Amp Kit Question

[Texicaster]

I'm very interested in building my own amp. Start with a 5F1 Champ I guess BUT if I do I'd love to go DEEP! I mean study up on best parts etc instead of just the stock. I noticed price difference between the cheapest caps and transformers and most expensive is not all that much for such a kit...

So I'm interested in finding a site that sells plans and parts ala carte so I can choose exactly what I want to use.

Yeah I know just learn to build one first but again the cost simply isn't much more for better parts.

Is there such a resource? Or could I find a list of parts and specs I need and just gather on my own?

Thanks!

 

[schmee]

Chassis are cheap on Ebay if you can find the model you want. "Zachmanhunter" are good.
I would not spend the money on Mercury Magnetics trannys, there are other reasonable options. Nothing wrong with Hammond transformers.
Use Switchcraft jacks, Carling switches.
If going traditional solid push back wire watch out, many just get very fuzzy fraying after cutting. I use waxed traditional push back wire from Marsh Amps.
I like Metal Oxide resistors for their durability and accuracy. Many Carbon Comp now days are way off value wise when new.
Just use a Fender layout or schematic found on line to order parts.
Some of Weber's kits on their site have a parts list available if you want.

Maybe buying a cheap kit on Ebay then replacing some of the iffy parts is a deal? Or a plain chassis is only $40 for the 5F1

5f1 Amp Chassis for sale | eBay

Get the best deals for 5f1 Amp Chassis at eBay.com. We have a great online selection at the lowest prices with Fast & Free shipping on many items!

www.ebay.com

It all adds up though, trannys, speaker and cab are a lot of the cost.

 

[Peegoo]

@Texicaster

For components, I use Amplified Parts. Pretty certain it's the same company as Tubes And More and Antique Electronics.

I start with a schematic, then write up a bill of materials (BOM), and then I go shopping.

Examples:

Schematic - https://el34world.com/charts/Schematics/files/_miscellaneous/Eico_hf12a_Conversion.pdf

BOM - https://images2.imgbox.com/99/63/FJdo7evm_o.jpg

Then I heat up the stick and start making smoke.

 

[Texicaster]

Are there any good instruction books? I mean hold my hand step by step... I think the Stewmac one is like this but they only sell it with the kits....

I found a Mojotone pdf but quite slim.

 

[sds1]

As it turns out price is not a good metric of quality when it comes to capacitors and such.

None of the most expensive parts are bad, but most of the less expensive parts are just as good as the expensive ones.

If you post about a kit you're interested in we can comment with respect to any parts that should be upgraded.

 

[elpico]

Other than the external stuff like the speaker and tubes it's questionable whether there are any "better" parts to actually select in the champ. You can certainly get power supply caps that will last another ten or twenty years, but how much does that matter and you probably won't find them at any kit seller. You can get a more expensive mercury output transformer that claims to be an exact replica of the very cheap/low quality transformer they originally came with, but that's as likely to sound worse as it is better. There are no tone shaping caps in that circuit so buying pretty ones is literally just jewelry you'll never see and can't hear. You can select a less hissy resistor composition I guess, but it's such a short, low-gain circuit nobody is really struggling with hiss anyways.

I'd suggest if you want a "champ but better" what you need to select is actual changes to the circuit, rather than different colored parts in the same curcuit.

 

[Kev-wilson]

Are there any good instruction books? I mean hold my hand step by step... I think the Stewmac one is like this but they only sell it with the kits....

I found a Mojotone pdf but quite slim.

https://robrobinette.com/Amp_Stuff.htm

That guy has put a fantastic web resource together, it enabled the novice me to build a couple of decent amps.

Edit, that site, this site and some theory courtesy of 'Uncle Doug's' Youtube channel.

 

[wabashslim]

Tube amp Information, Guitar amp Schematics, Tube amp Information

tube amplifier parts, tubes, guitar tube amps, vintage tube amp parts, tubes, guitar tube amplifier building supplies, tube amp information

el34world.com

When I built my 6V6 Plexi I bought Hoffman's board & its bag of parts but everything else I shopped around for or already had in my junkbox.

 

[VintageSG]

If you're going to build a Champ, do yourself a favour and either build it in a custom chassis, or go for a 5F2a instead.
There's not much difference between them, but the 5F2a chassis is easy to work with. A proper Champ chassis can feel like dentistry combined with proctology.

Build head units. They take up less shelf space. A decent 1x10" or two and you're set for many LoWatt builds. Low power amps are a joy unto themselves.

Buy a soldering iron that has a hefty tip. Spindly tips are for PCB work. Whufty tips let you get the job done without too much heat transfer to the components.

Buy a couple of inexpensive multimeters; inexpensive, not cheap, and get the croc-clip and hook adaptors for them. Seeing the voltage/current at a glance without having to switch scales/inputs makes life so much easier. Have a really good one to hand too.

If you want to get deep into things, buy or build an oscilloscope and signal generator.
A 50 Watt 8 Ohm metal cased power resistor is a good startup load.
Don't use lead-free solder unless you enjoy misery.
Flux is good. Isopropanol is very good at removing flux residue.

Kits.

I don't know what's available in your region. Here in the UK/Europe, we have Musikding, whose build instructions are comprehensive and Tube Town, who don't provide anything other than a layout and schematic. We used to have Ampmaker. Ampmaker instructions were exemplary. Ampmaker kits were superb too. Other kits are available over here, but I've not had dealing with them.
For your first build, a kit is good. A kit with Ampmaker or Musikding levels of instructions is better. Don't hair-shirt yourself on your first build.

What @Kev-wilson put regarding Rob and Uncle Doug too.

Be warned. It gets addictive.

 

[King Fan]

Tons of good advice here. Yes, boutique components don't matter all that much. IF I swap in my own components, I'm often looking for things like longer leads on resistors, or I want to avoid hard-to-see and hard-to-interpret labels (looking at you, ODs), or to avoid nightmare wire (looking at you, loose-stranded).

Yes, a 5F2a is a smart alternative to a 5F1. The bigger chassis is a huge help; the tone control is a nice feature; the separate power switch is an upgrade both for simplicity and noise; the option for a bigger cab and 10" speaker is excellent.

Are there any good instruction books? I mean hold my hand step by step... I think the Stewmac one is like this but they only sell it with the kits....

Yes, +1 what everybody is saying. Very few kits come with perfect instructions and diagrams. You may be able to download StewMac or Mojo's files (StewMac just sells Mojo kits with StewMac instructions). But these, though workable, both have odd choices and weak points (SM more than Mojo in the past). Rob's diagrams and similar derivatives are better.

Plus, blindly following any instruction sheet will not give you any "why" and "how" learning that really makes amp building rewarding. Take more time; read, ask, read the answers, ask more, read more, plan more, repeat. Building an amp is fun -- the more you rush, the more fun you miss.

 

[pi]

I think the Stewmac one is like this but they only sell it with the kits....

The stewmac instructions are there on their site.

'57 Mini Tweed 5W Amp Kit Instructions - StewMac

The new StewMac '57 Mini Tweed will be a blast to play through and even more fun to build

www.stewmac.com

 

[Peegoo]

Before you build the amp, build yourself a "light bulb" current limiter. It does not have to be fancy at all; just safely built.

 

[Texicaster]

Thanks everyone!

I'm not jumping into this and have been studying how tube amps work and observing circuits.

Gotta sharpen my soldering skills and brush up on my dormant electronics knowledge

Before you build the amp, build yourself a "light bulb" current limiter. It does not have to be fancy at all; just safely built.

Hmmm. I've heard about these as a way to check current.

 

[Wally]

I'm very interested in building my own amp. Start with a 5F1 Champ I guess BUT if I do I'd love to go DEEP!

Do you understand the tube elements and their functions? If not, do a search for ‘History of the Vacuum Tube’ and read the Wikipedia article. Simple info.
Then, using “Tube Data Locator Sheet’ you can look up any tube to learn pin outs and as much as you want to learn about the tubes. With this info, schematics will become readable. Layouts are handy for ‘copy work’, but they do not teach one much at all about what the circuit is doing.
There are a lot of books available. There are also sites on the ‘net that offer technical information for free.
Aiken Amps’ Tech info is a good place, imo. The Valve Wizard, too. These two places ‘go deep’. If your local library has a resource on basic electronics, you might want to start there.

 

[sds1]

Hmmm. I've heard about these as a way to check current.

Kind of. They limit current so if there's a fault only so much current can flow, they also are a visual indicator of current flowing. Between these two things it gives you an opportunity to see there's a problem and protect the circuit before any serious damage can occur. Highly recommended. Once you have one you will rely on it in all future situations where the power-up state of a circuit is unknown.

 

[capohk]

At the risk of being repetitive…

Uncle Doug is a superb resource. I believe he’s a retired physics teacher. He explains things really clearly without any fluff or sniffery.

Rob Robinettes site is a treasure trove. Great for troubleshooting and browsing possible mods.

Steve Luckey (sluckey) has a great list of projects archived on the Hoffman forum, very clear layouts etc.

My personal gateway drug was The Truth about Vintage Amps podcast. The early episodes especially are full of advice about the smaller fender circuits.

I’ve built several 5f2a style amps now, with various power and preamp tubes. I like the Hammond chassis - you can have fun with the layout according to your components. I’d echo the recommendation to make a head first, then you can plug in whatever cab/speaker you like.

Good luck.

 

[Bill Moore]

I have repaired my electronics most of my life, (I did lose a few radios while learning, but as a teenager in the 60's I kept my amps working!) I decided to take up Steel Guitar, and needed more amp than the little Airline I bought in the 60's, so I built a Twin, my first complete build. I used a Weber chassis, Hammond iron, and a turret board I purchased, believing the "magic" I used CC resistors, you won't believe how many you have to test to get the correct values, never again! I sourced most components through CE, and used Mallory, Sprague, Switchcraft, and other familiar brands. After I built it, I did have an amp tech friend who used to date my daughter help me on startup and bias, (he also talked me into a trade for a cabinet he had). Since then, I build my own boards, bought chassis from several sources, and still generally use CE for most of my parts. Schematics are everywhere, mods are everywhere, you can decide what you want when you build your project!
This group here is a good source of knowledge!

 

[King Fan]

Picking up on @sds1 's great advice to build a light bulb limiter -- *that's* the kind of thing I'd study before tackling an amp build, much more than picking 'better parts.'

Why? Cuz a) it really matters and b) it's not simple. OK, *building* an LBL is simple. But using it, understanding it? -- even pros (like Uncle Doug) can confuse new builders here, and we see a ton of threads where people are smoking fuses (or amps) because they don't have one *or* don't understand the sneaky simple way it makes startup safe and (with roughly the right wattage bulb) tells you if you have a short -- while protecting your amp.

For building one, Rob has this:

https://robrobinette.com/5e3_Modifications.htm#Light_Bulb_Current_Limiter

For some discussion of how to use it:

https://www.tdpri.com/threads/light-bulb-limiters-why-so-much-confusion.994766/