SuperReverb Head

[jimsz]

Hi folks, I'm not really an amp builder, however I have built my first amp from a Weber kit just so that I can have some understanding of the guts of an amp and how things work. The kit was a 40 watt SuperReverb head which I had installed in a double-aged Tweed cabinet. I just finished it a few weeks ago and will be using for gigging. The amp delivers a tremendous amount of wonderful sounding clean tones from both my Strat and Goldtop. No distortion, so I'm looking to purchase a Holy Fire pedal soon. Currently, I have a FET Dream but will probably use it for more of clean boost once I get the Holy Fire.

The reverb is a bit over the top so I'll probably swap out the 820K resistor for a bigger value and may also change V3 to a tube with a lot less gain. Hopefully that should tame it down a bit. I wired it up so that both channels can take advantage of the Tremelo and Reverb.

The 2x12 open back cabinet I have is done in lacquered Tweed and matches the head fairly well. It sports a couple of Jensen Alinco 5's which sound pretty good. Again, I look forward to hearing the Holy Fire through this rig.

I can see a lot of you folks really know what you're doing and I hope to read and learn a lot of stuff here. I'm up in the Vancouver BC area, hope to hear from other local folks as well. Cheers.

Jim

[IMG:799:769]http://img.photobucket.com/albums/v330/ ... uitar1.jpg[/img][/img]

[jimsz]

A few gut pics. It started out neater but after some troubleshooting of few issues, it got a little messier.

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[jimsz]

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[jimsz]

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[Alexo]

Congrats! There's something really cool about blackface amps dressed up in tweed. I just finished a Weber 6A14HP kit for one of my co-workers in tweed/oxblood (the amp, not the coworker) and while, like a lot of Weber kits, it took its share of "massaging" to come together as it should, I have to admit that I'm jealous that she got to take it home.

...if your kit has the anachronistic "ground" switch hole, you could drop in a dwell control for the reverb to tone it down as needed, just replace the 1M R after the 500P cap with a 1M pot, wiper to grid of the 12AT7.

[JammyDodger]

Hey,

Try a 12AT7 in the V3 spot if there is a 12AX7 there now.

Cheers, Mike

[jimsz]

Congrats! There's something really cool about blackface amps dressed up in tweed. I just finished a Weber 6A14HP kit for one of my co-workers in tweed/oxblood (the amp, not the coworker) and while, like a lot of Weber kits, it took its share of "massaging" to come together as it should, I have to admit that I'm jealous that she got to take it home.

...if your kit has the anachronistic "ground" switch hole, you could drop in a dwell control for the reverb to tone it down as needed, just replace the 1M R after the 500P cap with a 1M pot, wiper to grid of the 12AT7.

Thanks Alexo, when I figure out what you just said, I'll see if it can work. Sorry, I'm kind of new to this game and haven't yet picked up a lot of the lingo.

[jimsz]

Hey,

Try a 12AT7 in the V3 spot if there is a 12AX7 there now.

Cheers, Mike

Hi Mike, the amp actually calls for a 12AT7 in V3. The Chinese tubes they sent along aren't that good, two have already failed and a third is on it's way out. I just replaced everything, including the 6L6GC' with JJ's and a couple of Ruby's I had.

In the V3 spot now is a JJ EEC81 which I think is the equivalent to a 12AT7. I can't recall which tube it is, but there is another one that has less gain factor than the 12AT7. Maybe it's a 12AY7 or 12AU7??? I wish I could remember.

[Structo]

That's quite the amp for a first timer.

Those old combo chassis with the tubes down are pretty cramped for the wiring.

As long as it sounds good that is the main thing.

Just be careful around the power supply and make sure nothing can short out or become a shock hazard to the chassis.
Never depend on a fuse to protect you or from burning the house down....

I never understood why Weber put that cap board in vertical rather than using a dog house or some other way of mounting.

For the tip of the day, you can take alcohol and a small brush and Q tips to the flux around the solder joints to clean that stuff off the board.
Makes it look neater.

How did you like working with the cloth wire?

There was a guy here a while back from Germany that used that stuff in a Dumble and every wire was perfect, no unraveled ends, I don't know how he did it.
Maybe super glue on the braid, not sure.

[Bob-I]

I built one of those kits years ago, but in a standard Super Reverb 4x10 cabinet. I replaced just about everything in it except the xformers tube sockets and chassis. The resistors are pretty good but I had trouble with several caps getting leaky and pots simply falling apart.

I actually swapped out the output xformer once with a MM Super Reverb replacement from another project as a test, but I put the Weber back in, sounds better than the MM, big surprise.

I tried several mods to reduce the reverb intensity, but everything I did hurt the overall tone of the amp so I put it back to stock and just leave the knob down around #2.

Today it's one of my "go-to" amps.

Congrats on the build, that's no small project.

[jimsz]

How did you like working with the cloth wire?

There was a guy here a while back from Germany that used that stuff in a Dumble and every wire was perfect, no unraveled ends, I don't know how he did it.
Maybe super glue on the braid, not sure.

Didn't like working with the cloth wire too much and the gauge was too thick to work with, especially the green filament wire. After finishing it and while troubleshooting a few issues, someone told me I could have used a drop of Cyanoacrylate glue for the cloth once cut and trimmed to length.

I originally had the filaments all wired but the ends were all frayed, looked bad. I took it all out and used some old 20 gauge Central Office jumper wire. This stuff was almost pure copper, can handle 300V with a heat protective coating, really nice stuff, way easier to work with. Still though, you can see in the pics the frayed ends of the red and yellow wires.

Thanks for the comments.

[jimsz]

I tried several mods to reduce the reverb intensity, but everything I did hurt the overall tone of the amp so I put it back to stock and just leave the knob down around #2.

Today it's one of my "go-to" amps.

Congrats on the build, that's no small project.

Thanks, I might go for something a little less complicated next time and definitely something in a bigger chassis.

They called this one, the "Ship in a Bottle" - and now I know why.

That's pretty much where the reverb setting is now, around #2, can't turn it up any higher. Maybe I should just leave it alone if you're saying you didn't have any success. I too am a little worried about hurting the tone if I start modding it. The tone is fabulous right now and I'm really quite satisfied with it.

[jimsz]

For the tip of the day, you can take alcohol and a small brush and Q tips to the flux around the solder joints to clean that stuff off the board.
Makes it look neater.

I gave that a try but it didn't really clean up very much. The flux around the solder joints didn't seem to clear up. I used the same 99.9% alcohol I use to clean my primary mirror.

[jimsz]

...if your kit has the anachronistic "ground" switch hole, you could drop in a dwell control for the reverb to tone it down as needed, just replace the 1M R after the 500P cap with a 1M pot, wiper to grid of the 12AT7.

Hi Alexo, I get what you mean now. I can see on the schematic and the layout where that 1M R is. Wiper to grid would be the connection going to pin 7 of that 12AT7? Ground switch hole is the ground point connected on the other side of the 1M R?

[Alexo]

Not quite sure what you're asking...

The 6A14's I've built ahd a hole in the chassis for a ground switch, just to keep up the vintage appearance, I guess. Nobody uses ground switches anymore now that we have 3-prong power plugs, so the 6A14 winds up with an extra hole in the chassis where you can mount a pot or a switch.

So I was saying: remove the 1M resistor, tie the "top" lug of a 1M pot to the 500pf cap where it used to hit the 1MR, tie the bottom lug of the pot to where that 1M used to connect to ground, and connect the wiper of the pot to pins 7&2 of the 12AT7 (the grid, aka the input of the tube). Now you have a volume control for the signal going into the reverb tank, this is what they called a "dwell" control on the standalone Fender Reverb boxes.

The dwell does a couple of things - it llets you tone down the verb to a much more usable range, and I find that the reverb has a less boingy, more ambient sound when the dwell is turned down and you're not hitting the reverb tank so hard.

If you turn the dwell all the way up, you're back to the stock circuit.

You may or may not have a convenient spot to mount the pot, and it may or may not be worth the effort. You could alternatively just hardwire a voltage divider - replace the 1MR with say... an 820K in series with a 150K r and feed the pins 7&2 from the junction of the two resistors, simulating a rolled down dwell control.

..or you could just leave 'er as is.