UCD180 questions

[stef1777]

Steff,

Because of the internal boost trap circuit to drive the positive fet you have an output voltage of 12VDC when the amp is OFF and without a load. You can remove this high impedance DC voltage when you connect a 47k resistor from the output to -V.

Or the best way would be to use a 12V zener and 33k from the output to -V. The kathode of the zener should go to the output of the amp, anode to the resistors and other side of the resistor to -V.

Regards,

Jan-Peter

Thanks JP for the answer.

But where come from the -20.6V with no charge and MUTE ON?

And why 180mV with 100 Ohms charge?

I can see the 12V when MUTE is OFF with no charge.

 

[Jan-Peter]

??? I don't know....

Does the amps works ok?

Perhaps you can post the full schematic of your setup?

JP

 

[stef1777]

??? I don't know....

Does the amps works ok?

Perhaps you can post the full schematic of your setup?

JP

Not done yet but the test circuit is really simple.

PSU (MBR10100 + BHC ALS10S = 42V) -> module (mute directly soldered on GND)

Input shorted. Output tested with charge and without charge. For the test, the GND is not connected to the box. I test the speaker output directly. The DC protection circuit have been completely removed.

The module have been tweaked as this : new op-amp OPA2134 and coupling caps replaced with 47UF BG NX HiQ (no 22UF in stock sorry).

The module works well connected to a 4 Ohms speaker.

What's the dark side of the zener+resitor tweak?

 

[Bgt]

Steff, how about the heat build up with closed lid and working for some hours?

 

[stef1777]

Steff, how about the heat build up with closed lid and working for some hours?

I tested only 5 hours box closed. More hot than I was thinking. The plate has to have holes above modules for vent but no more. The temp stay cool.

 

[Bgt]

The temp stay cool

Untill you measure the various parts.

 

[Jennice]

Hi all,

I am considering a pair of UcD180 modules to play with... but before I know what I'm dealing with, I would prefer to use some 24V transformers I have at hand (to keep costs down).

Is this possible, or will I get into trouble?
(I saw the data sheet for the UcD400, hich would indicate problems with my supply voltage being too low.)

Jennice

 

[UrSv]

24 VAC gives you some 33 VDC and the UcD180 modules ask for a minimum of 20 VDC as a supply so you should be fine.

 

[Jennice]

As low as +/-20 V DC? where do you read that (any link?)

Do you know about the low limit for the UcD400, also?

Jennice

 

[GregD]

As low as +/-20 V DC? where do you read that (any link?)

Do you know about the low limit for the UcD400, also?

Jennice

On Hypex's website under technical documents UCD180 user's manual, it recommends a minimum of +/- 30V for "optimum sonic performance".
http://www.hypex.nl/docs/UcD180_manual.pdf

For the UCD400 it says +/- 45V.
http://www.hypex.nl/docs/UcD400_manual.pdf

 

[Jennice]

exactly! I read those papers too. That is why I am wondering about the +/- 20V that UrSv mentioned.

But anyway... I guess I'll be ok with a 24V transformer to get a feel of things.

Jennice

 

[Jan-Peter]

The both amps work on such a low voltage! However the op amp stage and the voltge regulator are of course not optimised for such a low voltage.

For testing we always start wih such a low voltage......

Jan-Peter

 

[Jennice]

Thanks for the info

Jennice

 

[ojg]

I've found this page surfing.

http://www.ciaudio.com/D100.html

The specs are close to the UcD180 module!!! May be inside?

You're right. There's a review of it with full measurements in the August edition of Stereophile.

 

[Yves Smolders]

Yup,

and the D200 is Ucd400 it seems!

Check out the prices!

Check the reviews on audiogon: Audiogon



I'm going to scare my local high-end store when my dual UcD400 gets finished

Bruno and/or Jan-Peter, are you allowed to tell me how "custom" the modules inside the channel island audio's are?

 

[Bruno Putzeys]

It you want to know what kind of circuit companies are using inside their products, it's best to ask those companies themselves.

 

[Jennice]

I've looked at Hypex' web page, and it seems two versions are available. The only difference seems to be a (costly !) buffer change.
What versions are you guys (fellow DIY'ers) using?



Bruno: The signal connector looks a lot like the power connector for a 3.5" floppy. Is it the same?

Jennice

 

[koldby]

Jennice

If you live near Ruds Vedby in Sjælland you could hear these units! I even have a VariaC so a 24 VAC could be mimiced. And I have the 8620 and the 5532 versions on hand.

PM me evt.

Koldby

 

[Jennice]

koldby,

Thanks for the kind offer.

I must admit I have no idea where Ruds Vedby is, but I'll have a look. Personally, I have my home in postal area 4000.

Jennice

 

[koldby]

Postal 4291 here. Not that long from Roskilde. About 45 Km . It is 20 Km north of Slagelse...

Kolldby