[qingcai]

Removed the box of the transformers , the transformer hum gone. disconnected the fan, and ordered to quiet fans.
1st step is done.

 

[qingcai]

I think I will put this away and wait for winter come.

 

[AngryTank]

I have fostex , which is 50ohm, not sure viii se can drive it or not.

Oh trust me, it can run it easily. It had too much power for what I needed and even on the lowest gain it was loud. Using single ends on low gain was more than enough for my HD820 and Auteur (both 300 ohm).

 

[Nooborghini]

Well it looks like Apos gave me the option to Return it or Try and deal with Little Dot, but to be honest I’m kind of done with Little Dot. I don’t want to have to deal with them anymore. As for Apos I want to continue doing Business with them but I don’t know What I would get to replace my Little Dot.

Personally I would not get another Little dot, EVER.

My local repair shop stated this:

There was a chain reaction of failures.
Regulator transistor shorted, then a zener diode shorted, then a resistor burned up.
A well designed circuit would prevent this from happening, but this is not well designed unfortunately.

I don't see any other damage, but can't test it fully until I get all the bad parts replaced. I'll have to order those, will take a few days to get them.
This could end up being in the $300 range to repair.

I had this thing maybe for 1-2 months on a surge protector. Only other thing on it was my DAC.
Avoid it like the plague. Apos has been good on the relationship part but this ordeal with the product has been absolutely asinine.

It's tragic since I really liked the tube amp but I think I'm going to go with a DNA or WooAudio next since having his fail on me left a bad taste in my mouth for anything Little Dot. I might even scrap or sell my LD MK2.

 

[Alpha1Ric]

The LCD 4z, has impendence 15 ohm
I don’t understand too much the values impedance, the little dot Mk6+ is good to run the LCd4z?

And I cant find the "normal" specs from the MK6+ :/

Will drive well? the loud volume it will be ok? (like 120cloclk)

Whats is your opnion?

Thanks

 

[Wolvebain]

Hi bud...
I can tell you that the normal LCD-4 (non-z version) will run without issue on the LDmk6+ (5W per channel output. check Amazon, Shenzen, etc. for the specs).

Planars are inefficient, so look at the sensitivity more than the impedance.

 

[Maxx134]

My local repair shop stated this:

There was a chain reaction of failures.
Regulator transistor shorted, then a zener diode shorted, then a resistor burned up.
A well designed circuit would prevent this from happening, but this is not well designed unfortunately.

I don't see any other damage, but can't test it fully until I get all the bad parts replaced. I'll have to order those, will take a few days to get them.
This could end up being in the $300 range to repair.

I believe your repair shop guy was 100% correct. The regulator power transistors were an older version, that was discontinued for a much stronger one, which they never upgraded to. They don't even sell those old transistors anymore. Also the zener diode was a very low wattage so couldn't handle a problem if transistors failed. Then we have metal film resistors that should never been in a PSU. They should have had power resistors or wire wound.

The issue is that China is a very, very competitive market and they must cut every corner they can to be cost competitive. They did have some better resistors in older units but stopped that. Then we have issues of the anode resistors to start slowly burning with age because they are not high enough wattage. Today's market you can place physically smaller resistors that can handle double 5w no problem.

Bottom line is that the design was genius, but some of the critical parts used, was poor. Once you fix the PSU, there is basically nothing else that would fail.

My guess is that the super cheap and brittle stranded wire, that is used for the regulator transistors broke, causing failure. Also, if you have the MK6, that is more prone for the transistor issues.
I never had the transistor issues with my MK8se (less output power) and still have the old transistors, but I already bought the backup transistors which are a set. You can't buy one, you must buy both.

Parts for this was cheap. You can order them on "Mouser" website, so I'm not understanding why it would cost $300, so I'm assuming that it is labor.

Also I would get higher wattage diode for replacement.
In the Mod thread, we basically revamp most of the power supply anyways, replacing all that.
Anyways, remember to tell the repair shop about replacing those brittle transistor regulator wires to the board.

If this amp was done properly, with highest grade components, it would easily reach playing field with end-game amps.
As is, the stock performance is nicely mid-tier.
But this can be also said with 100% of ALL tube amps in the market. I have seen all the top units. I have worked on them. They could all be improved. None uses the best parts.
That's on the owner to do.

The ONLY tube amps, that are almost 100% NOT dependant on parts quality, is the designs by member @SonicTrance

I had this thing maybe for 1-2 months on a surge protector. Only other thing on it was my DAC.

Yes the MK6 can be susceptible to PSU strain with power tube rolling, or defective tube pops, or the dam internal wiring of the two regulator power transistors, sadly.

Recommendation is to not use stock tubes and use good tubes. And do not move unit around. Eventuality with age the anode resistors increase in value and any power surges are less, so the PSU doesn't fail except for heat and wire corrode. That would take some years.

Once you fix the issues it is a very reliable unit.
Up to you to fix. Then the next owner will enjoy.

 

[franci2105]

Can you name the best tubes for the Little Dot MK VI? Thanks

 

[SONYES]

Sorry to disappoint you all Little Dot MK VI
I came to the conclusion that the amplifier is bad
And caused me damage to the HE1000 V2
Left channel dies with headphones ...
That's how the amplifier moved to the side and that's it
I finished with lamps and headphones HE 1000V2
A waste of money
And the sound is no better than transistor amplification
That's my opinion

 

[Bonddam]

Little Dot Ian Wu customer service sucks. Amp broke in 2 hours and no response from Ian Wu. If Ian doesn’t respond I’m going to have to send my amp to guy in Massachusetts for repair. My $3000 paper wait looks nice. If he gets too many emails then that’s a business problem.

 

[Bonddam]

I got an email and it's says they'll send me the two resistors and I get to fix the amp myself!!!???? Also I asked Ian if I can use 274B rectifiers before even getting the amp and he said that’s what he uses. In email he told me not to use them as that may be too much plate voltage???!!!!! What do you know anything Ian!?? So paying a business $120 labor hours plus what ever else to get this amazing YD-L2 up and running. I’ll pay it because at least a competent builder can actually tell me what rectifiers I can use and also see if they are honest and parts used are highest grade transformers and capacitors they said.

Be careful and don’t make my mistake if you live in USA. Should have not felt bad when I canceled the order and Ian gave me a sob story about cancellation fees they would pay because now I’m paying the repercussions of my decision on a brand new amp.

Man can’t wait till my Woo WA234 is finished.

Only good thing about little dot is it sounds good but not as strong as they claim when using Abyss 1266 TC but great sounding.

 

[qingcai]

Sorry to disappoint you all Little Dot MK VI
I came to the conclusion that the amplifier is bad
And caused me damage to the HE1000 V2
Left channel dies with headphones ...
That's how the amplifier moved to the side and that's it
I finished with lamps and headphones HE 1000V2
A waste of money
And the sound is no better than transistor amplification
That's my opinion

the sound is very good. i like the sound of it.

 

[Jingle525]

Sorry to disappoint you all Little Dot MK VI
I came to the conclusion that the amplifier is bad
And caused me damage to the HE1000 V2
Left channel dies with headphones ...
That's how the amplifier moved to the side and that's it
I finished with lamps and headphones HE 1000V2
A waste of money
And the sound is no better than transistor amplification
That's my opinion

Sorry to hear that man. This sucks. Not sure what happened. But I know that little dot mk8 is definitely not designed to drive planar headphones. It’s designed to drive flagship headphones from 10 years ago, like hd800 or T1. I wonder how common it is for mk8 to damage planar headphones

 

[Deleeh]

That shouldn't really matter at that price.
If not, there must also be a warning that the buyer knows.
I had a defect on the ld 1+ last year and also wrote to them and received no reply from them.

Even if it was a cheap amplifier, they could have contacted me.
I repaired it myself and it works again.
I replaced two new quality sockets and capacitors and that was it, but I still replaced one or two things while I was at it.

But I won't be buying anything from them again.
Unfortunately I have already read a lot of bad things about Little Dot.

 

[Maxx134]

I wonder how common it is for mk8 to damage planar headphones

Both the LD6 & LD8 have a relay to cut outputs if there is any fault, but I believe a pop may still get thru.
This is why you should never leave a headphones plugged in any tube amp when turning on or shutting down.

I could been anything from amp failure, to bad tubes.

The HEK doesn't damage easily, in fact you could say near impossible without high current, but I have destroyed one inadvertently by one cup going into the other causing the magnet bar/strips to get cracked, then they slowly collapse inward into the driver...