Small Tube Amp Build - Step by Step (6 - Chassis Rear Plate/Transformer cables)

[@timburle4980]

Your attention to detail is amazing!

[@frankjesko8165]

I love how you make craftsmanship look easy

[@philipthomas8440]

Beautifully done! I also greatly enjoyed the Les Paul build.Keep them coming as your videos and camera work are top notch.

[@elams1894]

Thanks heaps Philip!!!

[@judges69]

Wow, great details in your construction of this amplifier. Well done

[@TurboE30M3]

Really neat work! I’m saving this video as inspiration 👍🏼

[@elams1894]

Im super OCD, its a curse not a gift. I accept it now and just expect things to take 50 x longer, but that is the way it is for me. Cheers fellow suffferer, we will get there.

[@nevillegoddard4966]

I EEEEEE C socket, not IC socket mate, mmmkay! I'm not gonna let that one go just cos you're a kiwi bro! Apart from that - beautiful job! The Astronauts will be able to listen to 'Mental as anything' or 'Split Enz' to their hearts content as they circle the earth!

[@simonkormendy849]

Personally, if I was wiring-up one of these amps for Australia's 240V AC/50Hz mains supply, I'd use either green, or green/yellow mains rated wire for the earth/ground, brown mains rated wire for the active, and blue mains rated wire for the neutral connections to the IEC socket.

[@Kevin-vq6rv]

Maybe a stupid question but why don't you drive the lightbulb with DC? It's just an indicator and driving it with AC can cause magnetic interfering, as you probably know.

[@elams1894]

You could, just as some run the filaments on DC, you just have to rectify the AC first. That means more money and more parts. I guess it all comes down to money in the end and perhaps tradition plays a big part as well. Traditionally the pilot light is runoff mains AC and filaments off a 6volt tap, but certainly doesn't have to be that way. Alot of builders now are running filaments off DC, it does cut out a few problems, cheers

[@simonkormendy849]

The cloth insulation on those cloth covered wires is only rated to about 300V DC, not sure what the AC voltage rating is, sure, you can get cloth covered wire that's rated to 600V DC too.

[@antoniushalim2829]

Very nicely build 👍. I notice your grouding point is to input jack. Do you isolated input jack from chassis ?

[@elams1894]

Cheers..No, input jack is not isolated from chassis. I have grounded V1 and V2 at the input, and the rest is grounded near the mains socket. Separating the preamp from the Poweramp in terms of grounding was beneficial in this case for reducing hum. Sometimes it is different. Seems grounding can be problematic and very difficult to get consistently right. Separating the preamp from poweramp seems to be the best approach for me. Cheers

[@antoniushalim2829]

@elams1894 thank you for explaining it .❤

[@efenderbls]

Thanks for the tips and great idea covering the high voltage lugs.

[@volkwolf2511]

As always high quality informative video! Thank you.

[@elams1894]

Wolf! Thank you!

[@volkwolf2511]

Yesterday I little bit repaired my cheap acoustic guitar and recorded by cheap cond mic))) kzbin.info/www/bejne/rpawoICrgNpkn9k

[@elams1894]

Was that you playing Wolf? Sounds real nice, great reverb, well done!!

[@volkwolf2511]

Yep, it's me. New video soon.)) kzbin.info/www/bejne/bZe4Znicdtl1h68

[@koldpants]

Your clean build makes my recently finished amp built from a bell colt look like a dumpster fire

[@petegiant]

Doesn't heatshrink make it more difficult to service and/or diagnose problems with wiring?

[@coltronex]

Superb construction technique!!!

[@SkyscraperGuitars]

Man... I can't wait until I get settled so I can start picking at this project.

[@elams1894]

Thanks greg! Hope things are going well your end.

[@GeorgeChristofi]

only thing I would have done differently is run that speaker jack wire over the top of the selector and as far away from the heater windings as possible.

[@elams1894]

Good point, thanks George!

[@diabolicalartificer]

Neat work, nice attention to detail. Only quibble - chassis/ground and mains earth should be separate. Mains earth should have it's own dedicated bolt/screw with lock nut.

[@elams1894]

Thanks DA. The mains ground is seperate from signal ground strap (chassis) and with a separate bolt and lock nut as seen in video 3 and 4. However, this may not even be necessary as audio circuits do not range into the high frequencies such as computer circuits so you could get away with a single earth point in a guitar amp. Earthing is indeed a complicated topic though, thanks again!

[@diabolicalartificer]

Apologies, haven't watched your earlier video's but will do so. I was refering to the lug at 5:25. Not sure where you are - NZ/Oz but here in UK earthing is part of mains wiring regs. Grounding as you say a complex subject, I'm still learning so any videos like the ones you make that go into great detail are much welcomed. I was looking at your ground bus on your turret board, good idea. What was the braid you used please? I've used single sided copper clad board with ground bus etc cut out using a Dremmel on one side, turret tags on the other side. Sort of part PCB, part tag board. Thanks again for the video.

[@elams1894]

No worries DA. I'm in the same boat, still learning myself really. I live in NZ. AFAIK the circuits with very high frequency, Mhz and above, have complex eddies that require multiple earthing nodes that are seperate from mains. Audio circuits in the low Hz can have a single ground but I think you are correct in keeping mains ground seperate from signal ground. I keep the the two ground points seperate, however I have them close to one another. Seems a good compromise. Also the transformer in this video has its windings insulated from the bell covers and therefore chassis. The engineers must have nutted out the eddies within the tranny. All complex stuff indeed. I use either 1/8 inch or 5/32 inch width braid which I order from partsconneXion. All the best!

[@allmetaliswelcome]

I'm interested in doing a project like this, putting time into creating something entirey my own. How much does a build like this set you back in parts roughly? What software did you use to create the chassis and turret board layout? Is there any way you could recommend to experiment with building on something like a breadboard before building the actual thing? I guess you could, considering the relatively low amount of current. Great series you've got going on here man. I mean that.

[@elams1894]

Thanks heaps Luuk! This amp cost around 350$ US in parts to build, however you can go cheaper or more expensive depending on component quality. I use Google Draw in the Docs application in Google Drive. I have used complicated software and others but none that are as easy as Draw. I draw it all from scratch. First on paper with the dimensions of the chassis and then go from there. I use a template to draw many circles and rectangles of known size then I scan them into Draw and overdraw my template and in that way I get exact sizes which print out correct. Takes a bit to get used to the commands but its easy once mastered. I first create a circuit with desired outcomes. Then I find a chassis that I want to use and scan a drawing of the chassis into Draw. I then draw a layout that best fits using the following rules: keep the leads of grid signal input and plate signal output components as short as possible and if possible, at right angles to one another (this will keep positive feedback (squeal) at bay); use shielded cable for all or most of the inputs and outputs of the pots and all those wires that go to the grids. Once complete, I build the amp and test her out and then use that as a template to iron out the problems and modify the layout or circuit. I find this approach easier than bread-bording a build. However I do use bread-boarding if I want to tweek, or develop a new circuit, in which case that works great, especially so if trialling a tone stack. I hope that helps. Cheers!

[@ernestschultz5065]

I have a question. Do the dotted lines on the diagram mean the wires go under the turret board?

[@elams1894]

No it just means that the cable runs underneath another component or wire. No cables run underneath the turret board. Cheers.

[@skullheadwater9839]

your build looks better than my stuff. I have had great success though without such a pretty looking build as far as sound and lack of hum. maybe I am just lucky.

[@elams1894]

Thanks Scott! You definitely can achieve hum free builds with less OCD than me ha ha. One of my first builds, a kit, was an absolute mess with tiny hookup wire and completely messed up filament wires with earth points all over the chassis, real nasty. However it was almost dead quiet. My father couldnt believe it looking at my mess. As long as there is no unwanted magnetic induction, no matter how it looks, your'e fine. Im just mega OCD neatness. Its a curse more than anything else ha ha, cheers!

[@timrussellguitar1516]

A work of art mate!!

[@elams1894]

Thanks Tim!

[@kubockferre5532]

hi id like to mount this on teflon board ,how long the turrets to buy and where .i check on amazon and ebay but it seem too short 17 mm ,your board seem like fiberglass thanks a lot

[@elams1894]

The ones I use are approximately 12mm in length. These will do the job, essentially the same, same width, only fractionally longer in length. www.amplifiedparts.com/products/turrets-0172-long-brass-premium-package-10

[@davekimball3610]

@Elams1894 I have a power transformer, which has all the secondary windings necessary to work with this plan, however, on the primary side, being in the US and looking to run at 120 volts, I only have one pair of wires to work with. I'm curious as to how I can wire up the power input and switch as I assume I'll only be working with one of the two turrets, the blue and red ones that correspond to the neutral on the power jack and the switch.

[@elams1894]

That's right. You can just connect the power and neutral straight to the two primary windings via the fuse/switch. You can either use a IC socket with fuse or bring a plugged cable straight into the chassis, to the fuse and switch, then onto the primary windings. Hope that makes sense..

[@davekimball3610]

Yup, that all makes sense, I already have a separate fuse socket. This was a fantastic series to follow and I'm thankful for all your attention to detail.

[@elams1894]

No probs, thanks for tuning in!

[@DiegoDurandet]

so interesting !! I think the components are expensive, no ?

[@rickg8015]

We done.. But yeah, Im not a fan of that all-in-one IEC socket/fuse holder. I’d rather have them separate for ergonomic and safety reasons.

[@philipthomas8440]

If I had 3 grand lying around, I'd beg you to build me one! Or at least get in line. What's upcoming? I'm salivating!

[@elams1894]

Thanks again Philip! I'm just uploading the final video now, should be ready in about an hour. Not sure whats next, I'll have to have a think. Many thanks!!

[@TheBoss1597]

As always a work of art! Just wanna ask you about your grounding scheme? No star ground or so?

[@elams1894]

A true star ground would be difficult to achieve with this chassis. You would need a larger square chassis and I think this would be a waste of resources. In this layout I have star grounded the circuit in nodes, centered around the filter capacitor. This is more practical for this kind of audio circuit and there would be nearly no difference in unwanted noise. Cheers

[@TheBoss1597]

ok.thanx!

[@paulludington4030]

Love your videos. What software package do you use to create your circuit layouts?

[@elams1894]

Thanks Paul. I just draw them up in Google draw, in the drive application. No software, I just draw it all up from scratch, cheers

[@michaelfolchetti736]

Do you sell kits?

[@remley8877]

Very neat work.

[@mazlan3622]

Terbaik bro....kipidapppp

[@gabrielcuevas5837]

Muy bueno. (So good)

[@RobertKohut]

Nice!!