Amps Sonzera 50

CapnDenny1

CapnDenny1

Student Of The Blues
i just bought a 50w PRS Sonzera combo. It has a busted cabinet, but I can glue it back together, or build a custom cab.

I was just playing the 20w Sonzera I have. It just sounds so good!

I wonder if the 50w has the same hiss issue. But it’s not that bad.
 
PapaBear

PapaBear

Guit Fiddlier
I'm sure you'll have it right as rain in no time, I'm guessing it's probably got some things shorting from the crush, walnut would be awesome!
 
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CapnDenny1

CapnDenny1

Student Of The Blues
Arrived yesterday. The top is only held on by the tolex on the left side.

It looks pretty nice though?

https://www.dropbox.com/s/bpn3wor8cq6ln03/image1.jpeg?dl=0



p.jpeg
 
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CapnDenny1

CapnDenny1

Student Of The Blues
Flickr is back, phew! I have been making some repairs to the cab. Just about every glue joint is either broken or at least loose. Some of the braces I went ahead and removed and re-glued. Some have Tolex so I just pried them up a bit and put glue in the gap and clamped it back down. The final one is the corner which is completely busted open. I stabilized it with tape so I could fix the other joints. The other corner on top is also loose, but the Tolex is still intact, so I will open it a bit and put some glue in there. I will probably add a couple nails to help stabilize it. I would use a glue block in the corner inside the cab, but that is where the amp chassis has to fit, so I can't? Actually I can. The chassis is open at the ends, so I can add a wooden brace inside. It will just go in the open area. That's important to make the top secure, since the amp weighs 60 lbs and the handle is on top!

Most of the amp chassis looks OK. The power transformer is loose, and the small transformer on top I think for the reverb is a little bent out of shape. But no wires are broken that I can see.

Amps by Dennis Kelley, on Flickr

The white areas are where the joint is busted.

Amps by Dennis Kelley, on Flickr

The worst seam.

Amps by Dennis Kelley, on Flickr

Circuit board is almost the same as the 20 watt Sonzera I have also.

Amps by Dennis Kelley, on Flickr
 
CapnDenny1

CapnDenny1

Student Of The Blues
Actually I can't put a wood block inside. It would prevent the amp chassis from sliding in or out of the cab? Maybe 3 or 4 finish nails from the side panel into the top panel from the outside?
 
zwantedone

zwantedone

Blues Newbie
Splitless finish screws and glue would probably do the trick, Cap't. Clamp the top down to the side panel, and predrill small holes for the screws. Finish screws are a narrow gauge and would work nice in that application...
 
CapnDenny1

CapnDenny1

Student Of The Blues
I don't want the screw heads showing. I will try to patch the torn Tolex, a little sharpie marker maybe? Screw heads, even small would be harder to do. You're right though, that would be better than finish nails. thanks for the suggestion.

I am thinking of using a thin piece of angled steel. And use epoxy on the inside. between the front and back edge of the chassis. If there is enough clearance to slide the amp chassis in past it, then it won't interfere with pulling the chassis up to the top with it's mounting screws. maybe some fiberglass cloth soaked in epoxy? But I think a thin piece of steel is about as strong as it gets. I will use wood glue on the wood first, and just use the metal to reinforce the joint, since that top has to support the full weight.
 
zwantedone

zwantedone

Blues Newbie
Screw heads are small. Pull the tolex back a bit and screw them in. A little wood putty to fill the holes, and glue the tolex back on. Works a treat.
 
CapnDenny1

CapnDenny1

Student Of The Blues
No seam on one end. The ripped one would work, but the other end is ok, so I’d like to leave it.

I put the chassis in, and there plenty of clearance, so the angle pieces should be ok.
 
CapnDenny1

CapnDenny1

Student Of The Blues
My knee has finally gotten better to the point I can get back down the stairs to my workbench! Man, I missed it.

The Sonzera 50 was my first target. I have some customer amps too, but I wanted to do something for me.

The amp had some real issues with the sound. The clean was really quiet and thin sounding. I tired turning it all the way up at after about 90% it dropped out and came back a little. So bad pot.

When I played it today when I played bass notes the speaker was breaking up. I was amazed that the amp could be demolished, but the speaker was OK? Well it wasn't. I verified using another speaker. No sweat I have other speakers.

Even with a good speaker it sounded bad. The gain channel was louder, but the master did absolutely nothing. It was really brittle and no bass.

I took the pcb out of the chassis, and I found the problem with the gain channel pot. The pot was completely broken loose of the pcb. The terminal were soldered in the board, but the rest of the pot was just broken off. The shaft was so bent I had a hard time getting the knob and mounting nut off. I tested all the pots and the VOLUME for the clean channel that showed issues, one of the legs was open circuited. So I think the sound was only coming into the circuit through the treble cap.

So I didn't have an exact replacement, since it was solid shafts, but I had a couple Fender pots that were also Audio ! Meg pots. They had a metal mounting frame I had to cut off, and the mounting threads are bigger so I had to drill the chassis mounting holes a bit.

But the good news is the amp seems to work really well now. It is loud as heck now. The Bright/Normal switch on the clean channel is kind of hinky, so i will have to address that and put a different speaker in it.

I also need to replace the rounded top screws I used on those braces inside, because they are hitting the chassis. It makes it a real pain to install or remove the chassis. I may go with counter sunk screws or go back to the epoxy idea?
 
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