[baronbeehive]

Haha, I didn't expect this.

First the Wimas with Shuguang power tubes:

Hey @CopperFox I've got most of my dynamics back! Over 200 hours burn in and with the Shuguangs in, it was worth sticking with it. As you said the sound has become clearer and opened up a lot, treble is nice and bass weight good and soundstage very good. Everything is there, I would say it's a tad warm and mellow and only the sharp edges are missing but if it's mellow you want this is it. I don't really see the sub bass tightening up that much though which is the reason for trying the Wimas.

Now with RCA's. As above except I've now got ALL of my dynamics back!! Not only is the sound clear as a bell and those Wimas have really opened up. The sound is seamless. Treble is back as before Wimas went in, bass is a tad tighter than before I believe and soundstage is a tad better than Shuguangs. The mellowness has gone and the attack has come back and these RCA's are really hitting the spot.

So I believe CopperFox is spot on when he says that the Wimas allow the other things in the setup to shine.

Given that there could be yet more to come after 200 hours burn in I shall stick with this for the time and live with it until deciding what to do next but I'm very happy.

 

[Maxx134]

Shuguangs

This is good to know, as the one I have we're a bit soft/dull, so I never gave them the chance to break them in..

 

[Maxx134]

That should be excellent. If you're going for Mundorfs they have the same construction as film caps - metallized polypropylene but the electrolytic is oil, so should be some qualities of both.

Hey what about those non polar Kaiseis for cathode bypass?

Even tho Iike the mundorf very much, I am striving for treble clarity instead of sweetness, so I will try some others.

About the kaiseis for cathode bypass, I am actually undecided on that area yet.
I'm worried that the kaisies might be darker than the Nichicons.

But I do think that for PSU those film Wimas would provide fast power to beef up the PSU also

I agree they should be perfect for using as the decoupling caps by the output circuit stage, but I (we) already have film caps there.


Remember?
That's why I keep saying this issue is moot. Any film cap ESR gains by the PSU area, is totally wasted, if not put directly next to the output tube circuit area. That's the whole reasoning for the "decoupling caps".

Guys! I was just checking out those non polar Kaisei's and I came across this in someone's DIY build thread where he mentions putting in the Kaisei's after having no bypass caps in at

Nah, the decision on wether a cathode cap is optimal in a given circuit, is basically depending on the design.
That's why that guy had issues.

Yet our WCF output circuit design is meant to have one

I seen single ended driver stages without a cathode cap(only the resistor), but it was designed to be that way (less gain, more linearity).

Our driver stage is devoid of one as well, but it's Totally different design.

 

[baronbeehive]

Even tho Iike the mundorf very much, I am striving for treble clarity instead of sweetness, so I will try some others.

About the kaiseis for cathode bypass, I am actually undecided on that area yet.
I'm worried that the kaisies might be darker than the Nichicons.

Yep, what about V-Caps? Possibly a bit over the top for cathode bypass.

Yes but the Nichicons don't do non polar KZ's.

Remember?
That's why I keep saying this issue is moot. Any film cap ESR gains by the PSU area, is totally wasted, if not put directly next to the output tube circuit area. That's the whole reasoning for the "decoupling caps".

Definately! I could not physically get them any closer!

Nah, the decision on wether a cathode cap is optimal in a given circuit, is basically depending on the design.
That's why that guy had issues.

Yet our WCF output circuit design is meant to have one

I seen single ended driver stages without a cathode cap(only the resistor), but it was designed to be that way (less gain, more linearity).

Our driver stage is devoid of one as well, but it's Totally different design.

Yeah!

Re: the cathode bypass position, I now believe that film caps.. maybe not Wimas if you don't like them.. are a good bet for this position. This is because it is not only about sound but largely about power handling which film caps excel at, as coin and others found early on in the thread with their huge monster caps. I definately think bass definition has sharpened up and the weight is substantial too. As I said above after 200 hours the sound is as I had heard just after I put in the uprated WCF caps, and with some burn in time left it can only improve further. The sound is dynamic and flows beautifully so I'm thinking of keeping them in as there would be nothing to be gained by putting back the Nichicons. I'm a bit shocked frankly .

 

[baronbeehive]

Well I've had time getting used to this new setup with 1uF WCF Mundorf SIO caps and 150uF Wima film cathode bypasses and I'm absolutely loving it! So I will give you a run down of the changes

Forget about the Wimas being dull and boring, I can now tell you that they are exciting and dynamic, yes you heard me right! In fact it is every bit as visceral as it was with the Nichicons in which makes me think that having film caps in the cathode bypass position shows the other parts to their best such as the WCF and Coupling caps. The difference with them in, between them and Nichicons is small but I think the resolution with Wimas is even a tad better because I'm hearing things I never noticed before. And that soundstage is all enveloping.

The bass deficit in mid to subbass with a soft sound the lower you go down has all but gone, with the bass now it is like there is a whole new dimension to music which I really like. I listened to an album that had bass which was very difficult to hear at all originally and it sounds really excellent now, punchy, powerful, but not overly so, and good definition.

Treble is still there and the extension is excellent so there is no loss at that end of the frequency band.

So I'm very happy with the end result, I believe the amp has gone from endgame to the beyond to an unknown galaxy of audio nirvana and they let me in there for a moment to enjoy their civilization where they listen only to the highest resolution music such as you would never normally hear back on earth.

To give an example of the piano the weight is perfect to reflect the real instrument with attack and timbre, solid bass notes and treble ringing out with superb definition.

This set up is staying for me! The uprated WCF caps give excellent weight to the sound, similar to uprated coupling caps so if it's bass you want you could do either with probably the same results. The Wima's are a must in the cathode bypass position now, they allow the music to flow. Looks like the 150uF is about right although CopperFox is happy with 200uF so there is probably leeway there.

So the changes are highly recommended!

 

[Maxx134]

I need to add this info to beginning thread. This is excellent news.

 

[baronbeehive]

I need to add this info to beginning thread. This is excellent news.

I've put together a handy one stop shop with all the finished mods gathered together in one place to save time looking through the thread, so anyone who's interested can see at a glance without having to trawl through the entire 270 odd pages. Even I started to lose interest after the first few pages! Quite a lot has happened since page 1 and the amp has been pushed to endgame and beyond since.

This is practically all the mods that can be done without a complete rebuild.

The mods (not covered in page 1 except for no 1):

1 - 5998/421A Bias switch mod (increased 5998 power) - Page 1
2 - Impedance mod (match with headphone impedance) - Conversion chart on Page 258
3 - Bias point mod (6SL7 tubes only) (optimum operating point) - Page 179, 230
4 - CCS (6SL7 tubes only) (constant current regardless of voltage) - Page230, 231
5 - Active filter (clean B- supply) - Page 234

The parts (alternatives in brackets):

Output wires - Neotech STDST-24 OCC silver (copper) wire
Main wires - 3 core 22AWG silver plated PTFE wire

Caps:

PSU caps - Mundorf M-Lytics AG 1500µF 160V (Wima DC Link MKP4 400uF (*film)) x 2
Output stage decoupling caps - Mundorf Mcap 47uF, 250V (Wima DC Link MKP4 100uF(*film)) x 4
Driver stage decoupling caps - Wima DC Link MKP4 40uF - (100 µF Wima DC Link MKP4(*film)) 800V 10 % x 2
Cathode bypass caps - Nichicon KZ 470uF 50V (Wima DC Link MKP4 150uF - 200uF(*film)) x 4
Coupling caps - Jupiter Copper Foil Paper and Wax 0.47uF 400VDC (Any other .47uF - 1uF) x 4
WCF caps - Mundorf MCap Supreme Silver in Oil 0.33uF - 1uF uF 1200V 2% (Any other .33uF - 1uF) x 4

Resistors and diodes (refer to diagram):

(See page 270 for a discussion of the SQ of different brands carried out by member @CopperFox .

1 - Mills MRA5 165R x 1 (Optimized for 6AS7 tubes) (or 330R in parallel with stock 330R's) (Left side shown)
2 - Mills MRA5 330R x 8
3 - TKD 2w 69K metal film x 4 (Optimized for 6SL7 tubes) (or 52K in parallel with stock 220K's) (Left side shown)
4 - Mills MRA5 1K x 2 (Left side shown)
5 - Mills MRA5 8K2 x 2
6 - Mills MRA5 5K1 x 2
7 - Mills MRA5 2K7 x 1
8 - 100v 2W (or higher W) Zener diode
9 - 100v 2W (or higher W)Zener diode
10 - Mills MRA5 2K2 x 1
11 - Mills MRA5 165R x 1 (Optimized for 6AS7 tubes) (or 330R in parallel with stock 330R's) (Right side shown)
12 - Mills MRA5 165R x 2 (Optimized for 6AS7 tubes) (or 330R in parallel with stock 330R's) (Centre shown)
13 - Shinkoh tantalum 1W 380R x 2 (Optimized for 6SL7 tubes) (Right side shown)
14 - Mills MRA12 56K x 2

Transistors (uprated):

1 x MJ15024G (NPN) for B+
1 x MJ15025G (PNP) for B-

* - needs chassis extension to fit

Edit:

Footnote: In keeping with the thread, like all the mods in page 1, by @Maxx134 and others, these mods have all been tested and found to add significantly to the performance of the amp. The impedance mod was not fully implemented at the page 1 stage, the same for the bias point mod, but several members have subsequently done so. The CCS was implemented by SonicTrance and myself later, and the active filter by myself only. Also changes to the WCF caps and cathode bypass caps were further modified at a later stage by @CopperFox and myself for optimum values and types of cathode caps

The performance gains of all these mods are significant and add to the gains from page 1, it has to be heard to be believed!

Finally the amp continues to perform after years without issues, and I am confident that the testing carried out had has been done to a good standard and that the outcome is enough to satisfy anyone that hears the results.

 

[Maxx134]

Right! You could stick this in if you want, might be useful to refer to.



I've put together a handy one stop shop with all the finished mods gathered together in one place to save time looking through the thread, so anyone who's interested can see at a glance without having to trawl through the entire 270 odd pages. Even I started to lose interest after the first few pages! Quite a lot has happened since page 1 and the amp has been pushed to endgame and beyond since.

This is practically all the mods that can be done without a complete rebuild.

The mods (not covered in page 1 except for no 1):

1 - 5998/421A Bias switch mod (increased 5998 power) - Page 1
2 - Impedance mod (match with headphone impedance) - Conversion chart on Page 258
3 - Bias point mod (6SL7 tubes only) (optimum operating point) - Page 179, 230
4 - CCS (6SL7 tubes only) (constant current regardless of voltage) - Page230, 231
5 - Active filter (clean B- supply) - Page 234

The parts (alternatives in brackets):

Output wires - Neotech STDST-24 OCC silver (copper) wire
Main wires - 3 core 22AWG silver plated PTFE wire

Caps:

PSU caps - Mundorf M-Lytics AG 1500µF 160V (Wima DC Link MKP4 400uF (*film)) x 2
Output stage decoupling caps - Mundorf Mcap 47uF, 250V (Wima DC Link MKP4 100uF(*film)) x 4
Driver stage decoupling caps - Wima DC Link MKP4 40uF - (100 µF Wima DC Link MKP4(*film)) 800V 10 % x 2
Cathode bypass caps - Nichicon KZ 470uF 50V (Wima DC Link MKP4 150uF - 200uF(*film)) x 4
Coupling caps - Jupiter Copper Foil Paper and Wax 0.47uF 400VDC (Any other .47uF - 1uF) x 4
WCF caps - Mundorf MCap Supreme Silver in Oil 0.33uF - 1uF uF 1200V 2% (Any other .33uF - 1uF) x 4

Resistors and diodes (refer to diagram):

(See page 270 for a discussion of the SQ of different brands)

1 - Mills MRA5 165R x 1 (Optimized for 6AS7 tubes) (or 330R in parallel with stock 330R's) (Left side shown)
2 - Mills MRA5 330R x 8
3 - TKD 2w 69K metal film x 4 (Optimized for 6SL7 tubes) (or 52K in parallel with stock 220K's) (Left side shown)
4 - Mills MRA5 1K x 2 (Left side shown)
5 - Mills MRA5 8K2 x 2
6 - Mills MRA5 5K1 x 2
7 - Mills MRA5 2K7 x 1
8 - 100v 2W (or higher W) Zener diode
9 - 100v 2W (or higher W)Zener diode
10 - Mills MRA5 2K2 x 1
11 - Mills MRA5 165R x 1 (Optimized for 6AS7 tubes) (or 330R in parallel with stock 330R's) (Right side shown)
12 - Mills MRA5 165R x 2 (Optimized for 6AS7 tubes) (or 330R in parallel with stock 330R's) (Centre shown)
13 - Shinkoh tantalum 1W 380R x 2 (Optimized for 6SL7 tubes) (Right side shown)
14 - Mills MRA12 56K x 2

Transistors (uprated):

1 x MJ15024G (NPN) for B+
1 x MJ15025G (PNP) for B-

* - needs chassis extension to fit

Thanks. I was only able to post this on my first post as I am not thread starter.

So I posted it there.

I am a thread starter at:
https://www.head-fi.org/threads/oblivion-ultrasonic-studios.902926/
So I also have to go over there and see what needs to update.
So yeah those are my two fav all time amps.
I still haven't side-by-side compared and when anyone ask I still recommend the other amp for not having to mod, and this thread for learning about what mods do for tube amps, and the only tube amp I would recommend to mod, as practically all other tube amps near this range are single ended and multiple times more expensive.

Actually if you wanted a balanced tube amp other than this, you literally and certainly be spending thousands..
So yeah this caliber mod I certainly would choose over all what's available in traditional design.

Yet there are different roads to get to same top level, and honestly I could not recommend any other design choice route except for the Ultrasonic amps. Otherwise your playing with mega thousand amp just to reach same peak.

Regardless, I love other tube designs, such as the Cayin HA300 I recently moded, and right away I saw the intentional placement of specific "non-audio" version of an electrolytic brand, in the "cathode cap" placement, which was a deliberate tunning for harmonics, proving that designers all have their own "recipes" for thier preferences/success.

But the bottom line is that once a device reaches a pinnacle, it's all a matter of signature preferences.
For instance, I upgraded a Cary 300b speaker amp which also was fantastic and was also modded for headphones.
So yeah different paths to reach the goal.

This thread has been a huge learning and growing experience. There is much to gain from many visitors.
If your a classic style tube enthusiasts, you will learn details on tunning amp here, but if you not want to mod, the Ultrasonic amps are the way to go, although I assume you would not be in this thread to begin with ...

 

[baronbeehive]

I've just added a footnote to the summary of mods above .

 

[baronbeehive]

...
So yeah those are my two fav all time amps.
I still haven't side-by-side compared and when anyone ask I still recommend the other amp for not having to mod, and this thread for learning about what mods do for tube amps, and the only tube amp I would recommend to mod, as practically all other tube amps near this range are single ended and multiple times more expensive.

Actually if you wanted a balanced tube amp other than this, you literally and certainly be spending thousands..
So yeah this caliber mod I certainly would choose over all what's available in traditional design.

Yeah .

The amp is superb! I'm even satisfied with the WCF design after an initial scepticism as I feel it is an excellent way of getting the Impedance down and the power up without compromising the OCL design .

Edit: Hey.. you forgot the little APPJ!!!

 

[Maxx134]

Edit: Hey.. you forgot the little APPJ!!!

Haha yeah I still have one... it's too cute to get rid of.

 

[Maxx134]

5 - Active filter (clean B- supply) - Page 234

I literally overlooked this..!
Ugg I don't have that one done, , lol

 

[baronbeehive]

I literally overlooked this..!
Ugg I don't have that one done, , lol

Yeah, it's nice to know it's there but it doesn't do anything for sound as MrCurwen said. Looks like you may have a few things to catch up with .

I don't see how this amp can be improved further so that's more or less it for me . The last Wima cathode bypass mod surprised me. It really improved some aspects, mainly the bass which is now really good so I'm very happy!

Be nice to see the cash disappearing down some other pit for a change... hmmm perhaps headphones update???

Hey Maxx, so what's new in NYC, anything going on?

... and what's happened to CopperFox, haven't heard from him for a while.

 

[Maxx134]

I don't see how this amp can be improved further so that's more or less it for me

There is nothing new under the sun...

**No new amp is going to eclipse anything TOTL that's already out.
**No new headphones is going to eclipse anything TOTL that's already out.
** IEM market is starting to reach it limits with more and more approaching TOTL levels, and many IEMs already superior to most of the headphone market.
**Daps are finally reaching limits to the level that topologies don't matter anymore (R2R, Delta-sigma, discreet FPGA). Only thier amplification stages will matter.
** Desktop setups will face overlapping competition with portable DAPs performing at above desktop levels. Only TOTL setups will still have slight edge.
At this point, a good Dap coupled with a good tube amp is all you will ever need for all solutions.
Throw away the computer setups.

Hey Maxx, so what's new in NYC, anything going on?

Nothing is up in NY except ghost town zombie land events. The thriving metropolis which used to be crowded in the streets, both day and night, is now a zombieland.

The NY vaccine mandate ruined the CanJam potential of more visitors.
Stupid NY libtard politics lifted the mandates only after CanJam timing, so at least now you can visit Audio stores withouta mask.

I don't see ANY closed headphones today of any value, when it's purpose&value is totally eclipsed by IEMs.
Not one closed headphones today can match even a mid tier IEM.
I view desktop closed headphones a total waste.
The small portable headphones will always have a good market, but even cheapo Bluetooth earbuds can replace them.

So basically you can be "golden" with just a top desktop open headphones like HD800 or HEKV2, and a top IEM for closed usage.
Those two types can be all you need, if you was to narrow down the hobby with just two units.
Everything else is a futile sea of never-ending mediocrity.

 

[baronbeehive]

There is nothing new under the sun...

Haha, my thoughts exactly .

**No new amp is going to eclipse anything TOTL that's already out.
**No new headphones is going to eclipse anything TOTL that's already out.
** IEM market is starting to reach it limits with more and more approaching TOTL levels, and many IEMs already superior to most of the headphone market.
**Daps are finally reaching limits to the level that topologies don't matter anymore (R2R, Delta-sigma, discreet FPGA). Only thier amplification stages will matter.
** Desktop setups will face overlapping competition with portable DAPs performing at above desktop levels. Only TOTL setups will still have slight edge.
At this point, a good Dap coupled with a good tube amp is all you will ever need for all solutions.
Throw away the computer setups.

Yep, will do as soon as I can! I remember discussing Daps years ago with my friend at work, who also had an iPod classic, we were moaning about sound quality, why couldn't Apple and others produce TOTL sound given they already have the bit perfect bitstream with all the data necessary for TOTL sound. Well years later they've finally caved in an done it. I think one factor was most users of the technology didn't, and probably still don't care about SQ.

As far as I'm concerned I will never use IEM's. I used them at work, and fortunately for my hearing, I couldn't get on with them. They kept dropping out, were uncomfortable and constantly getting gummed up etc etc. Pretty good technology though. The technology of some systems, which I won't name, seems so clever and to do miraculous things, but when it comes down to it I don't believe they perform any better for it.

As far as any new amps eclipsing anything TOTL I would go as far as saying eclipsing any TOTL old school technology as well. I have to admire those guys back in the day coming up with make and mend solutions to problems they had then.

I've listened to TOTL speakers and how the sound quality can ever get any better is beyond me. They are all at a level that makes them virtually indistinguishable from each other. I always think back to live performances and if it matches that then it can never get any better IMO.

I was half joking when I said I must find another money pit such as new headphones, when really I have been very happy with my existing ones for some time and would only maybe add another model for soundstage, then I would have one with up close and personal emotional sound, my HE-500, and another for 2 or 3 rows back more laid back sound such as HiFiMan 1000SE.

My modding now is transferred to my Mini Cooper S which is a whole lot of fun! I will always be interested in others though who want to achieve what we have done with our mods. That and my guitar is what I'm most interested in these days.

I expect those baby fish of yours have grown into monsters by now... .

Nothing is up in NY except ghost town zombie land events. The thriving metropolis which used to be crowded in the streets, both day and night, is now a zombieland.

The NY vaccine mandate ruined the CanJam potential of more visitors.
Stupid NY libtard politics lifted the mandates only after CanJam timing, so at least now you can visit Audio stores withouta mask.

Wow, I can't imagine that New Yorkers have taken to that easily.

Our restrictions are lifted here but owing to the extreme high infection rates that we still have business and social life is still having to adjust. I live in a holiday area and they are having difficulties still. Last year owing to the invasion of holiday makers who couldn't go abroad and now there are difficulties with getting seasonal workers for hotels, resorts and farm produce and such like, so not back to normal any day soon unfortunately.