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PostPosted: Sat Jan 05, 2008 11:18 am 
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So this is hardly the ideal case for a dual monoblock, were there even such a thing. I got it for the stereo setup of UCD180, but it's already here and I'm sure I can squeeze it all in there in some fashion that will work rather well, certainly the wiring _will_ be short!

What an ugly case though... but I still have the granite slab for it too... only ever lacking the handsaw to cut it with :glare:


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PostPosted: Thu May 01, 2008 6:46 pm 
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I had a few victims stop by the other day, who shall be known as subjects A and B. "A" had experienced UCD before, from a

single surviving modified 180, that made her jump a clear foot off her seat while playing "Beneath Alricsha" off of Hans

Zimmer's soundtrack for The Da Vinci Code, to modded 400AD's. Clearly it was B's first experience with "decent" sound, made

known by his proudly announcing "if it's not loud, it's crap", in doing so holding himself to that same standard.


Interposed with subject B's discussing a longing for taking a snowmachine over open water for his last ride of the season,

while leaning forward on the couch with his ear less than a foot away from the midrange, were taunts to "craaank it uuuuuup".

I commented on B's being obviously suicidal, and then decided to oblige them in some brain scrambling.

I denied the subjects the distortion begged for, keeping it well below clipping, and played a quality recording of some TOOL

in FLAC format, which is perhaps somewhat compressed, but still clean and dynamic, with a very natural feel. I cranked it up

enough for a cobweb clearing spring cleaning experience with a little airing out too, nothing but clean, spine gripping

power. B toughed it out like a true hero, for all of 30 seconds, before gluing himself to the back of the couch as far back

from the speaker as he could get without going so far as to put on a skirt and change seats, in his first demonstration of

self preservation. He had the wide eyes of a six year old on xmas morning as he commented how that was the kind of clean

power he feels front stage in the mosh pits.

I guess it depends which concert you go to.. I personally saw one band on two seperate occasions. The first time was at the

tail end of a several year long world tour, where they were a self proclaimed finely honned machine. The sound of that was

just phenomenal. I never felt my spine shake like that before, or since, but it was pristinely clean sound where every single

note of the lead guitar could be heard cleanly floating it's way over to you from some direction or other as the bass had you

under full assault from all directions, and you had no trouble making out any of the words. It was that very experience that

got me into audio.

To see the very same band just a few years later was a massive disappointment. There was another headlining band going on

just before them, called SoundGarden. They played after a number of no name bands, and when they got on they cranked the amps

right up, it hurt, but within seconds they backed off again so that it sounded dynamic and CLEAN. As a result of their

putting reason over ego, they had an awesome sound and put on an equally awesome show. Then the EGO band came on after and

just had to play a little bit louder, but there was no where else for the amps to go but well into clipping. It ruined it

completely and I personally spent their entire set, waiting for the rape to be over, wanting to leave, and they were who I'd

come to see (up yours metallica). Of course that was followed by .. getting kicked out of the hotel room after the concert.

Due to a bit of a misunderstanding regarding wanting a better room for the second night, and their refusal to let us pay for

both nights in advance along with the concert being on our brain the second day, we forgot to pay for the second night bright

and early that morning. They'd given the room away during our absence, despite my trans am still being parked in the lot. I

remember hearing the girl panick as I stupidly reached around the door to undo the security chain thinking it was still our

room, probably thinking her husband showed up. After a minor debate with the greedy clerk, who wanted to keep the deposite

for "storing" our belongins for a few hours, in a cardboard box by the door, we wound up driving the six hour trip back home,

where I got a three hundred dollar speeding ticket half way back, one that I damn near lost my license over, and almost ran

into a bear, but still managed it in 4 hours. It's almost hard to imagine ever being so young now.


Subject "A"'s comments soon followed. She'd not heard it in over a year, with the older modified 400's, and you know how they

say you have no memory for audio?? How then do children recognize their mothers voice? I was truly impressed with her

listening ability, and recollection over such a long period of time. There was no suggestion as to what to hear or listen for

at all on my part as I appreciate a genuine and original opinion from anyone willing and able to give it. "WAY BETTER... WAY

WAAY BETTER". Stating how obvious it was, how it felt solid from one side to the next, and with waving arms from left to

right portrayed how the image transited fluidly between speakers, lacking any seams or voids. I had to laugh just a little

bit when I heard how "RELAXING" and "SOOTHING" it was, as it snowed cobwebs, but I understand all too well what was meant.

The subjects in question made a mad escape to the bar after the assault. I had been looking for some Telarc intro from

"Chiller", and wound up clicking on the "synthesizer effects" track, so as they left it was playing some deranged finale and

I sat there with a smirk... why not.


I have tested the Hypex Tr400, 250VA transformer recently, in place of my 500VA Plitron. The voltage was well within spec

without any threat of ever tripping the overvoltage protection even under worst case conditions. Some could live with, if not

even prefer the kind of trade off in sound such a small transformer can produce. It's lightning fast, punchy, and the lower

load regulation can somehow seem involving, throwing around transients. It's like trading ambience for presence (but you can

have both). Power drops off rapidly for the very deepest lows only, which after a day you don't really notice anymore, and

appreciate hearing a richer envelope of textures, reproduced with a livelier and more detailed edge, if not harsher and

grainier as well.

As the volume increased so did distortion, becoming brighter, even offensive, much like clipping which it probably was. Given

the reduced load regulation, the same comfort levels as before no longer applied. Overall, spaciousness, ambience, and detail

in general were still present but as a mere hint of their former selves, yet no worse than your average commercial

receiver...more on that later in fact.

A hard, slightly ear tensing edge, was experienced at low volumes as well, which I attributed to several things from old caps

now working at higher voltage and having to contend with burning in again (it was improved by day two), to a smaller core

being more susceptible to saturation via mains offset and noise, and an undersized transformer working well below anything

close to its 100% duty cycle rating.


With my 4ohm speakers, and basic setup of parallel jensen 4 poles feeding two 400W modules in stereo, I surely do prefer the

raw clean power being felt in the deep lows, and unwavering, immersive ambience conveyed so fluidly that the larger

transformer provides. While it was rated to power 180W modules and is of lower voltage, the increased load regulation, and

more than 100% duty cycle operation provides substantially more clean power, while the other only transitions to "louder",

something I've come to find intolerable these days, spoiled as I am, yet subject B would have approved.

Neither transformer benefits from additional input filtering in my current setup, and the same noise is at times present with

the Plitron as well, however at ghostly low levels, and much more rarely is it ever noticed. It stands to reason either of

them could benefit from additional input filtration, but with the dirty mains around here I'd consider it an absolute must

for the smaller core.

That said, to me this was a worst case test of the Tr400, taking it beyond intended use by way of too large a cap bank for it

and also stereo UCD modules driving low impedance speakers, when they are intended for a cap bank less than half what I

tested it with and in mono operation. This wasn't meant as a sound quality test, but I think when used as intended it will

tend to sound cleaner and with even more ambience. I can easily say they work very well with 120Vac mains and pose no threat

of ever tripping overvoltage even under worse case conditions.


Previous experience with a similarly sized transformer, also presented with similarly unoptimal conditions, had much the same

sonic characteristics.

In that similar setup, the bargain bin transformer was pushed right to the edge. Allowing the amps to idle an hour with no

signal produced a transformer that was considerably warmer than ambient levels, fifteen minutes of listening at comfortable

levels made it hot enough that you could not keep your finger on it for more than a few seconds. After playing it loud for

five minutes, you'd really not want to touch it at all. Given that they both were similarly sized 250VA cores, I can confirm

the core saturation issue with such a core on these dirty mains by recalling how the older one danced around, if not vibrated

violently.

The Tr400 is fully encapsulated, and so avoids either of these symptoms. No reasonable load is going to make it heat up much

at all above ambient temp, in fact it stayed even cooler than my 500VA, and no level of saturation is going to produce the

slightest hint of vibration. However the distortion and noise produced remain, so I think it wise to not plan on overloading

them, and also use them in conjunction with additional input filtration for the best possible outcome. With the right load,

and used as intented, they should prove excellent sonically, and I'll have no reservations using them in a monoblock setup

with the HG supplies.

However, if your speakers are capable of extreme bass as mine are, and one is building themselves a UCD400 amplifier, they

might be wise to not ignore the less rich looking 500VA transformer Hypex also stocks.

As per the "no worse than your typical commercial off the shelf" comment earlier:

A few weeks ago I found myself at our local AV dealer since a friend wanted to spend some of his ill gotten green on a new

amp for his rustang. The transmission has about about 99% slip in anything other than first, but if he can make it louder...

I spent my time there checking out their demo home stereo setup. T'was a Yamaha "natural sound" receiver, coupled to a set of

Paradigm speakers, which are known themselves to be very precise, and low distortion. Exact models are unimportant. It wasn't

Paradigm's best, but it was the best the store carried. They looked so.... cheap, with see through plastic midrange cones.

Their sound? Somewhat plastic as well, and I can't yet say if I like it or not, but I'm leaning towards not.

The receiver I found, did have a fairly natural sound. It was laid back, open, somewhat detailed, yet where there should have

been ambient microdetail, there was nothing but grain. I wasn't there to review it though so that's about all I'll comment on

as far as that goes. However, one of the pet peeves I've had with the early UCD400AD (never shared by the 180ST at all), and

also a problem for the 1820M audiodock, was the utter lack of precision in the high's. The combination of the two being less

than ideal let to a smeared mess for cymbals, with a total lack of focus and just no cohesion worth a mention. It doesn't

always matter though, because I found that most recordings were already guilty of the same, and that's how I got away with

listening to MP3's for so long, it just didn't matter so long as they were of sufficient quality, they would convey as much

as the electronics were capable of.

With certain choice mods to the 1820M and even 400AD's largely resolving that, and the UCD400HG's being very near blameless

already, I can still point out half a dozen areas where my system can, and will eventually improve. I have however come to

now largely ignore anything less than at least decent recordings, with better sources for them, having amassed my Flac

collection drastically. It was high time to do so, in that the electronics could finally convey that extra resolution I

craved.

There are improvements towards ultimate coherency to be made throughout my system, mostly in the audiodock and then the

speakers, wich are Beavis and Butthead Heavy Metal specials, and never at all intended to play anything with accuracy. These

day's however, they seem to manage somehow, better than ever, and would drastically shame what I heard at the AV store, which

was more than reminiscent of those trying times when I had the worst of the worst.


They drove that Yamaha "Natural Sound" receiver, as I noticed with several effects enabled, something I never (need)to use,

one for bass to drive their subwoofer with more authoritah, and the other some sort of presence/image enhancer, that must

have been faultering.

The receiver was being fed by a DVD, that I'm certain contained one of those special test disc's they love to play. All I can

say is that it instantly made me better appreciate the system I have at home, and made me realize how truly spoiled I'd

become. When I later got home and turned mine on, with the "natural sound" still fresh in my mind, it was as if hearing it

for the first time... words to describe how infinitely superior it is in every respect will never do it justice.

PS: I finally found someone to cut my granite, so I don't think I"ll be using that ugly case after all. I tried laying things

out every which way and just couldn't bring myself to compromise the layout to such an extent. So it's looking like it's

going to be a pair of black granite + AL monoblocks.

PPS:

Battlestar Galactica Season 3 sound track, very cool.
Eddie Vedder - Innocent Bystander (anthology 1992-2006), great sound.
Eddie Vedder- "Into the Wild" Soundtrack.. some good stuff but compressed. Seriously though, watch the movie.


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PostPosted: Wed Apr 21, 2010 10:34 am 
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Joined: Sun Dec 19, 2004 9:36 am
Posts: 54
Location: NORWAY
More TITANS ?

UcD 400 HG monoblocks...with 1500VA trafos!
And 80 000 uF each.

Arne K


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Last edited by Cobra2 on Wed Apr 21, 2010 10:49 am, edited 2 times in total.

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PostPosted: Wed Apr 21, 2010 10:38 am 
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Sheep

Joined: Sun Dec 19, 2004 9:36 am
Posts: 54
Location: NORWAY
-they ROCK! (and do all other music well too!)

Arne K


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PostPosted: Wed Apr 21, 2010 2:45 pm 
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Dog
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Joined: Tue Dec 14, 2004 12:26 pm
Posts: 4981
Location: Lisbon, Portugal
Are those Jeff Rowland amps?

Tannoy Westminster speakers?

You...

:grin:

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"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius - and a lot of courage - to move in the opposite direction." Albert Einstein


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PostPosted: Wed Apr 21, 2010 6:52 pm 
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Sheep

Joined: Sun Dec 19, 2004 9:36 am
Posts: 54
Location: NORWAY
carlosfm wrote:
Are those Jeff Rowland amps?
Tannoy Westminster speakers?
You...
:grin:

(my friends system...)

China copy-cat chassi...to house the Hypex

Real Tannoy Canterbury SE
Bat 52SE
Transporter
AYA DAC & Analog Research PCM1704 DAC

Arne K


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PostPosted: Wed Apr 21, 2010 7:03 pm 
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Dog
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Posts: 4981
Location: Lisbon, Portugal
Cobra2 wrote:
China copy-cat chassi...


OMFG... the world is lost. :doh:

_________________
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"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius - and a lot of courage - to move in the opposite direction." Albert Einstein


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PostPosted: Sat Mar 21, 2015 8:13 am 
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Hen

Joined: Sat Apr 20, 2013 6:04 am
Posts: 2
I know this is quite an old thread, but since I just got myself a pair of UcD180HR's I only stumbled today.

My question is on the CRD at the output of the LM4562. There seems to be consensus that the CRD should be connected to the positive rail as the LM4562 is supposed to have a lower PSRR there. However, when I look at the graphs in the datasheet, to me it seems very clear that actually the negative rail has worse PSRR and hence I would arrive that the conclusion to connect the CRD there. What am I missing?

Another question I have is that many references are made to the circuit as if we are supposed to know the schematic. Specifically the arrangement with the preregulator and aux supply is difficult to understand without the schematic. I would like to try it, but I am in the dark.

Reference is also made to a couple of 22 uF coupling caps on the output of the opamp (and should be removed?). Assuming these are be electrolytics, I can't seem to find them. Does anyone know the designations for them?

thanks Lex


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PostPosted: Sat Mar 21, 2015 8:15 am 
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Hen

Joined: Sat Apr 20, 2013 6:04 am
Posts: 2
I know this is quite an old thread, but since I just got myself a pair of UcD180HR's I only stumbled today.

My question is on the CRD at the output of the LM4562. There seems to be consensus that the CRD should be connected to the positive rail as the LM4562 is supposed to have a lower PSRR there. However, when I look at the graphs in the datasheet, to me it seems very clear that actually the negative rail has worse PSRR and hence I would arrive that the conclusion to connect the CRD there. What am I missing?

Another question I have is that many references are made to the circuit as if we are supposed to know the schematic. Specifically the arrangement with the preregulator and aux supply is difficult to understand without the schematic. I would like to try it, but I am in the dark.

Reference is also made to a couple of 22 uF coupling caps on the output of the opamp (and should be removed?). Assuming these are be electrolytics, I can't seem to find them. Does anyone know the designations for them?

thanks Lex


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