As I finish up another pair of Anniversary Mods to the SE84UFO3's today I thought I would post a picture.  Since this mod is not on the web site this would be the only place for information about it.

Externally there are no changes made to the amplifier.  The mod is noted on the sticker otherwise the only way to tell is to look inside.  Here is a picture of the inside after mods.

You may remember in my earlier posts I first thought I wouldn't need an extra regulator tube but later realized it needed it, so we designed the circuit around the OC2 and placed it on the inside of the amp.  We can do this because it generates no heat and they don't wear out.  The only way it would fail is if an input tube shorted in which case the OC2 would become a fuse saving the amplifier from any damage.  We used a socket so that if it ever needs replaced there would be no soldering required.

 
Here's a picture of volume knobs installed on the amp.



We will be offering this amp with or without volume controls.  The beauty of this arrangement with the black base is that if you order the amp without volume controls it won't look like something is missing or has been left out because the black base remains.

Also for those who might be shocked that I would offer it without volume controls I have a simple way to do it without compromising your ability to "ride the gain" as many like to call it. That is when you turn the volume on the amp down a bit and the volume on the preamp up a bit to create more hit and overall density/weight in the music without playing it at a louder volume.  

Anyway if someone wanted the amp without volume controls, they have a preamp so we will simply wire the amp with an input sensitivity that matches having the volume control set at 75%.  This way you don't loose the advantage you would normally get from leaving the volume control in and adjusting it back from full.

Steve

Steve Deckert wrote on 03/30/18 at 03:32:49:

What a great set up Steve. And it will keep me from rolling the OC2! Which is probably a good thing! Thanks for sharing the photo, been eager to see one.

In an earlier post Steve called this a "3K" amplifier. . . so I figure that's about the ballpark price.

Early on in the thread Steve alluded to the possibility of it costing as much as the Torii, i.e. $3500.

The transformers are now wired as are the heaters which not only power the tubes but also the lights on the meters.





The trick is how to make lots of parts and wires look like less parts and wires... it's really a never ending challenge with any layout.

The grounds are being installed






Steve

Steve,  you must have the hands of a child to get into those tight spots and put it all together. It's awesome seeing it built in stages like this!

I think the OC2s inside the chassis are only a feature of the 25th Anniversary SE84UFO3 Monoblocks.

Just want to confirm Steve’s comment about 6n5p tube instead of 6n1p. I’ve tried it in my se84ckc amp and I am very glad I did it. Even my wife realized that something went completely different (in a positive way) even without entering the listening room. The bass is definitely better and naturalness of the sound also. But the main positive outcome is absense of listening fatigue now. With 6n1p I was very tired after the listening – something forced me to switch the tracks very fast because it was difficult to listen for a long time. I thought that the problem is in my speakers (Omega Super 3 XRS HO) but now I understand that it is not true.
I have tried the rare version of this tube (with black box anode) – this is an old design tube from fifties or sixties – more recent versions has very similar to 6n1p construction. There was a discussion in another threads about mislabeling but as far as I understood it is not mislabeling (i've searched the discussions on russian forums).
Pictures show how it looks like. Definitely it worth a try – it is inexpensive upgrade.

Correct, the SE84UFO3 monos are being modified internally with the anniversary circuit as an option.

Depending on the success level of the SE84UFO25 soon to be released, we might design a new chassis for the SE84UFO3 to match the new SE84UFO25.

Steve

Same step, different angle...

 

The blue caps are F&T 500 VDC from Germany. Each one is being fed from a 150 ohm 6W wire wound DALE/VISHAY resistor (the ones marked MEXICO).

The two 33K DALE 2 watt emanating from this same central node feed the OD3 serving the input stage. So the high voltage DC from the rectifier tube (yellow wire) is spilt three-ways at this node to feed each of the three audio tubes.

 


 


Wouldn't it be great if we could just quit here?  I mean we have 10 caps (the blue ones have two sections in each cap) already and the standard zen only has 2.

Artem, the 6N5P is a really really nice tube. I've done a lot of tube0rolling lately and what works best for my system is 6 of the 6N5P in the ZTPRE, and a 6N1P in the Taboo Mk IV. That is the tube complement that is making it sing for me right now. We'll see what happens with the Monoblocks coming soon! I plan on leaving the ZTPRE as is and rolling tubes later in the Monoblocks' input spot.

 


This is the complete amp now at this point. (I think)

The rest of the bypass caps are installed. The orange wires lead to a group of polyurethane bypass-caps.  The copper-foil beeswax cap and the 3.3uf film-cap under it are for the input tube's plate resistors.

Now here is an interesting paradox for you...  the "signal path" consists of the input jack, the resistor connecting that jack to the control grid of the input tube and the capacitor connecting the plate of the input tube to the output tube's control grid.

A control grid is like a window shutter.  When the shutter is open the electrons flow right through, just as light comes in your window.  When the shutter is closed, no electrons.  The electrons flowing through the shutter are actually those flowing between the cathode and plate of the tube. That means the electrons used to operate the shutter are not the electrons you "hear"... it is the electrons that flow from the cathode to the plate that you hear.  Well the cathode is connected to ground through a low value resistor, and the plate is supplied by high voltage.

This means the high voltage that supplies the plate is actually the electrons you "hear".  So what is more important, the coupling cap between stages, or the bypass caps in the high voltage supply?  Which ones are you actually listening to?

Steve, that's a thing of beauty!  If not for the dust, I'd order one bottom side up!  

Absolutely Joe! When your stuff is built and arrives you're going to be bounding around the place thirty years younger!

This was and is a feature of the TORII MK4 and you're pretty spot on about what is happening. In the Zen Triodes however, there is no positive or negative feedback loops and the output transformer blocks the back EMF from the voice coil leaving the amp largely unaffected by the loudspeaker.

I think with amplifiers like this it's the musical honesty resulting from the layers of resolution that unlocks a higher dimension of listening, just as live music can.

BTW,  Today I tested the amp and it actually worked. I'm listening to it now. It's good. We'll know more in about 600 hours when we A/B against the prototype.

While it's burning in over the next 30 days, I'll be working on hardwood base designs. Because the depth of the chassis is 1/8 inch none of the existing bases in the Decware line will work.  We have to make a custom base for this amp, so we are exploring different woods and different profiles hoping to find something that looks so good everyone will like it.  At this point I am pretty sure the amp will be offered with only one base design made from one exotic wood and anything other than that will be a custom order item and non-refundable.

Steve

This looks and sounds like a really special amp! I enjoy all the detailed work and love that goes into one of these.

I think it has been asked in this thread before, but haven't seen an answer to it, will it also work its magic with the ERRx or HR-1 speakers in a 200 sft room not playing disco level output, but reasonable loud? Or does that require the SE84UFO325?

I probably overlooked this in one of the many previous posts on this thread, but what are the two RCA-looking connections - right above the toggle switch - for?

Pretty sure that is where you input the signal from your source!

Oh wow, I never noticed their placement before until Tommy brought it to my attention.  Why put them there did he run out of space trying to stuff it into the smallish Zen chassis plate or something?

My guess is that since this amp is about ULTIMATE sound quality, he put the input there so that only parts leads would be used for the input to the input tube. . . as is an optimal way to have the ZP3 set up for instance.

Hello Steve,
What make pot is that in the SE84UFO25 ?
Does the SE84UFO325 get the same pot ?

Thanks,                     Crazy Bill

OK, Time for another update!

I'm actually listening to the new SE84UFO25 that I just built, now past the disturbing part of the VCAP burn-in with enough hours to already be indistinguishable from the red prototype!

Which leads me to my post:

Dammit!  This hobby... this addiction to the fidelity ladder!  Once we climb a couple rungs, going back down to where you were is simply not an option unless you're forced to by circumstance. Tonight I just took the 25th Anniversary amp experience about 3 more rungs on the ladder... a ladder I did not know was taller than the rung I was standing on, which is often the case...

You're never going to believe this... but I have to tell the story so bear with me.

I've been haunted by the sound of this amplifier since I made it and without any pressure leisurely and playfully contemplating how I could apply this technology to more stuff. The CSP3 preamp was one of the first things to come to mind.  So recently I developed the anniversary mod for the CSP3 preamp!  I had the perfect test bed to develop it.  Simply place it between the SE84UFO25 and it's source and hear what it did.

Let's talk about the source. The source is the ZDAC2 feeding the ZTPRE which feeds a ZBIT that feeds the amplifier. If I can place something between the ZBIT and the amplifier without ruining the spectacular focus I have, THAT WOULD BE IMPRESSIVE.

So I started with the stock CSP3.  I lost more than I gained. I preferred the sound without it. It felt like one preamp too many. This is my speedometer.  I take the CSP3 to the bench and begin surgery.  After I thought I was probably done I placed it back in the signal path and listened some more.  Still not there.  

Another three rounds of trials and additional stuff and then it happened. I put it into the signal path and knew immediately it was good.  A night to break in a little bit and then today...

Beautiful blue skies, no clouds anywhere as far as the eye can see all day. Just sun and music. I took the day to catch up on my digital music library maintenance so I was able to listen pretty much since this morning, 12 hours so far straight. I have no intension on stopping for at least several more hours.

What would motivate a man to listen non-stop for what will probably be 16 hours? Think about it.

Now, here's the rub... It has been sounding extra spectacular tonight, so I took the modified CSP3 back out of the signal path and damn it... I have to have it in there now. This is insane. That's another 2K to add to the puzzle but OMG I can't believe what it is doing to the sound of my reference signal path!  

This will be by far the hardest sound to describe, but it is firkin magic. When it plays, time slows down. You can feel the cheeks expand and the puff of air behind the words. I thought the density was good before, and the textures were complex before, but I just got taught another humbling lesson by my teachers.

I'm starting to realize that density is it's own form of power. The density counts as watts that you can't measure. Density is a watt multiplier.  

Sorry as usual I'm listening as I write, and it's so damn juicy and round with a subtle magnifying effect on the music that adds saturation to the colors and dimensionality to the shadows and focus. You don't see the hairs on the peach... you see the hairs and each hair's shadow on the peach. You can smell the peach.



Say hello to our new best friend!  The SG5B voltage regulator tube from Russia. This tube is rated for between 5 and 10 milliamps and has a voltage drop of 150Volts. It was selected especially for the CSP3 circuit where there will be one per channel. Each tube will see 7 milliamps.

How was this done to the CSP3 you ask? Visit the development thread here for more info:

https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1408725911/363#363

-Steve