Crack Build - #4

[ALL212]

Due to a misunderstanding between my brother and I he built a base angled the wrong way and it's too big for the standard Crack plate.  Not wanting to leave it behind and with the recent sale I bought another Crack to build.  This time with a redesigned/resized plate to accommodate this odd combination.

I was playing with the idea of doing alternate tubes but I don't think complicating this would have been wise.  I am going to use the 6SN7 in the 12au7 slot.

I've got cleanup and a bit of grinding to get the plate laid in the cutout (the plate is straight, the box cutout is not).  I'll probably go with my standard black plate with copper highlights - we'll see what's in the paint cabinet and go from there.

[Paul Birkeland]

(the plate is straight, the box cutout is not)

Those perfect miters on our alder bases often get taken for granted!  A belt sander will adjust that panel to fit pretty easily. 

[2wo]

I have also noticed that if you play really good music, people tend not to notice minor woodworking issues  ...John

[ALL212]

 

Turning down the lights helps also!!

For the group -
I'm going to change the value of the last PS cap to 450uf so I can drop the value of the output caps (will be a pair of ClarityCap ESA/CSA 39uf for 78uf total).  Is changing the value of the 2nd PS cap something to entertain or is that a moot point?  All my headphones are 300 ohm so I can work towards that final value.

[ALL212]

Should everything go well we should end up with the attachment below.
Heater test passes - on to input wiring.

[oguinn]

That’s ridiculous. I love it.

[Tom-s]

That's a good start!
There's so much space left! 

[ALL212]

Progress...

[ALL212]

Everything checks except volts at terminals 2 and 4 are 215v
It plays and sounds great but should I go back and recheck something?

Pics later.

[Paul Birkeland]

What's your incoming AC line voltage?

[ALL212]

120 - 122
I wired the tranny for the 115-130v config.

[ALL212]

No... I almost wired it for 115 - 130.  I moved the red wires over one terminal.

Wow...    Corrected that and now 180v at 2 and 4.

Exhibit A and B below will illustrate how NOT to wire the transformer and then how to do it as directed.

[Deke609]

Ferrite beads on the power wiring! Cool. Have you done, or will you do, with/without comparisons to see if and how they affect the sound? I'd be interested in your impressions.

cheers,

Derek

[ALL212]

I forgot my disclaimer.

Not everything that is installed has a specific purpose.  The ferrite beads were there, we had a discussion and it was decided that they would be used.  Yes...ferrite beads speak to me.   

[Paul Birkeland]

What ferrite beads would keep out is unlikely to pass through the power transformer.  If we used a toroidal mains transformer, that might not so much be the case.