it to have a permanent place in my system. But that's not really a design flaw of the amp, just one of integrating a battery powered amp with my particular subwoofer system.

Link to jackman's comments:

http://www.audiocircle.com/index.php?topic=108385.msg1120677#msg1120677

BTW, he now runs ncores on his killer Bromberg speakers.

My ncore impressions:

http://www.audiocircle.com/index.php?topic=105310.msg1106866#msg1106866

Sorry if this is getting OT, but I found the similarities to what jackman and I heard on the ncore tour were interesting.

Looking forward to the TBI. And I am procrastinating on AC while I wait for my recently returned Rogue Stereo 90 Super Magnum to warm up, so I can bias those KT120 output tubes. You can bet you will be reading a comparison of it to the TBI. Thanks to OzarkTom for tweaking the tour so I could get the TBI when I had my Rogue back!

[srclose]

This review is out of order, since I sent the amp out April 23.  This was my second chance to hear the TBI and, if memory serves correctly, this was a definite improvement.  I first listened to the amp for a day while working at home.  This is an amp that is easy to live with.  No long term irritation or edginess.  The TBI stayed right at a 3 o'clock volume setting and followed an UltraFi tube buffer into Super V speakers.  Only the external battery was used.  Compared to the Clayton S40 50W per channel SS amp, the soundstage was slightly recessed but equally wide.  Depth was essentially the same.  The TBI was clean, quick, and articulate.  Instruments were easily distinguished.  Tone was realistic.  The Clayton provided a weightier bass and a thicker presentation, like more meat on the bones of the images.  This was a trade off, in that the TBI provided greater delineation of instruments.  In contrast, the TBI had a leaner sound.  Not in the sense that is was lacking something but rather a different presentation.  I thought this was a terrific performer for the money, and a good amp regardless of price.  It would be easy to live with.

Stephen

[Freo-1]

This review is out of order, since I sent the amp out April 23.  This was my second chance to hear the TBI and, if memory serves correctly, this was a definite improvement.  I first listened to the amp for a day while working at home.  This is an amp that is easy to live with.  No long term irritation or edginess.  The TBI stayed right at a 3 o'clock volume setting and followed an UltraFi tube buffer into Super V speakers.  Only the external battery was used.  Compared to the Clayton S40 50W per channel SS amp, the soundstage was slightly recessed but equally wide.  Depth was essentially the same.  The TBI was clean, quick, and articulate.  Instruments were easily distinguished.  Tone was realistic.  The Clayton provided a weightier bass and a thicker presentation, like more meat on the bones of the images.  This was a trade off, in that the TBI provided greater delineation of instruments.  In contrast, the TBI had a leaner sound.  Not in the sense that is was lacking something but rather a different presentation.  I thought this was a terrific performer for the money, and a good amp regardless of price.  It would be easy to live with.

Stephen

 
 

 
Sounds like you captured the essence of the sonic strengths of the unit.  Well Done.   

[wushuliu]

This review is out of order, since I sent the amp out April 23.  This was my second chance to hear the TBI and, if memory serves correctly, this was a definite improvement.  I first listened to the amp for a day while working at home.  This is an amp that is easy to live with.  No long term irritation or edginess.  The TBI stayed right at a 3 o'clock volume setting and followed an UltraFi tube buffer into Super V speakers.  Only the external battery was used.  Compared to the Clayton S40 50W per channel SS amp, the soundstage was slightly recessed but equally wide.  Depth was essentially the same.  The TBI was clean, quick, and articulate.  Instruments were easily distinguished.  Tone was realistic.  The Clayton provided a weightier bass and a thicker presentation, like more meat on the bones of the images.  This was a trade off, in that the TBI provided greater delineation of instruments.  In contrast, the TBI had a leaner sound.  Not in the sense that is was lacking something but rather a different presentation.  I thought this was a terrific performer for the money, and a good amp regardless of price.  It would be easy to live with.

Stephen

Just popping in to say TBI's designer should be encouraged to increase the PS caps - or a third party encouraged to provide these mods. Beefing up the 2 PS caps fleshes out the midranges further and adds audible improvements in bass. The TBI chip is very sensitive to these changes - much more so than your typical amp. Doubling the stock value from 470uf to 1000 was a good start. The difference is immediately evident and noncontroversial to my ears. Someone with a proper solder station should be able to do this mod easily provided the TBI pcb has not changed since I last owned one.

My .02

[DaveC113]

PS caps make a big difference in my tube amps too, the best I've found so far is Clarity Cap TC series film caps although the voltage rating is probably huge overkill the ESR is super low. They could be installed in parallel with existing electrolytic caps rather than spending big $ on the largest ones. Something around 50 uF would make a good bypass... This should be a huge improvement over using any kind of electrolytic cap.

[wushuliu]

PS caps make a big difference in my tube amps too, the best I've found so far is Clarity Cap TC series film caps although the voltage rating is probably huge overkill the ESR is super low. They could be installed in parallel with existing electrolytic caps rather than spending big $ on the largest ones. Something around 50 uF would make a good bypass... This should be a huge improvement over using any kind of electrolytic cap.

I totally agree with you as far tube amps, but with these TBI/TPA chips you HAVE to keep the cap leads as short as possible or the board will get fried.

[Freo-1]

Any updates? 

[wushuliu]

Seriously, given how inexpensive the chips and stock designs are it sucks more companies aren't releasing similar amps. The sound quality for the cost is astounding.

I have been using the $10(!!!!) TPA board I got from Parts Express for 6mos. How good is it? I have not thought about it for 6mos. For a habitual diy tweaker like me that's saying a lot. One day I was like huh I haven't even thought about this dang amp! I built new speakers for the nth time, new dac for the nth time, busted out old turntables. I've been tinkering with everything BUT the $10(!!!!HAHAHAHAHAH) amp. Now I am not saying it is as good as the TBI - not even comparable really, since the PE board is a raw board no enclosure no preamp/buffer and is lower power blah blah, but I have read enough feedback on this family of chips elsewhere to know that they all punch far, far, far above their weight. It is certainly similar enough to the TBI I had for me not to miss it too much. But I guess since these chips are primarily used in TVs and soundbars they just slip under the radar. Too bad.

I hope Jan at least comes out with both higher and lower models, including the new TPA chips released last year. Maybe he can get a proper Stereomojo review?

I and others at diyaudio have asked Cristi from Connexelectronic to build an amp based on the newest TPA chips. He's agreed and is in the prototype stage. Of course these will be diy-focused - no enclosure, buffer, etc. so not competitive to the TBI. But at least if that takes off it may get the ball rolling for others to notice and build on...

[OzarkTom]

Any updates?

The amp has made it to Az on Wednesday for the next listener.

[OzarkTom]

A very well written review on the TBI MkII by John Hoffman has just been released in Positive Feedback online.

http://www.positive-feedback.com/Issue67/tbi_millenia.htm

[mikeeastman]

 It was a very busy week so I didn't get to check  out the amp as much as i've liked. First I couldn't believe how small the amp is.  Compared to my Ncores I acutely  liked the mids better with the TBI, not a big difference but I thought there was a little more presence. The highs weren't quiet as detailed with the TBI, but still very nice. Overall the Ncores had a little more presence  I tried amp with provided battery and my PI Audio buss, not a big difference but more detail and fuller sound with the buss.

I also tried it in my bedroom system and it was better sounding than my Jolida jd 1501, not night and day but definitely a step up.

I want to thank Tom for doing the tour.

   Mike

[srb]

Compared to my Ncores I acutely  liked the mids better with the TBI, not a big difference but I thought there was a little more presence.

Overall the Ncores had a little more presence

So I'm reading that the TBI had more a little more presence than the Ncore and the Ncore had a little more presence than the TBI.

 

Steve

[roscoeiii]

So I'm reading that the TBI had more a little more presence than the Ncore and the Ncore had a little more presence than the TBI.

 

Steve

If I am reading that correctly, it is overall (ncore>TBI) vs. mids (TBI>ncore).

[mikeeastman]

The TBI had a little more presence in the mids only. But overall the Ncores had more detail and presence except in the lower mids.