diyAB Amp - The "Honey Badger"

[discrete]

That failure could had been easily fixed by adding an aluminum thermal bar across all the outputs.

Yes, but I was stubborn .
My chosen layout and heat sink height does not give much flexibility with mounting arrangements:

http://www.diyaudio.com/forums/solid-state/192431-class-ab-amp-diyaudio-30.html#post2719715

My only options now are to drill/tap a new set of 13 holes 1/2" away from the current set and live with the asymmetry, or to start again with a fresh
($$$) heat sink.

 

[niss_man]

I must say I didn't check every voltage across the 0.22 resistors last time but only adjusted by the test points. This time it will happen though. All transistors weren't hot though and heatsink was at hottest luke warm.

Regard

Simon

 

[JojoD818]

Yes, but I was stubborn .
My chosen layout and heat sink height does not give much flexibility with mounting arrangements:

http://www.diyaudio.com/forums/solid-state/192431-class-ab-amp-diyaudio-30.html#post2719715

My only options now are to drill/tap a new set of 13 holes 1/2" away from the current set and live with the asymmetry, or to start again with a fresh
($$$) heat sink.

That's a nice looking board you got there. Though I'm biased with OS's approach because I love those casings with the heatsinks at the sides ala Krell.

You're right, I hope someday (in our lifetime) heatsink prices drops like a rock... though I doubt it...

 

[JojoD818]

Slow day at the office...

 

[JojoD818]

matched hfe for the LTP transistors...
applied thermal compound and tied the LTP transistors...
mounted and soldered...
I also did this to the small CCS transistors...

 

[454Casull]

I wonder if nylon cable ties suffer from creep.

 

[TonyTecson]

^not if that is a genuine nylon, besides those trannies do not heat up that much if at all.....

 

[JojoD818]

I wonder if nylon cable ties suffer from creep.

I have used the same in my more than 8 year old diy amp and so far I see no problem. The cable tie I used is somewhat stretchable and not that brittle.

I'd welcome it very much if you have a better technique to share.

 

[TonyTecson]

you can also use this "panduit" stainless steel ty-wraps.......Stainless Steel Cable Ties, Permanent Identification

 

[mlloyd1]

heat shrink tubing also works well here for small signal devices

mlloyd1

 

[454Casull]

I have used the same in my more than 8 year old diy amp and so far I see no problem. The cable tie I used is somewhat stretchable and not that brittle.

I'd welcome it very much if you have a better technique to share.

Yes, as mlloyd1 pointed out, I would expect heat shrink to work quite well. Superior to cable ties? Perhaps not significantly so.

 

[JojoD818]

you can also use this "panduit" stainless steel ty-wraps.......Stainless Steel Cable Ties, Permanent Identification

Thanks tony, those things looks real sturdy...

heat shrink tubing also works well here for small signal devices

mlloyd1

thanks, that's a great idea and should really work well too..

Yes, as mlloyd1 pointed out, I would expect heat shrink to work quite well. Superior to cable ties? Perhaps not significantly so.

I'd stick with the cable ties for now, will try the heat shrink tubes in another project though...

 

[JojoD818]

got some diy on a Sunday morning...

 

[JojoD818]

Torn between these two... big brother or baby brother?

I need a drink...

 

[jacobthellamer]

Big Brother

 

[JojoD818]

Big Brother

There's one vote, anybody else?

I actually have both sets of the MJW and the MJL... I'm just looking for enough reason to use the bigger ones I guess...

 

[AndrewT]

If you are using multiple pairs then the little brother may give adequate cooling/dissipation.
If you are using big brother than a one pair output stage is more feasible.

 

[JojoD818]

Baby steps... It's a holiday today so I got some time to work on the boards...

and some bokeh shots...

 

[AndrewT]

Why does the Forum still allow remote server locations for automatically downloaded pics?

 

[JojoD818]

If you are using multiple pairs then the little brother may give adequate cooling/dissipation.
If you are using big brother than a one pair output stage is more feasible.

Excellent point, I might just be wasting Big Brother for this amp if 3 pairs of Baby Brother is more than enough...

That's one point each for Big Brother and Baby Brother then...