Metropoulos Forum

This box will feature a multiple amp load settings (4, 8, 16, 20)
and a few different line-outs:
1) sah51050/Egnater line out
2) Jose line out?
3) Ralle line out

Progress so far:
The amp side of the load box is complete. NO line-out components yet.

Here you can see the amp side connections.
From the left:
1) The input from the amp's speaker out.
2) Selector to determine the load that the amp sees.
3) 16 ohm load boost. Push it to the right and the amp sees 20ohms when the selector is set for 16 ohms.

Click pic for larger view.


Gut shot! Just the load components so far. Line-out components will be added to the right side.

Match the wire colors to those on the schematic to figure out the layout.

Click pic for larger view.


Schematic!
Based on the 4, 8 and 16 ohm load box (version 2) from Aiken Amps
Click pic for larger view.

Awesome , i will give it a try , thanks for sharing.

Thanks!

But, I guess I should point out that as it is right now... it just a load box...
... not much good to you all (unless your a tech)!

Once its finished it will be cool for slaving!

This is just for your review until I add the line-outs.

The thinking is, there are lot of theories (and cool clips to support all of them!)
about the nature of the loadbox/lineout Ed might have used.

16 ohm amp -> 20 ohm load -> Jensen Tx -> lineout
8 ohm amp -> 16 ohm load -> this or that...
etc
etc

I'm hoping to cop all possible combinations here...
Stay tuned...

I think I'm going to ride along with you on this if it's OK?

What size enclosure are you using?

12x10x2 Enclosure: Hammond 1444-29
tubesandmore.com P1444-29
mouser.com 546-1434-29

12x10x2 Lid: Hammond 1434-29
tubesandmore.com P1434-29
mouser.com 546-1434-29

Thank you!

I don't know any of this shit, I would buy a Suhr ISO box for this because I haven't any experience doing this building...

The Surh ISO cannot be used as a load.........

Where's the amp in jack on the diagram?

Remember guys... what we have to far is just a load box...

vanhalen5150 wrote:Where's the amp in jack on the diagram?

If you mean the Line out to the slave amp (or whatever), there will eventually be 3 of them.

Here's the first one...
Hmmm... why does this line out look familiar?

Click pic for larger view.


Not sure what part of the resistor array will eventually feed each lineout. Right now the lineout is in parallel with the impedance selector setting.

This is a work in progess... let me do some testing this weekend before you all start drilling!
Speaking of which, the resistors are mounted on a piece of aluminum from HD... minimizes the number of holes that need to be drilled in the chassis. Everything should be aluminum (not steel) for better heat distribution.

Couldnt you just have one line out with a 3 way switch for each impedence?

I'm making a new one as well. Just need some fresh ideas. I want something that splits to 2 cabs. One dry and one with a dialed down volume for a wet delay/reverb only. Essentially, an album sound from a head.

Looks like Mark's line out.

vanhalen5150 wrote: I'm making a new one as well. Just need some fresh ideas. I want something that splits to 2 cabs. One dry and one with a dialed down volume for a wet delay/reverb only. Essentially, an album sound from a head.

Lots of thing you can do downstream from the load box.

vanhalen5150 wrote:Looks like Mark's line out.

Bada bing bada boom! We have a winner!
I don't know the true lineage of the line out(hey as long as its good!)

Here sah5150 describes it... but you see similar version from Mark earlier in the same thread.
http://forum.metroamp.com/viewtopic.php ... 1&start=12

Here Mark shows it:
http://forum.metroamp.com/viewtopic.php ... 1&start=58

vanhalen5150 wrote:Couldnt you just have one line out with a 3 way switch for each impedence?

Each of the three lineouts will be completely different beasts. Will have to see where it makes sense to hook them up.
Keep in mind that these are my interpretations of the 3 line-outs AS THEY HAVE BEEN DESCRIBED on this forum... at this point none of this has been tested.

Here is the scematic showing all three line outs.
EDIT: The more I look at this, we may want to switch between the top and middle lineout if it turns out the are both connected to the same point in the resistor array. They are essentially in parallel with each other... hmmm...

EDIT: Wondering why the Jose line-out has a such a large pot (250K)... seems like a smaller pot would help keep the output impedance lower... more testing will have to be done...

Click pic for larger view.

Ok, I see where you are going with this.

I'm working on my 4th version. The one thing have really noticed is the sound is really affected by the heat sink. When the resistors are really working hot the load changes in a bad way. Really good heat sink. I think the impedance varies some how. I think Im adding a fan as well from a different source(AC).

Interesting about the heat vs. the tone... part of the reason I wanted this thing way overrated...
At 400w of handling for 8 and 16 ohms, I hope the resistors barely get warm. I don't expect to use it too much at 4 ohms.

I will need some openings in the top at the very least.
I have also left space in one corner of the top to put in a small 12vdc fan if necessary.