Phase Linear 400 Amplifier Upgrade to WOPL

[laatsch55]

View attachment 6564 View attachment 6565

I do have stuff hooked up - just need to hunker down and take numbers.

DAYAM!!! that setup screams pro --all the way--- Like Joe's setup!!

 

[NavLinear]

Just need to learn how to use it.

 

[NavLinear]

Here are my thoughts on some improvements for this bias bracket.

View attachment Bias Transistor Bracket Mods.pdf

 

[laatsch55]

I take it the notch is too small for a standard 4" cable tie??

 

[laatsch55]

Also, that sleeving was not standard fiberglass was it??

 

[NavLinear]

I take it the notch is too small for a standard 4" cable tie??

Yeah - the notch is a little too small for a 4 incher but lacing tape or a very small spot tie works. The depth of the notch makes the tongue weaker at that point although it seems strong enough. So changing the depth of the notch and making the tongue thicker will make it more robust. Just having fun dialing it in.

 

[laatsch55]

The sleeving in the last goody box----that wasn't standard fiberglass was it??

 

[NavLinear]

I'll have to get back with you on that - got it for a higher temp environment but I don't have the spec in front of me at the moment.

 

[laatsch55]

No biggie, just way smooooooooooooooooooooooooooooooooooooth to be 100% glass.............................

 

[NavLinear]

This sleeving was put to the test - direct flames and no melted wires. Good shit.

 

[laatsch55]

That's always a plus!!

 

[NavLinear]

Lee,

Here's the one page spec on the sleeving:


View attachment hilec-210-C.pdf

The sleeving you have is 210C.

 

[NavLinear]

I took a photo of a left and right bias transistor bracket along with a couple of photos of a new part that incorpotated the design changes I wanted to make.

Photo one - left and right bracket.
Photo two - new bracket with embedded nut, thicker tongue and notch change.
Photo three - side view of old and new brackets to show tongue thickness change.
Photo four - top view of old and new brackets to show notch change.
Photo five - had to show the other side.




When thickening the tongue the modification transferred through the entire bracket. This affected the opening where the transistor legs enter the bracket as it is now smaller due to the increased thickness. It still works with the transistors that I have but I want to open this area back up to accommodate any potential tolerance issues. Another change will be to use a smaller tip on the fuse deposition machine that translates to more layers and a smaller tool path so the part will be "smother".

I would like to have a vapor degreaser for components made from ABS - I'll have to work on that one.

 

[laatsch55]

Dennis....I think we're missing a very serious point here..... when depositing the bracket...F%$#.... have it deposit a transistor too.....and be done with it!!

 

[NavLinear]

Here's my sketch of the bias tranny bracket and I've shown where the change will occur based on your inputs Lee. Is there any other dimension that should change based on your touching and feeling the bracket?

View attachment Bias Transistor Bracket1.pdf

 

[laatsch55]

Dennis, that looks good!!

 

[NavLinear]

Cool - I'll make a couple of flavors of this and get them out when they're done.

 

[laatsch55]

Ok Dennis, fine by me Bud. Where's all them pics and THD & N figures???????

 

[NavLinear]

Ok Dennis, fine by me Bud. Where's all them pics and THD & N figures???????

Here's the frequency response data along with some pre-load tests. As you will see the right channel is a little sick - the response is non-linear and the input voltage required to get the amp into clipping varied by quite a bit. The left channel looks good though.

View attachment Frequency Response Test Pre WOPL - Data.pdf

 

[laatsch55]

Dennis, I don't know if it will make a difference but bias on a pl 14 board which is what I'm assuming you have should be taken with positive on the base bus bar and negative on the common tie point for the emitter resistors. Ya might try that and see if there is a difference.