How to layout a tube guitar amp chassis by D-lab electronics Homebrew
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- Опубліковано 7 жов 2024
- Working on my fleet of Opti-Plexer heads. These are D-lab's flagship amps. A unique design that is sure to please. Look for them to be selling this fall. The cabs are custom built by my uncle John in TN.
Well done, I’ve learned a lot from your teachings! You n uncle Doug really rock!
Nice quick video with lots of tips to keep in mind. Thanks!
VERY HELPFUL ! Now I know what might be wrong with my Hammond A O 35 amp conversion.
Keyways, brilliant. Also, the cone-shaped with a hole-through countersink tools are great for deburring both aluminum and "metal" (and wood and plastic).
I highly recommend using a de-burring knife over a Dremel to de-bur any holes in the chassis.
Aluminum chassis is the only way to go. I had a fender custom shop vibro king from the mid 90's that used a high grade steel chassis that worked perfect and added to the weight but no hum or noise interference.
You make it look easy. Very cool.
+SendARope Thank you Sir. It took me a few years to get this method down. A complete layout plus hole punching/drilling is about 2 hours. I use tap magic when performing the operation. Makes the aluminum cut like butter.
Very helpful, thanks so much :)
aluminium is metal too
Maybe forgot the modifier "ferrous". Over and over.
Transformer end bells are an interesting topic. My original Valve Jr had them, but the upgraded Mercury Magnetic parts do not. Strange to lose an important piece like that on an upgrade... Would it also be wise orientate controls based on the chassis layout you described? Thank you for the great information!
great video!
Only 10W output but the 6AQ5s ROCK! Probably my favorite little output tube. Much cheaper than other output tubes, and in my opinion, better sounding than it's 6V6 big brother. I don't think I'd try to make a 50W amp with 6AQ5s but for 10W they are perfect.
+PaulinTaegu I agree my friend. You can also run 6005W tubes. They can handle about 300 volts. Many military 6005's are offered on ebay for about $2.00 ea. Great tubes
+Terry Dayton Looks like you have a nice design there. I've got a converted Bogen PA using an Bugleboy EZ80 rectifier, Mullard 6AU6 to 12AX7 preamp, and 2 6005W output tubes. That little thing is a BEAST! Probably the best sounding amp I have. I've got quite a few 6AQ5s in stock, and they seem to last forever at around 300V. Why use an expensive big iron PT to push 400+V when it's not needed? Just try to get a NOS EL84, 6V6, or 6L6 for $2.00 a tube on Ebay. Ain't gonna happen, more like $20+ per tube.
Nice video, as are all your others as well. Do you not worry about the orientation of the power, choke and output transformers in regards to keeping power unit at right angles to the choke and output transformers. You seem to orient them all the same- no cross talk or other interference??
+Frugal Amps Hello, Not on this model, only about 10 watts push pull
I don't really like having the input valve so close to the power transformer. It's much more important to put the input stage as far away from the PT than to put the OT far away from it, simply because all the hum picked up by the input stage will be amplified by the entire signal path. The OT, on the other hand, will not pick up a significant amount of hum from the PT, even if they are close together, as long as the cores of the two transformers are positioned perpendicular to one another (which admittedly would be difficult here because both trafos are intended for vertical mounting).
It is good practice to lay out the amp, left to right, PT, rectifier, output valves, input valves, then put the OT somewhere close to the power stage. This layout might be OK here, as this a very low gain amp, but I don't think it's optimal.
yeah, i was going to say, all those cores look like they are "magnetically mingling"
my OT can be mounted either way, so i am laying that down and away, because my PT is vert mount only..
just trying to put together some layout rules of thumb here ... still in the works with it.
I don't think you would make a Mesa Mark V with this method but still... :D nice vid as always.
Hi! Thanks for the videos! Question: Everywhere I see that the power transformer is mounted perpendicular to the orientation of the output transformer. (I don't know how the choke should be oriented). Doesn't it matter?
Also, I would have liked to see you drill the larger holes for the tube sockets.....for those of us who can't afford a punch!
Check out stepper bits. They are great for the larger tube socket holes
Yup, I always heard they should not be oriented the same way, and that this reduces any pick up of electromagnetic interference from the PT in the OT.
Yes, power and output should be rotated 90 degrees with the choke at 45 degrees
@D-Lab, Thanks! Helpful tips. Question: on the power/output transformer orientation: I've seen many amps where the cores are set 90-degrees to each other. Is that helpful or necessary?
you should turn one of the transformers (main and output) by 90° if you put them side by side. it reduces hum pickup of the OT.
It can be extremely important. I had one tiny 5W voice of music amp that would loudly hum when plugged in with no tubes due to the transformers being super close, one below the other beneath the chassis.
turning them 90⁰ can help, and spacing them out helps even more.
I'd try the headphone trick. You tape off all the secondaries of the power transformer and connect it to 120V. Then you attach the secondary of the output transformer to headphones and move it around until you find a place where it is quietest.
Great tips on eliminating stray magnetic fields.
Old vid, I know, but I never knew aluminium is not metal. WOW
Hi Terry another great video. I would have never thought about the difference between aluminum and metal chassis, but now when you explained it it made perfect sense. When you make the hole for the tube sockets are you using a Greenlee punch or the step drill again?
73,
Kevin
+Kevin Elliott Hi Kevin, Thanks for the kind words. On this amp, I simply used a 3/4" stepper bit. With a little tap magic, the bit cuts as thru butter. On metal chassis, I use the punch.
What about Input and Output Jacks, using non-insulated or insulated? Or non-insulated Input and Insulated Output to avoid ground loops? What can you recommend?
Hello, Terry! Another nice video of yours.
Just got one question - you've used the so-called "blind rivets" for mounting those tube sockets to the chassis. Are the rivets as good as lockwasher nuts and screws (as you normally seem to use in the other videos) in terms of holding the sockets securely in place? I assume they could come loose due to stress, metal fatigue, heat/cool down cycles etc?
Hello, great video. I want to build a 5F1 champ amp, where might I find an aluminum chassis? thanks
Hello, I usually buy Hammond chassis from Mouser
Great video! I don't suppose you've got a good methodology/resource for creating a layout from a schematic do you? Cheers!
Hello, That video (Subject) is being produced this weekend.
looking forward to it!
Did you do this video?
That's some choke you got there...
perfect good video wine is goood
If I am cloning an old UK vintage Vox amp which originally had a steel chassis and used an aluminium on instead would I run the risk of changing what the original sounded like if I duplicate the amp as closely as possible with components and layout?
No hahaha aluminum is just lighter and more prone to warping, most manufacturers use steel because its stronger.. however they punch the holes in a press.. most diy guys dont have that luxury so aluminum is easier to cut/drill its also a better conductor than steel as well as a better sheild and heat sink.
Hello, Terry. What about this chassis dimensions?
Sick Vid. question, could I re-purpose an old Magnavox TV entertainment chassis to build a guitar amp?
Hello, Thanks for signing up for my channel. Yes, I have made neat amps out of console radios. Works well. You just need to tweek the input gain to work with a guitar input.
so HV leads of output transformer dont want near input jack!
I agree, you get nasty feedback if they are too close
May I ask where you buy those aluminium chassis?
Thank´s and greetings from Germany
Hello, From Mouser electronics
Thanks a lot! Finally Mouser is now operating in Germany as well.
I think Tube-town.net sells them.
What thickness do you use for the chassis?
He uses Hammond, so looking up their products will tell what thicknesses they are available in.
Would you ever consider using copper chassis?
+Jack neff Yes, for sure if I could find them.
I have 1 here but its pretty large for an amp project