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Little Dot MK VI / Little Dot MK VIII SE Owners Unite - Page 73

post #1081 of 1335
Quote:
Originally Posted by DefQon View Post

 

As with my point about removing the bottom plate yep sure works did it with MK6 while it was in one piece.

 

Here is an example of concept that I'm talking about to combat heat, maintaining circulated ventilation and maintaining longetivity of the components in there.

 

That is point to point wiring though. Main problem I have seen with the Mk6 is the heat kinda damage the resistor near the tubes. It's quite rare but I don't really wanna look it up once in a while just to make sure. 

 

I plan to have some furniture made this week (compy table + rack ..etc) - I was thinking on something similar to pkjames in the past:

 

 

 Where I live temporary now the summer can get up to 36ºC/96ºF. I think Australia also got a hot summer as well? You think Mk6 can survive bottomless in the summer? - or should I stick a big ass 200mm fan below just to be sure?

post #1082 of 1335

When you take the bottom off a large fan spinning at a low speed should do the trick. You just need a gentle breeze to carry the heat away and you should have low fan noise as well. The fan does not need to right against the bottom and you might get some air flow at the top for cooling as well. Being creative you may find a cooling solution that will work very well for your needs. Even a quiet USB fan blowing a few inches from the bottom with the amp bottom cover off can do the trick when the amp is placed on slats.  Putting on longer feet with the bottom on can help just a bit in some cases.

post #1083 of 1335

Got a new shelf at my pc so fixing it atm.

It is sleeping atm, hopefully feeling real good at it's new place tomorrow :)

post #1084 of 1335
Quote:
Originally Posted by khaine1711 View Post
 

That is point to point wiring though. Main problem I have seen with the Mk6 is the heat kinda damage the resistor near the tubes. It's quite rare but I don't really wanna look it up once in a while just to make sure. 

 

I plan to have some furniture made this week (compy table + rack ..etc) - I was thinking on something similar to pkjames in the past:

 

 

 Where I live temporary now the summer can get up to 36ºC/96ºF. I think Australia also got a hot summer as well? You think Mk6 can survive bottomless in the summer? - or should I stick a big ass 200mm fan below just to be sure?

 

Yeh I know it's P2P wiring but the catch is P2P allows better airflow and ventilation compared to components cramped onto a PCB even if the PCB has ventilation holes for possible hotspot components (power resistors and such).

 

But you get the idea of what I was trying to say with removing the bottom panel which allows for further ventilation and air flow which is pretty poor of the amount of stuff in the MK6 and MK8.

 

As with the resistor being burnt that was zenpunks MK6. One can always change the resistor to a higher watt spec.

 

Hot summer in Australia? It's currently Summer here and in our state we just had a 4 day Summer heat wave of 40-44'C yes centigrade not fahrenheit, it's finally cooled down to 23'C or so now, bipolar weather for sure.

 

Personally I stick by old school engineering design principles and that is fan's + tube amp's don't go well, it is an invitation for more dust to go in and I don't like the idea of an oscillating circuit from a DC fan going at it inside the amp, measurable or not it's a point to keep in mind.

post #1085 of 1335

I would not worry about dust. I have to keep the filters in my PC clean every moth with all the fans that runs in it. I have seen some horrible dust levels in PC's at work. Even with SS amps having a fan will extend its life even with a huge heat sink. One of the conditions that heat is good for a tube amp is that if you are using beewax caps in it. A gentle breeze is also good for the power tubes and transformers as well. The fans are not as close so I do not have to worry about interference. Water or oil cooled tubes are not unheard of.  Heat is not really a friend most of the time with amps.

post #1086 of 1335

Point to point is a selling point with value chinese amps now, for example, which only put in the components that are the most basic to ensure great sound without interference and low cost. I think this gives them greater control over the design, manufacturing and signal path as well as keeping to their back to basics approach. I've got to hand it to them with the way they are focussing on every element of the design process, for example my miniwatt which I use for speakers has a very small footprint, especially next to the MkVI and that's due to the switch mode PSU.

post #1087 of 1335

I want a p2p version of the MK6 in a slightly bigger chassis (but still retains the general styling) :cool: 

 

Guess I'd go with the fan like this - couldn't be louder than the TYF 140 fan in my Silver Arrow :D

 

post #1088 of 1335

khaine1711

Looking pretty  good. One of the advantages of using a larger fan is that generally the fan noise would be lower pitch. What is the RPM of the fan?

post #1089 of 1335
Quote:
Originally Posted by khaine1711 View Post
 

I want a p2p version of the MK6 in a slightly bigger chassis (but still retains the general styling) :cool: 

Personally, I just want a better chassis. On the one hand to put a stepped attenuator, and on the other hand to put big capacitor !

post #1090 of 1335
Quote:
Originally Posted by john57 View Post
 

khaine1711

Looking pretty  good. One of the advantages of using a larger fan is that generally the fan noise would be lower pitch. What is the RPM of the fan?

That was pkjames pic, mine is still in the planning stage :D.

 

Looking around local store I can only find 1000 and 800 rpm 200mm fan (Xigmatek). I'm thinking of either getting two silent 120mm fan (Cougar/Scythe) or order a 230mm fan - I think I got two noctua 80mm laying around my drawer too.

post #1091 of 1335

I followed 'pkjames's' design, even used exactly the same fan,Bitfenix Spectre 230mm 900 RPM <20dBa. I fitted 2 stainless steel mesh filters on the bottom of the Little Dot (to replace the wire fan covers) and fitted a plastic mesh filter before the fan. The plastic mesh filter is designed for computer fans and mounts magnetically. I cut out some steel plate from an old computer case to get a steel surround for the fan, so that the filter mounts easily and can be removed and refitted quickly and easily. The steel plate is stuck down with duck tape, not pretty but it is under the shelf that holds the amp and can only be seen if I am laying down on the floor. I am using an external power supply to run the fan so that no electrical interference from the fan affects the amp. This also allows me to continue to cool the amp after the amp is switched off, and down here in Aus the temperature gets HOT so keeping the amp cool is an important thing.

 

I have found this design to work very well. Even with the bottom plate still on the amp and air being forced through the stainless steel filters, the air flow can be felt when I hold my hand above the tubes. And the noise of the fan blowing the air is almost nothing. I did make a wooded 'skirt' around the base of the amp, to force the air through the amp and not out the sides through the gap under the amp beside the feet. And the BLUE LED lights on the fan remind me that the fan is still switched on so that I don't forget about the fan and leave it on all night.

 

I found the photos and instructions from 'pkjames" to be very helpful. 

post #1092 of 1335

Wooden skirt under amp.

 

Before the wooden skirt, and on it's side for some reason?

post #1093 of 1335
Quote:
Originally Posted by baronbeehive View Post
 

Point to point is a selling point with value chinese amps now, for example, which only put in the components that are the most basic to ensure great sound without interference and low cost. I think this gives them greater control over the design, manufacturing and signal path as well as keeping to their back to basics approach. I've got to hand it to them with the way they are focussing on every element of the design process, for example my miniwatt which I use for speakers has a very small footprint, especially next to the MkVI and that's due to the switch mode PSU.

 

P2P wiring also increases the cost of the amp, it's only been recent years that the Chinese have started to use it (some designs and circuits to be frowned upon though), I for one hate crowded PCB designs for tube amp's. 

post #1094 of 1335

I just ordered a 'Jensen Transformers DM2-2RX' 

 

 

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It will allow me to attach single ended output audio equipment to the Little Dot MK VI+ XLR inputs. The Jensen Transformers are said to be very transparent, often used by the broadcasting industry and recording studios. I bought it especially to connect my new phono stage to the Little Dot.

post #1095 of 1335
Quote:
Originally Posted by ozaudios View Post



Wooden skirt under amp.






Before the wooden skirt, and on it's side for some reason?

Just wondering what tubes are you using on the little dot MKVI?
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