I'm looking to put a tube on top of a small amp. For the purpose I intend to use a stepped drill to make the hole in the metal enclosure.
Not knowing much about tubes I was wondering as to the smallest socket I can fit and the diameter I can expect to need so that I can purchase the right sized drill bit.
Any advice gratefully received.
Not knowing much about tubes I was wondering as to the smallest socket I can fit and the diameter I can expect to need so that I can purchase the right sized drill bit.
Any advice gratefully received.
Is this just for show?
Or are you going to use the tube in a circuit?
What type of tube ie power tube, rectifier tube, sweep tube, pre amp tube?
You can get sizes from the suppliers..EG small tubes B9A bases (20mm), power tubes can be octal (30mm) or other types. The type of base dictates the hole size..
valve bases page
You will find a size drawing next to the sockets a small icon.
Hope this helps
Regards
M. Gregg
Q-Max hole punches do the job very nicely. Bluebell have them in the Tools section.
Bluebell Audio
Although if it's a one off job you could drill and file and de-burr. By the time you've finished you'll wish you bought a hole punch.
Bluebell Audio
Although if it's a one off job you could drill and file and de-burr. By the time you've finished you'll wish you bought a hole punch.
It's only for show but I intend to power it to make it glow.
hmmm, I didn't realise there were so many types. A 'glow' tube would be about right.
As long as it's small and glowy and reasonably pretty looking.
Thanks for that very helpful link.
hmmm, I didn't realise there were so many types. A 'glow' tube would be about right.
As long as it's small and glowy and reasonably pretty looking.Thanks for that very helpful link.
I did think of hole punches but the enclosure is fairly small. Also I;m trying to keep the cost down while at the same time I need to drill some front panel holes, so it seem a stepped bit on a drill is probably the best I can do. Thanks for that though.
If you use a stepped drill bit, I suggest using it in a drill press and clamp the chassis down to stop it turning and cutting your hand.
Having said that, the idea of putting a non-functional tube on top 'just for show' is pretty tacky. As said above, anybody who knows anything about audio will think it is stupid. Anybody who is impressed by its non-functionality is probably not worth impressing anyway!
Cheers,
Chris
Having said that, the idea of putting a non-functional tube on top 'just for show' is pretty tacky. As said above, anybody who knows anything about audio will think it is stupid. Anybody who is impressed by its non-functionality is probably not worth impressing anyway!
Cheers,
Chris
An ecc82/83 is around 13mm. I always used a sheet metal punch it does a neater job. They dont cost that much maybe £10 ish.
It's fun and it adds that certain je ne sais quoi of tube amps. Also it glows!!!!!!
It's nothing to do with impressing people: it's about aesthetics and fun. And that warm glow.
It's nothing to do with impressing people: it's about aesthetics and fun. And that warm glow.
That's handy! Thanks for the tube info.
For hole punching I assumed that I would need an expensive contraption that may, in any case, not be able to be used for a small enclosure. Looking on youtube I see that in fact it's an all-in-one; I just need a wrench.
However, since I'm also making arbitrary sized holes in a face plate it seems to me that a step drill may be more economical. I suppose it depends on the cost of the file/deburrer.
If you plan on using a step drill (the"Uni-Bit" is a well-known brand here in the states), it is important to use plenty of cutting oil and the proper drill speed for best results. This will help insure that the bit doesn't "grab" the workpiece and turn it into a circular saw blade - ruining your hole at best and amputating a limb at worst!
Here in the U.S. we use the formula RPM=(CS*4)/D where:
Here in the U.S. we use the formula RPM=(CS*4)/D where:
- RPM is the bit speed in Revolutions per minute.
- CS is the cutting speed of the material in Surface Feet per Minute (SFM). For aluminum, this number should be somewhere around 250.
- D is the diameter of the drill bit in inches. This will be around 1.125 inches (30 mm) for an octal socket, or 0.75 inches (19 mm) for a 7- or 9-pin socket.
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