UCD180 questions

[classd4sure]

Hi,

I'm in agreement with everyone else on this.

A regular fuse may have blown though but just in case double check alllll your wiring/circuit make sure the rectifier is wired properly and the caps aren't in backwards, just test the power supply on its own at first with the UCD removed from the circuit.

You can tell a slow blow fuse right off from a regular one, the wire inside is coiled.

Sizing the fuse: There's no science to it. Once you can power it up OK, try to find a slow blow where the wire just sags a bit when you first turn it on, then move up a few sizes until it doesn't sag anymore, this would be the best value to use in that it won't blow just from turning it on a few times and should burn quickly enough in case of a problem.

[kvistarn]

I have a big problem (I think) on the speaker outputs there is 14vdc!! why??
i have a 200va 2x33v trafo, 2x35A/600v rectifiers, 2x 10000uf capacitors.
i have only one module connected, shouldn´t matter right?
the blue led is shining so the module shouldnt be broken? could it be broken and still the light would work?

please help me, and sorry for my english, (I´m from sweden).

[classd4sure]

sounds like a cooked output fet, fets usually fail closed/shorted, so it could short the rail voltage to the output, but yeah you'd think the protection would kick in, is your module modified at all? I believe when the protection circuitry is working the light will blink on /off every few seconds.

Far as I recall its' only current limiting though.
I don't think there's any DC voltage protection on it.

No need to freak out about it anyway, Jan-Peter seems excellent in supporting his product I know he'll fix you up one way or another. Might want to send him an email about it in case he should miss your post though.

[peranders]

Originally posted by kvistarn
please help me, and sorry for my english, (I´m from sweden).

There is no need for any excuses. Your english is very good!

BTW, kvistarn, do you have three wires from the PS, +45V, -45V and ground and all are connected?

[UrSv]

I could easily be wrong here but how did you measure it ? Without load I would not trust the value. Connect a 100 Ohm resistor or something and check again. Without a load there is some switching residuals that could easily cause misleading readings. An oscilloscope would be useful.

[Golgoth]

UrSv, no, no more switching residuals in no-load condition, why should there be? A multimeter should be perfectly adequate, especially since the UcD has very little switching noise on its output.

Kvistarn, check first the rail voltages are ok on the module itself.

If they are, it would be a good idea to find out which of the two stages (buffer or power stage) is guilty for the DC offset. For this I would suggest to desolder the 22uF interstage coupling capacitors (or the straps which replace them depending on version), and then turn on and measure outputs of both stages.

[classd4sure]

Hi,

Yeah and depending on your version or modifications it may be useful to ground the inputs and double check the output as well, it might be amplifying a DC offset, though it would have to be an unacceptably ugly offset to begin with to get 14volts out of it. I kind of dont' think you'd have a blown fet since your rail voltages would be higher than 14V right, unless you hooked it up wrong and put ground as one rail, instead of +30/-30 like you should have, could you have hooked it up as +30/0? triple check your supply rails, this makes the most sense as you didn't say the light was flashing or anything, then again, your rails are higher than 30, I'm just stabbing the dark

Maybe just for kicks you could put an ohmmeter across your output fets and make sure none measure 0 ohms. Do that with the power disconnected though so you can't short anything out. I agree with Peranders too your english is excellent.

Keep us posted you've peaked our interest.

[peranders]

Acme has tested and built ICE, Tripath and Hypex.

http://www.hififorum.nu/forum/topic....chTerms=,hypex

He and his brother (=brorsan) have reviewed the UcD180 and the other amps.

ICE-power:
Brorsan:
Här finns det värme men samtidigt ett väldigt distinkt och klart ljud. Det låter gott helt enkelt. Transienter tas om hand på ett bra sätt, även om en liten tendens till släp finns. I basen finns det gott om kraft för en utmärkt kontroll. Röster målas upp på ett naturligt sätt och låter mycket bra. I de övre registren finns inget att anmärka på. Kort sagt: allting stämmer helt enkelt.
Acme:
Håller med i allt, nästan. Jag kunde överhuvudtaget inte uppfatta något "släp" i återgivningen. Sammantaget var det ICE-power som presterade det bästa ljudet i samlingen. Den gör allt i musiken bättre än både Tripath och framförallt Hypex. Diskantåtergivningen är minst lika bra som hos Tripath.

Tripath:
Brorsan:
Detta ljud är det absolut klaraste av de tre. Här finns ingen tendens till förmörkning eller grötighet. Förstärkaren levererar transientrik musik med ett enormt klipp. Snabba attacker och en mycket bra förmåga att hålla emot. Det finns gott om kraft för att ta hand om basen. Sångröster låter ofärgat och väldigt naturliga. I diskantområdet briljerar verkligen Tripath. Det känns som om det finns någonting bortom 20KHz som gör att diskanten blir väldigt krispig och klar.
Acme: Kan bara hålla med. Möjligen tyckte jag transientåtergivningen var lite återhållsam jämfört med ICE-power. Men mer naturlig än Hypex. Fullt i klass med ICE-power då det gäller basåtergivning.

Hypex: (Efter en tids lyssnande på Hypex råder lite tudelade meningar...)
Brorsan:
Blir nästan lite besviken. Möjligtvis påverkad av alla positiva intryck från de som byggt med dessa förstärkare. Därför var förväntningarna från början ganska högt ställda. Men det är något som inte stämmer. Det är nästan som om det ligger ett "dis" över ljudet men samtidigt låter det inte varmt heller. Transientrik musik släpar i attacken och ligger kvar ett tag efteråt. Den klarar inte av att kontrollera basen i musiken utan låter väldigt tam. Detta kan kanske bero på att den är effektsvagast i samlingen med sina maximala 180W/kanal. Mellanregistret låter lite "grötigt", sången får ett helt annan ljud än med de två andra. I diskantområdet känns det som om det saknas en dimension, det låter väldigt avhugget i det allra högsta tonområdet.

Acme:
Ibland är det konstigt vad man hör. Själv tycker jag Hypex förtjänar bättre än brorsans "brutalsågning". Jag tycker nästan att den når upp till återgivningen från ICE-power och Tripath. Men den har något skumt för sig vid transienter. Lite svårt att peka på vad som händer, men den verkar nästan "överbetona" anslagen i musiken. Till en början tyckte jag Hypex nästan återgav transienter bättre än ICE-power, men efter att ha skiftat fram och tillbaka några gånger låter ICE-power mer korrekt. Hypex transientåtergivning påminner lite om en loudnesseffekt, fast då för transientåtergivning iställer för tonåtergivning. Imponerande i början men tröttsamt i längden.

/Peter

ICE-power:
The brother of ACME, brorsan (brother in swedish):
I can find lot's of warmth but at the same time a very distinct and clear sound. It sounds good , simply. Transients are well taken care of, even though I can hear some "släp" (something which lingers on, delays... etc). The bass has lot's of good power and is controlled beautifully. Voices are painted up naturally and sounds very good. The upper range has no faults, no remarks what so ever.. In short: Everything fits, is there.
ACME:
I agree in everything... almost. I couldn't hear any "släp" at all! As a conclusion ICE was the best performing module in this test. The music is reproduced better than in the Tripath and Hypex. The treble reproduction is at least as good as the Tripath

Tripath:
Brorsan:
The sound from this module was the most clearest and best of all three. There is no signs of darkning, blurring. The amp delivers transient rich music with an enormous "clip" (don't know what he means, klipp is cut?). Fast attacks and a good ability to withstand. There is lot's of power to take care of the bass. Voices are uncoloured and very natural. In the high range the amp really showing it's real face. It feel almost that something is beyong 20kHz which makes the treble crispy and clear.
ACME: Agrees...possibly the transient repoructions was a bit hold back compared to ICE. Much more natural than Hypex,. Bass in class with ICE.

Hypex:

After some time of listening there are mixed feelings about Hypex.
Brorsan:
I got kind of disappointed. Possibly influenced of all positive impressions form those who have built UcD amps. Due to that my expectations were pretty high, but it is something that doesn't feel right. It's like there is some kind of haze over the sound and in the same time I can't sense any warmth. Transient rich music lingers on in the attack and gets behind. The amp can't control the bass and sound very lame. Maybe this is caused by the fact that this is the weakest amp amongst the three, only 180 watts/channel.

The mids are blurry and the vocals sounds totally different compared to the other modules. the treble lacks of dimension and sounds very chopped off in the very highest freqeuncy range.

ACME: Sometimes you get puzzled of what you hear. Personally I think Hypex deserves better than my brother's brutal-rejection. I feel that Hypex is almost in the same level as ICE and Tripath but Hypex has some weird behavoir when it comes to handle transients. I have some trouble to pin point exactly what it is but it seems that the module wants to over-emphasize musical impacts. After a couple of swaps back and forth, I think ICE is a bit better, sounds more correct. The transient reproduction of Hypex reminds me a little of "loudness effect" but instead of sonics more transientwice. Impressing to begin with but tiring out in the long run.


Don't laugh at me becasue translating text which is about emotions is really hard but I'll hope you will get spirit of what they are saying.

[koldby]

Hej Peranders

Who are these guys???

I haven't got time to translate either. Even though it is written in Sweedish i get 95% of what they say, but I do NOT agree with their findings!!



Koldby

[Thmartin]

Originally posted by koldby
Hej Peranders

Who are these guys???

I haven't got time to translate either. Even though it is written in Sweedish i get 95% of what they say, but I do NOT agree with their findings!!



Koldby

Hi,

For non-swedish readers like most of us, can you please let us know roughly what's the point ?



Thanks