[baronbeehive]

This is a pic of my mods to show how everything fits:

 

[coinmaster]

Redge???...... who????

The guy who made the thread.

I just implemented the "5998 bias mod" on my new output stage where I had the 5998s installed (consisted of changing out a 1 meg resistor with a 10meg resistor, easy) and while there was an improvement in holography and bass the vocals went to crap. Terrible mid range.
I switched it back and it was way better, far more realistic and intimate vocals. No doubt this anomaly is due to the tube mixing I'm doing. If only I had distortion testing equipment, the things I could learn.

 

[baronbeehive]

The guy who made the thread.

......

I know .....sorry, bad joke...... sorry Redge, if you're there.. I do know who you are!

 

[coinmaster]

Well isn't that interesting.
I don't have a 5998 spice model but I simulated my above situation running 6as7 tubes with the follower on the left half of the load @ 75ma and the right half running @9ma and the distortion of the output (no nfb) went from 1.9% to 0.7%, quite an interesting result, that may explain why the 5998 mod sounded bad when I implemented it in mixed tube configuration. I may be onto another potential mod here.
I simulated it with the original white cathode follower and my "leamy follower" topology (Named it after myself, a bit pretentious and I feel uncomfortable doing it since broskie did all the tough maths for me but broskie already has a "broskie follower" and the concept was my idea plus this mod has no name so I gotta call it something, maybe the leamskie follower? )

The distortion was lower on both topopogies when one of the stages was running on low current, although mine was maintaining push pull while the WCF was not, which is good because it means mine does what it's supposed to.

Someone that doesn't have the 5998 bias mod in place try out this configuration and let me know what you hear 6080/5998/6080/5998 left to right.



"edit" It looks like the distortion reduction may be assisted by the load dissipating around 1/4 less power due to the lower current in one of the follower stages, interesting how the distortion got cut by 65% and not 25%.

 

[gug42]

BTW have you seen this: http://www.humblehomemadehifi.com/Cap.html
It may help you make up your mind about caps.

Nice website ! I wasn't thinking the Caps could be tested (in heard way) as tubes ! First for me.
Thank you for sharing

Anyone try the "Intertechnik Audyn True Copper Max MKP 630VDC - 2% tolerance" ?
Seems really close the Jupiter PIO for more than half the price, so could be really interesting ! Need x4 for coupling caps (driver stage <=> power stage ), and x4 for WCF coupling caps (inside power stage) ...

This is a pic of my mods to show how everything fits:

Nice peace of work ! impressive !
Did you remember what's stuff/composents did you use ?

Well isn't that interesting.
Someone that doesn't have the 5998 bias mod in place try out this configuration and let me know what you hear 6080/5998/6080/5998 left to right.



"edit" It looks like the distortion reduction may be assisted by the load dissipating around 1/4 less power due to the lower current in one of the follower stages, interesting how the distortion got cut by 65% and not 25%.

Can I try with TS 6AS7G insteed of 6080 ?
Really I found the stock thomson to be a little too much bright and agressive ...

 

[coinmaster]

The rules get thrown out when you mix tubes. I found the stock 6080WAs to sound superior when tube mixing in nearly all combinations, although mullards are also really good.
Rather then being bright the stock thomsons add low end heft and lushness to the sound.
I think adding 6as7 with the 5998s will actually be on the bright side but you can try both and see what you like more.
Unfortunately I've forbid myself from listening to my headphones until august to give me ear a chance to heal.

 

[gug42]

I have try stock thomson 6080WA and Sylvania 5998A in this oder, left to rigt : 6080 5998A 6080 5998A.
- There was a little hum
- I found the sound a little too bright, a little bit aggressive. Like it was with the 4x thomson 6080A.

Indeed I prefer my 4x Tung sol 6AS7G.
Well, now, I'm hopping that 4x Sylvania 5998A will do a good job .... I'm waiting for the other matched pairs

 

[baronbeehive]

Nice website ! I wasn't thinking the Caps could be tested (in heard way) as tubes ! First for me.
Thank you for sharing

Anyone try the "Intertechnik Audyn True Copper Max MKP 630VDC - 2% tolerance" ?
Seems really close the Jupiter PIO for more than half the price, so could be really interesting ! Need x4 for coupling caps (driver stage <=> power stage ), and x4 for WCF coupling caps (inside power stage) ...

Yeah, they were what I was going to try but didn't because of the size. What I've heard is that they are practically as good as you say. I know Maxx has these in his other amp, so he might tell you, but they are BIG!

.....

Nice peace of work ! impressive !
Did you remember what's stuff/composents did you use ?

Yes my parts list is on page 53.

The rules get thrown out when you mix tubes. I found the stock 6080WAs to sound superior when tube mixing in nearly all combinations, although mullards are also really good.
Rather then being bright the stock thomsons add low end heft and lushness to the sound.
I think adding 6as7 with the 5998s will actually be on the bright side but you can try both and see what you like more.
Unfortunately I've forbid myself from listening to my headphones until august to give me ear a chance to heal.

Agreed about the tubes but I think 6AS7G RCA's might give the mellowness gug42 is after.

That concert you went to must have been LOUD, sounds like you might have damaged your eardrums.

Edit:
I think you will find Sylvanias a bit on the bright side, TS5998's would be much mellower if you can get hold of any at a fair price.

 

[coinmaster]

Hmm, maybe its the difference in our headphones, mine isn't bright at all. Try mixing them like this 5998/6080/5998/6080. I encourage you to try with the 6as7s too.

That concert you went to must have been LOUD, sounds like you might have damaged your eardrums.

It was so loud it should have been illegal.

 

[gug42]

Yeah, they were what I was going to try but didn't because of the size. What I've heard is that they are practically as good as you say. I know Maxx has these in his other amp, so he might tell you, but they are BIG!

Audyn Body dimensions: 30mm (diameter) x 45mm (length)
Jupiter Dimensions: 21mm (diameter) x 52mm (length)

Duno if it's a problem within the mk6 ... did it feet in the boxe ?!?

But Well did you have some caps in the same price range ?
Ineed 80€ for a jupiter is a bit high

Yes my parts list is on page 53.

Thank you !
https://www.head-fi.org/f/threads/l...re-on-first-page.782183/page-53#post-12280541

Agreed about the tubes but I think 6AS7G RCA's might give the mellowness gug42 is after.

That concert you went to must have been LOUD, sounds like you might have damaged your eardrums.
Edit:
I think you will find Sylvanias a bit on the bright side, TS5998's would be much mellower if you can get hold of any at a fair price.

I have a quad cetron whos coming (the plate looks like Tung Sol 7236 but without the third mica and the added support for this third mica).
Well RCA 6AS7G is on my test list ...but well can't test evrystuff in the world

Hmm, maybe its the difference in our headphones, mine isn't bright at all. Try mixing them like this 5998/6080/5998/6080. I encourage you to try with the 6as7s too.

It was so loud it should have been illegal.

Why not !
Sorry to read about your ear problem bad news

 

[baronbeehive]

Audyn Body dimensions: 30mm (diameter) x 45mm (length)
Jupiter Dimensions: 21mm (diameter) x 52mm (length)

Duno if it's a problem within the mk6 ... did it feet in the boxe ?!?

But Well did you have some caps in the same price range ?
.........

No I went for the Jupiters in the end.

The dimensions you give 30mmx45mm are for Audyn True Copper Max, the True Copper are 40mmx36mm for 0.47uF so be careful. They would not fit. The True Copper Max might if you arranged them like this but it would be tight:

I didn't do this in the end because I had to get 2 large Wima caps in for the driver stage!

 

[coinmaster]

I'm surprised no one here has tried that "bathtub" mod.
If you fill your bathtub halfway with water and make sure the water temperature is about 50c and put your amplifier in it, it makes the sound so much more "liquid", you should try it.

 

[gug42]

Thank you for this nice photos ! Impressive jobs by the way (blow job ? )
I was talking about the max version

Well indeed if you a good cap, small physical size, money value (=< 30€), I will go for it

 

[gug42]

And after some more readings, the "antzen Audio Superior Z-Cap" could be the better money value ... any opinions ?

 

[coinmaster]

You're getting caught up in the details, don't mess with success. The jupiter caps are almost as good as duelund caps meaning if you like transparent sound then just go with the jupiters. If you wana roll the dice with sound shaping then try something else.