[smeggy]

I finally ordered the resistors and caps to convert my ground to a channel board. Hopefully it'll work and I can put this thing to bed finally.

 

[MoodySteve]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif spend the extra for a FULLY shielded trafo. it does matter. big-time. in this amp more than any other I've ever seen. believe it.

X3

Upgrading to a fully shielded/encapsulated transformer from SumR cured a line-borne buzz that I was hearing in sensitive phones. The difference was not subtle.

 

[aloksatoor]

x4 I have the 80VA SumR too... The encapsulation works like a charm

Quote:

Originally Posted by MoodySteve /img/forum/go_quote.gif X3 Upgrading to a fully shielded/encapsulated transformer from SumR cured a line-borne buzz that I was hearing in sensitive phones. The difference was not subtle.

 

[linuxworks]

can you take some shots of that sumr?

I keep wanting to order a custom one from him, but I haven't seen any good photos of them and I'm kind of curious..

did you have any quant. a/b on how well the shielding worked?

I do have the faintest hum on my setup and I'm very tempted to upgrade from the avel unshielded to a sumr shielded.

I believe you can also request extra voltage windings. that might also make the deal, for me, as I need a few strong 5v lines and some -12/+12 lines. if he can add those in and not have to go to a 2nd physical core, that gives a cleaner install and saves a lot of space and weight.

 

[linuxworks]

for now, I've remoted my toroid in a small box WAY away from things, on the floor.

but I really don't like that solution. not really. not long-term.

 

[oneplustwo]

I'm ordering one for a build. He quoted me $105 for a 100VA unit, +-30V, 115VAC out the door.

 

[linuxworks]

my toroid was for 30v but I am thinking, if I had to do again, I might opt for 25.

less heat = goodness. I kind of believe that.

 

[linuxworks]

Quote:

Originally Posted by oneplustwo /img/forum/go_quote.gif I'm ordering one for a build. He quoted me $105 for a 100VA unit, +-30V, 115VAC out the door.

well, if you have not finalized it yet, do consider getting an extra 5v winding, for any control circuits and some dual rail set of windings for any 'analog things' (lol) you might also want to bundle into the box.

that's my thinking, at least.

 

[NoValidTitle]

So I got a tad bored and started playing with sketchup haha...

The board dimensions and heat sink height are to scale. I wasn't sure the board thickness so I guess on that. 0.09"

 

[El_Doug]

Quote:

Originally Posted by NoValidTitle /img/forum/go_quote.gif So I got a tad bored and started playing with sketchup haha... The board dimensions and heat sink height are to scale. I wasn't sure the board thickness so I guess on that. 0.09" http://farm4.static.flickr.com/3607/...95d6edd4_b.jpg

dont power up! you installed Q1-Q4 incorrectly!!!

 

[ShinyFalcon]

I bought some Context Engineering case from Fry's and am doubting that the σ２２ will be able to slide in smoothly due to the heatsinks. There is a 6" clearance slot edge to edge, and if I'm lucky there will be 1mm of clearance from the edge of the board to the heatsinks' edges. Otherwise I'll have to fit the transformer and the board in awkward positions and more than likely I'll have to move the transformer to a smaller case. I guess I'll find out when the kit arrives...

 

[amb]

The board thickness is 0.062" (plus a smidge more for the copper, plating and soldermask).

 

[ShinyFalcon]

The slots are approximately 2mm high, so I'm definitely hoping that it will slide in. What I was concerned about is the vertical distance from the edge of the σ２２ to the heatsinks' edge. The case's slots are about 2mm wide.

Also, when I decide to add the ground channel, will the separate matching of the JFETs cause the ground channel to be "different" from the left/right channels?

 

[amb]

Quote:

Originally Posted by ShinyFalcon /img/forum/go_quote.gif Also, when I decide to add the ground channel, will the separate matching of the JFETs cause the ground channel to be "different" from the left/right channels?

No.

 

[TStewart422]

Does saving up and looking for a builder count?