Pictures of your diy Pass amplifier

[cubicincher]

Hello out there,

I made the first PSU-test today:


very important - first the dim-bulb-test - all o.k. till now


without dim-bulb-tester:
+- 34.1 V DC on the rails (will sag under load)
ripple at PSU-output: 0,2 mV AC. Not so bad.
Cheers
Dirk

 

[MEPER]

It is a C-R-C-R-C filter?
If you are still below 1 mV ripple at 4A load it is impressive
This will probably require chokes

 

[cubicincher]

to MEPER

Hello MEPER,


yes, it is a simple C-R-C-R-C-filter. But measured without any load
hanging on the PSU.
Cheers
Dirk

 

[homme_de_terre]

My two balanced Sony VFET amps have been finished.

--Manfred

 

[maximax77]

My two balanced Sony VFET amps have been finished.

--Manfred

Which circuit is that?

 

[homme_de_terre]

This one: https://www.firstwatt.com/pdf/art_diy_sony_vfet.pdf

--Manfred

 

[maximax77]

This one:

Thanks!

 

[maximax77]

My two balanced Sony VFET amps have been finished.

They are push-pull though, not balanced.

 

[homme_de_terre]

I use two of the push-pull amplifiers in balanced or bridge mode for each channel; delivers about 50W.

--Manfred

 

[cubicincher]

to homme_de_terre #6164

Hello Manfred,


this is a nice amp. Enjoy the sound!


Cheers
Dirk

 

[bwater]

My Aleph J build...

 

[Eric]

What a neat and tidy build. Congrats!

 

[luvrockin]

B1 and F5

Awesome looking!

 

[cubicincher]

to bwater #6171

Hello bwater,


looks nice inside and outside! I like the frontplate


Enjoy the sound!
Cheers
Dirk

 

[WalterW]

hahaha, frontplate upside down....but looks great!

 

[bwater]

Indeed it is. Real estate's at a premium inside (the enclosure is just too small for the job really), having the faceplate upside down was the only way I could get the on/off switch working without hanging the transformer from the top of the enclosure! Didn't think that would have ended well...

 

[zman01]

Good thinking bwater , and your build looks nice.

How tall is the chassis?

 

[bwater]

142mm tall inside, 300mm deep. The heatsinks are about 10% smaller than a 4U deluxe. I'm getting about 51 - 53 degrees on the heatsinks with an ambient temperature of 25ish degrees and 400mv bias. So, either only just big enough, or just a smidgen too small.

I wanted the front panel switch as my children aren't old enough yet to think that there's something really cool about reaching over a hot amp and fumbling for a power switch on the back...

 

[SoaDMTGguy]

You might be able to fit the power supply boards on either side of your transformer. That would free up room up front to flip the front panel over. I was able to manage it in my Deluxe 4U

 

[bwater]

Good suggestion (and nice build by the way!). I thought of that, but decided against it, as it would have obstructed the ventilation slots in the base plate. With those puny heatsinks I wanted all the airflow I could get. I even moved the feet from their original position so that the ventilation slots weren't obscured. Plus my enclosure is 30mm narrower than the 4U (330mm vs 360mm internal), so it would have been very tight.

I feel like I've satisfactorily explored the limits of the smallest feasible enclosure for an Aleph J! Next time I'll pony up for a more appropriately sized unit.