pix of Custom built guitar amps/cabs

[drteming]

Humble little build.  My first foray into the high voltage world of tube amps.  Original creator here:  http://www.frontiernet.net/~jff/pipsqueak_pentode/Pentode_DIY_guitar_amp.html.  Like the original author, I built the amp in a dead PC power supply chassis.  The only modification was a 3.3ohm 3W resistor for the filament winding.  The transformer was putting out 7.3V.

I have a bunch of different EF95 tubes for a headphone amp and was looking for something simple.  The 6AK6 power tubes are pretty cheap too.  Nice clean sound.

[bluebunny]

^^ Neat.  Like it a lot.   

[drteming]

Cobbled together a little cabinet to go with the little amp using some scrap plywood and hand tools.  My woodworking skills leave a lot to be desired.  Got the four 4 1/2" full range speakers from Parts Express for cheap.  Sounds exactly like what one would expect from little speakers, thin, no bottom end, but it's hilarious.

[davent]

It is what it is sonically, visually a very cool little setup. The cab looks exactly right!

dave

[rocket8810]

my first amp build. it's a little 100watt solid state Sunn Model T. mostly a practice amp and to hold me over till i build a tube amp. first time building a cabinet and wrapping with tolex, not perfect, but i'm happy with the result. just have to have a faceplate done

[bluebunny]

That is so sweet.  Lovely little build. 

[rocket8810]

That is so sweet.  Lovely little build. 

thanks Marc. it looks so funny sitting on top of my mesa 4x10 bass cab, makes it look even smaller. but, then again the chassis is only 8" long, so with the cabinet its not even 10". i took it to a local guitar store to try out some actual guitar cabinets and you should have seen the looks of people when they saw it and heard it. lol

[statzern]

my first amp build. it's a little 100watt solid state Sunn Model T. mostly a practice amp and to hold me over till i build a tube amp. first time building a cabinet and wrapping with tolex, not perfect, but i'm happy with the result. just have to have a faceplate done

Any chance we can get some more build details? This is cool! what kind of power amp chip did you use? Did you design it on your own or use existing designs? Gut shots?

[stallik]

I’m putting together a champ clone. I’m hoping to be at the stage of testing it at the weekend through my existing cabs/ speakers. I have mostly 12” guitar speakers but some hifi 8 and 10” which are unlikely to be ideal for guitar. I want to end up with a very compact  combo so I’d appreciate any opinions on speaker models. I’m thinking that I’ll have to go with at least 10 but would love to do it with an 8 if there was something suitable.

I don’t think I’d be pushing the speaker much as I’m aiming for that amp on full, guitar on 1/4 kind of thing

Any recommendations?

[thermionix]

The Jensen C8R is great in a Champ, after considerable break-in, if you're after that original 8" Champ sound.  A 10" or 12" may sound "better" but it's not the same thing.  The C8R is also way cheaper than the P8R.

[stallik]

Thanks, I'll check it out

[stallik]

Now it's built and tested through 6 - 12 inch speakers, I can't decide which sound I like best so I'll probably turn it into a tiny combo with an extension speaker out to get the best of both worlds.
It's an Ampmaker kit - basically, a champ circuit with silicone rectification.

[thermionix]

Hmmm...looks based off the 5F1 Champ, but with an added filter stage for whatever reason.

The single jack is set up to mimic the #2 (lo gain) input, if you'd rather have the #1 input, change the 68k to 33k.

The cathode resistor of the first gain stage in a 5F1 is bypassed with a 25µF cap.  It is erroneously omitted from the original Fender schematic, but the actual amps had the cap.  IMO it sounds way better with the cap.

What power tube are you using?  The original K resistor is 470 ohms, many 6V6s will red plate in a Champ and need a higher value, but you have a 270R.  Is your plate voltage considerably lower than the Fender?  Are you using a different power tube?

[stallik]

Well spotted. I'm using a 6L6. Plate voltage is 312v and the current 31ma. Plate dissipation (if I'm measuring it correctly) is just over 9 watts which may be a little low but hey, this is my first tube amp build so what do I know?
I was looking for a simple, small form factor combo with a warm clean tone that would take pedals well. At the moment, it's a little bright and though I've yet to be able run it flat out, the basic tone is good. I intend to use it as a bit of a learning tool and I'm sure I'll end up frying a few tubes along the way.

[thermionix]

Ah cool, a "coke bottle" 6L6G.  Something more like 50mA idle current would fatten the tone up considerably.  RCA manual specs 220 ohms for Class A pentode connection, 300V plate-to-cathode.

[rocket8810]

damn kevin that amp looks awesome. i've never seen coke bottle 6L6 tubes before, only seen that shape in KT88 and KT66 tubes, which i've had an unnatural obsession for for years. did you make that layout? its stupid neat.

[davent]

There're Coke bottle 6v6's out there  as well.
dave

[bluebunny]

Nice one, Kevin.  I had a go with the same kit.  It was very straightforward and sounds good (I'm only putting it through an 8" Orange cab at the moment).  Been tempted to go back and get another of Barry's kits...

[stallik]

I picked the kit up directly from Barry as he’s quite close to home. Nice chap, very knowledgable.

[rocket8810]

nice. didn't realize it was a kit, and not that i re-read your post i see that is from Ampmaker. man do i feel like an idiot for missing that. i've been eyeing one of their kits for awhile, but figure shipping to the US is going to be insane.