[penguindude]

Quote:

Originally Posted by jirams /img/forum/go_quote.gif Can I just add to this thread a precautionary note for those users who are monkeying around inside this amp. Valve amps (equipment) use some high voltages - on the anodes and screen grids of the valves. [size=medium]These can be upwards of 200 vdc and could prove fatal if bridged accross by the human body.[/size] So be warned !!!

Yes, dont try to fiddle with electrical boards if you are not experienced or trained. I was trying to clean the inside of my digital camera the other day (took out the batteries and opened it up) and I got shocked BAD when I accidentally touched something i shouldnt.

 

[jirams]

Quote:

Originally Posted by penguindude /img/forum/go_quote.gif Yes, dont try to fiddle with electrical boards if you are not experienced or trained. I was trying to clean the inside of my digital camera the other day (took out the batteries and opened it up) and I got shocked BAD when I accidentally touched something i shouldnt.

Yeah - the flash capacitor can be sitting with 600 vdc - see what I mean about monkeying around in things you don't fully understand. I believe there is a recorded case of a domestic fatality due to this very same thing !!!

 

[rain_uk]

Quote:

Originally Posted by jirams /img/forum/go_quote.gif I don't quite understand what you are saying here. If you mean your running 240 vac mains into the amp with the amps voltage selector set to 120 vac then [size=medium]DO NOT DO THIS[/size]. You will very quickly wreck it - it may even catch fire. Stop fiddling with the b----y thing and just listen to it

From what I gather...'apologies' has a 240v model but thought it was 110v and used an adaptor to knock down to 110..now he is using it at the correct voltage and its working correctly he is seeing an increase in temperature of coarse...correct me if im wrong 'apologies'...?? apologies where are you located?

 

[apologies]

Quote:

Originally Posted by rain_uk /img/forum/go_quote.gif From what I gather...'apologies' has a 240v model but thought it was 110v and used an adaptor to knock down to 110..now he is using it at the correct voltage and its working correctly he is seeing an increase in temperature of coarse...correct me if im wrong 'apologies'...?? apologies where are you located?

Woop, im still alive

yeah thats exactly right. Im based in Exeter, UK. I'm waiting until next friday, im gonna order the mullards with the sovtek 6C19PI that pelayostyle (that right?) recommends...

I'll say if this fixes the harsh treble im getting. (with me grados).

 

[Hi-Finthen]

[size=small]READ THE SIGNATURE![/size]

 

[jamato8]

Quote:

Originally Posted by Nasir /img/forum/go_quote.gif Would the pre-amp functionality alone be reason to choose this over the LD-MT? I received, "The sound quality of the Micro-Tube is pretty comparable to the Little Dot 2++. Due to it's "hybrid" design, the bass will be a bit more razor sharp around the edges and very dynamic." from the Little Dot guys, what exactly is meant by "dynamic"? The amp will probably be used with SR225s, source being AV-710 to Entech 203.2.

The way tubes are used in a number of pre amp/headphone amp designs, when the amp is used mainly as a headphone amp, I have found the sound to be a compromise in the preamp section. The micro tube looks interesting and I have ordered one. With two 634 buffers in parallel per channel it should have plenty of kick and the tube input should be very nice. With a change to the pin placement even the fine 6111 tube could be used and there are many manufactures of this tube from the 1950's on.

 

[Advil]

Yep, I'm pretty sure the jumpers are to be changed only for LOW impedence cans.

And 600 sure isn't low.

 

[m8o]

Quote:

Originally Posted by Nasir /img/forum/go_quote.gif I received, "The sound quality of the Micro-Tube is pretty comparable to the Little Dot 2++. Due to it's "hybrid" design, the bass will be a bit more razor sharp around the edges and very dynamic." from the Little Dot guys, what exactly is meant by "dynamic"?

from my experience with ss vs. valve I'd say that is meaning impact & attack being quicker. The LD II+ for example "really takes the edge off [man]". It's not a 'fast' amp. Meaning the attack is a bit subdued. I take that statement as this amp should prove to have a 'faster' attack.

edit: a thought came to mind re-reading your post and I thought I'd pass on this word of caution. I notice you stating possible use of an Entech 203.2 driving the amp. I've read about a negative experience from someone using that driving one of the pure-tube LD amps. The Entech 203.2 puts out a max voltage that is greater then what the max input of the LD amp is. That results in a 'crackling-like' distortion on the bass kicks. I'd check with the manufacturer as to what the max input voltage is that the micro-tube amp can handle. It should be greater then 2.5v.

 

[DanT]

Just an update on the CN1/CN2 jumper. This confirm that they are indeed an impedance switch


DavidZheZhe has answer on his forums.

http://www.little-tube.com/forum/for...sp?TID=52&PN=1

Quote:

Dear DanT, The later revisions of the Little Dot 2+ had CN1/CN2 jumpers and the Little Dot 2++ does as well. This is just an impedance jumpers to bring the output impedance to the 120 ohm standard used in many amplifiers. You may want to play around with the impedance jumpers if you want a "brighter" sound.

For those who miss my earlier post I found out that the CN1/CN2 jumper can be used to switch impedance mode from this tread

http://www.little-tube.com/forum/for...p?TID=30&TPN=3
Quote:

Question: i read that Jumpers CN1/CN2 affect Headphone Impedence ON for Higher impedence headphones OFF for Lower impedence headphones

 

[penguindude]

So, its CONFIRMED that in LD2++, caps ON = high impedance and caps OFF = low impedance?

 

[DanT]

Quote:

Originally Posted by penguindude /img/forum/go_quote.gif So, its CONFIRMED that in LD2++, caps ON = high impedance and caps OFF = low impedance?

Actually I'm not sure. But since DavidZheZhe never denied it in neither tread I would guess it it so. But his reply can be a bit confusing. Anyway rely on the good old maxim: Try both and use the one that sound the most pleasing to your ears.

 

[Jo6Pak]

Have any U.S. buyers had to pay customs/tax/duty (whatever you want to call it) on one of these upon its arrival from China? THANKS!

 

[Advil]

Quote:

Originally Posted by penguindude /img/forum/go_quote.gif So, its CONFIRMED that in LD2++, caps ON = high impedance and caps OFF = low impedance?

I just got this exact quote from David in an email regarding my purchase.

Quote:

Sure we will pre-configure it for low-impedance, and for future reference if you open up the Little Dot 2++, there are two jumpers labeled CN1 and CN2, if you un-jumper these you can reset it to "stock" mode. To Iowa I'd roughly estimate 6 days after shipment.

So jumpers OFF = stock/high impedance..?

Oh the confusion!

 

[penguindude]

Yes, it should be the same with LD2+. Caps OFF= high and Caps ON = low. Some people, however, have suggested otherwise.

 

[feifan]

Quote:

Originally Posted by Jo6Pak /img/forum/go_quote.gif Have any U.S. buyers had to pay customs/tax/duty (whatever you want to call it) on one of these upon its arrival from China? THANKS!

No customs/tax/duty, but the box was ripped open by U.S. Customs. The wording on the retaping: "OPENED FOR INSPECTION BY U.S. Customs and Border Protection AGRICULTURE." They had also torn off a corner of the box, presumably to determine if they needed to open it up. This gaping tear wasn't retaped. The LD2++ was in good shape when I took it out so the rough handling didn't harm it. However, I can see how the included RCA cables or brochure could have been slashed in the opening. The packing material used is excellent -- a sturdy, resilient foam that fits the components like a glove. The main unit and each of the 4 tubes is in its own foam chamber. The foam is thick and will protect the parts from any accidental drop or normal shuffling or banging.