T-amp (Off Topic)

by PeterSt. , Netherlands, Friday, October 06, 2006, 23:08 (6409 days ago) @ Bert

Disclaimer : All what I say in the below may be the truth, the half truth or just complete lies after all.
:wacko: :wacko: :wacko:

Well, it seems that more of us tried the T-Amp. Possibly that is because we ran out of money because we *had* to buy a couple of BD speakers ...

I used the unmodded Super-T, you know, the one with metal case, gold plated speaker terminals, with a weight of a few 100 gramms, including the PSU.
The only amp which blows itself out of place, once connected to a pair of 112dB speakers ...

The T-Amp was connected to the mid/high part of the Swings, AKA the Orphean.
By means of the way Bert applies the filters, it also was used as a pre-amp for the bass part of the Swings, those in the end fed by my 110W RMS SS amps.
My reference : the same SS amps, their other halve used for the mid/high (two stereo pairs).

The player ? GC.

The differences

First of all, and this is important to the story, I am trying to get back the imaging which in my old house could be even many meters behind me. I already determined that the most important "phenomenon" to achieve this is not the speakers, although it will be phase related. It's also not exactly the room (though that will help I think), and in the end it will be the complete setup. (Length of) Cables, I'm not sure yet. But as I said to myself the other day ... it's coming ...

The night the T-Amp was connected the first time, coincidentally all came together for some song, and a particular lower note guitar riff played at about 30 degrees at the right behind the listening position, at a few meters distance. In such a situation you just can point to it ... and it's playing at a few square decimeters ...
Reflections, right ?
I can tell you, 4.5 meters behind the listening position I could point out the exact same position where the riff was playing. Btw, nothing new for me (old house), but coincidentally this evening it was the first time that there was sound right behind the listening position in my new house. Note that this position was in front of the 4.5m distance position.

Of possible importance could be that it was me at the 4.5m distance, and it was another person at the listening position, turning around and shouting about the sound behind him, me myself shouting the same thing because the phenomenon happening. So we both pointed to the same place in space.
Btw, of complete unimportance is the fact that the person at the listening position has the initials B.D., really.
:drinks:

Oh, not to forget, the above story was with my non-T amps playing ...

Right. So what's the use of the above ?
Well, for me, everything;

Because we had a kind of formal session to workout results with the Swings, filters, placement and all, I prepared this stream of example songs for B.D.
And, because we for fun connected the feather weight T-Amp, we played part of the same stream to compare ...

With the T-Amp the riff playing behind the listening position, did not change 1 cm for position. Same for the 4.5m distance from the listening position. But, where before we heard a riff, now we heard a *far* more complete and bodied instrument. Wow !

More positives

Nice title, but no.
And this is exactly why I personally can't understand this thingy.
Remember, it was the unmodded far to few weighing amp.
At the third song we just had to switch it off.
Oh, I forgot ... at the first 10 seconds of it playing I already wanted to switch it off (witnesses present), and only because it was stupid to do so we encountered the far better imaging. But the rest ?

I tried to play with it for two more days before I said "the hell with it", and then I shut it off.

The vibes of the bass just weren't there.
The highs were smeared enormeously.
No emotion whatsoever. Complete "Grey" sound.
To me it appeared that there was no way this thing could be modded into something with decent sound.

But still there was this strange better imaging. In the beginning.
I'd even dare to say that the more it had breaked in, the worse it became.
Really really strange, and in the end I felt my judgements were worthless. I have heard something which wasn't true or so.

Later, I found that -indeed- the T-Amp Super-T will have distortion of no less than 20% or so, when it's driven over 6 Watts.
But also I found that other chip versions could do 100 Watts (4 channels, per channel) and can be bridged. This chips cost nothing, and a pair of 4 channel chips really would remain under the huge distortion level (by heart : 0.01 %).
About all around the chip can be improved, and who knows what it can bring.

One last thing to confuse the story once more :
Because the T-Amp is as it is and I didn't have two of them, it had to be positioned in the middle between the speakers. This meant different speaker cables from what I was used to. Later, when I shut it off, I kept on using the same cables with my own amps with more or less similar results now opposed to the T-Amp.
Because I had changed cables anyway, I tried more cable setups, all with the minimum length possible (which is about 20cm). Nothing satisfied me.
I ended up with the original cables of about 1,50m long. Cables ? better call them wires, because the plus and minus each consisted of one twisted pair of CAT5 Ethernet, as originally advised by B.D. ... (remember, this is to the mid/high).

You can do NOTHING with this "information". But I think the T-Amp chips have a potential which really should be tried out. I'd use the 4x100W chips (50W RMS I think), bridged to 400W (200W RMS) per channel to remain under the distortion level for sure (which would be 30% of total RMS level).
And you know, because it's a chip thing, the whole design is layed out in a data sheet, and you'd know what to tweak.

Give it a chance !

Peter

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