I was a machinist for 10 years or so, a good rule of thumb about mild steel to aluminum is aluminum is 1/3 the weight and 1/3 the strength. That would tell me that a 2 mil steel for the same strength would be a 6 mil aluminum. No matter what it will be better than it was but I would go with steel
This rebuild reminds me of the Napier "Sampson" :record car. The motor was taken out, used in a speed boat, sunk, recovered, left in a shed for years. Then they decided to rebuild the car, about the only usable original part, that found its way back into the car, was the crankshaft. The rest was recreated from the original drawerings. A similar heroic effort.
I think the Super Twin Reverb transformer is larger than the one you have. I can't weigh mine, but the chassis alone could be used as a boat anchor for a super tanker ship. I was about to suggest on your previous video that 2 strips of horizontal reinforcement steel plate would have been sufficient to secure the power transformer, to avoid the cost of a custom cutout.
The Super Twin/Studio bass I think had a slightly bigger transformer, running an extra pair of 6L6 and ECC83’s. The difference being that for that they used large nuts, bolts and heavy gauge L brackets to spread the weight. The PS 300/400 also had bigger transformers but they didn’t hang down
That is one heavy transformer! The local reinforcement you plan will help but nothing will stop that chassis bending in the event of a drop when made with 16g material. So don't drop it :-) Can't believe the designer looked at it and decided yeah, that'll be fine.. The amp is taking shape and can't wait for the sound test.
They look like Panasonic...they don't look very elegant but they are very "Reliable" and robust.If you look up "Matsushita" you will find the entire range.
Very nice series, and big project. Very nice, thoughtful work, too. However, I'm a bit confused why you didn't use the old blue astrons, besides them being gross. But then you use a part of old cable from the amp, which is arguably more dispensable.
7 kilos! Bloody hell 😂 I wonder if a strip of steel screwed on the inside of the chassis behind the knobs would be a good idea too? To stop the face plate bending again. That’s a hell of a lot of weight!
I've seen other techs (e.g. Lyle at Psionic Audio) go to great lengths to clean up old wire before reusing it, yet here, despite the incredibly filthy state of the old amp, you seem to be just giving it a quick wipe before soldering it in. What's different here that makes that an OK approach? (Or maybe you're just doing more rigorous cleaning off-camera?)
Great solution , a transformer that heavy needs a strong foundation. I would'nt be surprised if it has it's own gravitational field( nuts and bolts and washers orbiting the amp). Happy New year.
Hi Chris, I wish you a very Good New Year. I've watched your Bassman 135 project. If I understood you're fixing this Bassman for your own use.Does it still have to have IEC socket for mains when the amp is not for commercial use. In my honest opinion it's like butchering a piece of history with a big hole for the IEC. However, you're also searching an original vintage Fender knob from 70's.Something doesn't add up ? If the originality is already gone, why.... Best Regards, Mr JT
Everyone would likely do things differently. He certainly knows what he's doing, even if you or I would have done things differently. We're getting these videos weeks after the fact so there's really no point in second-guessing things as we're so far behind the actual progress. Just enjoy the ride.
I'm with Chris on this one. Sometimes, modifying something to modern Electrical Standards is for Safety Reasons... or Convenience. An IEC socket makes more sense than a Fixed cable. Firstly, you don't have to mess around coiling the cable when you are packing up your kit. It also makes it less likely to damage the fixed cable, by getting it caught under the Speaker cabinet. Secondly, in the event that someone Trips over the mains lead, the IEC plug will pull out of the socket, instead of pulling the speaker over on top of someone. Been There; Done That; Got the Scars. In the circumstances, Chris is being 'Mr Practical' and going with the Safety and Convenience of an IEC socket. Finally, by using an IEC socket, you can erect your system where you need it and then choose the appropriate length of cable to suit your needs. It also makes packing up easier, by bunging all your leads into one box, ready for loading/unloading your transport. Russ. Hampshire. UK.
I, wouldn't butcher a piece of history with a hole for IEC socket especially if the amp is for your own use only. Why search for original knobs then...originality is long gone
Have you seen what the amp looked like originally?? With that said, installing an IEC socket is far from “butchering?” lol! It’s for functionality and safety while original knobs are an aesthetic choice. It’s not that hard to understand.
I was a machinist for 10 years or so, a good rule of thumb about mild steel to aluminum is aluminum is 1/3 the weight and 1/3 the strength. That would tell me that a 2 mil steel for the same strength would be a 6 mil aluminum. No matter what it will be better than it was but I would go with steel
I agree. Steel is best. Although aluminium conducts as well as steel, it doesn't have the same magnetic properties. This may or may not be relevant.
I would go for steel as well. Using unlike materials like aluminum and steel can lead to corrosion over time.
Slaps forehead. That’s metallurgy 101!
Out of curiosity, have you seen Brad's examples of 70s era Fender wiring with the green slime corrosion? No sign of that in your wires?
This rebuild reminds me of the Napier "Sampson" :record car.
The motor was taken out, used in a speed boat, sunk, recovered, left in a shed for years. Then they decided to rebuild the car, about the only usable original part, that found its way back into the car, was the crankshaft.
The rest was recreated from the original drawerings.
A similar heroic effort.
I think the Super Twin Reverb transformer is larger than the one you have. I can't weigh mine, but the chassis alone could be used as a boat anchor for a super tanker ship. I was about to suggest on your previous video that 2 strips of horizontal reinforcement steel plate would have been sufficient to secure the power transformer, to avoid the cost of a custom cutout.
The Super Twin/Studio bass I think had a slightly bigger transformer, running an extra pair of 6L6 and ECC83’s. The difference being that for that they used large nuts, bolts and heavy gauge L brackets to spread the weight.
The PS 300/400 also had bigger transformers but they didn’t hang down
Ah yes, I forgot about the Super Twin. The OPTX was also at the opposite end of the chassis to help balance it all out.
That is one heavy transformer! The local reinforcement you plan will help but nothing will stop that chassis bending in the event of a drop when made with 16g material. So don't drop it :-) Can't believe the designer looked at it and decided yeah, that'll be fine.. The amp is taking shape and can't wait for the sound test.
You also need to consider that when aluminum and steel contact they resct and corrode, weakening borh.
In the aircraft world, that's referred to as a "doubler"
Cool, in the catering world it's called a Sliced steel sandwich with only crust.
Wouldn't a couple of pieces of right angle steel be just as strong & a lot less hassle?
Probably, but where's the fun in that?!
Hi Chris HNY & Love the rebuild series,,,,just saying!! Keep up the good work.
Hey Chris, what brand of film caps are you using? Are they Panasonic? They make those wide Fender jumps rather well.
They look like Panasonic...they don't look very elegant but they are very "Reliable" and robust.If you look up "Matsushita" you will find the entire range.
Panasonic ECQE(F), my absolute favourite
Very nice series, and big project. Very nice, thoughtful work, too. However, I'm a bit confused why you didn't use the old blue astrons, besides them being gross. But then you use a part of old cable from the amp, which is arguably more dispensable.
These are blue blobs, not blue astrons, and really are nothing special 👍
@@RiftAmps You're right of course. I noticed my mistake shortly after.
7 kilos! Bloody hell 😂 I wonder if a strip of steel screwed on the inside of the chassis behind the knobs would be a good idea too? To stop the face plate bending again. That’s a hell of a lot of weight!
I've seen other techs (e.g. Lyle at Psionic Audio) go to great lengths to clean up old wire before reusing it, yet here, despite the incredibly filthy state of the old amp, you seem to be just giving it a quick wipe before soldering it in. What's different here that makes that an OK approach? (Or maybe you're just doing more rigorous cleaning off-camera?)
Correct...all done off camera, I don't think anyone wants to watch hours of footage of me cleaning up wire insulation ;)
Great solution , a transformer that heavy needs a strong foundation. I would'nt be surprised if it has it's own gravitational field( nuts and bolts and washers orbiting the amp). Happy New year.
Hi Chris, I wish you a very Good New Year. I've watched your Bassman 135 project. If I understood you're fixing this Bassman for your own use.Does it still have to have IEC socket for mains when the amp is not for commercial use. In my honest opinion it's like butchering a piece of history with a big hole for the IEC. However, you're also searching an original vintage Fender knob from 70's.Something doesn't add up ? If the originality is already gone, why.... Best Regards, Mr JT
Everyone would likely do things differently. He certainly knows what he's doing, even if you or I would have done things differently. We're getting these videos weeks after the fact so there's really no point in second-guessing things as we're so far behind the actual progress. Just enjoy the ride.
Get hip, watch and learn.
I'm with Chris on this one. Sometimes, modifying something to modern Electrical Standards is for Safety Reasons... or Convenience. An IEC socket makes more sense than a Fixed cable. Firstly, you don't have to mess around coiling the cable when you are packing up your kit. It also makes it less likely to damage the fixed cable, by getting it caught under the Speaker cabinet. Secondly, in the event that someone Trips over the mains lead, the IEC plug will pull out of the socket, instead of pulling the speaker over on top of someone. Been There; Done That; Got the Scars. In the circumstances, Chris is being 'Mr Practical' and going with the Safety and Convenience of an IEC socket. Finally, by using an IEC socket, you can erect your system where you need it and then choose the appropriate length of cable to suit your needs. It also makes packing up easier, by bunging all your leads into one box, ready for loading/unloading your transport. Russ. Hampshire. UK.
@@russbetts1467 Dang sight easier to replace a damaged power cable, too.
I, wouldn't butcher a piece of history with a hole for IEC socket especially if the amp is for your own use only. Why search for original knobs then...originality is long gone
He won't butcher it. It will be a neat tidy and useful.
Have you seen what the amp looked like originally?? With that said, installing an IEC socket is far from “butchering?” lol!
It’s for functionality and safety while original knobs are an aesthetic choice. It’s not that hard to understand.
It’s a standard safety mod for all amps… far from butchering it’s a desirable, usable upgrade.