6G15 Reverb Build

[hackworth1]

Originally Posted by jchabalk

I think i'm ready to build. I enlarged the holes on my filter cap board a little which should make things a little more manageable.

I've got potentially 2 outstanding items and 1 question:
- Going to drill a hole for chassis ground. Following the layout I should have the mains ground, the filter cap ground and the ground from the rectifier all at the same point, is that correct?

You can use an existing PT Bolt with a star washer and its nut with a two or three lug terminal strip.

Expand the mounting hole in the terminal strip. Solder your grounds across the strip so the whole thing goes to ground.

Yes, all the things you mention go to ground at that point near the PT.

- I think i'm going to follow your example (JBennett) and just make my own filter cap cover. Yours came out nice. Any advice other than measure-twice/cut-once?

I also fit the chassis to the cabinet now that choke and OT are mounted. I was concerned that due to the size of the choke i'd have a problem with the reverb tank. Fortunately i don't as it site up higher than the reverb tank. If the tank was higher there wouldn't only be about 1/4" of clearance.

Here are a couple of pics of the rectifier and filter cap boards. I'll see about populating some more later tonight although it may have to wait until later in the week.

Looking very good. Its good to take your time and do it right.

Looking well-thought-out and carefully assembled.

[JBennett]

The Choke wires you asked about don't go back out of the chassis once they come in the grommet hole. They just get soldered to the circuit board. THEN those leads from the doghouse attach to them on the board at nearby eyelets.

For the doghouse grounds, you can see I just ran the grounds following the original fender layout, each ground come down through the grommet holes back into the chassis and grounds to the chassis on the inside. I tried to make mine as close to the originals as possible, figuring that they engineers at fender already worked out a quiet grounding scheme. My unit makes no unwanted noise (well, my neighbors might not agree) and therefor I didn't need to try any modern "star" ground schemes out.

Here was the doghouse drawing I came up with and followed. (ignore the incorrect resister in there, I fixed that later. It should be a 10K 2W)



I think those connections tying the grounds together are redundant, but they probably won't do any harm.

Do you have a drawing you're following for the grounding scheme? Are you sticking to the original 60's layout?

[JBennett]

If you are looking at this Photo... and now, you ARE:


Just above the tank damping bar you will see one grommet hole. That hole has four wires the pass through it. The two black wires come from the choke. The Red and Blue wires come from the output transformer.

The two Black wires and the Red wire all attach to points on the far left of the main circuit board. The choke wires are interchangeable and you don't have to worry about which wire is which. The Red wire goes to the left side of the circuit board too and the Blue goes to the Octal socket.


Then, just above the large tube socket (6k6) there is another grommet hole with a Green and Black wire. Those both come from the output transformer. They both go to the first RCA jack (reading left to right). Green to the tip, black to the ground on the outer tab.

you can see those two holes better here:


THEN, there are two more grommeted holes at the TOP of my chassis, near the control pots. Harder to see. Those are the two holes that lead to the doghouse. You can see wires passing through in this side shot.



Here is a better shot of those two doghouse holes.

[jchabalk]

I need to get a better handle on how the choke ties into the filter caps in the layout you're using. I've been looking at the weber layout and in it the choke attaches directly to the filter caps. I think the layout you're using does the same thing but with an easier layout.

On my filtering board i tied the grounds together so i only have to run a single wire from the doghouse to chassis ground (instead of 3). That's something i picked up from the weber layout.

It probably doesn't play as big a part when it's filter grounds but i've been trying to follow to a less-is-more approach to the amount of wire i use in my builds.

One of the reasons - and we'll see if i finally fix it with this build - is that my current reverb unit acts as a radio and there hasn't been really anything i can do to fix it. (i happen to live on a hill covered with antennas and am in direct line of site with another hill full of antennas, but it's only when i use the reverb that i have a problem).

[jchabalk]

So i've kind of halted on progress until i get the filter cap cover sorted out. Since it requires drilling a few more hole in the chassis i really want to do that before i get anything mounted. I spent some time on it this morning with the $.97 piece of metal i bought at Home Depot yesterday.

I made a paper template, cut and folded it to make sure it fit, transferred it to the metal and cut the metal out.

Unfortunately I really don't have a good way of bending the metal with good corners. In the end it looks like an amateur POS. I'm thinking of eating crow on this one and ordering the $15 cover.

Here are my pics from this morning's work. I don't have one of the "completed" cover but rest assured it's an uneven 3 dimensional razor blade with mounting holes drilled in it

I think i'm going to place an order tonight and hopefully be able to have a go at it again next weekend.

[printer2]

When I do some bending at home I clamp the metal in the vice between two pieces of bar stock and if I need a sharp corner I will finish the bend off with another piece of bar stock and a hammer. I am sure you could do the same with a few pieces of hardwood.

[jchabalk]

this is the problem with city living. i've got some hand-tools, a power-drill, a rubber mallet and some short scraps of 2x4, that's about it.

today the rubber-mallet and 2x4 was trying to do what you're vice, hammer and square-rod stock was doing. maybe i'll get a piece of square stock tomorrow, or a brick. i might be able to make that work.

[printer2]

Originally Posted by jchabalk

this is the problem with city living. i've got some hand-tools, a power-drill, a rubber mallet and some short scraps of 2x4, that's about it.

today the rubber-mallet and 2x4 was trying to do what you're vice, hammer and square-rod stock was doing. maybe i'll get a piece of square stock tomorrow, or a brick. i might be able to make that work.

There is only so much you can do with what you got. Sometimes you can't do it all yourself.

[tubeswell]

http://www.tubesandmore.com/scripts/...XP?item=P-H712

Either that, or buy yourself a decent box and pan brake

[JBennett]

Yeah... I made mine the same way and kind of regret it... a little, not really. It's imperfect but I just couldn't bring myself to spend 25 bucks (after shipping) for the cover. And it has its charms. (and you'll never see it) I wish I'd taken a bit more time since even my mounting holes were off, but in the end, it serves the purpose and I own a cool pair of snips.

[jchabalk]

i've got one of these en route:

Fender Deluxe Reverb Capacitor Cover

I got a few other things i'll need for future (mostly to try and justify the shipping to myself)

I hope it comes this week so i can build this weekend. I'll be out of town the week after.

i'll keep you posted.

[jchabalk]

The part arrived last night and i did a test fit this morning. It looks like it's going to fit perfectly - which is a big relief. It's larger than it needs to be but will work great.

That should be the last piece, i've got to drill the mounting holes for the cap cover but otherwise i should be able to start with my build this weekend.

[jchabalk]

I had a little time this afternoon and got the chassis drilled for the capacitor cover and then went ahead with the A/C mains power and getting the heaters run (my least favorite part of building )

Here are some pics. I'm going to try to work on the circuit board tonight and hopefully have some time to put in tomorrow.

[Jcn3]

good start! it's always interesting to see how different folks do things. I like stranded wire that's not cloth coated. I do the circuit board first, pots second, filaments third, sockets fourth, and transformers last. the order doesn't matter as long as it works for you!

I'll keep watching!

[birddog01]

Nice work, I've been watching this one and good to see you getting some progress done.
Getting close now.

[jchabalk]

Can you guys help me with capacitor codes? I think at this point i'm confusing myself but everything i'm finding is telling me i don't have the right caps.

I need a couple @ .1uF and .047uF. I ordered them as part of my build. The caps that I have have the following codes:

103k on one and 472k on the other. Not being familiar with capacitor codes i looked them up to double-check before building.

103k = .01uF (I need .1uF)
472k = .0047uF (I need .047uF)

I think i've got the wrong caps. if that's right it'll be another bummer and more delay.

[birddog01]

AES has .047uf in orange drop 715 series
http://www.tubesandmore.com/
and in 716 series
http://www.tubesandmore.com/
use the drop down box for size

.1uf is listed there too

[Jcn3]

Originally Posted by jchabalk

Can you guys help me with capacitor codes? I think at this point i'm confusing myself but everything i'm finding is telling me i don't have the right caps.

I need a couple @ .1uF and .047uF. I ordered them as part of my build. The caps that I have have the following codes:

103k on one and 472k on the other. Not being familiar with capacitor codes i looked them up to double-check before building.

103k = .01uF (I need .1uF)
472k = .0047uF (I need .047uF)

I think i've got the wrong caps. if that's right it'll be another bummer and more delay.

I'm not an expert on this, but I've gotten a lot of caps that seem to be measure in pf so have seen numbers like yours. I would think the 103k is .1 uf and the 472k is .47 uf. can you,just call the vendor and ask them?

[hackworth1]

http://www.turretboards.com/capacito...sion_chart.htm

472K = 47+00's =4700pF = 4.7nF = 0.0047uF
473K = 47+000's =47000pF = 47nF = 0.047uF

[tubeswell]

1F = 1,000mF = 1,000,000uF = 1,000,000,000nF = 1,000,000,000,000pF
(farads, millifarads, microfarads, nanofarads, picofarads)

See notes about markings for E series