DIY Guitar amp

[letterbeacon]

I've played guitar for years now, but always with crappy practice amps and now I'm thinking of building a 'proper' amp.  Despite playing a years, I've never really been that interested in the techy aspects, so I have no clue when it comes to amps and pick ups etc.

I wonder if anyone could recommend a good tube guitar amp to build?  I have an Epiphone Les Paul and I'm more interested in warm clean tones.  Tones like this:  http://youtu.be/g4HoDGqUWGU

I spoke to a guy in a guitar recently and he recommended a Fender Tweed reissue, and they look like popular builds on the internet.  What do you think?  Any other recommendations?

Thanks.

[jackies]

I gutted a crappy cheap amp and built a Champ circuit inside, then removed tone controls - awesome sound at practice volumes! I suppose it's THE best starter build.
Now I'm building a Princeton, coz I want vibrato and reverb...

[sahib]

Indeed Champ is a good start up.

[Gus]

Something to try is a better speaker or even try something like a 4x12 with practice amps.

Speakers are a big part of a guitar amp sound.

[bigugly]

check out AX84.com. in the "building blocks" section take a look at the "Clean Preamp" and in the "Archived Projects" area the P1 and possibly the P2 might be of interest.

here's the links

Clean Preamp: http://ax84.com/static/corepreamps/Clean/AX84_Clean_Preamp_Schematic.pdf

P1: http://ax84.com/media/ax84_m311.pdf

P2: http://ax84.com/media/ax84_m247.pdf

[usekgb]

+1 on the Champ.  Solid clean amp with no bells and whistles.  There are many kits available out there, and they aren't horribly expensive.

Cheers,
Zach

[letterbeacon]

Thanks for the replies!

The AX84 site looks great, I'll definitely have a proper browse later through there.  The Champ's schematic looks very simple indeed -something that can be knocked up quite quickly so that looks very tempting too.

Cheers!

[usekgb]

The trick to making a Champ really clean is to use good transformers and maybe beef up the power supply caps a touch.  Aside from that, it's a really simple circuit.  You can use a very wide variety of parts and see what you like in there.  Your biggest expense will be the transformers, chassie, and speaker.  Don't worry too much about using all sorts of crazy capacitors in this design.  Good ol' Orange Drops work just fine.  As for the carbon comp -vs- metal film resistors, that is a matter of choice.  If the metal films had been available when Leo Fender designed this amp, he would have used them!

Cheers,
Zach

[letterbeacon]

The original layout looks fairly straight forward, so I'll probably just use that and source the parts myself rather than getting a kit.  What transformers/ speaker do you recommend?

[usekgb]

Choice of transformers and speaker is really a matter of taste and budget.  The Jensen P12N is a pretty sweet 12" speaker, but can be kind of spendy.  Eminence has a wide range of speakers that you may want to have a look at.  You don't have to use AlNiCo if you don't want to.  It's YOUR amp after all.  As for transformers, Hammond has a nice selection of quality products.  Mojotone sells some nice ones.  If you want to get crazy, there are all sorts of boutique transformer builders out there as well.  I would do some searching and see what is out there that will fit your personal requirements.

Cheers,
Zach

[letterbeacon]

Great, thanks Zach!

[usekgb]

You bet.  Have fun!  I had a blast rebuilding an old Kalimazoo Reverb 12 I had lying around.  Since it was MY amp, I decided to replace the stock Gibson tone stack with a Fender tone stack.  I used modern metal film resisters instead of carbon because I wanted a lower noise floor.  I reused the original transformers and choke, and used a whole load of Orange Drops.  The amp sounds killer! 

Old guitar amp designs are pretty simple and leave lots of room for experimenting.  Have fun, and don't be afraid to try different things.  One word of warning though.......  Voltages inside guitar amps are high enough to kill you!  Always make sure that your power supply caps are drained before sticking your hands in there.  Another good practice is to keep one hand behind your back while you are poking around inside the amp.  This will prevent a 500V cap from discharging through your heart.

Cheers,
Zach

[MeToo2]

I've played guitar for years now, but always with crappy practice amps and now I'm thinking of building a 'proper' amp.  Despite playing a years, I've never really been that interested in the techy aspects, so I have no clue when it comes to amps and pick ups etc.

I wonder if anyone could recommend a good tube guitar amp to build?  I have an Epiphone Les Paul and I'm more interested in warm clean tones.  Tones like this:  http://youtu.be/g4HoDGqUWGU

I spoke to a guy in a guitar recently and he recommended a Fender Tweed reissue, and they look like popular builds on the internet.  What do you think?  Any other recommendations?

Thanks.

If you're a relative beginner to electronics I can really recommend Ampmaker's products in the UK. He has some of the best build instructions I've ever seen anywhere, and the kits are very good value compared to even just buying individual components yourself (especially after factoring in multiple postage charges). I built the SE5a for my brother. Even though I'm an experienced tube builder, just simple things like knowing in advance how long to cut the various wires, really speeds things up. Although Ampmaker's website and premises seems to be "relocating" you should drop him a mail to see when he'll next be shipping full kits.   I also bought my brother a G12H Heritage from Lean business in the UK and he built his own cabs from Tube Town in Germany. I can personally recommend all three companies mentioned (and I have no contact with them except as a satisfied customer)

[analogstud]

Also check here: www.ampgarage.com They have plenty of great, well supported, builds. Lots of Ken Fisher (Trainwreck) circuits. I'd recommend a "Rocket" build. Good clean "Voxy" type of tone. Would also be a great general-purpose amp to have in the studio.

[G-Sun]

I was considering building a champ myself (ax84)
but ended up buying a VHT Special 6 Combo -much cheaper, sounds nice
and should be easy to upgrade.

[lassoharp]

Fender Twin/Showman is "King of Clean" but those sounds in your link sound closer to Vox AC30 territory.  Most of the Matchless models will do that kind of sound well too.

Champ is fine sounding amp but it breaks up really quick and is more for dirtier tones.  Same with the Deluxe/Deluxe Reverb.

[alexc]

I read the comments regarding a Champ being 'clean' 

I have to say, that's not been my experience at all. I find it to be almost impossible to get clean tones from.
I use an AU7 instead of a AX7 to tame it somewhat.

For my part I would characterise a Champ DIY  as very, very 'not clean', except for inaudible levels.
I happen to very much like the tone I get from my one, but clean?  Nope. Not in a pink fit!

Maybe I need to get a really good output traffo for it.

Like a Mercury Magnetics. My DIY Super Reverb sounds absolutely amazing with them

[letterbeacon]

Thank you very much for the replies -lots to think about.  I guess I'm after something simple I can DIY as I wait for various transformers etc. to turn up for my BA-6A build.

The Vox AC30 looks like something I'd definitely like to try at some point down the line.  Weber has a cleaned up schematic and layout that makes the project much more manageable.

I have to say, that's not been my experience at all. I find it to be almost impossible to get clean tones from.
I use an AU7 instead of a AX7 to tame it somewhat.

That's interesting. There's a YouTube clip here: http://youtu.be/G8MzmN0YNuI that demonstrates a Champ with clean tones.  Do you think it's a case of changing the bias point of the AX7/ AU7?

[daal]

I'm quite a newbie but can't it be related to your guitar ? Me and my 2nd guitarist both have Gibson SGs but with one different pickup and different settings on pickup height, and it's quitte impossible for her to have a clean output in her amp, but my guitar is fine in the same amp. Maybe your circuit does amplify just on the edge of distortion or saturation and your specific guitar makes it go to the dark side ??

[alexc]

Surely the distortion could be related to the guitar.

Although I have a variety of them, they do tend to be hotter output than normal, as I've replaced the stock pickups with a variety of after market ones.

Still, when I use them with my other amps, I don't get undue overdriving of the input tube.
I've tried a few too, since the early 70s   

My champ build is using not so great output transformer, tho' I've tried a couple of different ones.
And it is not really a completely faithful clone or anything. Pretty close but no clone.

However, the circuit is pretty simple!

The main thing is that the bottom end breaks apart pretty quickly when the volume knob is up - and I mostly have it most of the way up - a single ended 6V6 is probably only 3W or so. Mind you, if you switch out the tone stack it can push that 6V6 hard and get pretty darn loud.

As previously said, clean champ tones are all about the output transformer (and speaker!)

It's all good!  Just saying the Champ wouldn't be my first choice for clean tones is all.

Cheers