Nah it's more than übercool... Might have to pop over one day up North and check it out!Quote:
/<\\/p>[]<\\/p>/Quote from dingobass on June 1, 2014, 17:43
That is übercool. 8-)
Loz, could you share the diagram for the amp?
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Nah it's more than übercool... Might have to pop over one day up North and check it out!Quote:
/<\\/p>[]<\\/p>/Quote from dingobass on June 1, 2014, 17:43
That is übercool. 8-)
Loz, could you share the diagram for the amp?
Sure. Happy to post both the schematic and layout diagram, Pest. The power and output transformers are both made by ClassicTone and can be bought on line. The tag board is from Jaycar and all other bits were from all over the place. Make sure that the 22n capacitors are rated at 400 volts or so. This is only an 8 watt amp but it easily keeps up with a Vox AC15.
This is an all-tube amp in that it even has a tube rectifier. You can swap this for solid state if you wish. Use 1N4007 diodes as they are rated at 1000 Volts.
Oh yeah, one other thing. I am using a 12AT7 for the preamp because I like a lower gain for a cleaner jazz sound. If you want more drive/overdrive use a 12AX7.
I'm going to make a disclaimer here for anyone who wants to build this.
This amp uses very high voltages that can kill you before you know you are dead.
Build it at your own risk.
If you do build it you will end up with one shit hot little tube amp!
http://www.pitbullguitars.com/wp-con...1hr0-image.jpg
http://www.pitbullguitars.com/wp-con...57hx-image.jpg
Lawry - would love to do this sorta thing one day, but lines like "I'm going to make a disclaimer here for anyone who wants to build this.
This amp uses very high voltages that can kill you before you know you are dead.
Build it at your own risk."
scare the heeby jeebies out of me... Well done on the build!
awesome Lozza, would love to build the mini amp but like Brendan know very little about circuitry and know how to electrocute myself !
Nice amp schematic Loz, might put it into storage for some secret plan later....
Ya know, this stuff has serious bities inside but as long as you're careful I'm sure you could do it.
Just don't stick your fingers in when it's turned on or the caps are holding a charge.
Yeah Lozza, I'll keep my hands completely away from those caps!
Also, what is a good chassis for this build? And will the caps STILL hold a charge when the amp is unplugged?
Lozza looks like you could be Pest's amp coach !
I'd guess the caps hold charge for up to a few mins after being unplugged from the power source ? I really got no idea
Quick quessie Lozza....
Where did you get the tubes from? E-bay? or is there a more reputable local supplier. I don't wanna blow myself up with some imitation import?
Try Jaycar or Altronics Gav
First place I checked! and they don't stock them other than the 12AT7's in Perth. :(Quote:
/<\\/p>[]<\\/p>/Quote from keloooe on June 4, 2014, 12:44
Try Jaycar or Altronics Gav
Weirdly saves the day :)
Yo.
My first stop for valves in OZ is Lucas Miles Audio in Melbourne, then Evatco. Both companies are great to deal with but Lucas has on-line ordering whereas Evatco need you to print out a form then Fax or Email it to them. Maybe that's changed but it was the case about 6 months ago. I have bought valves on eBay without issue but I usually want them yesterday. The 6BM8 tubes may be a little more difficult to find but I've had half a dozen for years so didn't go hunting for them. An equivalent is an ECL82 or 6F3P. You should be able to pick them up for $10-$15 each.
As for a chassis, I just go down to the local sheet metal man and get him to cut and bend a bit of mild steel to the dimensions I want. Usually only costs a few bucks.
The caps? My schematic doesn't show a bleed resistor across the terminals and without this the caps can hold a charge for several DAYS. So put some in. 270k -1 watt will be fine.
For those about to electrocute themselves (namely me and possibly Pest)....where 'exactly' do we put the bleed resistor?
LOL Gav.
The bleed resistor goes across the power supply capacitor terminals. In this instance it is the 22uF 450v capacitor shown on the middle right hand side of the schematic. And apart from where stated, use half watt resistors throughout. You can get these at Jaycar. Also, the three 47n and the 470n capacitors should be 400V minimum too for safety. These caps are associated with the tremolo section.
Looks like the 450v caps on the schematic are shown as 400v on the layout diagram, just to prevent confusion.
Well spotted Scott. Didn't notice that myself. 400V will cover it but higher is always better with valve stuff as I'm sure you're aware. I'll post some build pics if I can find them, that way an idea may be had of how it all was done.
So cool! Have ordered all the valves at double quantity since i'm thinking stereo!!!!! :)
Hey Lozza, will these tubes work well?
Hey man. Not for this build, no.Quote:
So what tubes are best for this amp?
Loz I hope you realise you are now Pest's amp coach !
@Wokka. LOL. That's cool. It's hard to find people who want to have a go at building valve amps and Pest told me he's built a Lamington before, so he knows the deal.
@Pest. For the preamp stage you will need 1 x 12AT7 (you can increase the distortion/gain by swapping this for a 12AX7 later if you like), for the output you will need 2 x 6BM8 and for the rectifier you will need 1 x 5Y3GT. If you want to have a solid state rectifier you can use 2 x 1N4007 diodes instead (I can draw how to hook these up for you - they will also cost you about 50 cents each instead of about $30.00 for the valve).
How about the transformers? Can I use any 15W transformers (both power and output), or is there a specific set that I need?
Hi Pest. You will need specific transformers for this build. I have started a new thread for the amp so go there for more details.
Cheers.
[quote]/<\\/p>[/<\\/p>[]<\\/p>/]<\\/p>/Quote from lawry on June 5, 2014, 21:09
Pest told me he's built a Lamington before, so he knows the deal.
quote]
I think that's possibly a typo? built or baked? ;)
http://www.pitbullguitars.com/wp-con.../47vum-lam.jpg
Baked lamingtons in a lamington tray, then used the tray to build an amp, then a mate bought the thing off me!
haha nice one Gav, baked lamingtons
I'm still a few posts behind you Gavmeister, I will have to lift my game !
Not behind Gav for long Woks. You should be head of the leader board before the weekend's done!
Gav. The Lamington is a 15 Watt valve amp designed by Grant Willis (from Sydney, I think) and built on a lamington baking tray. I've made a couple for mates and they're damn good!
OK. In order to see how I put the Knee Trembler together I took the chassis out and took a few pics (I called it the Knee Trembler because it has tremolo in it).
As you can see, there's not much room in there but you don't have to build one that tightly.
http://www.pitbullguitars.com/wp-con...jo3c-image.jpg
http://www.pitbullguitars.com/wp-con...1b8h-image.jpg
http://www.pitbullguitars.com/wp-con...365y-image.jpg
damn thats impressive Lozza to fit all that in the small space. So does the tremelo setting oscillate the volume of the output ?
Note to all. Please go to the
http://www.pitbullguitars.com/commun...topic&t=1291.0
thread to continue this topic.
Number two.
OK. I was so pleased with how the first CBG turned out that I decided to build another. And a cigar box ukulele. And another cigar box amp.
First to the CBG. I have an exceptionally musically talented mate who was quite amazed by the original CBG so I have decided to make one for his birthday (it was actually last week, but shit happens). This time I thought I would come up with some sort of resonator type setup so I bought a small pie bake tin at Big W but it was too deep. So then I grabbed a lid from an empty coffee tin and thought I would give that a go. So, fingers crossed on th sound!
So... I started today. The good thing about these CBGs is that you get a lot done very quickly. I have gone even swankier with the neck and headstock this time by laminating a couple of sections for strength and shape. Anyway, I'll let the pictures do the talking.
http://www.pitbullguitars.com/wp-con...6d1b-image.jpg
http://www.pitbullguitars.com/wp-con...a432-image.jpg
http://www.pitbullguitars.com/wp-con...2717-image.jpg
At the heel end too. Did some shaping etc...
http://www.pitbullguitars.com/wp-con...9955-image.jpg
http://www.pitbullguitars.com/wp-con...l329-image.jpg
http://www.pitbullguitars.com/wp-con...sh5x-image.jpg
And finally (for today) a mock build. I'm expecting the fretwire and machine heads to turn up next week. Sure hope so!
http://www.pitbullguitars.com/wp-con...e581-image.jpg
http://www.pitbullguitars.com/wp-con...6u99-image.jpg
http://www.pitbullguitars.com/wp-con...5v1a-image.jpg
That's bloody neat mate! Got any plans on embellishing the resonator in any way?
Thanks man. Really not sure how this resonator will sound to be honest. I wanted to make it out of readily obtainable material rather than buying a spun cone. Also not sure what I'll use for a saddle. I have a wooden mandolin saddle lying around so may try that although it looks a bit tall. We'll see.Quote:
/<\\/p>[]<\\/p>/Quote from bargeloobs on June 14, 2014, 15:35
That's bloody neat mate! Got any plans on embellishing the resonator in any way?
Whereabouts are you sourcing your cigar boxes? I had a bit of a look on ebay and the pricks obviously know people are using them to build guitars and are charging accordingly.Quote:
/<\\/p>[/<\\/p>[/<\\/p>[]<\\/p>/]<\\/p>/]<\\/p>/Quote from lawry on June 14, 2014, 15:46
Thanks man. Really not sure how this resonator will sound to be honest. I wanted to make it out of readily obtainable material rather than buying a spun cone. Also not sure what I'll use for a saddle. I have a wooden mandolin saddle lying around so may try that although it looks a bit tall. We'll see.Quote:
/<\\/p>[/<\\/p>[/<\\/p>[/<\\/p>[]<\\/p>/]<\\/p>/]<\\/p>/]<\\/p>/Quote from bargeloobs on June 14, 2014, 15:35
That's bloody neat mate! Got any plans on embellishing the resonator in any way?
Yeah. They're not overly cheap but I have tried the two tobacco shops in Mackay and they don't have any, so what can you do? I have bought mine from an eBay seller called Boxed-Roc and they have been OK. Costs me about $15 each by the time they arrive when I bought three at a time. Here are the links to an email I got from him just the other day in case you want to check them out.
http://members.optusnet.com.au/blank...cigarbox15.htm
http://members.optusnet.com.au/blank...igarbox8.5.htm
http://members.optusnet.com.au/boxed.../cigarbox6.htm