Where do the various parts of the speedbal fit?

[jrebman]

Can somebody give me an idea of where the various parts of the speedbal package fit physically inside the enclosure?  Right now I'm mostly concerned with the spaces near the front tube and between it and the volume control and headphone jack.  Are the two extra, larger holes for the front tube socket used at all for the upgrade, or can I use them for something else, or fill them in before painting?

Thanks,

Jim

 

[Paul Birkeland]

The big cathode sink board fits on standoffs right where the 10 watt cathode resistors are now. The driver C4S boards fit on standoffs that bolt into the unused holes.

 

[jrebman]

Thanks again, Paul, I'll just leave the holes alone for now then.  I was considering putting some standoffs and a small piece of g-10 to mount a switch to switch between 12 and 6 volt pin configurations, but maybe I should put that on top if I can find a nice DPDT locking mini-toggle instead.

BTW, the TKD pot fits in the chassis beautifully -- not even as tight as the s.e.x., and it looks as if there may even be enough room for a goldpoint.

-- Jim

 

[Paul Birkeland]

When you do the Speedball upgrade, there will be tons and tons of space to mount such a switch right where the large 10 watt cathode resistors sit now.  I would put the switch between the 5 lug switch and the cooling vents. 

 

[jrebman]

Thanks, Paul.  Actually, a second benefit of putting it there is that the handle could get hot enough to discourage toucching it while the amp is hot .

Ok, those problems are solved...

-- Jim

 

[Dyna Saur]

Whwn I built my Crack, I pre-planned for Speedball by soldering in the two 22.1K and  the two 3K resistors without bending the leads around their respective terminals, in order to make them easier to remove (and possibly re-use in other DIY projects). My motto: never waste or throw away ANYTHING, if there is any chance it can be used again...  I placed the added "bypass" caps so that they would not physically interfere with the Speedball boards. 

I would like to try it with the plate C4S first, then add the cathode C4S later, just to seperience each change one step at a time,  but it appears that the cathode PC boards overlap the plate boards slightly. 

/ed B in NC

 

[jrebman]

In case anybody's interested, here's the digikey part number for a locking mini dpdt toggle switch with solder lugs and 6a @125vac rated contacts:

360-1834-ND

About $7.80 in single quantities.  Stock looked lowish though -- around 50 pieces left.

HTH,

Jim

 

[jrebman]

PB,

Got the switches and they are just the perfect size.

Couple more questions about the speedball upgrade:

Does this upgrade add another 5-lug terminal strip on the 6080 socket?

How are the large heatsinks mounted and how close do they come to the sides of the box?

Can you also give me some idea of where theysit in the front-to-back dimension?

And finally, are the heatsinks electrically hot or are they grounded?

Thanks,

Jim

 

[Paul Birkeland]

Does this upgrade add another 5-lug terminal strip on the 6080 socket?

How are the large heatsinks mounted and how close do they come to the sides of the box?

Can you also give me some idea of where theysit in the front-to-back dimension?

And finally, are the heatsinks electrically hot or are they grounded?

No additional terminal strips are added.  The heatsinks are 2" tall, and are mounted on 1" nylon standoffs.  They are mounted right on the center axis running front-to-back in the Crack, so they don't get super close to the sides.  They are electrically grounded.  In the front-to-back dimension, they sit right over where the 10 watt cement resistors are now, above the vent holes.  The other two smaller plate load boards for the driver tube sit right over the 9 pin socket.

 

[jrebman]

PB,

Thank you -- that all sounds great to me.  The filament configuration switch will sit under the heatsinks then, but it seems there will be plenty of clearance if I mount it where you suggested.

Thanks again,

Jim

 

[Paul Birkeland]

Ah, yes, the filament switch.  When you do the speedball upgrade and yank out the 10 watt resistors, you'll have plenty of space to get that switch in.  Otherwise, I don't think there's a ton of space on the front side.