Chris has discovered that my two UCD180ad modules have different versions (one v4 the other v5): this could affect sonic performances of my amp. Maybe all Ucd people would open their chassis and look at modules version 
Today I wrote to Hypex support to have explanations:
If Chris is right, I expect to have some more fun
Thomas
Today I wrote to Hypex support to have explanations:
If Chris is right, I expect to have some more fun
Thomas
Hi,
The difference is output filter caps is no trivial matter, especially in terms of recreating imaging with any level of precision.
The resistor you see, probably no big deal at all.
Are not the two 22uF 63V caps next to each mosfet different as well? On the older version they're BC caps in metal cans, on the other, at least from the picture, they appear to be different.
From the picture I saw it looked like even the bigger 470uF caps might be different, might just be lighting though, made them look black on one module.
Have a look at R56/55 on the two modules, you should see some difference there as well, which I'd want a specific answer from Hypex on, just to make very sure they at least both have the same current capability.
You really haven't experienced true UcD stereo yet, but we'll get you fixed up.
Regards,
Chris
The difference is output filter caps is no trivial matter, especially in terms of recreating imaging with any level of precision.
The resistor you see, probably no big deal at all.
Are not the two 22uF 63V caps next to each mosfet different as well? On the older version they're BC caps in metal cans, on the other, at least from the picture, they appear to be different.
From the picture I saw it looked like even the bigger 470uF caps might be different, might just be lighting though, made them look black on one module.
Have a look at R56/55 on the two modules, you should see some difference there as well, which I'd want a specific answer from Hypex on, just to make very sure they at least both have the same current capability.
You really haven't experienced true UcD stereo yet, but we'll get you fixed up.
Regards,
Chris
Yes.. i have different versions of the modules too. I am ticked off with the dealer over issues like this.
Anyway, i thought i heard a difference between the two versions, so i ripped off the capacitors and replaced them with ZL's and BG's as well as mmkp for the output caps.
you know what, i still hear a difference.
Chuck
Anyway, i thought i heard a difference between the two versions, so i ripped off the capacitors and replaced them with ZL's and BG's as well as mmkp for the output caps.
you know what, i still hear a difference.
Chuck
thomaseliot said:
classd4sure said:
Here's a question regarding the differences between versions: Why would the slightly different components make such a huge difference when all these things are inside the feedback loop? Did anything that would have more of an effect on the sound - like the modulator circuit - change as well?
And Thomas - were you able to notice a difference between the two channels before Chris informed you that you may have modules with different versions?
BWRX said:
Fair questions. The filter cap plays a big roll in the sound, just like any other passive with all their non idealities in the signal path. Gertjan posted some test results of a few different filter caps on the UcD back in the hotrod thread someplace, measurable difference!
The older cap is likely to be far more microphonic for instance, based on its construction... if both amps are doing different things in terms of clarity and precision you're not going to enjoy the spatial info that the now smeared microdynamics would normally give. That's my half baked theory at least. Just look at the hotrod thread, 98% of all the discussion there revolves around the choice of passive components, it sucks but that's just it is. The other caps that I believe to be different are for damping the switching wave, you can imagine how having the two of those different would screw things up too?
We don't yet know if Thomas actually hears a difference between channels, but it's something he's going to be looking at, which will be interesting. Even if he doesn't hear one, or much of one, I still feel confident that two identical modules will show him a new world.
My other big concern was if one module had the current source loading of the op amp while the other did not, which would also be a huge difference. Turns out they both have it though, so it likely is all just the passives. I believe the results of fixing this little problem will prove to be very interesting for us all.
Cheers,
Chris
PS: I also wanted to add this earlier, most cases of people saying UcD doesn't sound very impressive has proven to be a poor implementation on their part, which is the main reason I asked to see pictures of his amp before giving him tweaking info on it. First things first you know?
I think he put the effort into it and did a fairly decent job of it though, his grounding is right on from what I can tell, wires twisted.. he did a decent job with what he got.
BWRX said:
If you want to know if Salvatore Accardo is playing his Guarnieri del Gesù violin or his Stradivari, I can accept the blind test. But if Chris says that different versions of UCD module would affect sound, I must trust and look for informations.
I reversed channels to hear differences in imaging, but I found nothing objectively relevant. This doesn't mean there are no differences.
For objectively relevant I mean something you can communicate to others, about a specific passage of a recording, so that they can repeat the experience and find the same thing. For istance how loud and distinct is a solo flute, while contrabasses are playing loud, or the sound stage distance between violas and cellos if they are distinct.
Thomas
Well the amps all have their place.
The SE OTL is probably still my favorite, it shares the clarity and bass with the tripath amps but it depends on my mood and what is being played. The tripath amps sometimes sound better but I believe it is when more power is required.
The only "issues" I have with the SE OTL is the low power which is not so much of an issue with the right speakers, although it can and does run out of steam sometimes and it does sound better after being played for a few hours when it really gets hot.
My preferences follow my moods. When I want to "rock out" or having a get together the PP el34 or kt88 comes out. Often times when I want to just listen to music
its the RH84 SE amp and when I am playing something I want to listen into or "experience" such as classical music I use the SE OTL or tripath amps.
The other amps mostly sit and watch and gather dust.
Andrew
classd4sure said:
As I said before, it happens that I have two different versions of UCD180ad: Version 4 and version 5. The topic of this thread is not to make comparisons to vote for a winner, but through comparisons to learn to how to get better amps.
From this point of view, Hypex mistake in distributing mixed versions of their amps can be a good new, as maybe there is space to further improve my UCD.
Here is the answer from Hypex support to my question about differences between the two versions. I report only extracts that can be interesting for others too:
In a further email I asked about evident differences in passive components on top pcb, but I got no answer yet.
the undropped shoe
I've discovered this thread and find it fascinating... An example of cooperative research for a good cause haivng little to do with the behemouths of commerce, politics, and religion who attempt to throw their weight around in the interest of a larger bottom line profit or more power or some such. Pure research for a noble goal, better sound. and I'm interested in the 41Hz amps myself, so there's that too.
What's maddening is that it seems to have halted with much still in the air. Thomaseliot has not reported the results of his experimentation (eg, the filter substitutions) and no conclusion's been reached about whatever it is that the Bertus coils do that improve an already very good power amplifier.
Enquiring minds want to know... What was the result of the comparison?
Why does it work?
Curious minds yearn for an answer. They want to see the shoe. Like a cat chasing a string. Or something.
w
I've discovered this thread and find it fascinating... An example of cooperative research for a good cause haivng little to do with the behemouths of commerce, politics, and religion who attempt to throw their weight around in the interest of a larger bottom line profit or more power or some such. Pure research for a noble goal, better sound. and I'm interested in the 41Hz amps myself, so there's that too.
What's maddening is that it seems to have halted with much still in the air. Thomaseliot has not reported the results of his experimentation (eg, the filter substitutions) and no conclusion's been reached about whatever it is that the Bertus coils do that improve an already very good power amplifier.
Enquiring minds want to know... What was the result of the comparison?
Why does it work?
Curious minds yearn for an answer. They want to see the shoe. Like a cat chasing a string. Or something.
w
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