[csroc]

For the most part I saw a lot of those power supplies with the different outputs all selling for roughly the same price.

 

[kuroguy]

The bigger power supply would allow you to modify the amp to use 6j6 tubes. you would need to rewire the filaments with a voltage regulator and install resistors where the filaments currently act as resistors for the MOSFET. No where near as elegant as the Millett design, but it would be much easier to source 6j6 in lieu of 19j6 tubes. Of course, the trade off is increased power consumption.

 

[Sancho86]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Agreed. However, an oversized power supply may actually have trouble producing enough voltage under a very light load. I think this was more of a problem on older switching supplies, but still - there is a greater chance of poor regulation under a very light load than not. That could mean worse sound with a bigger power supply, not better.

How about an undersized one? I found a 48v .25a supply too small?

 

[zkool448]

Quote:

Originally Posted by Sancho86 /img/forum/go_quote.gif How about an undersized one? I found a 48v .25a supply too small?

Quote:

Originally Posted by Sancho86 /img/forum/go_quote.gif How about an undersized one? I found a 48v .25a supply too small?

I'm thinking you should stick with the .38A or higher current ps. If you get a higher one just load your mssh up with a pair of super bright, hi mcd tube LEDs, pwr indicator, enclosure etc. sounds like a good way to spare those extra amps

By the way, can anyone recommend super bright red LEDs rated at 600-800mcd range? and what resistor value would you recommend to use if I tap to the stock 48v/.38A ps?

 

[sachu]

well,

I scored 2 more 19J6 tubes.. I will try to mount the heatsinks inside the case and if it gets too warm I will punch some vents on the bottom of the case..

Now to place that mouser order I have een putting off for so long

 

[nightanole]

Quote:

Originally Posted by zkool448 /img/forum/go_quote.gif I'm thinking you should stick with the .38A or higher current ps. If you get a higher one just load your mssh up with a pair of super bright, hi mcd tube LEDs, pwr indicator, enclosure etc. sounds like a good way to spare those extra amps By the way, can anyone recommend super bright red LEDs rated at 600-800mcd range? and what resistor value would you recommend to use if I tap to the stock 48v/.38A ps?

The diode is almost impossible. It would have to be anywhere from 10 watts to 40 watts depending on the led. Think about it, a led is basically a short (dropping only 1-3.6v) and the resistor drops the rest, So your just putting a resistor across your powersuppy that has to suck 20-150ma or higher. the 1000mcd ones are 3v 20ma, so thats a 1k 2.5watt resistor.

LED calculator for single LEDs

 

[rds]

Quote:

Originally Posted by zkool448 /img/forum/go_quote.gif By the way, can anyone recommend super bright red LEDs rated at 600-800mcd range? and what resistor value would you recommend to use if I tap to the stock 48v/.38A ps?

I have no idea what the previous poster is talking about, but if you want the LED to be bright you should give it close to its maximum current rating - which is generally 20mA.
From a 48V supply 2.3K will give you approximately 20mA. That resistor will be burning up 0.92W of power so you're best to use a 2W resistor for safey (ie it is specified to handle 2x the expected power).
Mouser has very bright red LEDs. They are called "hyper orange" but they're really just red.
Here's a suitable LED resistor for your application.

EDIT Here are those LEDs lighting up the tubes on a Starving Student:

 

[DopeNessMonster]

Quote:

Originally Posted by rds /img/forum/go_quote.gif EDIT Here are those LEDs lighting up the tubes on a Starving Student:

Very sharp. I prefer the soft orange glow of the tubes themselves, but it's a nice looking amp. What 1/4" jack is that? I was looking for a black one, but could only find the locking Neutrik which wouldn't fit.

 

[zkool448]

rds, that's one sweet compact ss unit you have there!

Thanks for the LED and R source info, I like your tubes look a lot and I will go ahead and grab a couple. As good as they look with a black case I'm however unsure how it'll match with my light maple enclosure though... perhaps blue's?

 

[tomb]

Some of you may not realize (lots of new people), but rds's rendition of the Starving Student is also sold at Whiplash Audio (a Head-Fi sponsor) as the "Mini-Millett":
Mini Millet DIY Tube Amplifier

They're out of stock right now - maybe they're waiting on the new PCB's.

 

[Coreyk78]

I like the case RDS used, I used the same one for my second SS build in my avatar

 

[Vaughn]

I have ordered all of my parts for a SS and I am starting on the chassis...

I have a couple of heatsinks which are sufficiently large and I am wondering if
it is ok to mount them to the chassis so there is no stress on the mosfet legs?
I don't know if this will create a grounding problem, I ordered the mounting kit which includes an insulator but I wanted to make sure before I start building.

 

[csroc]

Quote:

Originally Posted by Vaughn /img/forum/go_quote.gif I have ordered all of my parts for a SS and I am starting on the chassis... I have a couple of heatsinks which are sufficiently large and I am wondering if it is ok to mount them to the chassis so there is no stress on the mosfet legs? I don't know if this will create a grounding problem, I ordered the mounting kit which includes an insulator but I wanted to make sure before I start building.

It's fine, I think that's what basically everyone has been doing if you look at the builds so far. I soldered mine to the enclosure because I couldn't get the damn pins out.

 

[zkool448]

Yes I soldered the pins to the copper clad board also.

Regarding the pins, I wonder if it is forged steel (or whichever material they use) that can be filed down with a bench grinder flushed to the heatsink, then tap the other end and use screws for mounting it to the case.

 

[DopeNessMonster]

I pulled the pins out of mine with some vice grips. You just need a really good bite on the pin then twist it out. Then you can either tap it, or use self-tapping #4 size (~3mm) screws. If you're careful, you can use 4-40 machine screws without tapping it first, but I broke a couple screw head off doing that.