Amp advice.

Kev-wilson

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Friday night’s jam night so a little break in time for the greenback and a decent play with the amp to see how hot it gets, so far so good 😊
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Kev-wilson

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I dropped a right ballhook yesterday, roundovers and for some reason I'd left a ogee bit in the 1/2" roundover box so I'm hoping I can recover the profile with the right bit as the cut I did on a test piece seemed ok but the first cut on the cab left a lip :( but these things happen when a metal machinist messes with wood...

I do like the sound of the amp/speaker though.
 

Kev-wilson

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They say the most stupid questions are the ones that don’t get asked:p so will a leather handle go on top of the head? Remembering it’s a lunch box type now, as I’m struggling choosing handles, and there’s a limited selection with brass fittings.

Also, the cab is semi open at the back, was there an optimal size for the opening or is it random as it appears?(when I went to the store for the greenback I had a nosy at the back of their amps).

Edit, the lip I got when starting the round overs was due to some fool leaving the wrong bearing attached to the bit, but came out ok with a 1/2” cutter.
 

Nicko_Lps

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so will a leather handle go on top of the head?
Leather looks awesome combined with wood, for sure its a perfect choice!

Also, the cab is semi open at the back
Since youre still working on it... You know gear changes, you change.. Make a panel to have a fully closed back option as well!

When i made my cab i was like open back diehard fan. Nowadays after several modifications, closed back works alot better with my celestion golds. I dont have a god tier right hand to control the massive dynamics and the closed back suppresses the dynamics by little on the bass strings.
 

VintageSG

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The optimal opening for a cab back is calculated by twatting about with the positioning of the cab relevant to walls. Make it 1/3rd open in the centre with a top and bottom plank. To try a closed back, secure some card or hardboard with masking tape. make a top/bottom board pair for a 1/2 open and a fully closed back -with- a pair of those cable hole thingies you find on office desks.
 

lowatter

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Looking great so far. If you top vent the head cabinet you can get aluminum expanded metal gutter cover material from your big box lumber store and staple or screw it to the underside. This is how I did my combo amp for venting.
Sorry for the crappy pic but you'll get the idea.
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Kev-wilson

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The finished thing though the grill needs a tap to the right (on 2 dowels)
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Vermoulian

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They say the most stupid questions are the ones that don’t get asked:p so will a leather handle go on top of the head? Remembering it’s a lunch box type now, as I’m struggling choosing handles, and there’s a limited selection with brass fittings.
The most important thing to take into consideration when choosing a handle for the top of your cabinet is clearance between the handle and the amp on top of it. Famously, you can't stack a Fender amp with glides on top of another Fender amp with a strap handle without it teetering and tottering, because the handle is thicker than the glides. So just make sure that you have feet on your head that are high enough to clear the handle.

Also, the cab is semi open at the back, was there an optimal size for the opening or is it random as it appears?(when I went to the store for the greenback I had a nosy at the back of their amps).

On the continuum between closed- and open-backed cabinets there are points at which the size and configuration of the opening (e.g., slot/folded horn, port with tube, etc.) make a sometimes dramatic difference in how the cabinet performs. But past a certain point, a cab is open enough that it's just an open-backed cabinet, and I think that point is reached fairly quickly, and past that point the size of the opening doesn't mean much. Other factors in design or construction may still affect how the cabinet responds, but as long as the air around the speaker can move relatively unimpeded it's an open cabinet for practical purposes.
 

Kev-wilson

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And a little bit further down the line 🙂 although the front plate needs a rethink as I was crack handed with the jigsaw 🧐🤨 which was annoying as I was using a piece I’d left over from the speaker cabinet (yup another mistake) but I’ll get there 🙂
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Kev-wilson

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As I ruined the first plan for a faceplate I’ll frame it similar to how I did the speaker cab, I just need to add a horizontal strip at the top of the amp housing to create the top hole for the mesh and the bottom for the controls.
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Kev-wilson

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I spied the neighbours going out earlier so loosely assembled the head to test for heat 😁 so it can stay like that till the finishing touches arrive.

‘Twas fun was that!
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Kev-wilson

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There's nothing more frustrating than waiting for mail order parts :confused: (other than receiving the wrong ones) so I'm hoping the postman's been when I get home.

In better news I was allowed to root in the skip where I found my oak board and now have some more stock, there's a cheap 2nd hand 12" speaker for sale near me and a Laney cub 8 chassis on *bay so I might have a crack at making a combi next, or a bigger cab with a smaller head (most likely).

I need to find a cheap Leigh Dovetail jig as well, but add that to the list as I've been on the look out for a metal lathe to replace the one I sold on, I'm tempted to sell my surface grinder as it's rarely used these days and a nice similar size cnc router could use the space...

Edit, I’m waiting for feet, black plastic penny washers (for angling the cabs) and handles so popped home at lunch to find the penny washers have arrived 🤨
 
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Davecam48

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Great workmanship Kev! Just something you may have overlooked could be airflow vents in the actual floor of the amp cabinet. They don't have to very large but with the circuit containing valves and capacitors/resistors etc. they can produce fairly high temperatures so a couple of screened vents in the base of the amp cab will allow the component part of the circuit to vent off some heat during extended on time!

You have done a great job building it by the way!

Reminds me of an amp cabinet I built for an ex-boss of mine which was made with three 10inch speakers driven by a high powered valve amp. Sadly his home was severely flooded about a year after he got it and was totally ruined!

Good work mate!

DC
 
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Kev-wilson

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Great workmanship Kev! Just something you may have overlooked could be airflow vents in the actual floor of the amp cabinet. They don't have to very large but with the circuit containing valves and capacitors/resistors etc. they can produce fairly high temperatures so a couple of screened vents in the base of the amp cab will allow the component part of the circuit to vent off some heat during extended on time!

You have done a great job building it by the way!

Reminds me of an amp cabinet I built for an ex-boss of mine which was made with three 10inch speakers driven by a high powered valve amp. Sadly his home was severely flooded about a year after he got it and was totally ruined!

Good work mate!

DC
Thank you! :) (and fair point about venting the base, so far used for an hour or so there's not too much heat, but I probably will put a couple of small holes in the bottom when I finish it)

I'd hoped to have it finished by now but am still waiting on the handles, the seller had 1 in stock and more on order, he was willing to send one and then the 2nd when it arrived and me just pay for one postage but I suggested he could wait till he had them both so Monday I'll chase them up.
 

Kev-wilson

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I chased the handles up on the phone :confused:, so they're refunded & re-ordered from another supplier as the ones I'd paid for hadn't come into stock :rolleyes:.

One thing I've learned from this is that 15 watts is loud for home use :lol: which leads me to believe it's a 5 watt amp I'm really looking for, so perhaps a kit will have to be a winter project...
 




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