[Gordy]

I've been putting this together over the last week or so after running in the amps for about 100 hrs. in a more slap dash version.  I still need to re-route the speaker jumpers in a more direct fashion, shorten up the left side power jumper and shield/wrap all the power lines, any other suggestions would be greatly appreciated!!!!  

There was no soft start included in the group buy kit, I still need to order one up from Kevin...

http://www.audiocircle.com/circles/modules.php?op=modload&name=gallery&file=index&include=view_album.php

[G]

You don't need to get crazy on the PS to get great results.   I think a lot of people like to throw money at them.

Absolutely Kevin! And you don't have to use the typical POS toroidal transformer which lets all sorts of crap in (and out). Use 2 of these dual bobbin ($40 retail) transformers, each providing 175va @28v AC, one for each rail of your UCD180(s), and you've got the start of a fine powersupply.

http://www.bgmicro.com/prodinfo.asp?sid=078189814814814869201136182&prodid=PWR1164&page=1&cri=signal+transformer&stype=3

and if you call BGmicro, tell Tammie that Paul sent you and she'll put up to 4 of these $9 transformers in a $8 PriorityMail box. Your postman will love you.

Will a dual bobbin EI transformer hum?

[dem626]

I'm planning on building a UcD400AD amp and I'd really like to use the battery PS approach.  This thread has tons of good info but has gotten really long and I'm getting lost trying to piece it all together. 

Can someone describe the basics for the battery PS or post a diagram/schematic to help me out? (hopefully a simple version).  I'm pretty handy and can follow instructions but don't know too much about electronics yet, although I'm finding it very interesting. 

Also, I noticed that the activity on this thread seems to have died down.  Hope this doesn't mean that the Hypex amp has lost favor.

Doug

[JoshK]

The UcD's haven't lost favor in my eyes, I have just haven't done much more on mine for some time. 

Do you understand series and parrallel?  Basically you have 12V SLAs and you need +/- 48V for your PS.  4 SLAs for each side of the PS will get you there.  Put the 4 SLAs in series to derive a 48V voltage source (+ to - of next battery).  Now put two 48V sources in series, now your -48 / 0 / +48 is the - terminal, the node between the two 48V banks, and the + terminal. 

Where are you located? 

[JoshK]

G,
The fact that the tx's are EI core dual bobbin doesn't mean they will hum or not.  It is basically up to the individual tx's, how well they are balanced.  With those tx's, if they are the same as the Felicia's txs, then they may hum lightly but probably not too bad.

[dem626]

Josh,

Thanks for the reply.  I'm anxious to get started on this project.

I live in Richmond, Virginia.  Occasionally I travel to Reno, NV and Anchorage, AK on business, usually once a year to each of my two customers.

I understood creating the two 48v sources from the 4 12v SLAs in series but not the part about connecting the two 48v sources in series.  I was expecting you to say to connect each 48v bank to a UcD400.

Are you describing the procedure for powering a single UcD400 or both?

[JoshK]

the UcD needs two rails, both a +48 and a -48V.  Between +48 and -48 is 96V.  So put all 8 SLAs in series for 96V and take three wires from this bank at 0V, 48V & 96V, this is your +/0/-.  Voltage is all relative so as far as your UcD is concerned, 0/48/96 is the same as -48/0/+48. 

Said another way, not to confuse the matter but -48/0/+48 biased up by 48V is 0/48/96.  This biasing is done all the time, especially in tube amps where you are working with high voltage and you have to be careful not to exceed certain insulations. 

Does this help?
Josh

P.S. the reason I asked about where you live is because I have the two huge battery packs (with built in chargers) that I used to run my UcD's off batteries.  I am not using them now and would sell them to you but they are extremely heavy, so shipping wouldn't work out to be very worthwhile.

[Gordy]

Dem626,

I have photo's of my battery supplies that I think show the wiring fairly clearly, inluding the various dt4p switching you'll be needing to charge/power.  PM me if interested...

The switching chargers Josh has are sweet!  Worth the shipping charges to VA. I suspect...

[dwk]

FWIW, I'm going to take a shot at a battery powered UcD. I'll be using +-24V rails which is lower than ideal, but based on positive feedback from another ACer it seems worth a try.  I have 4x 33Ah AGM cells that I'll be using. Eventually I'll probably hook up a solar charge controller, but in the interim I have a couple small 12V chargers I'll run in series. Power output should be ~65W into 4 ohms which should be OK with my 97dB/W speakers, even with the eq I have to apply.
 It'll probably take me a couple weeks to get things running, but I'll report back.