[jamato8]

The Mills are used for the large voltage drops as they are in the larger wattage and you want to use more wattage than needed for safety and sound reasons. The Riken are used in the smaller voltage drop areas and for the bias and .5meg ohm resistors. Actually using a wire wound inductive resistor in the power supply isn't a bad thing as they just add to the inductance and get rid of a bit of possible noise on the DC. The large value resistor is the one bolted to the internal chassis. You need to use a large wattage Mills or inductive wire wound for that 500 ohm position and if a Mills then know that suspended in air is fine as they are rated for that but some resistors that are suspended that were meant to be mounted have to be derated if not mounted. Either the Mills or an inductive resistor is fine.

 

[jantze]

Thank you takezo & jamato8!
Jack just confirmed what resistors I should use, so everything is clear now.

Here is the "final" list of resistors:
1 X 510R Mills 12 watt
2 X 330R Mills 5 watt
2 X 1K Mills 5 watt
2 X 2K Mills 5 watt
2 X 56K Kiwame 2 watt
2 X 470K Kiwame 2 watt

And these are my new capacitors, if someone is interested later:
2 X V-Cap TFTF 0.15uF/600v
2 X Black Gate Power Tank 220uf/200V (WK)
2 X Black Gate 150uf/350V (VK)
4 X Black Gate 470uF/16V (N)

I just bought a small low temp glue gun, so I'll probably use that to hold down those caps. But I guess I'll try to use those plastic strap fasteners first. I just don't want to drill those holes any bigger.

I'll try to upgrade my amp this weekend and I'll take couple of pics of the process.

 

[jamato8]

I would divide the power supply to the output tube section while doing this. You will get better sound as each output tube will have its own cap, which adds up to better dynamics and in general, sound. You would use 1000ohm resistors in place of the 500 ohm and one more cap.

 

[takezo]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif ...You would use 1000ohm resistors in place of the 500 ohm and one more cap.

hi jamato. can you clarify this last sentence...which "cap" are you referring to,
to double? thanks in advance.

 

[jamato8]

The cap that feeds the output tube section of the two 6DE7's. It is one cap for both sections so one tube will rob power from the other. The power resistor to these two tubes is the larger one mounted to the internal frame, the gold wire wound encased in aluminum 500 ohm, by using two 1000ohm (1K) power resistors in place of the 500 ohm resistor and dividing the power supply and then using another cap, one cap now for each output section, you have a pseudo dual power supply.

 

[takezo]

i see what you mean...the 200uF/200v WK series after the power
resistor...but using a 1000 ohm power resistors, shouldn't i also use
two WK series cap that comes before the 500ohm power resistor?
...or is that unncessary? thanks.

 

[jamato8]

Quote:

Originally Posted by takezo /img/forum/go_quote.gif i see what you mean...the 200uF/200v WK series after the power resistor...but using a 1000 ohm power resistors, shouldn't i also use two WK series cap that comes before the 500ohm power resistor? ...or is that unncessary? thanks.

You could but room becomes a factor.

 

[takezo]

have you modified your unit yet? if not, what SQ improvement do
you predict with the power supply modification? and it would probably
be ideal to have two separate output transformers wouldn't it?
thanks again!

 

[jantze]

I think I'm going to skip this modification. If someone is willing to try out this upgrade and it proves to be something to try out, I will consider this later.

I just don't have enough experience/equipment (testing) to modify my amp.

 

[jamato8]

The amp does have two separate output transformers. Greater dynamics, better transparency and separation of instruments and performers and possibly a larger soundstage, though I find the soundstage of the 6 to be fine. I do find that the 470uf red Black Gate cap on the cathode bias to be a positive step in musical fidelity.

 

[takezo]

it was unclear to me what jamato was pointing to with the power supply mod,
but with his clarification i see that it's actually a very simple mod. you're just
using two separate hook up wires from the power resistor to each of the
output tube section, instead of using one in a series configuration...sorry if
i'm just confusing you more...seeing a pic of the finished mod will clarify what
jamato means...i may do it in the near future and post pics, if jamato hasn't
done it by then...

 

[takezo]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif The amp does have two separate output transformers....

ah...i think i meant, two individual power supply toroidal transformers...

 

[takezo]

Quote:

Originally Posted by jantze /img/forum/go_quote.gif 1 X 510R Mills 12 watt

can you tell me where you're replacing this resistor? i don't remember
using this resistor in the wa6...

 

[jamato8]

Quote:

Originally Posted by takezo /img/forum/go_quote.gif can you tell me where you're replacing this resistor? i don't remember using this resistor in the wa6...

This is the main dropping resistor the the output tube section of the 6DE7.

I would use two 1000ohm resistors because I want the other tube to see just its supply and not the other one. Using one dropping resistor, the current 500ohm doesn't achieve that when you just have two caps coming off of the same resistor. This is not the same as a good dual power supply but it get you close and does improve the sound as I have done this in the past with various systems.

I do have a dual supply in my Elaborate Dac that is a pseudo but when I compared it to a full blown dual I could not hear a difference because the pseudo has and inductor in each supply and is a RLCR achieving almost zero ripple and great reserve for both channels.

 

[takezo]

jamato, shouldn't he be using the aluminum housed 500R MRC
50 watt power resistor instead of this 12 watt axial resistor?

i see your point with the dual 1000 ohm resistors to separate
the power supply from that point...my fingers are getting itchy
to do your mod...