Little Dot MKIII Tube Rolling - Page 186

Ooouuu, my little dot mk3 started smoking furiously and then flames catched my window curtains :( Had to take out fireestinguisher...

Just kidding, but left channel is now dead and I can spell some plastic. The tubes glows but right side gets hot while left side tubes stays luke warm

Any tips?

Can anyone with electronic skills fix this? If not I guess I have to send it back to china...

thankyou

Assuming you already tried swapping the tubes to make sure that its not because of dead tubes?

Quote:

Originally Posted by junkimchi 

Assuming you already tried swapping the tubes to make sure that its not because of dead tubes?

yup. guess i have to send it back, seems david is ok with free repairs eventhough i bought it 5 years ago or something. pretty awesome

my stereo will have to do in the meanwhile

Heya. I'm 100% sure that I have a version 4. My circuit board says Jumpers off for ef95 family. I removed the jumpers (They were on @ manufacture) and installed my new tubes. They sound great. Does that make sense? I hope that I have the correct jumper settings. Thanks.
 

Quote:

Originally Posted by MonolithNZ 

Heya. I'm 100% sure that I have a version 4. My circuit board says Jumpers off for ef95 family. I removed the jumpers (They were on @ manufacture) and installed my new tubes. They sound great. Does that make sense? I hope that I have the correct jumper settings. Thanks.
 

Look on page 185(previous page) the pictures  tell the story .

Quote:

Originally Posted by MIKELAP 

Look on page 185(previous page) the pictures  tell the story .

I think its differs for different circuit board versions.

Quote:

Originally Posted by MonolithNZ 

I think its differs for different circuit board versions.

What i meant is that is there more versions of the circuit board i know only of 2 the  v1.0 and v2.0 for the mk3 you have a 4.0 board it should be written on the side of the board where i put a circle in the picture let me know im curious .Thanks

I'm new to this forum.

Also shared this same comments in the Little Dot forum page.

I received my little dot mk III almost three weeks ago, and now I feel can share my impressions about driver tube rolling (strictly IMHO).
I listened using a Sennheisser HD-650 and a upsampling DAC (Lars-Gigawork modified DAC).
(Using an upsampling DAC I don't recommend gain 10 for the HD-650 because this can exagerate to the un-natural the dynamics -literally sounding peaks popping inside your head-). I used gain setting to 5 and almost never go to more than 50% of total volume knob.
I tried the following tubes:

Tung Sol JAN 6AJ5
Russian Voskhod 6J1P-EV
GE JAN 5654W

The most impressive tube for me in the first listening sessions was the 6J1P-EV. Has a very strong sound. Bass and middles becomes beautifully round, robust and instrument separation is easy. In other words: In an Orchestra the Double basses, cellos and violas become so evident, diferenciated, natural and never busy that is realy amazing. The highs (violins in my analogy) are laid back, some how dark, and maybe lacking of that crisp and clear sound compared to the other two tubes, but this can be an advantage in hiding the harshness and grainy sound of bad caps, bad input equipment or bad recordings, making the listener experience more easy, exclusive "musical" and less "critical" or "analytical", if you know what I mean. This tubes remind me the oldie tubey sound with a single full-range speaker, but with stronger and thicker bass. Soundstage: this tubes creates a very seductive sensation of bigger ambience (is like adding a very small spice of reverb) and that's why this tubes sounds more like a hall than a damped recording studio. This sound signature contributes to give the overall sensation of a thicker sound and allows you to hear something more than the sum of the individual instruments.

The second place (very near to the russian tube) is for the Tung Sol JAN (made for military) 6AJ5. I love This tube because has a very clean, crisp (almost edgy) sound in the highs (violins sound clear and beautiful like being in heaven). Also has a very extended range in those highs. This tubes can be so revealing in the upper frequency side that they can make you want to upgrade your AC coupling (or DC de-coupling) caps. The Tung Sol 6Aj5 have less gain but this is not an issue at all. This tubes are so well balanced but don't have the "stamina" of the 6J1P-EV Russian tubes (we are talking about little fractions). The overall tonal balance of these tubes make them less "tubey" and less warm sounding than the russian, but are a very good tube rolling partner for the LD mk III if selected for the rigth music. Soundstage: contrary to the 6J1P-EV tubes, the Tung Sol's sounds "dry" in comparison, creating an ambience more like a recording studio plenty of damping panels. Maybe that's why you can have a more analytical listening experience paying more attention to small details than to the big picture. The sound of soloists and voices also becomes more intimate, and maybe this tubes can be very nice to hear a small group of musicians playing blues.

Finally the General Electric JAN (military) 5654W is a clear upgrade for the stock GE 5654 tube and is not a bad tube at all, but compared to the other two only remains as a winner in the upper frequency side, bringing clear and well rounded highs, and an overall well tonal balance. This tube is a bang for the bucks (I paid $10 for 4 tubes including shipment) and also can greatly improve the soundstage of the stock tubes. I strongly recomend this tubes if you want to roll-up tubes for a very little budget.

Hey jdamico,

Great that you had such a detailed look at these different tubes. From which year were your Voskhods and 6AJ5s? Personally, I found that the bass quite changes with year of production for the Voskhods. I found the very special feature of the 6AJ5 the very seductive mids with this not very tubey sound signature. The GE JAN 5654W are great universal tubes in my opinion. My personal overall favourite are the CV4015 tubes (so far) because they are very detailed, neutral, have a great stage, extended treble and also go deep in  bass. They are not warm sounding kind tubes.

Be sure to also look into http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide if you haven't done yet.

Best

Hi Acapella11,

The 6AJ5 are dated May 1945, and the Voskhod are suposed to be 1983 ones.

These are the first tubes I tried. Maybe soon will try another tubes.

Thanks for your comments...

Regards