Congrats! I'm probably 4 or 5 months out on my UFO25s.

So, to your question. I feel like the stepped attenuator is a small improvement in SQ over the volume pot. My UFOs had them and so will my UFO25s. You may be missing out on something, but you are not missing out on a lot IMO.

Question is what are you planning on using for volume control? I feel like the steps on the stepped attenuator are too big if that is your only volume control. I have a (non Decware) preamp that I use for volume control, I rarely change the attenuators, just for extremely hot recordings or particular tube combos in my preamp with above or below average gain.

IMO If you were planning on using the volume control on your UFO25 as your primary volume control I'd stick with what you have. If you have something else, I'd still stick with it at least for a while. If you can't get past the FOMO you can always send the amp back to Decware for the update, it goes into a different queue and is usually turned around in a few weeks.

Great replies gents! Yes I was on a work call via zoom when the email came in that my order changed to "parts pulled" and I hollered YES. Had to explain to everyone why I got so excited haha

Herb,

Congratulations…. Talk about exciting!  CAJames is spot on with the utilization of what you have.   I have the dual stepped attenuators on my ZBIT.  I like the adjustability of the positive clicks on the unit.   Once I dial and lock it in…it almost never moves unless I switch between my Decware amps.   I use the smooth action volume control on my ZSTAGE preamp for fine tuning.… so think you will be fine.  

Dom

Thanks everyone, I feel like only those on here understand the excitement haha I tried to explain to a friend of mine that I ordered and amp in 2021 and I will probably receive it soon and they just did not get it.

I have built several kits so they know its a passion but could not comprehend a nearly 2 year wait for something I already have (an amp) like surely they are all similar ? LOL

I am trying to decide if I need a new pre-amp lol currently I run a Bottlehead Moreplay and LOVE it but I might build the 300B version or get something totally different but at first I will try it with no pre-amp and as little between the source and the UFO25

I find it all pretty relative. I agree with everything said, part of which, the pot Steve uses sounds pretty darned good in comparison to the attenuators he used last I checked (may be different now), and options to upgrade later after learning the amp and getting it burned in are nice.

But also, starting in revealing and beautiful places, I have found progressive improvements in timing, clarity, resolution, balances... from carefully upgrading parts by-sound in my Decware. And no doubt, smaller changes at first are easier to notice if you are playing with this stuff. And with progressive improvements overall, the improvements help each other, and I hear more, so notice the effects of parts improvements more. Your having built, and or modded things, you probably noticed this, how a little change from even a really good baseline, can turn into a bigger change after the baseline gets more resolving... that is if finer resolution and timing are musically improved part by part. Then what had been a little change can equal bigger improvements in realism.

That said, Steve is always playing this these things... signal path lengths, improving more vital parts and wires, finding design improvements for better resolution and timing musically... And it looks like he keeps using the same potentiometers he has used a long time, presumably because he likes how they work in his synergistic approach to making parts sound good together.

And I agree, I think Steve's smooth pots sound quite good, especially for the cost. If the stepped attenuators are those he used for a while, the smaller Chinese ones built with I think gold plated copper contacts, they are pretty nice too.

Something like this:



Not really state of the art to me, but decent. I used two of these in my CSP3 for input stage attenuators and preferred the sound over the little pots that were there, and the Audio log on these is pretty good in my system if I have tubes that need a little help with left/right balance. At the same time I put a nice resistor in the place of the output tube pots and that sounded more complete/complex. I found over time that I was not adjusting the outputs, but did adjust the inputs, so I went this way, chose a resistor to match the pot settings of the output tubes... a nice improvement.

But when I tried this attenuator in the place of a TKD 2511 potentiometer I had for my main CSP3 stereo volume, I thought the TKD was better for my needs, more smooth sounding, solid and resolving (it also feels this way)... bigger sounding while being more complex if I am remembering correctly. But the TKD costs something like 5 time more!

When it gets this good, it is just pretty difficult to judge these things for others with different rooms and systems... and your UFO25 has lots of cool upgrades built in, all tuned by tech and sound. Thus the 25th Anniversary of Decware's first amps! So long story short, I agree with the others... I highly suspect you will find your new amp really enticing as is.

As to pre or not, it will be fun to try it both ways with what you have, perhaps especially after the amp has several hundred hours on it. Maybe play with gain balancing if nothing else and see what you think. I never use a pre as volume myself, but love to play with gain relationships between pre stages and the amp for optimizing sound. Then usually the more neutral amp is my main volume, and I can fine tune for sound refinement for different recording balances with gain adjustments with pre stages.

Seems like that could be a good idea on the epoxy.

I tried one of these small attenuators in my ZBIT also... The TKD 2511 won there too for me. I use the cheaper Eizz 24 step in my Torii right now. Its steps seem pretty strong, but workable for me for fine tuned volume with other gain stages (and probably fine without). I like its' "japanese" carbon film resistors, doing the carbon thing nicely, textured and open and not held back feeling per se, though a touch warm. Before that I used a "Valeb" (not sure on spelling) that was labelled "TeraDak 100K-2" stepped attenuator with surface mount resistors and liked it compared to the TKD... A little less dense/concentrated, more complex, and slightly warmer without veils if my memory is correct. The Eizz I find similar in enjoyment, but a little richer probably... I don't know, it has been a long time ago. I changed in this case because the Valeb was getting weak and rather than messing around with it with no backup, I ordered the Eizz, not able to find the Valeb at the time. Both of these take some room though!

Will, I’ll have to try your way of using the CSP3 to dial in the optimal gain settings and using the amp to control volume. I was thinking of it the other way for the ease of having one master volume control on the preamp, but your method makes sense. I’ll have to try both and see which works better for me.

LiquidBlue,

Yes, with the right tubes, cables, and settings, adjusting the voltage into the amp with Decware pre things can make a lot of difference to the signal intensity in every way. Yet just turning the amp up and down, usually sounds about the same within working limits, though louder and quieter. So I like having the more neutral basis of the amp for basic volume. But if the pre stage(s) gains are within realistic limits themselves with the amp wide open, this can be pretty nice too obviously, as most do it this way.

With a slightly tuned-down Torii, and with relatively efficient speakers (92.5) I have tuned my stuff relatively fast, open and balanced so that I can still push the pre-stages pretty hard in order to bring out their lucidity, weight and speed without being too intense. This in mind I get better sound with the Torii less than wide open, though it is nearly maxed at immersive listening levels for pre distortion power, just not turned up all the way.