UcD400 Q & A

[egonnaud]

I have no heat issue at all with 1 smps180 powering 2 ucd180 in a 40mm enclosure.
The output coil should be the hottest part.

[Crafty]

Thanks for the reassurance - hypex also confirmed its quite normal and safe for the voltage regulators to run hot with the smps. So looks like nothing to be concerened by.

[teflon1]

Originally Posted by vincent s

I test almost every hypex module,including oem version and hg ad version.
the test result is not so good.
I think they could make them better,but it seems that they do not think much of DIY market.

Have you a better amp to recommend then? Are there any on Ebay that you like? I don't know what to get anymore.

John

[Virtalahde]

I'm going to stuff one UCD400HG and two UCD180HG's in one chassis for a monoblock. This is going to be used for a 3-way project.

What do you think, should I have separate 30-0-30 VAC (for the 180's) and 40-0-40VAC transformers (for the 400), or would a big, chunky 30-0-30v do fine with separate bridge rectifiers & caps for the 180's and the 400?

The capacitors used are going to be of good quality. Got a bunch of big 10,000uF Sikorels here..

[muzzer]

Originally Posted by Jan-Peter

Resistor R3 (value 560), straight to the small side of the OPA2134/AD8620.

The gain is now 26dB, when you decrease R3 the gain will increase.

Regards,

Jan-Peter

[muzzer]

One for JP or Bruno I think.

I am using a Ucd400 with a SMPS400/67 installed as a "plate amp" in my Schroeder 1210 bass cab for live work. The sound is fantastic but I can't seem to get the output I would expect from this amp without causing my EBS MicroBass preamp to overload. I would like to increase the gain of my UcD400 slightly if possible to see if this solves my problem.
After trawling through the posts here, I found a reference to this:

Originally Posted by Jan-Peter

Resistor R3 (value 560), straight to the small side of the OPA2134/AD8620.

The gain is now 26dB, when you decrease R3 the gain will increase.

Regards,

Jan-Peter

I have had a look at my UcD400, but there is no OPA2134/AD8620 on the board - R3 is near a N5532 and seems to be 1.2k (marked 1201).
The board has UcD400v8 silk-screened on it and the sticker is marked 06091204-0095 so I would guess this is a newer version.

JP - can you tell me what I need to change to get the gain up to about 30?

Thanks
Steve

[NicMac]

Hi guys,
On the Hypex FAQ (at http://www.diyclassd.com) I have seen an entry regarding "supply pumping" due to transient reverse current flows?!
For my UcD180HG HxR modules I am planning to test a regulated high current series supply. This supply type does not support reverse currents and I was wondering what type and size of the supply caps I need to deal with these reverse currents. I guess that also SMPS do not accept reverse currents - still they seem to work quite nicely with the Hypex modules.
Thank you,
Nic

[AIS]

Anyone compared the sound quality of the ucd400 powered by the SMPS400/67 compared to a standard transformer setup (for driving normal speakers, not subwoofers)? Is the difference noticeable?

[totte]

I am planning to build Hypex UcD400 amps for a line source system and wonder:

To what extent will I benefit from using HG-modules with voltage regulators instead of ST-modules in the frequency ranges 15-100Hz and 100-500Hz?

How well will the UcD400 do with 3 or 4 8ohm woofers (6.5") in parallell? If I give them such a difficult load, should each have a separate PSU and will the SMPS do equally well as or better thatn the linear PSUs?

[renpetra]

Hello I am starting soon on an dual mono project with the Ucd700 modules.
Everything to power my magnepans and I suspect a real good sound of of them.
Driving the maggies now with a rotel rb1080 amp.
I have order the first lot of mudules and a housing from hypex and mudus.

regards rene