Closed - Anyone built the 60Watt Poweramp??? - see build thr

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Mick@ITC
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Closed - Anyone built the 60Watt Poweramp??? - see build thr

Post by Mick@ITC »

Hi all

As a pre-cursor to building the Baby Animal I have decided to give the poweramp kit a go. Has anyone here built one? Would enjoy having a reference or two for when I get stuck :? :)

Looking forward to hearing from you.
Regards
Mick :)
Last edited by Mick@ITC on Sun Feb 10, 2008 5:14 pm, edited 1 time in total.

chrisp
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Post by chrisp »

Err .... that would be me. I've built 2x60W for my DIY pair of powered monitors (see the kit thread above). Rob has built the same kit for his 30W stereo amplifier. The difference is simply in the voltage supplied to the IC.

Very simple kit to build, but before you start, what will you be using it for? You can tweak the kit a bit to optimise it for for various uses.

My only tip for beginners is to mount the IC last, and don't push it too far into the PCB. Its not supposed to sit flush (see the photos on the kit thread) and the longer leads give a bit of flexibility that can come in handy for the heatsink bolting exercise.

The other thing to do is buy the heatsink - you will be bolting the amplifier IC to this, and its good to get an idea of its size before you try to design this thing in a matchbox.
Chris P
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I do lots of things. I believe eclectic skills are best.

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Mick@ITC
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Post by Mick@ITC »

Thanks for the reply chrisp.

Here's some background...

heres what I'm buying...

2 x Amp kits

2 x 75mm heatsinks

1 x 2unit high case

1 x 160VA power transformer

1 x 35A bridge rectifier

The reason I am building this is to get a bit of experience before tackling a BBA2 or 4. Also my son is a bass player and I am"giving" him the kit for Christmas so he and his grandad and I can work on it together. Bit like why we all buy our kids toys we like!!! We intend to feed the amp with a pre-amp (presonus eureka) and power a Lorenz cab that he is getting made. Mount the Pre and Power amp in a portable 3 unit rack box.

I'm a real novice so would love some direction if you are ok with that. I intend to document the journey in photos so it will be fun.

One question that struck me straight away was the mounting of the heatsink. If it is mounted "under" the IC that will mean the IC will have to be mounted vertically???? Have I missed something??? I'll check out the photos you mentioned and might even ask for some directions if you are ok with that???

Thanks for the reply. 8)

Mick :D

chrisp
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Post by chrisp »

Your a good father, Mick. That's what I call a nice Christmas present.

Some thoughts and answers ...

(1) Do you intend to bridge the two amps to get 120W? If so, the power transformer should be 18-0-18V: 160VA should be fine. Here's one:
http://www.electusdistribution.com.au/p ... sp?ID=1865
Usual warnings about 240V being deadly and the legal requirement to get it done by a qualified electrician.

(2) You'll need a bigger heat sink: In a 2U case, try 2 of these
http://www.electusdistribution.com.au/p ... asp?ID=703

(3) You can control the volume using the master on the presonus, which gives you the opportunity (not that I think you'll need it) to do some low eq control using a resister/capacitor combination if you'd like. The 2U box could thus just have a single red LED and a PANIC! mute button on the front. That would be cool.

(4) The IC is not the dual in-line package (DIP) typical IC you're probably thinking of. It sits perpendicular to the PCB, right at the back so its very easy to bolt onto the heatsink. A dab of thermal paste always helps, but be careful with this stuff - don't handle with bare skin if you can avoid it.
http://www.electusdistribution.com.au/p ... sp?ID=1888

Note: Electus is simply the commercial front for Jaycar (or is Jaycar the retail front for Electus?), so the parts should be available in your local store.

Feel free to post questions or send a message - there's many here happy to help.
Chris P
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I do lots of things. I believe eclectic skills are best.

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Mick@ITC
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Post by Mick@ITC »

Hi Chrisp.
Thanks for the info. Really looking forward to doing this...a bit excited and a tinge of trepidation. But whats the worst that can happen...! no wait dont answer that :P . Great thing is that Sean's grnadad is an electrician (so are his two uncles) so we should be right. I noticed that you use the amps to power monitors. Did you build them into the monitors or a seperate amp unit? :?:

We will be bridging the two of them for a 120 watt outcome. Joe told me how to do this in an email so hopefully I can follow his instructions. He seems like a good bloke, very helpful when I ask questions. Its an interesting concept isn't it, building such high quality gear and allowing others access to his wealth of knowledge. Guess we are just lucky.

Anyway, time to get my beauti slep...no wait, too late :cry: :cry:

Mick :D

chrisp
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Post by chrisp »

I built 'em right into the monitors, and spent a bit of money on nice full range 50W drivers . The precision and crispness delivered by the combination astounds my friends - you won't be disappointed by the amp cards.
Chris P
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Mick@ITC
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Post by Mick@ITC »

Forgot to ask, what mods would you recommend across the Vol terms for Bass amp applications? you mentioned resistor/cap, what specifically? Remember I know Jack a :oops: bout the details of circuits, understand the basic freq principles of resistors and capacitors but need real help with the detail. 8)

Also, later on...i.e. after I successfully get this project up and running, I am seriously thinking of a third card with a crossover. The reason is Lorenz here have a bass speaker set-up (award winning acording to the paper clipping on the wall and used by someone famous...who I don't know :wink: ) which has the two woofers and a bullet for the HF. Would be nice to bi-amp that set-up.

Sean (the son and heir to "these vast tracts of land" Month Python) just learned James Jameson's bass-line for "whats goin on" and he surprised me with his skill so I don't mind putting in the effort to give him a special set-up. Apart from that, he has discoverd funk, jazz and afro beats so that metal...well you know... is slowly sinking into the west...Thank goodness.

Have a great week-end.

Mick

Ausrock
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Post by Ausrock »

It's likely that I'll be buying a pair to drive my nearfields.

They'll be configured as per Joe's drawing, however, I'm wondering whether there are any particular potentiometers (quality wise) that would be better to use other than Jaycar's stock line.

8)
Digital information lasts forever......................or maybe five years.

Whichever comes first.

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Mick@ITC
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Post by Mick@ITC »

Ausrock wrote:It's likely that I'll be buying a pair to drive my nearfields.

They'll be configured as per Joe's drawing, however, I'm wondering whether there are any particular potentiometers (quality wise) that would be better to use other than Jaycar's stock line.

8)
Can't help you there with the Pot spec..., I'm not putting in a volume control. Anyone else help???
I have started a build thread to share the ups and downs and will upload pictures and a document when I can figure out how to.

Regards
Mick

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