Finally starting my Rocket Combo build!

[Tone_Chaser]

Thanks OT - I was going to unsolder them tonight and check for an open but I didn't think about checking for voltage with them out of the circuit.

I didn't have a screw small enough to mount the heat sink on the IC so I hadn't bolted down the VVR when I took the picture but it's good to go now (or to not go anywhere in this case).

Thanks for your thought, I really apprecitate it.

[Tone_Chaser]

I took the heater secondaries off tonight and they weren't open so I checked the voltage again. I had been checking the voltage on the DC setting which is where I got 0V but across both leads I got 6.4VAC and each lead to ground I got 3.2 to 3.3VAC.

This has me really confused. Everything seems to be working except there is no audio.

At least I think I've eliminated the PT but I'm not sure where to go now. I'll just keep plugging away though and I'm sure I'll figure it out (of course I'll take any suggestions you guys have).

[overtone]

it is a little difficult to help diagnose from here without standing over the amp.
It will probably be something very simple which you cannot see. You need to hunt it down. Basically you need to divide and conquer - like you did with the heater circuit, isolate sections and test them.
Handy is a signal generator to put in a low voltage. But you can get by with an old wall-wart that puts out AC (most put out DC) or some kind of ghetto trick like that.
Keep us posted,
tony

[Tone_Chaser]

Tony, you were so right it is stupid and a little embarrasing!

I was in the car today thinking about my problem that everything checked out but I just had no sound. Then it hit me, what if the speaker is bad? I was using an old speaker that hasn't been used in a really long time.

So I get home and put my meter on it, OL!!!!!

I have a couple of old Pyle speakers from 100 years ago so I checked one of them and got a reading. I soldered my cable on to it and I have now got sound coming out of my amp!!!

Thank you so much for your help with this.

Now I just need to figure out why my VVR makes no difference in the volume when I go from 1 -10. But that's a minor issue compared to no sound!

Thanks again to you and Mark!

[Tone_Chaser]

I've been playing though my amp when I've had time (spring/summer is always crazy) and it sounds great with single coils and humbuckers. I ended up with a Weber Blue Dog Alnico speaker and it really sounds great in this amp.

I hadn't put the chassis in the cabinet because I still have a couple of issues to work on. The VVR didn't work at all and there is almost no reverb. Neither of these issues are make or break for playing through the amp and we had a job on the 7th so I stuck it in the cabinet and took it to practice and had almost no volume at any level and a very distorted signal.

Took it out of the cabinet and bypassed the VVR just to be sure it wasn't causing a problem (besides not working) and everything seemed fine, even in the cabinet. When we got to the job I fired it up and there was no sound coming from the amp and something smelled hot. I didn't get to use it for that job!

I took it back out of the cabinet and everything is good again. Left it on for about 3 hours with no hot smell and it sounded normal. Took it to practice last week and played it sitting on top of the cabinet. It went great!

I've got to have one of two possible issues causing something to ground out. Either the aluminum flashing I'm using for shielding is touching something or the screws on the handle are touching something they shouldn't. I'm going to cut the screws down tonight but my big question is, how important is the shielding? I could cover the flashing with cork, felt or vinyl but it would eventually wear through if something is touching the top. Can I get by without any shielding on top of the chassis?

Thanks!

[Gibsonman63]

Check the lugs on the pots. Sometimes they get so close to the fold-over of the chassis that the torque of screwing the chassis down to the cabinet is enough to ground them out. My Liverpool was that way and I had to bend the lugs slightly for clearance.

On my first build, I drilled the chassis cover holes in the wrong spot, so I have one screw that grounds out the signal if I put it in because it makes contact with one of the pot lugs. Now I center them between the pots instead of equally spacing them.

[Tone_Chaser]

That's a great observation. i hadn't even thought of the pots. I will check that tonight. I want to be able to use it at practice tomorrow night inside the cabinet like it's supposed to be! That way I can give it a good test before our next job.

Thanks again!

[M Fowler]

Barry,

Use either a lighted magnifying glass or hand held regular unit and look everything over carefully. You would be surprised what you find.

Mark

[Tone_Chaser]

That's a great idea too. I'm amazed at how much worse my eyesight has become over the last couple of years. I always had 20/20 vision but too many years in front of a monitor (and getting closer to 50 years old) has really taken the edge off.

I'm also going to mount it with as much of a gap as possible and draw it up slowly from the front and then the rear to see if I can see anything. Will really need some good light and my cheaters for that!

[Gibsonman63]

Barry,

Use either a lighted magnifying glass or hand held regular unit and look everything over carefully. You would be surprised what you find.

Mark

For me, it's the optovisor and lots of light... the entire time I am soldering!

[Tone_Chaser]

I did finally figure out what was causing the issue. The cap stack was taller than the chassis but I couldn't find anything else that was touchig between the amp and cabinet. I routed out a small pocket in the cabinet where the caps would have made contact and that seems to have fixed the issue.

We have one last Eagles tribute job next week and then I should have some time to get back into the chassis and see why the reverb is not working. I've looked it over numerous times and can't see any wiring/soldering error. I'm going to build an audio probe and check it out that way (I did already hook the tank up to another amp to make sure it's good) and if I still can't find it that way I'll post pics and see if you guys can see something I'm missing.

Thanks again for all of your help.

[Tone_Chaser]

Before I take this apart to start working on the reverb, I thought I'd take a couple of shots and show what the finished project looks like. I ended up ordering the faceplate before I came up with a logo so there is a nice open space waiting for it. I guess I'll either have to make a sticker or screen print one later. Other than that I'm pretty happy with how it looks.

[M Fowler]

Nice look all dressed up

Where did you get the cab?

Mark

[Tone_Chaser]

Thanks Mark. I built the cabinet and covered it. You can see on the back side that the corners are a little sloppy. I had planned on using corners on the back but I haven't found any to fit the 90 degree edges.

It looks pretty good if you don't look too close! I also made the head cab for my 100W Plexi build and the 4X12 cabinet for it. I'm getting better with covering the cabinets and I think you probably really have to do a lot of them to get reall good.

[M Fowler]

Well that cab looks good to me and like you say the more you wrap the better you will get. Give Taylor (amplifiednation) as shout about where to get the correct corners.

Mark