[TrollDragon]

TrollDragon thanks for answering my question!

I have a DIY Class A/B amplifier with a DC protection board, I don't understand electronics, but it looks like my speakers are protected, am I right?

Thanks.

Yes the DC protection board should keep your speakers safe.

 

[Estratica]

Sim, a placa de proteção DC deve manter seus alto-falantes seguros.

Thanks, the instructions helped a lot. Hugs.

 

[JazzVinyl]

New tube today. May be my favourite. It is a JAN CHS 6SL7WGT by Sylvania. Really clean sound. The "noisiest" song in my test list is Around the World by Red Hot Chili Peppers. This tube slides smoothly though it.
Not as bass focused as the stock tube and a little cleaner than the re-branded RCA.
BF2 to MK9 to LSA HP-2's is very nice. My third tube and the winner with these 'phones.
Now I want to run back to the Grado's and Elex's and try them with this tube.

Not a bass monster now, but a great sounding amp.

i knew if you liked Grado cans, that you would dig the Sylvania tube “house sound”.

 

[jonathan c]

Interesting that your favourite (?) is the Sylvania 6SL7WGT. In the Woo WA6SE, my favourite driver tube (pair) is the Sylvania 13DE7….very clear, detailed, extended…

 

[JazzVinyl]

Interesting that your favourite (?) is the Sylvania 6SL7WGT. In the Woo WA6SE, my favourite driver tube (pair) is the Sylvania 13DE7….very clear, detailed, extended…

Yep, just about the opposite of the RCA house sound...which tends to be lazier, laid back and a bit darker

 

[Shane D]

i knew if you liked Grado cans, that you would dig the Sylvania tube “house sound”.

Now it is a tube amp without being thick and bassy. Going with this for a few days and then back to the Grado's and Elex's.
Nice to know that this amp will be more than a one dimensional bass monster, with tube rolling. Every week I like this amp more.

I am sure these headphones (LSA HP-2's) make a big difference too.

I am now thinking I should go back to the Grado's in the morning.

 

[Shane D]

Today I put my Elex's back on to try out that clean new tube. A funny thing happened after one run through the test list...I went back to the stock tube.
It turns out that thick and bassy was why I bought this amp and why I like it.

 

[triod750]

I hear you. But remember that a new tube might need plenty of time to perform at its best and that the change can go either way.

 

[mordy]

This is my first forum contribution, the goal is to quickly solve the LD 2 strong blue LED problem.
I just bought an LD 2 and the high-brightness blue LED is very annoying, especially if the LD 2 is close to eye level.
How to solve without disassembling the entire LD 2, using a soldering iron to remove the original led and install another one with lower brightness?
The procedure is simple and uses only two tools: a phillips screwdriver to remove the 4 screws from the front panel - keep them in a closed box because they fall to the floor and disappear - and a 10mm wrench to remove the screw that secures the volume control on the panel.
The sequence: pull the volume knob, remove the 4 screws and the volume control screw and washer, remove the front panel, take the nail polish, shake to mix the pigments well and paint the led, avoid excess on the nail polish brush until it is homogeneous, without flaws in the painting.
Wait 10 minutes, repaint, wait 15 minutes, mount the panel in reverse order and enjoy a discreetly bright LED.

I am not handy enough to open up the amp and solder etc etc. I have solved bright LEDs by putting a little piece of colored tape over it. Not elegant, but it works.

 

[mordy]

Nice job on the LED change, I converted my MK IV over to an amber LED within the first week.

The headphone jack on the MK2/3/4 series LD is directly in parallel with the RCA pre out jacks. There is no circuitry difference between the two outputs, you can most definitely use the pre outs to your speaker amplifier without headphones attached.

The only problem is that Little Dot highly suggests that you do NOT connect the pre outs to a Direct Coupled amplifier. If you end up getting an extremely rare output tube short, the LD can send high voltage DC out the RCA ports into your amp and that could take out your whole audio chain all the way to the speakers. It would also take out any headphone you have plugged in for that matter. I think during the whole history of this thread there has only been one user with that experience but I don't remember the details as it was quite a few years back.

This is just something for you to be aware of if your amp is Direct Coupled (check product literature or contact the dealer/manufacturer).

I had a Little Dot MKIII and didn't see that it said in the manual not to use it plugged in into an equalizer circuit. As you mention, a very large spike of high voltage could occur. It did, and fried the circuit board in my ss 100W amp. It actually happened twice - until I finally understood what was happening. Nothing happend to the tube amp though.

 

[triod750]

I had a Little Dot MKIII and didn't see that it said in the manual not to use it plugged in into an equalizer circuit. As you mention, a very large spike of high voltage could occur. It did, and fried the circuit board in my ss 100W amp. It actually happened twice - until I finally understood what was happening. Nothing happend to the tube amp though.

Tube amps rule! They are real solid state killers!!

 

[lapmic]

@stuntmanx8
6N6P… well probably I have 8 -10pcs of them, 3 - 4 different manufactures and production date... they are all just nice, nothing really special (imho)… they drain a lot of current and transfer heat to the amp body

if you really want to have an upgrade buy/build an adapter 6N6P to 6SN7… then do not search for white unicorn, just a good Russian NOS tube is fine and cost few bucks… or GE… or Sylvania… Tungsol are, imho, too light and doesn’t match well with Voshkod… RCA are also nice, a little slow and fat… the modern Chinese are good too, probably not the same quality as the nos from Russia and not the same expected life time, but modern sound fast and with punch, and cheap

but before of all a couple of 6H8C, the older the better, for few bucks

I know it's been a while since your comment, but can I ask what 6SN7s are you using (with adapter to 6n6)?
Thanks!

 

[TrollDragon]

I had a Little Dot MKIII and didn't see that it said in the manual not to use it plugged in into an equalizer circuit. As you mention, a very large spike of high voltage could occur. It did, and fried the circuit board in my ss 100W amp. It actually happened twice - until I finally understood what was happening. Nothing happend to the tube amp though.

Nothing specific about an equalizer but it definitely mentions Direct Coupled amplifiers.

Little Dot MK III Pre-Amplifier Use​

The Little Dot MK III is not to be used with a DC or direct coupled power amplifier. Doing so may
result in damage to your Little Dot and/or downstream components!

Little Dot MK IV / SE Pre-Amplifier Use​

The Little Dot MK IV / SE is not to be used with a DC or direct coupled power amplifier. Doing somay result in damage to your Little Dot and/or downstream components! The Little Dot MK IV / SE should only be used with AC / capacitor coupled power amplifiers. If you are unsure if your power amplifier or receiver is AC or DC coupled, please contact the manufacturer’s support line.

 

[mordy]

Nothing specific about an equalizer but it definitely mentions Direct Coupled amplifiers.

Little Dot MK III Pre-Amplifier Use​

The Little Dot MK III is not to be used with a DC or direct coupled power amplifier. Doing so may
result in damage to your Little Dot and/or downstream components!

Little Dot MK IV / SE Pre-Amplifier Use​

The Little Dot MK IV / SE is not to be used with a DC or direct coupled power amplifier. Doing somay result in damage to your Little Dot and/or downstream components! The Little Dot MK IV / SE should only be used with AC / capacitor coupled power amplifiers. If you are unsure if your power amplifier or receiver is AC or DC coupled, please contact the manufacturer’s support line.

Thanks - I did not make myself clear in my post. What I meant was that I unfortunately plugged in the Little Dot MKIII into the jacks of the equalizer circuit on the back of my direct coupled receiver.
POOF!

 

[triod750]

But it was an exquisite POOF!, wasn't it?