[baronbeehive]

Yes, although I do have the muse(kz), which are very good, I decided to go for what I feel may have more depth.

In this cathode position, we had already placed nice paper/oil bypass caps for upper end, so my goal instead, was to increase capacitance for bass sustain, and then pick a brand that I feel will give me unique attributes.

The elna is known for smoothness which I not need. Then, the Nichicon KZ-muse is known for clarity and balance, which I already have.
But Then this kaisie is supposed to be closer to "blackgate" in attributes, plus in my research it was said to have more depth and life.
So we will see.

I am interested to hear your findings. I went for stock values, 220uF, purely because they fitted in without yet more modification!

I certainly wouldn't change the Kaisei's in my APPJ.., I continue to be shocked by it, and I see the APPJ thread is still going strong. The APPJ and LD MKVI make a great combo, with similar performance levels. The APPJ for speakers, and the LD for headphones.

Hope you can remember where you left your LD lol!
.

 

[baronbeehive]

... probably gathering dust in the broom cupboard... .

 

[Maxx134]

... probably gathering dust in the broom cupboard... .

Nope, my unit

is safe in a drawer at my mom's house.

I learned a lot with this amp.
Changed/altered every stage, but main thing was the realization of all the choices that a designer picks & chooses, for their recipe of design and parts.
That's why I am being selective this last time.

 

[Maxx134]

I should & will eventually update my choice of main coupling cap, from Jupiter, to the MIFLEX KPCU Film Capacitors.

Although it lies in the realm of preference, as both are in same league, I am enjoying it's delicacy.
I consider the "Jupiter" being more natural, and the "Miflex" being with a hint of signature.
It has been mentioned in past to be between the Jupiter & the Deulund.
They all already at top level resolve in this circuit position.

The main advantage is cost.
The Milflex are less than the rest, and even bring a hint of the mundorf in sweetness.

I consider the mundorf to be very nice in sound, but a touch artificiall in trebles and a slight lower in absolute image resolve.

I have noticed that the mundorf are the most common used in tube amps because of their sound and popularity.
I only preferred the mundorf in the "WCF" position.
In that specific position, they imparted their sweetness majic there without any loss of resolve.

 

[baronbeehive]

The main advantage is cost.
The Milflex are less than the rest, and even bring a hint of the mundorf in sweetness.

They look very good value!

I have noticed that the mundorf are the most common used in tube amps because of their sound and popularity.
I only preferred the mundorf in the "WCF" position.
In that specific position, they imparted their sweetness majic there without any loss of resolve.

By a roundabout process I eventually used Mudorf SIO in the WCF position. Originally they were for coupling, then as the capacitance and composition was ideal for WCF I decided on that together with Audyn True Copper for coupling, then as they were too big to fit I went with Jupiters for coupling... my wallet has only just recovered... glad I did, but might well have used Miflex had they been around at that time.

I think the amp does need something which will emphasize trebles such as the Mundorfs do in WCF position. That's also why I went for OCC silver output wires, eventually I will finish replacing the wires to the headphone socket. I realised this when comparing to the APPJ which to my mind has a perfect bass-treble balance and just the right amount of treble presence. I feel that pure silver wires just might make all the difference to the treble register.. but this is already good.

 

[baronbeehive]

Nope, my unit

is safe in a drawer at my mom's house.

I learned a lot with this amp.
Changed/altered every stage, but main thing was the realization of all the choices that a designer picks & chooses, for their recipe of design and parts.
That's why I am being selective this last time.

I apologise lol!

...not a trace of dust in that cupboard... but looks like your mom left the amp on all that time!

Good to see that amp again...

It should be interesting to see what effect your choices have made on the amp.

 

[baronbeehive]

I learned a lot with this amp.
Changed/altered every stage, but main thing was the realization of all the choices that a designer picks & chooses, for their recipe of design and parts.
That's why I am being selective this last time.

Yep, quite right!

I feel that the mix of upgraded parts is just about right. It has pushed the amp right up there with the big boys. I realize that there are amps out there that do this or that better, but the LD and APPJ do nothing wrong and pretty much everything right for me. ottom line is that when you have reached the sound signature that you really like it would be silly to change anything so I'm very happy. The amp has great resolve, clarity, airy soundstage, great balanced frequency range and extension, liveliness, euphoria, everything you could want. Only thing I will do is go for a top level cable such as the one you have for a few percentage points increase but I'm enjoying this so much I haven't bothered as yet. Of course if I had limitless finance available on tap....

I don't think there's anything else that could be done to the amp without completely rebuilding it, same goes for the APPJ, so I think we've reached the end of the line... probably...!

When I took the amp to the engineer after I had done the first lot of mods to check there was nothing wrong his mind was boggled when he saw what we had done inside lol!
.

 

[Maxx134]

When I took the amp to the engineer after I had done the first lot of mods to check there was nothing wrong his mind was boggled when he saw what we had done inside lol!
.

Haha that would've been great to see.

I believe you did the CCS mod in the driver stage, correct?

I didn't because of all the work and trial to manually tune my bias point for a specific tube.

After all my tube roll(which I did initially), I was in effect bias point rolling on a few of my favorites tubes to tune in my selected bias point. So it was alot to tuning and listening.

Then the topic of applying a CCS, I was afraid because I would probably loose any tube characteristics that I had tuned in, from the traditional design.

So although the CCS makes is full-proof and easy to have more optimal parameters for the tube, I chose to not use it on my amp.

Why?
Because I essentially rolled every 12pin variant that existed, then went thru many 6pins that the MK6 was using.
I spent easily over $1.5k of tube rolling, before I settled on a 6pin, on an MK8, which is normally designed for the much smaller 12at7 tube type.
So I'm pretty much settled on my combo of tube and bias circuit setting, for that amp.

 

[baronbeehive]

Haha that would've been great to see.

The only problem with that was that it means they don't want to work on the amp because of the difficulty level. But they said that they were mightily impressed that a relative beginner did that, many experienced engineers would have had difficulty with work of that sort!

Looking back it certainly wasn't easy and especially wouldn't be for those of a nervous disposition not to burn out the insides with a slight tremor of the hands!

 

[baronbeehive]

I believe you did the CCS mod in the driver stage, correct?

I didn't because of all the work and trial to manually tune my bias point for a specific tube.

Yes, and the active filter MrCurwen suggested using to clean up the PSU.

After all my tube roll(which I did initially), I was in effect bias point rolling on a few of my favorites tubes to tune in my selected bias point. So it was alot to tuning and listening.

Then the topic of applying a CCS, I was afraid because I would probably loose any tube characteristics that I had tuned in, from the traditional design.

So although the CCS makes is full-proof and easy to have more optimal parameters for the tube, I chose to not use it on my amp.

That was exactly what I was afraid of losing. I had already tuned in the operating point in the listening tests and found my preferred one which was close to yours. However the operating point chosen by Sonic for the CCS retained the characteristics that I had already preferred for the 6SL7 so that was a massive relief. All the liveliness and impact, and the signature of the LD, were still there.

The other thing I found with the CCS was a total lack of the negative harmonics which can spoil listening... HOWEVER... this was very difficult to detect and I wasn't sure that I was just imagining it until MrCurwen said that this was a characteristic of the CCS and force balance. So I have kept the CCS mainly because I don't need the tubes to do the balance for me now. Bottom line is that the amp sounds great with it in, and I am reassured that the sonic benefits of the CCS and balance will always be there.

The filter didn't affect the sound in any way, but again I am reassured that it will keep the PSU clean.

I spent easily over $1.5k of tube rolling, before I settled on a 6pin, on an MK8, which is normally designed for the much smaller 12at7 tube type.
So I'm pretty much settled on my combo of tube and bias circuit setting, for that amp.

You're still using the TungSols? I forget which one.

I'm still using the bog standard TS GRP's. I did think of trying the Brimars again which are so euphoric but having decided on keeping the TS's a while back I will probably stick with those, they are also euphoric with a cleaner and more balanced sound IMO.

 

[baronbeehive]

Just been looking at the new LD website. They have an interesting range of new products including a mono block amp.

A couple of interesting quotes from the site:

"Good sound comes from good electronic components"

"listening to any music will give you a refreshing and transparent feeling."

"The own enthusiast can replace the op amp of the decoder part, the coupling capacitance of the amp part, etc., but it is not recommended for the novice DIY."

Looks like they've been pretty busy!

... maybe I shouldn't have tried to mod the amp according to the last quote, underlined, lol!

 

[Yaska729]

I should & will eventually update my choice of main coupling cap, from Jupiter, to the MIFLEX KPCU Film Capacitors.

Although it lies in the realm of preference, as both are in same league, I am enjoying it's delicacy.
I consider the "Jupiter" being more natural, and the "Miflex" being with a hint of signature.
It has been mentioned in past to be between the Jupiter & the Deulund.
They all already at top level resolve in this circuit position.

The main advantage is cost.
The Milflex are less than the rest, and even bring a hint of the mundorf in sweetness.

I consider the mundorf to be very nice in sound, but a touch artificiall in trebles and a slight lower in absolute image resolve.

I have noticed that the mundorf are the most common used in tube amps because of their sound and popularity.
I only preferred the mundorf in the "WCF" position.
In that specific position, they imparted their sweetness majic there without any loss of resolve.

Hello Maxx, do you use the same spec 600v 0.47uf with the Miflex? It seems quite large compare with the Mundorf and Jupiter, does it fit into the original chassis? Thank you

 

[Maxx134]

n

Yes, and the active filter MrCurwen suggested using to clean up the PSU

ugg, I forgot to add that post!

That was exactly what I was afraid of losing. I had already tuned in the operating point in the listening tests and found my preferred one which was close to yours. However the operating point chosen by Sonic for the CCS retained the characteristics that I had already preferred for the 6SL7 so that was a massive relief. All the liveliness and impact, and the signature of the LD, were still there

This is really, really good to know... I should also add it also to beginning posts... Still not going to do it though lol.

Hello Maxx, do you use the same spec 600v 0.47uf with the Miflex? It seems quite large compare with the Mundorf and Jupiter, does it fit into the original chassis? Thank you

Nope it not needed as .33 still good for the coupling and the WCF caps... there is a calculator to calculate the low end cutoff point,(https://www.v-cap.com/coupling-capacitor-calculator.php) which is already lower than stock .22uf cap.
I would also mention what is not mentioned, which is not the size, but the voltAGE... higher is better for film cap in this position (in contrast, not for electrolytic types which works best at an optimal value).
Anyways, to me, anything past .33-47uf max in the coupling here is not really any gains. the 47uf was a bit too enthusiastic and not that practical. sub bass will be just fine with .33uf..

 

[CopperFox]

Hi everyone,

As my first mod for the mkVI+, I installed 0.68uf 600V Miflex KPCU-01 caps as coupling caps...



...so I needed to build a case extension as well.



The difference in sound is certainly not small. More detail, clarity, dynamics and dimensionality everywhere.

I'm thinking of adding the decoupling caps and possibly silver wires as well.
Are there some good recent options or recommendations for the decoupling caps that aren't mentioned in the early posts in this thread?

 

[Maxx134]

Hi everyone,

As my first mod for the mkVI+, I installed 0.68uf 600V Miflex KPCU-01 caps as coupling caps...



...so I needed to build a case extension as well.



The difference in sound is certainly not small. More detail, clarity, dynamics and dimensionality everywhere.

I'm thinking of adding the decoupling caps and possibly silver wires as well.
Are there some good recent options or recommendations for the decoupling caps that aren't mentioned in the early posts in this thread?

Yep those Miflex are tops with any others.

The decoupling caps should be small sized like the Rifa.
Yet they won't give you as much improvement as the WCF caps...
Do the WCF caps first for larger gains in sound clarity.
Use your choice of cap.