Used a dimmer instead of a variack. (Had a dimmer, didn't have variack.
Just curious, what are the differences between the the 71 and the 76, and how would they affect the sound? Obviously the speaker sizes and cabinets are different
We are doing our best to figure that out. Seems trem is different. Construction/design was for a lot of clean sound. Barely gets dirty at the hugest volume. Has microphonic chassis. The main speaker is mounted on heavy wood, the rest is 3/8 ply. Trem goes through three preamp tubes before last stage of preamp. Without the trem, it's a nice clean PA system. Three instruments and one voice channel. Trem option for instrument channel. ( if I can get trem to work, I will see if trem affects the mic input. ). The trem cap is up by the controls and looks like it's been very hot. We agree that caps should be replaced and all resistors tested. I've got a buddy who is a hi if tube expert reviewing the circuits. He offered to upgrade all the parts for me after powdog gets all the info he wants. We have been emailing and on the phone daily. I'm very happy to be helping the amp guys to discover what's in this amp.
Wow! 3/8th of an inch is slim for a cabinet, I guess that's all part of the mojo. For me, it's great to know that there's a lot of headroom. If they dirty up quick I always feel there's no place left to go and that's tricky in small bar rooms. Plus the mic inputs will yield different voices of course, some more gnarly than others.
I'm pretty slim on knowledge of how amps work so I LOVE hearing about this stuff and learn a little all the time. Many thanks for this, it's going to be a unique piece of research
Plus Premier amps are famous for their trem of course so it will be great to hear that throb into life.
Had a bad tube. Replaced it. Trem curcuit isnt working, will fix that next. All caps should be replaced. Tubes too. As soon as everything works, im gonna ship it to powdog so he can replicate amp.
Jupiter makes some really nice red astron style capacitors that replicate the old wax caps like the ones in your Model 71. I think a filter cap job is wise. They’re 60 years old, and that 120 cycle hum is pretty annoying.
I'm not gonna do anything major until after your satisfied about the drawings and photos. After I'm positive I've got it correct, then I'll put together a parts list and do it.
First run 3D printed Premier knob.
Well ain’t that something! Absolutely amazing to them recreated
I guess they can be sprayed? The red and yellow was a bit kooky on the original but it’s funny how we end up accepting things and perceive them to be cool. Apart from Pink Floyd (just joking)
Wow, that 3D printed knob is really smooth - usually the layers are visible. Was it put through an acetone bath?
No. This 3D printer uses a liquid resin. Really quite amazing.
They have colored resin, but til then I’ll try spraying them first.
Wow, that's impressive. What's the make/model of the printer?
“Printer is the Wanhao Duplicator 7. Each knob uses 7mL of resin, so probably about 50¢ not accounting for the waste. Takes two and a half hours or so, but you could probably print 8 at a time which doesn't increase the printing time.”
From my son Seth, the Chem E. I have no idea how they work.
The whole 3D resin printing is fascinating. The print quality looks a lot better than the FDM types, but it looks like there are more limited colors to print. From what I've read it appears there's a high temperature resin to use to make molds for standard ABS injection molding. That would be pretty cool.
They can print food now too..so star trek!
Can they print a 3D printer? Then we can all have one. It’s The future!
Update. New tubes. Trem still not oscillating. Gonna replace caps. I don't wanna give up.
Tremolo Dilemmo! Could be a good title for an instrumental. How’s everything else shaping up?
I've got all the paper work done. Amp works, gotta fiddle with trem. Still on my table in the test jig. Ethan and I have been taking on the phone. Caps are old so I suspect them. So far every resistor I've tested has been close enough. It does look like beer made it's way into amp. (Probable the reason for new tubes in 1992). We never used tremelo circuit. Three tubes in preamp stage oscillate at low freq (audio) and vary the input to the finals. Think feedback loop. Ethan found the main D.C. Cap is still made! And paper caps are still being made for the boutique market. The cap up at the trem control looks like it's been hot. At one of my outdoor jams, it was running full throttle all day in the hot sun. It felt and smelt hot! She's been used. I'm gonna pack it up soon and ship to powdog.
Got a bit sad, noticed my dad put scotch tape over the tremelo jack at one point. Has his thumb print on the tape.
That’s quite something Mun. Quite a moment, bless ya.
Hey Mun, what did he have tape over it? Do you still have the footswitch?
I'm happy your documenting his amp Here for us and everybody!
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