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Little Dot MK VI / Little Dot MK VIII SE Owners Unite - Page 62

post #916 of 2374
Quote:
Originally Posted by 2K9R56S View Post
 

 

Close to it.  And only on low gain.

ofc only on low gain... my old Hybrid Tubes where really noisy on high gain with the w1000x as well 

post #917 of 2374
Quote:
Originally Posted by Opethian10 View Post

I took my busted MKVI+ to a local reputable shop in San Jose yesterday. Originally thought it was just a bad fuse, but the shop owner thinks the power transformer malfunctioned as well. Looks like I'm biting the bullet and sending this one back to China for repair.

Aside from that, has anyone tried drilling holes into the top of the amp for ventilation? It seemed to us that there is no place for heat to escape with the standard enclosure. Wondering what good the fans even do under this assumption.

Thanks for any feedback.

 

Ouch! Sounds like the same problem my unit had. 

post #918 of 2374
Quote:
Originally Posted by elwappo99 View Post

Ouch! Sounds like the same problem my unit had. 
This is the same amp!! I bought it from you, remember smily_headphones1.gif
Edited by Opethian10 - 10/25/13 at 4:21pm
post #919 of 2374
Theoretically the ventilation in the VI and VIIi SE is fairly poor for the amount components inside, the holes around the tubes is not sufficient enough. The case work is definitely an area David skimped out on in costs which explains some of the overheating problems presebt in the unit.
post #920 of 2374
Quote:
Originally Posted by DefQon View Post

Theoretically the ventilation in the VI and VIIi SE is fairly poor for the amount components inside, the holes around the tubes is not sufficient enough. The case work is definitely an area David skimped out on in costs which explains some of the overheating problems present in the unit.

Sword yang is the designer and there was just a few slots on the circuit board for ventilation. That is a pitfall of using circuit board in hot running amps. My Quicksilver mono M135 blocks amps do not have fans since it is a hand point to point wired design. My concern is the transformers do not get any ventilation at all.  My custom tube amp from Glenn did run hot most of the time.  

post #921 of 2374
Using point to point for amp like this would've meant more ventilation but would mean the amp will cost 2-3x as much and a bigger chassis required.
post #922 of 2374

Yes, all designs involves compromise. Just hopefully that my LD VI+ will last a long time.

post #923 of 2374
Quote:
Originally Posted by john57 View Post
 

Yes, all designs involves compromise. Just hopefully that my LD VI+ will last a long time.

I'd probably rebuild the LV VI+ in a bigger chassis if I were to keep it as an end game amp. That said I need to find the pieces of my VI+ that I salvaged for another amp. (Yes guilty).


Edited by DefQon - 10/25/13 at 6:40pm
post #924 of 2374
Quote:
Originally Posted by Opethian10 View Post
 
Quote:
Originally Posted by elwappo99 View Post

Ouch! Sounds like the same problem my unit had. 
This is the same amp!! I bought it from you, remember smily_headphones1.gif

 

Gah! I was in a rush and replied without even looking at your name. Wonder what the issue is? David had Sword do a lot of testing on the unit to ensure it was in really good shape. Please mention to him you purchased the unit from me and really push him on it. He assured me it wouldn't be an issue. 

post #925 of 2374

That's a shame, don't anybody try to follow my speaker setup mentioned earlier. I just found out that it is not advisable to use the LD as a preamp to a direct coupled power amp due to the danger to the speakers if a valve malfunctions. I say a shame because it was pretty much the perfect setup with the LD moderating the digital tendencies of the power amp, a nuforce icon-2, and producing a lovely round sound without any annoying splashyness of the high hats etc. Oh well no tubes in my speaker setup, damn!

post #926 of 2374
Hello Everyone,

I am a long-time reader and finally decided to buy a Little Dot VI+ and DAC_III. I am using them with my eight year old HD650 which I bought a set on balanced cables to use with the MK6. Still have the original tubes, GE 6080 x 4 and some Chinese 6N9P, but have already bought 4x Western Electric 421A and 2x TungSol 6SU7GTY. Unfortunately those have been shipped to my home and I am traveling. I chose those tubes based on a lot of reading here and the fact that I found them very cheap.

So far, I love the MK6. Even with the original tubes, the sound is much more defined and rich than any other source I have used in the past. Having said that, I must say I am looking forward to the 421a and 6SU7GTY replacements!

Now for two questions I have. I know I am new here and no one here owes me any answers, but I would appreciate any feedback from anyone that might know. Hopefully, I will learn from now and be able to help others in the future.

1) In 4 power tube amps, like the MK VI, do all four tubes need to be matched or is it OK to have two matched pairs?

2)My DAC_III output channels are reversed. Right is left and left is right. I texted the designer and he replied "The SAMP key output channels can be exchanged". Is he saying that there is a setting, or is he saying I should simply reverse my cables and plug the right cable into the left output, etc...? I suppose that would not have any adverse affect, but not sure if I am completely pleased if the output channels have been wired backwards in a brand new unit.

Sorry to sign up and start off by asking questions. I just found from reading this forums there are many knowledgable, helpful members here.

Thanks in advance!

Karl
post #927 of 2374
Quote:
Originally Posted by Karllin View Post



1) In 4 power tube amps, like the MK VI, do all four tubes need to be matched or is it OK to have two matched pairs?



Karl

one matched pair for one channel is ther minimum.

i always bought quad matched tubes for not having balance problems

post #928 of 2374
Thank you, alota.

Is the issue that the lower rated tube channel will have less volume, different sound, or both?

The reason I asked that question is I bought four 421a tubes that are rated 77/76, 77/77, 76/75, 76/76 with 40 being min. good. Now I am thinking to buy a spare set, but I have only found one pair, so far that is rated 46/47 and 44/45. So if I were to place the 40s pair on one channel and a pair of the 70s on the other, will there be a large discrepancy in sound quality or volume, I guess both?

Thanks again!
post #929 of 2374
Quote:
Originally Posted by Karllin View Post

Thank you, alota.

Is the issue that the lower rated tube channel will have less volume, different sound, or both?

The reason I asked that question is I bought four 421a tubes that are rated 77/76, 77/77, 76/75, 76/76 with 40 being min. good. Now I am thinking to buy a spare set, but I have only found one pair, so far that is rated 46/47 and 44/45. So if I were to place the 40s pair on one channel and a pair of the 70s on the other, will there be a large discrepancy in sound quality or volume, I guess both?

Thanks again!

i don´t know the answer to this.

but when i had problem with my tubes, i bought one pair with diferent vlaues and i did not hear a big difference.

probably, this is due to the dual-mono configuration.

i hope that some head-fier with technical knowledge will help you

post #930 of 2374

The amp is self-biasing so it shouldn't matter. Your seem to have nice strong tubes measuring very close to each other so you are good.

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