Little Dot T-100 class T amp

Cacophonix · « **Reply #20 on:** 28 Jan 2007, 12:29 am »

Quote from: DZetye on 27 Jan 2007, 11:01 pm

Surface shipment to USA is $63 US according to Eddie or $235 US total shipped. Don't know what delivery time would be though.

How about if a bunch of us here order it ? Maybe that'll cut the shipping cost to quite an extent ....

shep · « **Reply #21 on:** 28 Jan 2007, 12:53 am »

Oh God it never ends! Here I though I was home and dry and I'm off and running...

slbender · « **Reply #22 on:** 28 Jan 2007, 04:32 am »

Guys -

I see what looks to be a mu-metal shield in that picture around the toroidal, I doubt if they could build it without it...

What I don't see is more than adequate headsinking for the Tripath 2022 6 wpc stereo chips. That these 2022's are already a bridged device, unless they somehow bridged the already bridged circuit of the Tripath 2022 there is no way this could deliver 60 Watts per channel. It does look like there are two 2022's or twice as many channels as a stereo amp of 6 wpc would need, it is my guess that is what they have done. The Tripath spec sheet says it is already bridges and can't be increased in power any further. So I'd be inclined to doubt that 60 wpc claim...

That being the case, with some suspician, I have to say, this thing might have a tendency to blow up.

I don't know where this photo came from... but the two connectors on the tube board seem to be not connected to anything ???

I have an old DVD Home Theater system that came from China, and has 5.1 built-in it takes the form of three of these Tripath 2022 chips inside for six channels at 6 wpc.

I'd have a lot of questions before I'd send my money for this thing...

-Steven

Quote from: Gordy on 27 Jan 2007, 08:52 pm

Adding a mild steel shield around the toroidal would go a long way, notice how the speaker outputs laying right up against it?

Gordy · « **Reply #23 on:** 28 Jan 2007, 05:50 am »

Here's a 100w / 4ohm evaluation board using a TA2022 chip...

http://www.tripath.com/downloads/RB-TA2022_new.pdf

and the spec sheet...

http://www.41hz.com/downloads/TA2022.pdf

slbender · « **Reply #24 on:** 28 Jan 2007, 06:10 am »

OK,

I see now, I was talking about the Tripath 2020 IC, I didn't notice that this was the 2022, which I had not come across before. I'm not sure Tripath even exists anymore, there was a lawsuit or two, but that 60 wpc figure does look legit.

Bridged the TA-2022 can do 150 W into 8 ohms, but this must be one IC running single ended. Still a lot of caveats on the design of the coils, voltage points, and the circuit board.

-Steven

Quote from: Gordy on 28 Jan 2007, 05:50 am

Here's a 100w / 4ohm evaluation board using a TA2022 chip...

http://www.tripath.com/downloads/RB-TA2022_new.pdf

and the spec sheet...

http://www.41hz.com/downloads/TA2022.pdf

Gordy · « **Reply #25 on:** 28 Jan 2007, 06:38 am »

You have better eyes than me, the torodial just looked plastic wrapped

Now I see a shield, you think it's mu metal at that price point? I thought mu was very pricy.

shep · « **Reply #26 on:** 28 Jan 2007, 11:49 am »

I also thought that was just a plastic wrapping. I''m working out a deal with M. Mardis to order one and do a complete mod; caps,cable re-routing, sheilding, etc. He did brilliant work with my little Trends T-10. The good thing is that there's some space in there to play around in. He's trying to get more solid info.form the company. Any ideas about those tubes anyone?

Woodsea · « **Reply #27 on:** 28 Jan 2007, 01:02 pm »

I think for the price, I would like to try this as well. How about getting a group purchase in the works. I hate shipping prices. But, it might be good to have someone receive and give us a quick thought on it as well.

shep · « **Reply #28 on:** 28 Jan 2007, 02:48 pm »

This is going to take some time (mine) so if someone else takes the plunge it would be a great thing to share about. Shipping costs really suck. That's what put me off ordering speakers from the states and buying them here instead. I don't know how this thing can possibly weigh 7kg. It's small, if the photo is any indication.

KT · « **Reply #29 on:** 28 Jan 2007, 05:27 pm »

From the way the material around the transformer conforms with the fine contours of the windings, especially at the top, I'm thinking that it's some sort of paper wrapped around the toroid, perhaps with some brand markings and voltage and VA specs.

Unless it is foil, metal would not conform that closely to the contours of the surface. The whole thing, in turn, looks to be encased in the standard plastic toroid wrapping.

That seems to be a lot of money for shipping. Is anyone familiar with shipping from HK? Several years back I purchased a Sun Audio 300B amp from HK, replete with the requisite heavy power tranny, choke, and output transformers, and the shipping came to around $200 US. I can't understand why shipping for the Little Dot would be so expensive unless they were making some profit from the shipping fee.

But I really have no clue on HK shipping prices.

Best,
KT

shep · « **Reply #30 on:** 28 Jan 2007, 08:37 pm »

I have a green light. I'm going for it.
"The two things that worry me about the T_100 is it really available? Seems like they are ready to ship.
We looked into becoming a dealer, but they don't want to do a dealer network right now.
And, is the power transformer big enough? Looks pretty beefy, but won't know 'til we see it in the flesh. But I doubt your going to be stressing the amp, anyhow. You don't need that much continuous power. Peak, yes. And that I can supply you.

Technically the amp looks to be well laid out. What isn't right should be easy enough to fix. Having not seen the top or sides of the case, we don't know about ventilation, but there is at least one vent in the floor. You're right about tube rolling. It could make a big difference. Especially is I do my bypass magic on the Tripath chip. I have a way (trade secret) to bypass the input circuits of the Tripath and use the tubes instead. With good tubes, could be very, very nice indeed. =)

So there you go, Mr. Itchy Audiophile! I'd be glad to "Pimp One Up" for you. I hope that it will lead to a whole bunch more."

DZetye · « **Reply #31 on:** 2 Feb 2007, 09:34 pm »

AARGHHH surface mail delivery time to the US is 2 months. I was thinking of trying one but might wait to see if anyone posts their impressions first. So did anyone order one?

shep · « **Reply #32 on:** 3 Feb 2007, 12:08 am »

me. Wasn't I clear? It's going to Hawaii so I think it will get there fairly soon. This is fairly typical of new-ish, small Chinese firms. They launch products and wait to see what the reaction is before actually going into serious production. Then they are caught out when the demand exceeds the supply and experience assembly problems (the Trends T-10 was/is a perfect example...many of the delivered units had faulty bits) It's a pity about this because the designs are innovative and the prices unbeatable. I pointed this out to the importer/moderator on their (Little Dot/ghastly name... site and got a resounding silence. I don't think they take very kindly to criticism or are at least unused to it. As soon as mine gets hot-rodded I will post a review.

DZetye · « **Reply #33 on:** 3 Feb 2007, 03:18 am »

cool, I'll look for your review.

kbuzz3 · « **Reply #34 on:** 7 Feb 2007, 06:43 pm »

I really want one. Ive been intrigued by the tube pre tripath integrated concept for a while. There were a few posts here on a european company offering such a product but i dont think anyone posted any listening impression. See, http://www.autocostruire.com/. I also dont see that amp on their website now. Anyone have any updates?

http://www.autocostruire.com/

FYI The obad website says available on 2/15. I need someting for my office that i dont have to worry about if i leave it on overnight.

shep · « **Reply #35 on:** 7 Feb 2007, 07:40 pm »

You are absolutely right. This Italian one came first. I am patiently waiting. As of last night, mine has not left the shores of China. Since I never got a rebuttal from the site, my statement above still holds (unfortunately)

Russell Dawkins · « **Reply #36 on:** 8 Feb 2007, 09:04 am »

Reading some of the posts on this forum:

http://www.little-tube.com/forum/forum_topics.asp?FID=3&PN=1

proved more than a little disconcerting.

I see someone complaining of a pair of resistors discoloring due to high operating temperatures and this being explained away as due to hot soldering iron during assembly!

Check out this litany of woes, also:

http://www.head-fi.org/forums/showthread.php?t=206890

Also, there were numerous incidents of arcing tubes where the reason was given as a bad batch of tubes, but free replacements also arced.

Seems to be a different model from the same company, or am I mistaken?

shep · « **Reply #37 on:** 8 Feb 2007, 10:34 am »

I read thru all that. Doesn't make one feel too good..Still my amp is on order and I will grimly see it thru.
Maybe the delay is due to the problems being sorted out...(if wishes were...) I'm personally not worried for the simple reason that mine is going directly to M. Mardis who will sort out any build foolishness and turn a sows ear into a silk purse

Just to underscore that head-in-the-sand attitude of these people, their so-called forum has had no movement and not a single post from the head honcho for a week+
Rome wasn't built in a day, neither was Pekin!

kbuzz3 · « **Reply #38 on:** 11 Feb 2007, 04:56 pm »

Quote from: shep on 8 Feb 2007, 10:34 am

I'm personally not worried for the simple reason that mine is going directly to M. Mardis who will sort out any build foolishness and turn a sows ear into a silk purse

Im really tempted to buy this one as i just recieved an email from the co. that the amp is available next week. However, my main use here is for an office system and to replace a vintage tube amp, so I dont have to worry if i accidentally leave it on overnight. Now the arching problems on the prior models are starting to scare me a bit. If i wanted to worry i could leave my vintage restored sherwood with fans on it running all night-not such a great idea. Plus dont know what my fire insur. coverage is (LOL)

Can you let those of us who are considering purchasing one please give us a little more info on M. Mardis- would certainly like the comfort of knowing someone checked the unit first....otherwise looks like a blue circle integrated for me -at a much greater cost

I repeat from my prior post that this really seems like an excellent idea. I think i speak for the poster above that the general concern seems to be about ultimate execution.

Finally, any thoughts about running this thing with 15 ohm LS35a's. I have heard rumours of less then stellar results with ls35a's and the inital low powered tripaths but have not hear one my self. Hence, my curiosity of the addition of the tube front end/buffer what ever you want to call it in this application. Plus the new higher powered chip.

shep · « **Reply #39 on:** 11 Feb 2007, 10:38 pm »

Mine is still on order and still, as of today, hasn't been sent. Even though we are buddies, and I have given him both a green light and sent money, M. Mardis takes this stuff (and his reputation in the DIY world) seriously. So much so, that he has sent someone in HK to sniff out more info. and have a hands-on look and listen before actually buying the unit. This amp is so new that as of tonight, no one has actually given a first-hand report, although someone on the DIY forum has one and is in the process. The reports of tube flair appear so far only to apply to the head amp. To date there has been no "official" explanation of this or why the sudden change of tubes mentioned. On the other hand, they seem to be eager to plea
se (lot of good that does if you are 5,000 miles away) My most recent communication with M. is in substance that the tube front end seems to have been an after-thought to get "our" attention, and probably not very well implemented, but M. is of the opinion that he can re-do this is the right way. Having put my money where my mouth is, you could say I'm committed to this little project (I'm even thinking of giving it the same paint finish to match my speakers (I didn't ever say I was sane in my profile!)
That's about the only reassurance I can give anyone considering this amp, other than to say that my dealings with M. have been a pleasure and that he knows his stuff and is very receptive to comments and ideas. One of mine that he will probably do is to run the amp section directly to one of the unused inputs (making it an out P.) so I could eventually use a passive pre. if the tube front end disappoints. Having taken a walk on the wild side with my Trents T-10, I 'm ready for the big time aa I have zero knowledge about compatibility issues with the LS35's but some here must.