UcD400 Q & A

Jan-Peter, Bruno, I see that you have gotten soft and fallen for the pressure of the demanding DIY community, you offer now UcD modules AD8620 :nod: Can you notice any improvements yourself?

Free of choice of cource but I recommend your webmaster to change target for your link to this thread. It's better if it's not in your frame at your website. Target= blank is good.

One more thing: Hifi-Kit in Sweden is listed but they doesn''t sell any Hypex products? How come?
 
Edwildgoose;
OK, I just studied your diagram some more and realised that I don't in fact understand it properly... I see now that you use two secondaries going into the one rectifier - correct?

The secondaries appear to be connected in series, but I don't understand that part of the diagram in the middle? How does one practically use the two secondaries here?

OK, so coming back to the real problem. I was going to try to build dual mono supplies for my UCD, but I only have a single torroid with dual secondaries. So, assuming that I have 2 rectifiers and 4 10,000 caps that I bought from you, how would you suggest that I best wire these?

a) Keep a single PS
b) Keep a single rectifier, take two lines from the DC out to each pair of caps, and from each pair of caps on to the modules
c) Some design involving paralleling the outputs from the transformer to two rectifiers....?

Thoughts on design appreciated, but mainly I realise that I have no idea how to wire the two secondaries to a single power supply now..

Thanks for answers to this most basic question!
Click to expand...

Ed I agree with you the questions are quite basic 😀

First, we must have a symmetrical powersupply so we need two secondaries. One for the positive voltage and one for the negative voltage. It's the same if you put two batteries in serie, then you also have +9V / 0V / -9V.

Peranders;
Jan-Peter, Bruno, I see that you have gotten soft and fallen for the pressure of the demanding DIY community, you offer now UcD modules AD8620 Can you notice any improvements yourself?

Free of choice of cource but I recommend your webmaster to change target for your link to this thread. It's better if it's not in your frame at your website. Target= blank is good.

One more thing: Hifi-Kit in Sweden is listed but they doesn''t sell any Hypex products? How come?
Click to expand...

I did not listen personaly to this upgrade, several customers did and the most of them found it a major sonic improvement.

I have informed our webmaster!

Hifi-kit do sell our stuff, please contact Stefan.

Regards,

Jan-Peter
 
Peranders,

Can we stay by the subject?

I do not have problems with Hifikit, the UcD modules are sold thrue our distributors and ourself. So you can order them by Hifikit or thrue our website.

Regards,

Jan-Peter
 
UCD400 gain

I have just received the UCD400 module. Looks very nice! I am sure it will sound the same.

The module is the one with AD8260 upgrade. However, I need to have the gain of the module reset to 20dB and the existing value of R4 is 152. Is this correct or should I change it to a different value?

Thanks

Arthur
 
Thanks Jan-Peter!

The equation that was posted on the forum was G = (1+2*A/B)*C/D

where A = 1000
B=560
C=1800
D=8200

for the origianl module.

Does this equation still true for AD8620?

Thanks
 
Jan-Peter,

How do you disable the current limit on the UCD400?

If you use two UCD400's in bridge mode does the current limit for the modules have to be changed.

Thanks,

Jam (Still waiting for the UCD700....😉 )
 
Hi...

Just wanted to share some pictures of todays work...🙂

A Woodie UcD400

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


800VA 2*42V transformer
2*22000µF Rifa Capacitors

/Stefan
 
Stefan,

Nice pictures!

Where did you mount the UcD400? And how do you like to arrange the cooling of the UcD400? Class-D has an efficiency of 93%, but a small heatsink is still necessary!

Regards,

Jan-Peter
 
J-P, re heatsinks for the UCD modules, my 180's are just screwed to the outside of the case and they run very cool, however I am probably not pushing them very hard at the moments as the neighbours don't like my taste in music especially Magma 🙂

Also do you know when the UCD400's will be back in stock?

And lastly looking at the UCD 400 datasheet it looks as though the speaker connections are now small pins rather than the spade terminals on the 180's? if this is the case are they OK for the power available from the 400's I am sure you have thought of this but the change seems odd when going up in power?
 
Wytco,

In your setup it looks ok. Steel is a very bad thermal conductor, but in this way you remove some heat. In normal use the heat stays quit low. However the ucD400 is running from a higher voltage and the gatedriver powersupply is feed by the high voltage rail so the UcD400 will need a better cooling. The standby power of the UcD180 is +/-3W and the UcD400 +/-8W.

In about 4 weeks we will have the UcD400 again in stock. The pins are JST connectors and can hanlde 10A RMS current, can't be a problem.

Regards,

Jan-Peter
 
Jan Peter...

The modules are located, one in each copper housing (shield)

An externally hosted image should be here but it was not working when we last tested it.


Cooling is done by mounting the modules firmly to the bottom plate of the amp... this one is 5 mm aluminium, there is also venting holes in the bottom, to let air in, close to the UcD and outlet vents on the side near to the UcD...

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


Regards
Stefan
 
Current Limit

Hi Jan Peter,

With the UCD400, I understand the current limit is 10A rms (approx 14A pk). This is, therefore, equal to the rated power at 4 ohm load. This obviously leaves no head room for load impedances that dip below the nominal 4 ohm's. Are users with difficult loudspeakers having any problems with cut out?

Does the protection work as soon as a current peak is detected, or is there a time constant? Also, why is the limit set so close to the rated power output and how long does the limit activate for? Although this seems ok for active speakers (which I am working on at present), it does not seem so good for a free standing amplifier with undefined load if there is signal cut out when the amplifier is driven hard.

This is not meant as a criticism, I am just trying to properly understand the operation of the protection (I am sure you guys have thought through the engineering decisions very thoroughly!!)

Robin
 
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