Shaka 1590BB Project Done - Check It Out / Q for Aron

[Aharon]

Hi PAul,nice work man!.
Listen,I wouldn't concern myself with heat and the tube,tubes love heat and are made to work hot (within limits)and besides the 12Ax7 is not the hottest tube around.
I would be concerned with the tube cooking everything else in the box,from the IC,caps to the footsitch.
I don't remember seeing a shield,do you have room for one?.
You may want to consider drilling holes neatly somewhere on the box for ventilation.Some sort of grill on top of where the tube rests would look great,maybe even drilling a few holes and adding a faceplate like a small computer fan protective  mesh etc.
Anyways,just an idea.
Aharon

[GreenEye]

That's amazing.  You could sell those suckers.  People on ebay would eat those up.  Call them boutique tube preamps/overdrives and you'll have people dropping $200 on them easy.

On longevity: the tube in my Tube King has lasted for six years now (on and off playing).  One tech I consulted said it's running at such a low voltage, it'll last for maybe 10 years.

[MartyMart]

Thats a fantastic build Paul, well done !

Perhaps you could cut a hole in the top of the box and use some "mesh" a little like the mesh on a Sure SM58 mic ? soldered to the inside of the box, just a thought,
Cheers,
Marty.

[Paul Marossy]

Well, if it bothers me too much, I could always drill a series of holes on both sides of the enclosure...

I thought about a tube shield, but it won't go over the tube when it is in the socket, and I am not convinced that it is absolutely necessary, either.

[Aharon]

The shield is not absolutely necessary but it would be nice if you could fit it in there.
I have built amps and preamps without shields with no noticeable adverse effects.
Again,I wouldn't worry about the tube ,instead worry about the other components being affected by heat.
Aharon

[Paul Marossy]

Well, I'm not really worried about the components. I think thay can handle it. It's just my nature as a mech. engineer to want to find a way to keep it well ventilated. I design HVAC systems to keep building cool here in the desert... I guess I should leave well enough alone, huh?  

A tube shield may fit over the tube if I took out the two screws that hold the main PCB in place and move it out of the way to install it.

[aron]

>Just curious about one thing. I'm wondering about tube longevity. I use my ST all the time. With it in a non-ventilated enclosure now, I'm wondering how long I can expect my tube to last... My enclosure does get fairly warm to the touch.


Mine got a little warm but I wasn't worried about it.

>Do you use yours often? If so, have you had to replace the tube yet?

I never had to replace it, but I don't use it that much. I modified my amps so I need to modify the ST to match them. 12AX7 tubes are so cheap, that I don't worry about their life span that much. Anyway, ever felt a Fender amp chassis after a few hours :-)?

Your work is awesome!!!! Thanks for all the posts!!!!!

Aron

[Paul Marossy]

Thanks Aron.  

Yeah, that's a good point, preamp tubes are pretty cheap. Yeah, my Twin Reverb gets very, very hot after a couple of hours!!

[Paul Marossy]

I added a template for the tube socket bracket. It can be found here:
http://www.diyguitarist.com/PDF_Files/ST1590BB-Bracket.pdf

[Paul Marossy]

I know, I keep making this thing rise to the top.  :oops:
But, I keep thinking of something to add...

Regarding the bracket template linked above, looking at the Tube Driver layout at GGG, it looks like this bracket may work with that project as well.

[Paul Marossy]

The mechanical engineer in me finally overcame the "leave well enough alone" part of me. I drilled some ventilation holes at the back of the pedal. It just makes me feel better.  :oops:



For the curious, to drill the holes, I just laid out a 1/4" grid with an extra fine point Sharpie. Then I marked where to drill holes with a regular Sharpie, alternating the location of the holes in each row. Then I stuck the enclosure in a vise and drilled away with a hand drill fitted with an 1/8" drill bit.

[inverseroom]

Holy moses!  You have to have known the kind of reactions you'd get here--those pics are amazing!  Gives us all something to aspire to...

[MartyMart]

Thats fantastic work Paul !
"Your the Daddy" !!  :wink:

Marty.

[Paul Marossy]

Thanks guys.  

I only waited six months to do this.  :oops:
Anyhow, I think the ventilation holes look kinda cool.  :wink:

[kusi]

hi paul

very nice work!  :shock:

but, little question: how did you do the "bright"-switch? it isnt show in the layout....

nice greetings kusi

[Paul Marossy]

how did you do the "bright"-switch? it isnt show in the layout....

It's just a 0.1uF cap to ground on the output to smooth out the highs a little bit. It makes the overall tone a little more friendly (less harsh on the high end).