Amp Kits

[Shadoweclipse13]

Anyone around here ever build a Mojotone kit? I'm kinda looking at the Bassman head kit...

[jthomas]

Well, I built a Weber kit and can offer my experiences if that would be helpful at some point.

[Shadoweclipse13]

It might be awhile (money...) before I do one, but how'd your Weber kit turn out? Is it based on anything specifically?

[Jimmy Rocket]

The mojo kits are great. I built a few of those before I started free-building amps.

The Bassman is a great amp, but not an easy place to start. If something goes awry there's a lot to debug. The conservative advice is to start with a 5f1 tweed champ or something like that so you have a chance to learn what's going on in there.

If you're really set on a blackface, the vibro-champ would be a good place to start.

[Shadoweclipse13]

I know it's not quite the same, but I've built plenty of pedals, built and rebuilt a number of guitars, and have been SOMEWHAT involved with electronics for almost 15 years. I certainly appreciate the advice and wisdom of that, but I honestly am not a HUGE fan of the little champs. They just sound too tinny/hollow with little bass response to me. BYOC has a really cool Champ kit that with push/pulls seems to do a lot of different tones, but I'm not sure.

I know I shouldn't really judge those tones on online videos, but I played through a Blues Jr. in a local shop the other day and hated it (ok tone, but sounded soul-less and dry, again, with little bass response). Am I misreading that (i.e., do you think the champs could sound decent used as a head or similar)?

EDIT: I just found a video of a guy playing his homemade Vibro Champ and I LIKE it. I MAY start with that. Any recommendations on kits (price-wise AND quality)? Mojotone seems pretty good, but it certainly wasn't cheap either.

[morganp]

The Weber kit I built was the "Maggie," their version of the two-stroke, a popular first amp build. It's very similar to an early Princeton, runs a single 6L6 for about 8ish watts, and has a 10 and 8 inch speakers with a switchable impedance to run either or both at the same time. I find it loud enough to be pretty useful, but still portable and light weight. To my ears it sounds a LOT like the early Steve Cropper tones, Stax/MGs stuff when he was running his tele through a tweed Harvard amp.

Not much tougher to build than a champ, but I find it more useful than my champ-like build.

[Jimmy Rocket]

If you've got experience with a soldering iron you'll be fine, but building an amp is a different beast than pedals. Wire placement and layout are critical to avoid noise/oscillation/etc. and most of the "classic" kits have already worked all that out a million times over. I personally get very tired of working inside tweed chassis because they're a tight fit for my big fingers, and blackface chassis are a lot more spacious

The usual rules apply for high voltage. These amps can kill you so keep one hand behind your back when testing, drain the caps, don't drain a six-pack of beer before you work on it, don't stand in a bucket of water, etc.

Here's the thing I've found with the kits. Mojo is a little pricier, but they run sales and at the end of the day I've been happiest with the quality of components.

Weber is better than they used to be but they still use little poly caps and generally uninspiring components. If you don't care about what it looks like inside they're a fine option.

Here's another idea for you. There's a company called Boothill amps that puts together decent tweed kits with better components than weber and cheaper than mojo.

If you do go tweed, I'd advise building a 5f2a Princeton because it's a slightly more versatile amp than the champ with the addition of the tone control, and it's no harder to build. If you order from Mojo you can probably get them to upgrade the baffle to a 10" speaker.

[Shadoweclipse13]

If you've got experience with a soldering iron you'll be fine, but building an amp is a different beast than pedals. Wire placement and layout are critical to avoid noise/oscillation/etc. and most of the "classic" kits have already worked all that out a million times over. I personally get very tired of working inside tweed chassis because they're a tight fit for my big fingers, and blackface chassis are a lot more spacious

The usual rules apply for high voltage. These amps can kill you so keep one hand behind your back when testing, drain the caps, don't drain a six-pack of beer before you work on it, don't stand in a bucket of water, etc.

Here's the thing I've found with the kits. Mojo is a little pricier, but they run sales and at the end of the day I've been happiest with the quality of components.

Weber is better than they used to be but they still use little poly caps and generally uninspiring components. If you don't care about what it looks like inside they're a fine option.

Here's another idea for you. There's a company called Boothill amps that puts together decent tweed kits with better components than weber and cheaper than mojo.

If you do go tweed, I'd advise building a 5f2a Princeton because it's a slightly more versatile amp than the champ with the addition of the tone control, and it's no harder to build. If you order from Mojo you can probably get them to upgrade the baffle to a 10" speaker.

Wow! Great advice dude! Thanks! I've always been a fan of Tweed amps (looks wise) and never really had a huge thing for Fender amps (color scheme-wise, dark grey tolex, etc.), but I do like the shape (and size if there's more room to work with. My main amp is a Peavey Delta Blues, so I may do something different. The Mojo site shows a whole bunch of different tolex and grill options to play with.

It sounds like quality-of-components-wise, I'm gonna go with Mojo. I wouldn't mind it if it was just the way it looks inside, but I'd bet that the better components sound a bit better too, huh?

I might look into the 5f2a Princeton. There are a couple others I'm also considering (Deluxe Reverb, Vibro Champ, unless they make a Princeton with tremolo), but I really want at least 10" speaker and most of the Mojo cabinets for the Princetons are 8".

EDIT: Nevermind about the speaker size. Mojo offers other sizes for the separate cabinets.

[Jimmy Rocket]

I wouldn't mind it if it was just the way it looks inside, but I'd bet that the better components sound a bit better too, huh?

Generally speaking, yes. That's what I like about Mojotone. Every kit I've bought from them, and all of the parts I order, are quality. I never feel like I need to upgrade anything. I've developed preferences for certain parts in certain applications so I swap things here and there, but a Mojo kit will allow you to build a boutique quality amp right out of the box.

They do have options if you want to upgrade the cosmetics which is nice too.

Have you thought about a Princeton Reverb? It's more complex than the 5f2a, and more expensive, but it has the best reverb and tremolo of any of the blackface designs IMO and it's already got a 10. The Vibro-Champ has the trem without the reverb, and it could likely fit a 10" speaker baffle.

This is my mojo Princeton Reverb hanging out in the corner there:

photo 2.JPG by jimmyrocket02, on Flickr

[jthomas]

I also built a Maggie. Small world. It is a great little amp. I modified it to run a KT66 power tube and learned a lot in the process. A buddy of mine who is kinda picky was impressed and said that it delivered Brown tone. Weber doesn't provide step by step instructions, just a schematic and a layout. Building the Maggie was aided greatly by Dave Hunter's book on amp tech. As noted by another post, the Maggie is a single tube version of his 2-Stroke Amp. This is basically a tweed Harvard. Hunter shows a 2 power tube version in his book and the Maggie is a single tube designed around a 6L6GC. Hunter has a website somewhere where he basically endorses the single tube version. Two tubes is not appreciable louder in this kind of amp (i.e., class A, cathode biased).

The amp also has a boost/tone switch and 2 speakers (8 and 10 inch). The mismatched speakers give a bit of a natural phasing of the output that sounds great. It doesn't have reverb or tremolo, but that makes it easier to build. The amp is designed to be flexible (i.e. power and output transformers) so that it is possible to run any octal power tube that has a 6L6 pin-out. It is best to re-bias the power tube to not run the tube too hot or too cold, but that isn't absolutely necessary unless you get a bad tube that starts red plating. I had a 6K6 power tube for awhile. It didn't sound very good, but it worked. It also is designed to be pretty flexible in terms of the resistance of the speakers and the amp has a switch to use either a single 8 ohm or 2, 8 ohm speakers in parallel. It is a great amp for learning and is forgiving with a first build. I made a few stupid errors in my construction and did not blow anything up.

Weber components are Chinese and I think that everybody knows that it is possible to find components that cost more and are reputed to be especially desirable. I built the Weber and have no problem with the tone that the amp delivers. Weber is a small family run company and they seem to sometimes get a little overwhelmed. After ordering my kit, it took about 3 months for me to get it. I would have liked it sooner and they may be faster now. I mistakenly thought that they sent the wrong resistors (I knew about 4 band codes, but not 5 band coding) and they responded quickly to an email. The Weber webpage is a great place to get help from a community of custom amp builders and folks over there are very generous with their time helping out novice builders. (Thanks again, gentlemen) I would not hesitate to build another Weber kit. I would add that the Weber Maggie was about $550 when I got mine, 2 years ago. Victoria Amps had essentially their version of the same kit with higher-end components for about $1K at the time.

There are a few other kit vendors and I would suggest checking them out. For example, Amplified Parts has 2 MOD tube guitar amp kits. At Watts Audio (http://www.turretboards.com" onclick="window.open(this.href);return false;) there several kits. I really want to build the Supro-24 kit. There also is Triode USA (http://store.triodestore.com/5f1kit.html" onclick="window.open(this.href);return false;). There also is Tube Depot (https://www.tubedepot.com/t/diy-central" onclick="window.open(this.href);return false; ... e-amp-kits). I think that Tube Depot has a detailed pdf instruction manual that illustrates, in a step by step fashion, how to build an amp. They also have a great video showing a kit build. I think that it's from Tube Depot.

LASTLY... please be careful. Mr. Rockets is right on in his call for safety. The voltages in a tube amp are potentially lethal. Accidentally touching the wrong lead can absolutely kill. On that upbeat note, I will take my leave. Good luck with your build.

[Shadoweclipse13]

I wouldn't mind it if it was just the way it looks inside, but I'd bet that the better components sound a bit better too, huh?

Generally speaking, yes. That's what I like about Mojotone. Every kit I've bought from them, and all of the parts I order, are quality. I never feel like I need to upgrade anything. I've developed preferences for certain parts in certain applications so I swap things here and there, but a Mojo kit will allow you to build a boutique quality amp right out of the box.

They do have options if you want to upgrade the cosmetics which is nice too.

Have you thought about a Princeton Reverb? It's more complex than the 5f2a, and more expensive, but it has the best reverb and tremolo of any of the blackface designs IMO and it's already got a 10. The Vibro-Champ has the trem without the reverb, and it could likely fit a 10" speaker baffle.

This is my mojo Princeton Reverb hanging out in the corner there:

photo 2.JPG by jimmyrocket02, on Flickr

That looks awesome. Funny you say though, because Princeton Reverb IS the Mojo kit I've really been looking at. Their cabinets for it can also be had in a 1x12 which is probably what I'd be looking at. I was messing with their cabinet customizer and these are the two ideas that jumped out at me for a 1x12 Princeton Reverb Blackface combo cabinet:




jthomas: also great advice. I may look into those as well. Mojo seems to have everything I'm looking for (amp, options, cabinets to fit their stuff), but I am certainly not someone who buys the first thing I find, or on impulse with no research.

Amp building sounds like fun, challenging, but within my realms of possibility (at least with what I already know and how I am with electrical and mechanical things). I appreciate the call for safety, but I'm no stranger to electricity (and working on things with live electricity). I worked in residential appliance repair for 6 years and originally went to school for HVAC/R, am a fully licensed refrigeration tech and work with 120/240, and the occasional 480 now and again. Electricity is certainly nothing to scoff at and this would be no different for me in that regard.

[Shadoweclipse13]

Jimmy, just curious. What's the wattage on your Princeton Reverb? Can you mod any (or all with the knowledge I suppose) of the kits to be able to change output wattage? I have also had my eye on a Laney Cub 15 Head (which has 15W input jack and a <1W input jack for two different outputs). I mean, my eventual goal is to have a band/music room in the basement of whatever house I eventually buy and to soundproof the crap out of it so I CAN crank at home, but that may not be an option for sometime...

[sookwinder]

I get all my cabinets from MOJO (even though I live in Oz). Really good build quality.

I also basically only build Princeton size amps, and over the years have tried out a number of tolex / grille cloth combinations ...

[Jimmy Rocket]

Jimmy, just curious. What's the wattage on your Princeton Reverb? Can you mod any (or all with the knowledge I suppose) of the kits to be able to change output wattage? I have also had my eye on a Laney Cub 15 Head (which has 15W input jack and a <1W input jack for two different outputs). I mean, my eventual goal is to have a band/music room in the basement of whatever house I eventually buy and to soundproof the crap out of it so I CAN crank at home, but that may not be an option for sometime...

The PR checks in somewhere around 12-15 watts but it is a loud 12-15 watts and it is a beautiful 12-15 watts. You can upgrade the output transformer to the transformer used in the Deluxe Reverb which gives it a little more headroom and power, but realistically you're only going to get so much out of 2 6v6 tubes.

Removing the negative feedback also adds a little volume and girth to the sound.

I dig your color combos above. I used to be pretty conservative with build color, but I'm branching out. I've done several in Vox style Fawn tolex and that stuff is gorgeous.

photo 3.JPG by jimmyrocket02, on Flickr

Here's a blonde JTM45 style build

969945_10100376441060904_48921501_n by jimmyrocket02, on Flickr

and my latest, a sky blue 5C1

image by jimmyrocket02, on Flickr

[Shadoweclipse13]

Yowsa! I dig that sky blue combo! And Sook, those blue-green (seafoam?) cabs are gorgeous and THAT is coming from a guy who likes, but has never LOVED Seafoam green! Hot!

12-15 watts is perfect. My Delta Blues is 30 and though I LOVE it, I do wish it had a lower wattage mode (and I don't know that I want to mod something I bought already assembled).