Yet another Little Dot MkVI amp review ....

[eserafinojr]

 
Thanks for getting back to me. 
I just pulled the trigger, I have the MK-6+ with the fan upgrade coming with a new balanced dac, and the HE-560's with a balanced cable. Also have a set of 4 Svetlana Winged C 6AS7G, and a set of two Tung- Sol 6SN7GTB. Hoping I will enjoy these, and maybe they will be an upgrade over the stock tubes. 

 
Awesome!
 
You made a GREAT choice, it sounds better, has less noise and way more drive than much more expensive OTL offerings like the WA22... I owned one!
 
NOS Winged C's sound very good. IMO though Soviet tubes made after 1984/5 started to fall off in quality, anything NOS before you're good.
 
The Svetlana's are the creame of the crop for the 6AS7G type, my go to tube type for the 6AS7/6080 type is the WE421A or TS 7236.
 
I currently use 4x Early 50s Pale Grey Plate WE 421s with the "5998/421A" label, which are my favorite 421As variants. Late 60s TS 5998 Black Plates are also very nice.
 
And rotate 6N7Gs, and the 6J5GT/6C5GT as drivers.
 
Your tube compliment will sound very very good with TS 6SN7s. Are they NOS or Russian Re-Makes?
 
The New Sensor Corp Re-Makes are getting pretty good I hear, you're good either way!
 
Tube rolling can get very pricey. I have been collecting for awhile, good NOS tubes can get crazy expensive.
 
BTW even though LD calls for the high gain cousin of the 6SN7, the 6SL7 to be used in the MK6, I hear no difference in gain or drive with medium gain 6SN7 type tubes or the aforementioned tubes with adapters.

 

[ericohgb]

Hello friends,
 
I have also ordered a LD MKVI+.
 
It's indeed an excellent sounding amp. Far better than I expected.
 
I've order directly from David and mine came with Mundorf caps and fanless design. 
 
Does anyone also have the fanless design model? I noticed it runs very, very hot...
 
I do also hear a hum outside the amp. It's distracting only when you're not using headphones, so it's bearable.
 
I'm also thinking about upgrading the stock power tubes. What are your impressions of the Tungsol 7236?
 
Thanks in advance for any help you may provide.
 
Best,
Érico

 

[rudra]

I have the fanless design with mundorf cap upgrade. I place the amp on top of a laptop cooler (Cooler Master SF17 Gaming Laptop Cooling Pad). I haven't heard any hum in mine. Have u eliminated the possibility of a ground loop.

 

[ericohgb]

I have the fanless design with mundorf cap upgrade. I place the amp on top of a laptop cooler (Cooler Master SF17 Gaming Laptop Cooling Pad). I haven't heard any hum in mine. Have u eliminated the possibility of a ground loop.

Thanks, rudra.
I'll search for the cooling pad.
I'll also try to eliminate the ground loop.
Best,
Erico

 

[ericohgb]

I have the fanless design with mundorf cap upgrade. I place the amp on top of a laptop cooler (Cooler Master SF17 Gaming Laptop Cooling Pad). I haven't heard any hum in mine. Have u eliminated the possibility of a ground loop.

Dear rudra,
Have tried a lot of things, but couldn't eliminate the hum... Could you give some tips about this subject?
Best,
Erico

 

[rudra]

Is the hum from the transformer or the tubes. Also you can post in the mod thread. Have you contacted LD

 

[ericohgb]

Is the hum from the transformer or the tubes. Also you can post in the mod thread. Have you contacted LD

Hi, rudra.
It's not from the tubes. It comes from the transformers or from the servos I believe are placed between the transformers.
Have already contacted David, but had any kind of response whatsoever.
Thanks!

 

[rudra]

What you see between the transformer is a SS rectifier. Have you tried plugging the unit in a different room. Have you got any dimmer or A/C running, whose interference is being picked up. You can try plugging the amp at a friend's place to see if hum persist.

 

[Maxx134]

Tube rolling can get very pricey. I have been collecting for awhile, good NOS tubes can get crazy expensive.

BTW even though LD calls for the high gain cousin of the 6SN7, the 6SL7 to be used in the MK6, I hear no difference in gain or drive with medium gain 6SN7 type tubes or the aforementioned tubes with adapters.

Wow I didn't know the recommended type was the 6SL7,
No wonder I found them more lively.
I currently use the 6C8G equivalent because I find them either similar and sometimes more holographic,
and beautiful looking as well.

Hello friends,

I have also ordered a LD MKVI+.

It's indeed an excellent sounding amp. Far better than I expected.

I've order directly from David and mine came with Mundorf caps and fanless design. 

Does anyone also have the fanless design model? I noticed it runs very, very hot...

I do also hear a hum outside the amp.

The hum outside the amp is normal, but can be either noticable or not depending on tubes heater drain.

Also, between the two Transformers is a metal covering protecting the two power transistors that are used in the PSU for regulation purposes.

The two rectifiers that are inside are solid state devices, which are VERY heavily filtered with four massive electrolytics..
Then another two after those power transistors,
Making for a very good "musical " PSU.

The driver stage PSU Wich is different, is less so but takes advantage of RC filtering very well.
Also, the driver heaters are running on elevated ground to guarantee no hum.

Design wise,
Both MK6 & MK8 are very effective amps,
and make great units to learn about tubes,
and modify to greater heights..

 

[ericohgb]

Wow I didn't know the recommended type was the 6SL7,
No wonder I found them more lively.
I currently use the 6C8G equivalent because I find them either similar and sometimes more holographic,
and beautiful looking as well.
The hum outside the amp is normal, but can be either noticable or not depending on tubes heater drain.

Also, between the two Transformers is a metal covering protecting the two power transistors that are used in the PSU for regulation purposes.

The two rectifiers that are inside are solid state devices, which are VERY heavily filtered with four massive electrolytics..
Then another two after those power transistors,
Making for a very good "musical " PSU.

The driver stage PSU Wich is different, is less so but takes advantage of RC filtering very well.
Also, the driver heaters are running on elevated ground to guarantee no hum.

Design wise,
Both MK6 & MK8 are very effective amps,
and make great units to learn about tubes,
and modify to greater heights..

Thanks Maxx134,
 
In your experience,
How can I make the hum less noticeable?
 
Best,
Érico

 

[Maxx134]

Wow I didn't know the recommended type was the 6SL7,

No wonder I found them more lively.

I currently use the 6C8G equivalent because I find them either similar and sometimes more holographic,

and beautiful looking as well.

The hum outside the amp is normal, but can be either noticable or not depending on tubes heater drain.


Also, between the two Transformers is a metal covering protecting the two power transistors that are used in the PSU for regulation purposes.


The two rectifiers that are inside are solid state devices, which are VERY heavily filtered with four massive electrolytics..

Then another two after those power transistors,

Making for a very good "musical " PSU.


The driver stage PSU Wich is different, is less so but takes advantage of RC filtering very well.

Also, the driver heaters are running on elevated ground to guarantee no hum.


Design wise,

Both MK6 width: 600px; height: 338px">
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Thanks Maxx134,

In your experience,
How can I make the hum less noticeable?

Best,
Érico

On stock unit,
The Transformers are covered by black metal covers.

Make sure on the sides, that the screws are tight...

If that not help,
Unscrew and remove black cover, exposing the transformer.

The center bolt should be tight and snug..

With unit on, press onto Transformer with your hand.

If that reduces vibration/hum,
Then the center bolt may not be firmly tight.
Check if bolt of loose.
If snug, then only a few millimeters budge tighten will do it.

That is only if the hum reduce when pressing on Transformer..

Also, as stated before, tube heater current drain can cause more hum.
Swap tubes to see if it is a tube stressing the Transformer, as the heater elements are direct comnected AC to transformer.

Also,
I take no responsibility for your implied void warranty!
Lol.

 

[HiGHFLYiN9]

Sorry to bump an old thread, but noticed the MKVI+ is on Massdrop currently.

Also, if you're dealing with transformer hum, there are only two devices I know of that can help. The discontinued PS Audio Humbuster, and the Emotiva CMX-2.

One question about the amp, it looks like it has a volume motor for a remote control, but I don't see any mention of that. Any ideas?

 

[Corydoras]

can anyone share if PSVANE UK 6SN7 or general 6SN7 gives great sound for MK6+? I am trying to see if Alixpress is better as Ebay is f overpriced

https://www.aliexpress.com/item/1005005186654431.html?spm=a2g0o.cart.0.0.1e3438da2jDWJv&mp=1

 

[ViperGeek]

can anyone share if PSVANE UK 6SN7 or general 6SN7 gives great sound for MK6+? I am trying to see if Alixpress is better as Ebay is f overpriced

https://www.aliexpress.com/item/1005005186654431.html?spm=a2g0o.cart.0.0.1e3438da2jDWJv&mp=1

I can't speak directly about the UK-6SN7 but I will say that the Psvane CV181-Z Select (equivalent to 6SN7) driver tubes are currently my favorite. In fact, when I moved over to a Woo Audio WA22, I brought the CV181-Zs with me.

– Dave

 

[Corydoras]

Thanks a million! so i can use this for Little dot Mk6 plus ya? let me find and add it to my shopping cart! woohoo!