New amp project...One Watt JCM 800

[Lt. Bob]

Shanathan has moved on to better projects now.

[JD01]

We just have to hope WJ doesn't display an interest in yacht building...

At least it would give you somewhere to rock out, mate!

[WhiskeyJack]

I'm stoked on this. Currently sourcing some importanter parts right now.

Have you finished your telecaster yet?

Yea man ages ago. It has warts that need addressing and a few little mods and i'd love ot have a better neck on it but yea it is done. I even recorded it. It was on the last cover i posted in the listening booth like a year ago i think? It's a cool guitar. I hadn't played it either in a good long while and when my buddy was here (the signer in that ancient ska band from my childhood) visiting this last week he said it resonated super good and felt hella solid. He did not beleive it played like a 140 dollar kit guitar. However he is alot like @Greg_L and is not a fan in the least of telecasters but he did seem to enjoy playing it.

[Tadpui]

Interested in how this one turns out. Definitely a cool idea. Looking forward to seeing the combo amp come apart and become a head, and how the power section comes together.

[WhiskeyJack]

We just have to hope WJ doesn't display an interest in yacht building...

Nope. But, my last woodworkers group mnthly meeting was at this dudes acreage and he builds solid mahogany Runabouts.

Was a humbling evening to say the least. Here i am stressing out over baseboards, recipie card holders, and amp cabinets and this guy has over a half a milliom dollars tied up in a bunch of boats and canoes.

They are gorgeous though. I was pretty in awe of what the guy does.

[WhiskeyJack]

Ok @Greg_L , after some looking around and how i thought i was going to be picking this stuff up a little at a time i am kind of risking paying a little more in the long run in shipping. I have consorted with some other amp nerds on a Canadian forum who are guiding my shopping journey to avoid shipping (and duty stuff if i can only source some stuff in the US.) So it looks like to avoid paying shipping on stuff from some places i need to spend minimum 100 to almost 150 at different places. I am in the process of using the list you sent me and kind of compiling separate order lists for different sites based on the recommendations of others. 

One of the better sources apparently always does really nice sales during any and all major holidays and incidentally they have the best selection and quality of transformers to pick from domestically. So i am going to maybe order those on thanksgiving weekend coming up here soon and then also we have black friday to look forward to and i may get a bunch of shit then from some of the recommended sites. 

Not really as fast and furious as you are going at it (but did you really think i would be going it at it in Greg-time?? lol)  but i have a plan and it is buying me time to cross other things off my to do lists. 

Will still send along updates and cross check parts with you too. Also i just double checked and i  still can't access your parts list from that website. weird. ???? I still have the csv version of but when i load it into google sheets some of the ascii symbols get garbled up in translation.

What kinds of things do I need to keep in mind when part selecting? Like is it just corksniffing stuff or is there actual "you must have this unit specifically" stuff i need to have in mind. 

[Greg_L]

Ok @Greg_L ,

Here's a copy and paste from what I just emailed you....


Ok since you know nothing....and I mean that with all due respect....stick closely to the list.
Mainly...
Hammond 290AX power transformer
Hammond 125B output transformer
Hammond 5H 50ma choke

Those three are musts. If you know of a reputable Canadian replacement that meets the specs of those three Hammond units, then go for it. I'm pretty sure Hammonds are made in Canada though!

As for caps and resistors...you can go by budget for those. You don't need the most cork-sniffy Sozo or Jupiter caps that exist. Good ol Mallory 150s are great and inexpensive.
The big filter can cap can be a CE, JJ, F&T, whatever you want. It just has to have the right values.
The resistors...I'd stick with 1/2 or 1 watt carbon film for most of it. The power supply resistors will need to be 2 or 3 watt metal oxide though.
As for hardware like tube sockets and switches and stuff....whatever you can find that will work is just fine. Again you don't need boutique stuff here.

But as you get closer send me your list and we'll go over it.

[CrowsofFritz]

I find it interesting how people’s minds just click on certain things.

I can build a computer. Greg, I think I recall you saying it’s like Chinese to you.

Meanwhile, everything you wrote is gibberish to me. I can try to take the time to learn, but my mind is not clicking with this as fast as the computer stuff did. I got that stuff instantly. I don’t really get this, and the time to learn turns me off from continuing to try.

[rayc]

I have a fair idea of this stuff now - between Greg, Uncle Doug & Psonic Audio. I've tried other places Like Headfirst Amps but he runs too fast & assumes a lot of prior knowledge - he's talking to those who can I suspect.
Not that I'm going to do anything with it mind you.
THOUGH....my little Kustom 5H 5watt has a new version out with a bass response knob. I decided to revisit my little amp and yep...way too much bass in the thing and that was into a Peavey 8" speaker so I may be tempted, eventually, to find out what resistor or part to swap so that the bass response is reduced. I don't want a knob to do it as I've watched the vids and heard the audio samples of the new version and the only time the new bass response knob sounds good is when it's rolled back to minimum bass.

[Greg_L]

@CrowsofFritz I taught myself amp stuff out of spite and necessity. I got hosed one time a long time ago by a shady amp "tech" and I vowed then and there to never pay one of those fuckers for anything ever again. It wasn't anything major but I knew enough to know that something was off and I was right. I paid a bench fee for the guy to do nothing and tell me "nothings wrong". The amp blew it's power tubes the next day. 99% of these guys are complete hacks and I'm smarter than them so I'm thinking if they can "get by" then I can actually learn it. So I did. Little by little I studied and learned and tinkered and here we are. I'm far from being an electrical engineer, but I can find my way around tube audio gear.

I'm also fearless and naturally very mechanically minded. I was fixing cars...other people's and my own...in high school. I still have my GTO that I'd race all night, break something, and have to fix before I left for school or work the next morning. I remember one time spending about 4 hours combing through grass on the side of a road with a zippo for light because I dropped a tiny piece of carburetor linkage. Shit like that builds.....something. Character? Stamina? Will power? Mental fortitude? I don't know. But I found it and drove home undefeated.

So anyway yeah I'm a bit of a bad ass. I will excel at anything I actually put my mind to. Including computers if I ever decided to give a shit about them.

[Greg_L]

Ok some more parts showed up today so it's time to figure things out and cut some holes.

Deciding on a layout.


Something like this.


Holes cut and drilled and painted with primer.


Next up, actual paint....I've got some gold, green, black, and purple. I think I'll do the face gold like a Marshall....Maybe purple for the rest

[WhiskeyJack]

Ok @Greg_L ,

Here's a copy and paste from what I just emailed you....


Ok since you know nothing....and I mean that with all due respect....stick closely to the list.
Mainly...
Hammond 290AX power transformer
Hammond 125B output transformer
Hammond 5H 50ma choke

Those three are musts. If you know of a reputable Canadian replacement that meets the specs of those three Hammond units, then go for it. I'm pretty sure Hammonds are made in Canada though!

As for caps and resistors...you can go by budget for those. You don't need the most cork-sniffy Sozo or Jupiter caps that exist. Good ol Mallory 150s are great and inexpensive.
The big filter can cap can be a CE, JJ, F&T, whatever you want. It just has to have the right values.
The resistors...I'd stick with 1/2 or 1 watt carbon film for most of it. The power supply resistors will need to be 2 or 3 watt metal oxide though.
As for hardware like tube sockets and switches and stuff....whatever you can find that will work is just fine. Again you don't need boutique stuff here.

But as you get closer send me your list and we'll go over it.

Gotcha. I will just stick to the script. My concern i suppose was if something was corksniffy i wouldn't know why it was so why bother? For a first attempt though i will just do the thing and see what comes of it. Like you said i know nothing. won't even try and pretend otherwise. All i do know is that when it's done i will (should) have something kick ass to plug into.

[WhiskeyJack]

wtf does the choke do? Obviously not like a choke on my weed whacker right ?

[Greg_L]

wtf does the choke do? Obviously not like a choke on my weed whacker right ?

Lol not quite. An electrical choke is an inductor that passes DC but resists AC ripples. They basically do what filter caps do but chokes tend to react more to high frequency ripples which in a guitar amp helps keep the low end tight.

[Greg_L]

Gotcha. I will just stick to the script. My concern i suppose was if something was corksniffy i wouldn't know why it was so why bother? For a first attempt though i will just do the thing and see what comes of it. Like you said i know nothing. won't even try and pretend otherwise. All i do know is that when it's done i will (should) have something kick ass to plug into.

None of this stuff is cork-sniffy at all. When it comes time to order capacitors and tubes you can get cork sniffy but it's not necessary. Let's just get it to work first.

[WhiskeyJack]

wtf does the choke do? Obviously not like a choke on my weed whacker right ?

Lol not quite. An electrical choke is an inductor that passes DC but resists AC ripples. They basically do what filter caps do but chokes tend to react more to high frequency ripples which in a guitar amp helps keep the low end tight.

Cool. Thank you. I saw you and ray talking about it eons back in the earlier days of the forums and i was too afraid to ask then. I guess it matters now.

[Lt. Bob]

I find it interesting how people’s minds just click on certain things.

I can build a computer. Greg, I think I recall you saying it’s like Chinese to you.

Meanwhile, everything you wrote is gibberish to me. I can try to take the time to learn, but my mind is not clicking with this as fast as the computer stuff did. I got that stuff instantly. I don’t really get this, and the time to learn turns me off from continuing to try.

Might be an age thing... even though I'm never going to build my own amp, I do understand basic electronic componentry and what does what and how, and have since my teens, because back then there were no computers and people who built stuff built stuff with these components. I dabbled, but not much. By the time you've come along, high tech has moved to computers and the like, and so that's what people may gravitate to first. You just haven't had the exposure, I expect.

Pretty sure I could build a computer too, they make stuff so it plugs together pretty simply - I just don't want to. Happy to outsource that task. And amp building. But I like reading what Greg's up to with these things and I like reading what Tad and others do with PCs as well.

I think age is a big reason>
When I was a kid we built ham radios ...... that and music were basically the only things to do unless you were into sports.

[rayc]

Yeah age. I can rebuild a PC easily enough. I did all that as part of my unpaid work as tech manager/repair/gopher etc at the last school I worked at. From pulling/replacing cards, CPUs and fans to whole site networked software roll outs. Only because it had to be done & I was the only one foolhardy enough to give it a go. Mind you a PC box is a decent sized thing to screw around in & be able to see stuff.
I think "Meccano" sets were a better mechanical prep toy than Lego - I'm too old to have had Lego bricks as a toy. Mechanically I can do simple stuff like replace a head gasket on a 2stroke bike & then re-torque the head etc. but nothing modern.

[WhiskeyJack]

I'm too old to have had Lego bricks as a toy.

Ever seen the price of the stuff now? You might also be too poor to take it on now. My wife and i wanted to have a little winter something to do together last winter and we were in the west edmonton mall while we were talking about it so we said let's go to the lego store. She wanted ot get the Home Alone diarama kinda kit. It was almost 400 dollars !!!!!!

And the star wars stuff was out of this world priced. They have a bunch of star wars helmets you could put together and display and those were pretty cool but also pretty big price tags.

We got two jigsaw puzzles from walmart for under 30 bucks.

[Greg_L]

I never played with legos. I liked going outside and building actual things like bike ramps and tree houses and stuff.

I did like Erector Sets though.