looks great! what is the extra switch for?
Nobelium - tube bass preamp project
- Thread starter vigilante398
- Start date
Tassieviking
Member
He installed a Mute switch in his build, (Which I am going to copy )
He placed it on the wire between the In jack and In on the PCB.
Post 292 on the Talkbass forum
He placed it on the wire between the In jack and In on the PCB.
Post 292 on the Talkbass forum
Any idea on when this will be available again? It's always out of stock
vigilante398
Authorized Vendor
I'm on a break right now while I get things organized, I expect to have opening reopened next week.
irvmuller
Active member
Hi there! I’m sure you’re super busy but when might these be back in stock? I’m really looking forward to building one. Thanks!
vigilante398
Authorized Vendor
Back in stock right now. Sorry it took me forever to get them in, but I finally have them now.
irvmuller
Active member
Ordered! So looking forward to this build.
vigilante398
Authorized Vendor
In order to update the build documentation with detailed instructions like the other C2C projects have I had to build another Nobelium tonight, so just for kicks I decided to film it so I can turn it into a timelapse with narration and post it as a real "how-to" video for the project. I had all the parts pulled and organized as a "kit" so things would go as smoothly as possible, and the entire build process from start to finish was a little under 45 minutes.
I'll try to get an actual build doc together in the next day or two, the video editing will take a bit longer as it's harder to motivate myself to do video stuff.
I'll try to get an actual build doc together in the next day or two, the video editing will take a bit longer as it's harder to motivate myself to do video stuff.
vigilante398
Authorized Vendor
It's been a long time coming and I've been promising it forever, but I finally got around to putting together a Nobelium build doc!
Nobelium Preamp
Nobelium Preamp
Best I can determine looking at the gut shots of the Nobel is there are 3 voltages. The power transformer doesn't appear to be center tapped and with two secondary windings. One is HV for the plate, and the other is likely around 12VAC or a bit higher for the 9V PSU, and the 12.6VDC for the heaters.
I doubt he would use 9VDC for the heaters as this would shorten the life the tube. The designer is not interested in keeping the price down.
You can see two TO220 ICs which are probably the voltage regulators for the 9VDC and the heater DC. I doubt the designer would use 6.3VDC for heaters in this case. That would produce more heat in this case due to the need for 9VDC for the PSU.
It looks like one of the voltage output of the transformer is using half-wave rectifying while the other is using full-wave. Hard to tell, but I think there is 6 diodes tuck in there.
Tassieviking
Member
The Noble comes with cable ties holding the heatsinks to the voltage regulators, at least in all the photos I have seen, that is a really bad idea since cable ties will degrade with time and especially when they get hot.
Heatsinks should be mounted properly with screws or the correct clips made for the job, cable ties is a sure mark of a dodgy job by someone who does not know how to do the job properly.
The guy has more degrees than I have. Plus he designs power systems in real life. Nylon is going to work in that application. Melting point of nylon is 268.8C. There is going to be far bigger issues if it gets to that.
But it does look like an unexpected shortcut for that price point.
But it does look like an unexpected shortcut for that price point.
Tassieviking
Member
My main problem with mounting a heatsink with a cable tie is that you can not get a good thermal connection between the component and the heatsink, in fact, I doubt that even 50% of the heat would make it across.
You need to clamp the heatsink to the object giving off heat, and they have to fit hard up against each other so the extremely thin layer of heatsink compound can level out between the 2 surfaces for a good thermal connection.
Cable ties can only lock in on the pre-set steps in the ties ratchet surface so it would be nearly impossible to make a firm connection between 2 hard surfaces. (but a great hold on softer stuff like cables)
You can use a normal screw and nut to fix them together, even nylon screws and nuts are good for this.
There are lots of clips made for mounting heatsinks to components like a TO220 case, and they can be mounted in seconds so they would be quicker then a cable tie.
I do like cable ties, I have used thousands of them tying cables onto cable trays or cable ladders over the years so I have some experience with them.
Some people have absolutely no practical experience to go with their degrees and that is why they sometimes make silly mistakes.
Practical experience can be more valuable then any degree you get from any learning facility you attend.
I did my electrical apprenticeship for 4 years, then I went to uni for 4 hours a night 4 days a week after working all day for many many years, and I ended up working as an electrician most of my life because the engineers never could make what I got paid for being on the tools as an electrician.
I think the main reason was because I liked working with the variety of jobs I got fixing broken machinery and tracing faults on machines that might have a dozen PLC's and were up to 250 meters long.
Cheers
Mick
You need to clamp the heatsink to the object giving off heat, and they have to fit hard up against each other so the extremely thin layer of heatsink compound can level out between the 2 surfaces for a good thermal connection.
Cable ties can only lock in on the pre-set steps in the ties ratchet surface so it would be nearly impossible to make a firm connection between 2 hard surfaces. (but a great hold on softer stuff like cables)
You can use a normal screw and nut to fix them together, even nylon screws and nuts are good for this.
There are lots of clips made for mounting heatsinks to components like a TO220 case, and they can be mounted in seconds so they would be quicker then a cable tie.
I do like cable ties, I have used thousands of them tying cables onto cable trays or cable ladders over the years so I have some experience with them.
Some people have absolutely no practical experience to go with their degrees and that is why they sometimes make silly mistakes.
Practical experience can be more valuable then any degree you get from any learning facility you attend.
I did my electrical apprenticeship for 4 years, then I went to uni for 4 hours a night 4 days a week after working all day for many many years, and I ended up working as an electrician most of my life because the engineers never could make what I got paid for being on the tools as an electrician.
I think the main reason was because I liked working with the variety of jobs I got fixing broken machinery and tracing faults on machines that might have a dozen PLC's and were up to 250 meters long.
Cheers
Mick
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