[Redge78]

  I would like to re-echo Mogos' request for more particulars about each mod. E.g. in the coupling capacitor section, how are these labelled on the pcbs, where do we find them (arrows on photos would help)? What voltage specifications should replacements be, etc.

 
OK, no problem. I'll add the Voltage specs. And caps orientation (the Fen-shui of the amp ...) as we discussed that in the MK6/MK8 main thread
We may also add an "How to ..." chapter with all the "less formal" data we gathered and that can make one's life easier. 

 

[Maxx134]

Cathode bypass cap section updated...

I consider this a huge beneficial upgrade from the cheapo blue electrolytics,
Which seem as two tiny caps encased in an imitation bipolar configuration,
Inside a blue "see thru" housing...
Edit:
But actually is just one dual cap with 3 pins converted to two..

It is an Extremely smart cost effective solution for a manufacturer,
But far from optimal sonic performance,
So a clear upgrade potential.

Take note I am not bashing in any way LittleDot,
But commending how smart their solutions were to maximize cost effective solutions.

Yet remember, this thread is about maximizing the true sonic potential,
hidden in the Little Dot amps...

 

[coinmaster]

 
Quote:

Where to put those Decoupling caps ?
Each centimeter/inch of wire will bring an extra impedance that will have an impact on the speed of the current needed.
So those caps need to be put as close to their associated tube as possible.
Ideally, they will be soldered directly on the leads of the Anode resistor (+200V side)  and the Cathode resistor (Ground side). 
Don't underestimate the difficulties that this constraint will bring, having to stick large caps in a small space is not that easy.

True statement!!!!!!! 
I'm in the middle of ripping everything out of the aluminum chassis. It was simply too hard to put back together once taken apart with those giant capacitors I'm using for the decoupling. 
 
I'm going to make the entire structure out of wood and I'm taking this opportunity to upgrade the Enla Silmic electrolytic capacitors I'm using for the cathode bypass capacitors with 8 of the giant MKP capacitor types I have littering my wood box, like the ones below.


Why 8 of them? Because they don't come in 470uf so I'm doubling up.
The only reason this is going to work is because I no longer have the aluminum chassis getting in my way.
Now I just gotta blow 700 bucks on some more caps.

 

[Maxx134]

What you really need is to be very carfull you dont get shocked(!) By those caps!

You wont know if there is any charge on them if they have been tested before shipped...

Wear surgical gloves,
As this IS surgery when you go down the "rabbit hole" of supermods which will truley bring you to another world...
Another level where very few other amps reach(!)

 

[Mogos]

COMPACT VERSION

Ok this is a current picture of my amp internals...


...........

The gold "bypass" caps are also connected in inparallel to them,
and the combination provides for an extremly fast design(!).

Maxx134 all the bypass caps are as these ones:
PME-040: 0.033uF 275Vdc Evox Rifa PME271M

 

 

[Mogos]

One more thing. Could you guys point out the soldering points of the added decoupling caps on the PCB (Anode resistor (+200V side)  and the Cathode resistor (Ground side)).

 

[colliedoggy]

And I'd like to add further to Mogos' request for the same information please about the 'bypass' and 'cathode' caps.
 
Thanks

 

[coinmaster]

I'm sure he will update the guide with that information but for now

See the large brown capacitors in the middle? Those are what replaced the blue caps (cathode bypass), and the black resistors to the right and left of them? Those are the power resistors we replaced.
You want the decoupling caps to go between those two points from the south side lead, you will also be putting another bypass cap (those rifa caps) in .33uf between those points as welll. You see how this area will end up having a lot of components..
 
This is what I did for the bypass caps

 

 

 

[Maxx134]

That was a very good idea to put on other side of board, but I didnt want to go thru the hassle..

Only the bypass caps on my component side are .33uf, NOT .033uf

This side is not critical, and can be .22 as well.. but I would not go higher than .33uf, and use types (RIFA)suggested in fisrt page for optimal sonics.

What IS ALSO very important, are the Cathode bypass caps...
They were selected specifically for their sonic traits and need be the same .1uf RIFA, as stated in first page, exact type.
Size was determined so as to not interfere with the electrolytic sonics of the electrolytic choices of cathode bypass caps..

 

[Maxx134]

Here is a pic of the decoupling cap locations,
I May include it later in first page..

Once you see, it is very straightforward and easy..

 

[Maxx134]

There will be more info updated in first page, as we find time.

For example the resistors..
The MK8 has a more linear "enhanced" version of the "white Cathode Follower", which includes grid resistors to upgrade,
Which are not in the mk6..
Yet the mk6 still needs upgrade of grid resistors in driver tube stage, by volume control,
IF they are the blue resistors..
If they are the brown type, you are good.

 

[Mogos]

............

What IS very important, are the Cathode bypass caps...
They were selected specifically for their sonic traits and need be .1uf wimas, as stated in first page, and exact type,
so as to not interfere with the electrolytic sonics of the 220uf cathode bypass cap..

Maxx134 I am a little confused. On the first page as an example solution are shown (Elna Silmic 2 470µF/50v // RIFA PME 0,1µF/250V). So no wimas. My question was about bypass caps for decoupling (by the way thank you very mutch for the photo. I need to know the points of soldering to plann maximum "volume" capcitors).
So for the bypassing of the decoupling caps you have used 0.33uF 275Vdc Evox Rifa PME271M.

 

[coinmaster]

.33uf Rifa caps for bypassing the decoupling caps. 
Elna Simic caps for replacing the cathode bypass caps (blue caps)
.1uf Rifa caps for bypassing the cathode bypass cap replacements (Elna Simic)
 
He meant Rifa not Wima, that was a typo.

 

[Mogos]

Now everything is as plain as a day. 

 

[Maxx134]

...He meant Rifa not Wima, that was a typo.

Yes thank you