Love what you are doing here. On my 70's Twin Reverb which was stored in my loft for many years I noticed that the mains transformer brackets were also showing signs of weakness. I used a couple of steel strips that I found along the longest width of the transformer which made it completly rigid. That was about 10 yrs ago and it is as solid and firm as when I first did it. As you say it's your amp so you can do whatever you want.
I moved all of the power resistors on my Twin Reverb onto the top of the chassis using overrated aluminium resistors then covered them with a dog house type cap due to the high voltages. This removed all of the high temperature resistors from within the chassis itself improving the robustness of the amp. It doesn't cost that much to do and I like to spend a bit more money than Fender invest in their amplifiers as I am not under commercial pressure as they are for their production units. I'm planning on doing the same on my Fender Blues Deluxe for the 2 infamous dropper resistors on the circuit board.
@31:44 If you have any transformer mounting brackets (similar to the ones on the output transformer) that will fit the power transformer, you could use those instead of washers. Two sets with ears removed could sandwich the chassis top and bottom
@ 28:00 if I had been building that tag strip, I would have left the leads on the 17 watt resistor longer and sleeved them with some Teflon tubing, a length of wire insulation, or heat shrink the lead. I might have considered putting the balance resistors on a shorter tag strip and used a chassis mount Dale or similar for the high power resistor.
The 'Bracket' for the Super-Hefty Transformer is a good idea, you won't worry so much about moving or in which position the amp may be sitting when used or stored( you will probably let it sit flat on its feet) . Ratus ex machina . It's like a beat-up Ferrari , the owners don't care about it looking "As new" and they have a story for every bump and scratch. Character by the boot-load.Stick a lump of wood to hold the Mains T in place once in the housing.
Where you put Heat-Shrink on those two tabs, I would have used Nail Varnish. My WAD K5881 Valve Amp has RED nail varnish on all solder joints which carry High Voltage, so I don't get fried if I accidently touch one of them. It's a very effective Insulator. Just don't use a Metallic nail varnish! As for the Mains Transformer... use a couple of strips of 12-15mm Flat Brass, longways on each side of the Underside of the Transformer and a couple of strips of the same Crossways on the Topside, to strengthen the chassis. I had a laugh at your use of a De-soldering gun. I still use one of the old 'Plunger' types, with Teflon Tip. Mine is now 35 years old and still very effective. Cost me Two Quid from Maplins. (Damn! I Miss that company.) As the saying goes, '"If it ain't broke; don't fix it". Happy New year. Russ. Havant, Hants.
This would be dependant on clearances and length of screws/bolts etc. Could you get a flat plate that fits the whole surface and cut/drill holes to match? As the entire chassis is bowing in the middle, I'd also want do do the same on the inside of the control plate and back panel to add vertical rigidity to the structure. The knobs look like they have enough length on the shafts. No idea how feasible this would be in any aspect from obtaining the plates in the first place to doing the work to fit them.
Probably more feasible than building a time machine to go back to November. I knew you'd got the amp in November but missed that you'd started on it then.
I know hindsight is 20-20. You could have cut the new tag strip as long as that long wire wound resistor for a proper support with no leads trailing awkwardly back behind its body. I was shouting at the screen. :) Great watching you sort out this Bassman.
What about using two strips of flat bar stock, cut and drilled as parallel spacers, instead of using washers to support the chassis. Might disperse the weight better.
I was just about to say exactly that, although I have the tooling to produce a rectangular reinforcing plate that would support it all the way around, a couple of strips of 1/8" mild steel would probably add enough support.
I was thinking along similar lines but with just a reinforcement rib running across the chassis on the inboard side of the transformer. It would have to clear the other holes and components though and be installed up front.
Have you detailed your desoldering tool in a video? Perhaps a short review would be in order as it looks like a slick tool that i will be ordering. The latest i purchased has only temporary vacuum and sometimes spits moten solder back on work surface.😡
I prefer to use solder wick rather than sucking devices because you don't need to get the components quite so hot. Downside it is probably more expensive if you do a lot of solder removal.
@RiftAmps there's a guy in Arkansas that sells chassis on ebay that I've used for a few builds called zh music parts, and he has a blank twin reverb chassis listed. Though not sure if he ships to the uk. The one con to them though, is they are just bent, not welded or riveted.
At the risk of being blunt, the metal in this chassis doesn’t have a memory, you didn’t bash it enough the first time. It will probably still deflect a bit over time, but you can get it a lot closer to straight.
Love what you are doing here. On my 70's Twin Reverb which was stored in my loft for many years I noticed that the mains transformer brackets were also showing signs of weakness. I used a couple of steel strips that I found along the longest width of the transformer which made it completly rigid. That was about 10 yrs ago and it is as solid and firm as when I first did it. As you say it's your amp so you can do whatever you want.
I moved all of the power resistors on my Twin Reverb onto the top of the chassis using overrated aluminium resistors then covered them with a dog house type cap due to the high voltages. This removed all of the high temperature resistors from within the chassis itself improving the robustness of the amp. It doesn't cost that much to do and I like to spend a bit more money than Fender invest in their amplifiers as I am not under commercial pressure as they are for their production units. I'm planning on doing the same on my Fender Blues Deluxe for the 2 infamous dropper resistors on the circuit board.
I love the whole "this is my amp, I can do what I want". That is such a fun place to be! Thanks again for sharing.
@31:44 If you have any transformer mounting brackets (similar to the ones on the output transformer) that will fit the power transformer, you could use those instead of washers. Two sets with ears removed could sandwich the chassis top and bottom
@ 28:00 if I had been building that tag strip, I would have left the leads on the 17 watt resistor longer and sleeved them with some Teflon tubing, a length of wire insulation, or heat shrink the lead. I might have considered putting the balance resistors on a shorter tag strip and used a chassis mount Dale or similar for the high power resistor.
Loving this series. You are a lucky man to enjoy your work so much ❤
The 'Bracket' for the Super-Hefty Transformer is a good idea, you won't worry so much about moving or in which position the amp may be sitting when used or stored( you will probably let it sit flat on its feet) . Ratus ex machina . It's like a beat-up Ferrari , the owners don't care about it looking "As new" and they have a story for every bump and scratch. Character by the boot-load.Stick a lump of wood to hold the Mains T in place once in the housing.
Loving this series! It's been brilliant to see you go through the whole rebuild process.
Where you put Heat-Shrink on those two tabs, I would have used Nail Varnish. My WAD K5881 Valve Amp has RED nail varnish on all solder joints which carry High Voltage, so I don't get fried if I accidently touch one of them. It's a very effective Insulator. Just don't use a Metallic nail varnish! As for the Mains Transformer... use a couple of strips of 12-15mm Flat Brass, longways on each side of the Underside of the Transformer and a couple of strips of the same Crossways on the Topside, to strengthen the chassis. I had a laugh at your use of a De-soldering gun. I still use one of the old 'Plunger' types, with Teflon Tip. Mine is now 35 years old and still very effective. Cost me Two Quid from Maplins. (Damn! I Miss that company.) As the saying goes, '"If it ain't broke; don't fix it". Happy New year. Russ. Havant, Hants.
This would be dependant on clearances and length of screws/bolts etc. Could you get a flat plate that fits the whole surface and cut/drill holes to match? As the entire chassis is bowing in the middle, I'd also want do do the same on the inside of the control plate and back panel to add vertical rigidity to the structure. The knobs look like they have enough length on the shafts. No idea how feasible this would be in any aspect from obtaining the plates in the first place to doing the work to fit them.
Probably more feasible than building a time machine to go back to November. I knew you'd got the amp in November but missed that you'd started on it then.
I know hindsight is 20-20. You could have cut the new tag strip as long as that long wire wound resistor for a proper support with no leads trailing awkwardly back behind its body. I was shouting at the screen. :) Great watching you sort out this Bassman.
What about using two strips of flat bar stock, cut and drilled as parallel spacers, instead of using washers to support the chassis. Might disperse the weight better.
I was just about to say exactly that, although I have the tooling to produce a rectangular reinforcing plate that would support it all the way around, a couple of strips of 1/8" mild steel would probably add enough support.
I was thinking along similar lines but with just a reinforcement rib running across the chassis on the inboard side of the transformer. It would have to clear the other holes and components though and be installed up front.
Still really enjoying this rebuild. Can't wait to hear it!
Have you detailed your desoldering tool in a video? Perhaps a short review would be in order as it looks like a slick tool that i will be ordering. The latest i purchased has only temporary vacuum and sometimes spits moten solder back on work surface.😡
I prefer to use solder wick rather than sucking devices because you don't need to get the components quite so hot. Downside it is probably more expensive if you do a lot of solder removal.
Now i can't wait for the next episode. Darn they finish fast.
Honestly, I would get a new chassis .... but then it slowly becomes a new Amp 😉
Got a link to one? I’d love to build another from scratch 👍
@RiftAmps there's a guy in Arkansas that sells chassis on ebay that I've used for a few builds called zh music parts, and he has a blank twin reverb chassis listed. Though not sure if he ships to the uk.
The one con to them though, is they are just bent, not welded or riveted.
Yeah I’ve seen those but they’re only 18gauge steel which is thinner than the original (16g). Ideally needs to be 14g for this transformer weight.
At the risk of being blunt, the metal in this chassis doesn’t have a memory, you didn’t bash it enough the first time. It will probably still deflect a bit over time, but you can get it a lot closer to straight.