Yet Another First Build Thread (5F1 and 5E3)

Hello there folks!

My project for this winter is to build two amps, a 5F1 and a 5E3. I've spent a lot of time reading the great forums here and on other sites as well as various electronics books and publications.

I'm ready to getting things started and I'd like to chronicle my progress here. I hope it can be useful for other first-time builders but the real reason for posting here is to take advantage of all of the excellent and knowledgeable members of this site! I'm sure I'll have problems and questions that need answering as well as advice on the various steps I'm about to take.

Sincerely,
Fred

I wouldn't let myself buy a single capacitor until I could look at the original 5F1 and 5E3 schematics and identify each component and what section of the amp it belongs to. Of course, this meant that some research was in order.

Here are some good resources:


Tab Electronics Guide to Understanding Electricity and Electronics (ISBN: 0071360573)
NEETS and other U.S. Navy and Army (e.g. OD1725) publications on Electronics (great stuff and free, just google it)
Many other forums, tech pages, videos and such that I stumbled upon thanks to Google.


Now that I can make pretty good sense of the schematics** it's time for the next decision: build from a kit or from scratch.

**I still don't know what a lot of the components are doing and why the circuits are designed the way they are but I've got enough knowledge to start with. The rest will come later, I hope.

I have a tendency to make things more complicated than they need to be so I was automatically inclined to build from scratch instead of from a kit. When I asked someone (a shop owner that does this stuff for a living) about the learning potential for each approach, this is what he said, roughly:

"If you buy at kit, you'll learn how to assemble and solder. If you build it from a schematic, you'll learn huge amounts about electronics and tubes. Many substitutions and workarounds will be required which is when the learning really kicks in.

If your desired final product is a Bassman, then order a kit, but if you don't mind customizing a bit, and having something Bassman-like but totally unique, then build it from a schematic."

(Note: At the time, I wanted a Bassman but after looking at the schematics with a bit of an educated eye I decided on the 5E3 because a 5F6A (i.e. the Bassman) is, IMO, a lot more complex than the 5E3.)

Ok, great advice. Having a great amp and learning a lot is my goal so I was now leaning towards the no kit approach. Still, I didn't have a lot to go on and I had no idea how to put an amp together.

Googling for build instructions turned up Tubedepot's "How To Build A Deluxe Tweed Kit" and, subsequently, their 48 page assembly manual (for the 5E3) and thus I made the decision to build from scratch.

Videos and manuals available here:

http://tubedepot.com/kit-tweeddeluxe.html
http://tubedepot.com/kit-tweedchamp.html

Also, Weber has great colour-coded layout images that will be a great reference come build-time:

https://taweber.powweb.com/store/5e3_layout.jpg
https://taweber.powweb.com/store/5f1_layout.jpg

Excellent start! Time to start buying those capacitors (and at least one hundred other things)...

hi Fred, I've been doodling around with tube amps for a couple of years now. I started with simply trying to refurbish vintage PA amps. There are a lot of them that can be found on ebay for minimal $. Most recently I've taken a vintage amp and converted it to a guitar amp by modeling it after a vintage Fender circuit. I''ve had much better results this way, though it's more work and cost. Basically what you do is use the transformers, chassis, tube components, etc that are there and replace resistors/capacitors . . . assuming the carcass you start with is similar to what you're after. For a first project it's a way of saving some (a lot) $ compared to buying all new . . . and you'll learn just as much. The down side is the chassis will need more work to dress them up compared to some of the nicer kits.

just a thought . . .

Welcome aboard!

I would personally start with the 5F1, and go from scratch. There just aren't that many components.

First, open up your schematic in your favorite graphics program and label every single component. Resistors, capacitors, jacks, switches all get numbered. R1/C2/J3, etc.

Then, make up a spreadsheet of all the components and their values and how many you think you need to order. This should also help you to calculate pricing.

Then, label up the layout that you're using. I made up my own my first time around to incorporate a few small changes and slightly different component shapes. This will tell you what everything is, and where it should go, and also give you a good idea of signal and power flow.

Then order 'em up.

Make sure you know how to safely discharge filter caps before you begin. Other than "unplug it when you're soldering" that's the #1 rule.

I build my first amp out of parts from two sources:
-Antique Electronic Supply (http://tubesandmore.com/) - transformers and a couple odds and ends
-Watts Tube Audio (http://turretboards.com/) - pretty much everything else, and they carry turretboards (both loaded and unloaded) for the 5F1, which can make life a lot easier if you're not as insane about doing absolutely everything yourself as I am (which is why my cabinet is still not finished...).

Eager to start, it was time to start figuring out what I needed to buy. I used the parts list in Tubedepot's assembly manual and also the BOM document from the Weber site to compile the list of required components. Here is where and what I bought and some thoughts on my choices:

(I hope I'm not breaking any forum rules by posting this stuff...)

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Electronic components - tubedepot.com

Well, I did my first batch ordering from here. I bought caps, resistors, tube sockets, jacks, plugs, switches, lamp, fuse and wiring - all of the little things. Their site is excellent and I was on a high after watching their videos and downloading their manuals so I felt I should start with them. Shipping to Canada was quite cheap but I still haven't received anything from them and it has been two weeks. Also, they offer no indication when an order has shipped. Still, I like their site and most of their prices seem good.

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Trannies (part 1) - angela.com

I'm Canadian and, dammit, my amps are going to have Canadian transformers. Ironically, I had to order the Hammond transformers from the U.S. Anyway, Angela had the trannies in stock and gave good response and shipping notification with tracking numbers. Shipping these things isn't cheap so make sure you know your whole order when you place it. I ordered the 5E3 trannies and the 5F1 trannies separately (I wasn't planning on the 5F1 the first time around) and it cost me... Superfast shipping! I've already received both orders.

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Chassis - A guy in Toronto

I found some beautiful 5E3 and 5F1 chassis that a guy in Toronto makes. I found him on Craigslist but he also sells them on eBay. It was only after talking to him that I decided to build a 5F1 in addition to the 5E3. They are all cut out to original spec. Superfast shipping!

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Trannies (part 2) - tubedepot.com

Well, the Hammond 290AX output transformer (OT) doesn't fit in the 5E3 chassis I bought so, after discussing it with Rob Hull from tubedepot.com, I ordered a Blackface Deluxe OT which will fit and which is, according to Rob, electrically identical to the tweed version except for an additional tap on the secondary. Their transformers are made by Heyboer.

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Circuit board - mojotone.com

As previously stated, I like to make things difficult so I ordered blank vulcanized fiberboard from mojotone and I'm going to make my own circuit boards. It doesn't look like it's hard to do. I've already made the templates... Expensive shipping and I still haven't received the order (in 2 weeks).

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More wire - radiodaze.com

After more reading I decided I should have went for solid core wire so I ordered two spools of old-fashioned cloth covered solid core wire (18 and 20 AWG). This order is somewhere in the twilight zone, I haven't head back from them since I placed the order over a week ago but they have charged my credit card.

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Tubes - TBD

I haven't purchased any tubes yet. I'm got the impression that EHX tubes are great sounding and reasonably priced. Advice is welcome.

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Speakers - TBD

I haven't decided on the speakers yet. Jensens or Webers are the front-runners at this point. Advice is welcome.

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Cabinetry - TBD

At the moment I'm thinking of building my own using Scott Cole's great drawings (google it).

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The rest - Home Depot

I'll buy all screws and such at the local Home Depot.

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Lessons learned:


Triple-check your components shopping list against the schematic before ordering! I had to make an extra order for caps and resistors that I missed the first time.
Order the transformers (esp. the OT) after you have the chassis in your hands and have measured the cut-out and the screw holes.
Shop around and buy good quality components. There's no harm in spending $6 on a capacitor but $140 for an OT is outrageous!

bdgregory and Ben Harmless:

Thanks for your input! You posted as I was typing up my "sourcing the parts" post! I'm already into the parts ordering stage and the orders are starting to trickle in...

My future posts will be more "real-time" and not historic narratives... I look forward to more advice as I start building.

Cheers,
Fred