New amp build (a cautionary tale for new builders)

[Kap'n]

What Marshall circuit gives you the faceplate/chassis with the right control layout?

None of them. I'm guessing it's based on Weber's 5A40. Which is essentially a Super Reverb circuit crammed into a tweed Bassman-style cabinet. AFAIK, the only difference, circuit-wise is the 6M40 comes with EL34 tubes, which I just swapped back to small bottle Phillips.

The gold chassis looks really groovy on this thing.

Oh, and I figured out, replacing filter caps isn't going to be as bad as it looks. If you dis-assemble it one cap at a time, and then rebuild, you won't need to pull the board.

[NTBluesGuitar]

Okay, it's the chassis that threw me.

Did you have it made? I've never seen one like that before.

[Kap'n]

No, it's the straight Weber 6M40 kit.

Ordered it right off the page, gold/black chassis, green tolex, salt/pepper and white piping.

Only change I specified was 10A125 speakers, and I used the Phillips outputs I had lying around.

[ziess]

Q. How do you know you've gotten deep into the amp building game?

A. You've got spare tubes lying around and you actually start thinking up amps to build to use them in!

My impending Tremolux is based on a $14 5E7 chassis and a box full of 6L6GCs that weren't seeing any use since I started using Tung Sold 5881s in my 5F6-A. Well, you wouldn't want them to go to waste would you?!

Tommy.

[NTBluesGuitar]

I thought Weber was just selling the plastic gold faceplates on those.

Still...it looks good.

Tommy, wait until I start talking about why I'm planning to stuff a 5E3 into a 5F2A cab.

[pc]

Awesome, A. Just awesome.

[Kap'n]

Thanks all.

Why am I already thinking about what I'm going to build next?

[fenderdog]

im speechless..thank you so much for this thread, i couldn't wait to get up this morning and see the conclusion. it reads like a best seller on troubleshooting..wow...

[Kap'n]

Nobody said you had to open the thread.

[ziess]

Kap'n, how does the damn thing sound?

Tommy.

[Kap'n]

how does the damn thing sound?

Like a nice blackface amp. This thing loves everything I've plugged into it - Strat, Tele, LP, Gretsch, Ricky. Haven't plugged the Kitty into it yet.

It also likes both the OCD and and Mule dirtboxes. I was afraid that the Mule would sound kind of spiky, but it actually sounds more natural. The OCD sounds more 'steroid-y.' Good and bad, I guess. I suppose I should dust off that Bad Monkey, too.

I haven't done any preamp tube swapping yet, but the Shuguangs that came with the kit seem decent enough. Once I get a handle on the sound I'll be swapping, I'm sure.

[pc]

im speechless..thank you so much for this thread, i couldn't wait to get up this morning and see the conclusion. it reads like a best seller on troubleshooting..wow...

Y'know, I'm gonna give you the benefit of the doubt on this one. There are two eyerolling smilies, and the one you used is called (in a very misleading way, I think) "speechles."

So, I'm going to go ahead and assume that you really weren't being facetious and that you really appreciated this thread as much as the rest of us. Thus the "eyerolling" smilie was meant to convey how speechless you were (as you even wrote).

Because if it's anything else... well... we'll cross that bridge when we burn it.

[fenderdog]

Y'know, I'm gonna give you the benefit of the doubt on this one. There are two eyerolling smilies, and the one you used is called (in a very misleading way, I think) "speechles."

So, I'm going to go ahead and assume that you really weren't being facetious and that you really appreciated this thread as much as the rest of us. Thus the "eyerolling" smilie was meant to convey how speechless you were (as you even wrote).

Because if it's anything else... well... we'll cross that bridge when we burn it.

yes, i definitely meant speechless, i'm in no position to be rolling my eyes at anyone on this forum. i'm just starting to open up amplifiers..didn't see the eyes, sorry,all the best to everyone

[pc]

Cool. That's what I figured. That one smilie is poorly named I think.

Thanks for responding though!

[cdw2000]

Kap'n, congrats.

Judging from the photos, that was some undertaking. You need some nimble fingers to get into some of those nooks.

Looks like a keeper. Hows the response from the tone controls? My homemade design seems to be a little heavy on the bass and I'm wondering if I should change the tone caps.

[Kap'n]

Tone controls are smooth and responsive. I haven't had a real chance to open it up, so I've been running the bass higher than I would at gig volumes.

I'm especially liking the taper of the pots. Most of my 'faced' Fender experience has been with the SF amps with crappy taper pots. You know that massive jump in volume from whisper quiet to stupid loud? None of that here. You can really dial it in.

Just ordered an amp cover. Apparently the name of the official Marshall cover for the 1974x is COV56. It took a lot of digging to find it. Only $25, though. This thing looks so sharp, I don't want to ding it up.

[cdw2000]

Cool. I think I will be opening up Duncan Amps' Tone Stack Calculator and playing with those cap values. I'm already using the 250KA pots for the bass and treble.

Edit: Looks like this amp has a Fender style tone stack with the 0.047uF cap replaced with the 0.022uF, not the usual Marshall style tone stack. After running TSC, it looks like the 0.022uF cap actually increases the bass, but if I make both the mid and bass caps 0.047uF, I can drop the bass a bit (so caps are from top of stack down: 250pF, .047uF, 0.047uF). Time to get out the soldering iron...