blackone one: My JCM800 build

[stecykmi]

Built this over this summer. I think it turned out great and I'm really proud of my work. I learned a lot from these builds. The YouTube demos don't do the amp justice at all and are purely to illustrate the fact that they actually work and aren't empty boxes.

Tried to use top quality components whenever possible. Poly caps are Mallory 150 (they changed the colour for the entire line). Big electros are F&T from germany, small ones are Sprague Atoms. All 1/2W resistors are Dale, bigger ones are mostly Ohmite. Transformers are from Triode, preamp tubes are JJ 12AX7 Gold Pins, power tubes are JJ EL34L blue glass (paid $12 extra for that).

I went through the trouble of using shielded coaxial wiring for the input and first couple of gain stages and I think it helped because the amp is pretty quite.

I built the cabinet and the chassis myself. Cab is Red Oak and uses box joints. Chassis I bent from 0.05" aluminum (assuming you're going to make a bunch of these, it's the way to go since 1 sheet costs about $15 or so, as opposed to $50++ for a bought one). Next build I plan on silkscreening but I was worried about running out of time since school starts up again in Sept.

edit: missed a pic of the chassis layout

[Smeero]

 

[jimmybjj]

great job!

[pandadandan]

Love the bumblebee heater wiring.

Nice work!

[nzCdog]

Wow stecykmi! 
Did you make the turret board too?  Scratch build of a JCM800 is huge effort,well done man!  Surely this isn't your first build... making the Chassis would be a nightmare I should think... great job!
The demos sound really good

[stecykmi]

Wow stecykmi! 
Did you make the turret board too?  Scratch build of a JCM800 is huge effort,well done man!  Surely this isn't your first build... making the Chassis would be a nightmare I should think... great job!
The demos sound really good

It is, in fact, my first build. It was a summer-long project, definitely not something you can do overnight.

I also made the turret board, but the design is heavily based on plans published online.

The chassis took a lot of planning. The problem with the chassis going the whole length of the cabinet is there is very little room for error. I had to do some hammering and grinding to get this one to fit since I didn't account enough for the width of the aluminum and the radius of the bends.

I think if you did one of the plexi-style cabinets where the front wood panel covers all four corners, it would be much easier to bend since you don't have to worry about fitting so perfectly. I think my next builds might use that style, even though i like the look of the chassis spanning the whole cabinet.

[gtr2]

Awesome!

Josh

[Haberdasher]

Wow, that is impressive.  Congratulations!

[JakeFuzz]

Damn, nice work! Did you use one of those combo jigs to cut the box joint? There is one at harbor freight I was looking at but i'm sure we all know the quality of most of their tools...    Also check out BNP lasers. They are a small laser engraving place that will engrave and punch a faceplate for around $30, I have one coming in a day or two; I will post some pictures when it gets here.

[stecykmi]

Damn, nice work! Did you use one of those combo jigs to cut the box joint? There is one at harbor freight I was looking at but i'm sure we all know the quality of most of their tools...    Also check out BNP lasers. They are a small laser engraving place that will engrave and punch a faceplate for around $30, I have one coming in a day or two; I will post some pictures when it gets here.

I actually did it on a table saw and it took forever! I think I calculated that at a minimum, I had to do something crazy like 200 cuts, and that if I didn't undershoot the cut. I'll never do it again that way (at least not without a dado blade which is sort of an extra-wide table saw blade design to cut grooves). It's not very precise either, it took a lot of jimmying to get the joints to fit.

I'll probably invest in a dovetailing jig for my next build, there is a store here in Ontario that sells a couple of different ones that are apparently decent quality.

Please post pictures, I'm interested to see. I'm usually interested in doing as much stuff DIY as possible, but it's cool to know stuff like that is available.

[bigmufffuzzwizz]

That looks fabulous and sounds equal! I love how it cleans up to almost no gain.

[Analog Design Audio]

Good Job Man !!! you just need some NOS 70's 80's Mullards from Ebay (ECC83 and EL34) and you 'll have the best sounding amp in the world

You could bias NOS Mullards @40mA and play all day for 15 years without problems

[FuzzMonkey]

Sweet! Great job, sounds awesome!

[stevewire]

Very awesome!

[stecykmi]

Good Job Man !!! you just need some NOS 70's 80's Mullards from Ebay (ECC83 and EL34) and you 'll have the best sounding amp in the world

You could bias NOS Mullards @40mA and play all day for 15 years without problems

interesting idea. i don't think i could afford it now, but i've always been curious to see if there's a difference between big-name NOS tubes and new production tubes.

also, thanks for all the compliments guys!