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Help with DIY mono amp for center speaker

Don Dadda

Distinguished Member
Hi all

This is my first foray into self build amps and the main aim is not to burn up the house but have something that works and works well. So chaps, especially those who have been there, done that already i am going to need all the help i can get :D.

Long story short, I use a stereo amp for TV and music. I use to have an avr and 5.1 but then went to 3.1 when we changed the room layout and didn't want rear speakers in the only place they could go - the rear wall. I tried the speakers behind the sofa, 6-8" away from the wall but that ate too much into the room and I wasn't really that impressed with that config TBH. Music being the main priority, I'm ok with not having rear speakers so sold them and the AVR, but i do like a center channel for vocals as ts mor defined.
I am happy with the stereo amp but vocals do sometimes get lost hence me building a mono amp just for the center channel.

After much research and speaking with one of the team from hypex i have ordered the following bits from them:
1 UcD180HG with HxR
1 SMPS400A180
1 Cable set SMPS400
1 DSP - UcD signal cable

From the bay i bought a pair of speaker posts, a RCA phono socket, spacers and the chassis pictured below
Chassis .jpg


Dimensions of the chassis is W150mm x H70mm x D280 approx. In the box of the chassis came mains socket, volume knob and on/off switch. The chassis is the size i wanted as i don't need a full size one.

The only thing i need i believe that is left to purchase is a heat sink but i thought i waint until the Hypex parts arrive before i do, so i know what size to get.

As said above, this is my first foray into DIY amps build and once i have all the bits, not sure how to go about designing the internal layout. Though it doesn't look extremely difficult to do, i would like some help/pointers from your good selves on which should go where.

I also would like to add in the volume control as some of the films i have watched, the vocals could do with a boost or reduction.

I will be using a Oppo 105 as a pre amp to the mono amp and my existing Amp in HT bypass (removed its links and stuck a analogue input switch in between the pre-and power stages)

Any and all help would be much appreciated

Thanks in advance

H
 
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sergiup

Distinguished Member
Hello H! I would imagine PSU at the back, amp module further front - unless you want to potentially fit another amp module in that enclosure later on. I'm not sure how you mount each module onto the case and protect them from potential shorts etc..

Xav @tfboy has built a couple of much more complex Hypex-based amps here, he can probably be far more helpful!
 

Don Dadda

Distinguished Member
Hey Serg.

I have been looking at images of other Hypex builds and positioning of the modules when I 1st thought of doing this diy build and generally from what i see, that looks to be the case.
I also notice that some of them do not have a heat sink. Though the manual for the Ucd180 does say that mounting the module on a sheet of aluminium will provide enough cooling for use under normal conditions, i would of thought there would be a heat sink attached.

Anyhoo, all the bits arrived from Hypex - Wahey
hypex.jpg


and laid them out on the chassis where i want them with the rest of the bits and pieces
20151106_145923.jpg


I won't be adding any more modules and its a good thing as clearly, i couldn't add anymore if i wanted:D.

I have bought spacers and speakers posts of the bay for pretty much pittance really. The chassis came with a switch which is good. I just need to know find out where to attach the cabling on the psu. I now need to get a volume control Pot and RCA chassis sockets which i will raid a rca switch box i have.

The layout of the modules above is pretty much where they will be positioned. I thought I have the connectors facing each other since the cables Hypex sent are not that long
I believe that will be ok but if anybody has any alternatives or other suggestion (not that i have a lot of room to play with) my ears are open.

EDIT: Have been reading tfboy thread so will definitely be looking to PM him if he doesn't pop in soon enough :)
 
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Don Dadda

Distinguished Member
When looking at volume control pots, I see that there are a few variations

10k, 22k 47k, and 100k pots. Which do I go for?

I found this one at Maplins
47k Ω Miniature Log Single Gang Potentiometer | Maplin

The shaft is the correct length and diameter for the hole on the face plate, but that is all I know that is compatible. Will 47k do?
 

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