Millett "Starving Student" hybrid amp
May 14, 2008 at 5:36 PM Post #181 of 7,277
Quote:

Originally Posted by HypnoLobster /img/forum/go_quote.gif
This will be my first real project, all this talk of LM317's and such just zooms straight over my head.

Let me rephrase that; anyone have a suggestion for a nicely predetermined power supply project
biggrin.gif



No? Not sure that was re-phrased, but I gave a link just a few posts back that had a number of the recommended power supplies on e-bay. Pukka also gave several references and ideas, stating that this type of POI power supply is cheaply available at a number of places.

If for some reason you don't want one of the ones on ebay, then reference Pete's specs - 48VDC switcher supply at ~0.38A, if memory serves. Pick one out and then come back and ask in this thread. I'm sure Nate or Pete can confirm it as suitable or not.

Note that even the original $6.99 versions didn't count shipping ($7?) and a power cord, so $20 total from a current ebay seller listing is not that far off.
 
May 15, 2008 at 12:33 AM Post #183 of 7,277
Can someone help me out with parts list? Some of them are backordered and I wanted to make sure my alternatives are acceptable

Thanks, please shoot me a PM if you are willing to help
 
May 15, 2008 at 1:09 AM Post #184 of 7,277
Quote:

Originally Posted by Snicewicz /img/forum/go_quote.gif
Can someone help me out with parts list? Some of them are backordered and I wanted to make sure my alternatives are acceptable

Thanks, please shoot me a PM if you are willing to help



Why don't you just post your parts list.
 
May 15, 2008 at 2:38 AM Post #185 of 7,277
Because its long. Im tired I should have just posted what was out of stock and what I replaced it with:

Anyways I replaced the following: (mouser part #s)

replaced 539-150104K100AA with 539-168104K100H-F

and replaced 647-UHE1J221MPD with 647-UPW1J221MPD6

Also I cant find the tubes anywhere.

Sorry this is what happens to me when I have little sleep
 
May 15, 2008 at 4:15 AM Post #186 of 7,277
Quote:

Originally Posted by Snicewicz /img/forum/go_quote.gif
Because its long. Im tired I should have just posted what was out of stock and what I replaced it with:

Anyways I replaced the following: (mouser part #s)

replaced 539-150104K100AA with 539-168104K100H-F

and replaced 647-UHE1J221MPD with 647-UPW1J221MPD6

Also I cant find the tubes anywhere.

Sorry this is what happens to me when I have little sleep



Just MHO, but you can probably do better with the 0.1uf film cap. Polypropylene is better than polyester. A Wima MKP10 might be better if you are going with a box cap. However, there are many to choose from. Perhaps the one you've picked out may still be appropriate for the Starving Student, though. We'll see what Nate says.
wink.gif


The UPW electrolytic should be fine.

The 19J6 is available in quantity at vacuumtubes.net the last time I checked - very cheap, too.
 
May 15, 2008 at 7:58 AM Post #189 of 7,277
Hello Headfiers!

This is my first post, I was just lurking here before.
Starting with a question:
in my country, it is difficult to get 19j6 tubes. (Don't ask me why, because I've seen Tungsram ones also on the internet.)
So, I was thinking, would it hurt to divide that 19V down to 6V using a 38K resistor. Would this enable the usage of 6j6 tubes?
They are dirt cheap, and easy to get.

Regards
Peter
 
May 15, 2008 at 10:30 AM Post #191 of 7,277
Quote:

Originally Posted by -=Germania=- /img/forum/go_quote.gif
TEHE - just picked up the PS on ebay for.........$8.99 SWEET!


Plus 9 dollars shipping? That was the one I was going to buy =[ haha

And thank you tomb for the information on the tubes
 
May 15, 2008 at 10:55 AM Post #192 of 7,277
Quote:

Originally Posted by peter.star /img/forum/go_quote.gif
Hello Headfiers!

This is my first post, I was just lurking here before.
Starting with a question:
in my country, it is difficult to get 19j6 tubes. (Don't ask me why, because I've seen Tungsram ones also on the internet.)
So, I was thinking, would it hurt to divide that 19V down to 6V using a 38K resistor. Would this enable the usage of 6j6 tubes?
They are dirt cheap, and easy to get.

Regards
Peter



This wouldn't be a good idea, IMHO. The 6J6 has a heater current of 450ma. In the Starving Student, the MOSFETs and their bias are tied into the heaters. That would mean - even if you knocked down the voltage - the MOSFETs would be running at 450ma bias (not to mention the resistor would have to dissipate 13V * 0.45A = ~6 Watts).
 
May 15, 2008 at 11:09 PM Post #193 of 7,277
Very interesting design !

Just one thing, I reed all treed and no one ask this - 150 mf otput cap, are this enough for 32 ohm? Maybe something like 470 mf, usually used in OTLs, is better.
Maybe this is reason why Gross reported about not enough bass ?

Anyway, I want to try it one day!
Zigis.
 
May 15, 2008 at 11:11 PM Post #194 of 7,277
Quote:

Originally Posted by tomb /img/forum/go_quote.gif
No? Not sure that was re-phrased, but I gave a link just a few posts back that had a number of the recommended power supplies on e-bay. Pukka also gave several references and ideas, stating that this type of POI power supply is cheaply available at a number of places.

If for some reason you don't want one of the ones on ebay, then reference Pete's specs - 48VDC switcher supply at ~0.38A, if memory serves. Pick one out and then come back and ask in this thread. I'm sure Nate or Pete can confirm it as suitable or not.

Note that even the original $6.99 versions didn't count shipping ($7?) and a power cord, so $20 total from a current ebay seller listing is not that far off.



I think I'm just generally bad at making any sort of point on the internet.
What I meant was I was looking for a project power supply to build that would work with the Starving Student amp. That way I could keep everything inside the case, just something to help the learning process (and how much wall-power hurts!).
I see people talking about the TREAD, but it seems it can't supply the required voltage.
 
May 15, 2008 at 11:12 PM Post #195 of 7,277
THe only thing I am having trouble with now is obtaining a PSU. I need to have this build by next thursday for a school project .

Does anyone know where i can buy one and get 2nd or 3rd day shipping?

Also does anyone have any extra 7-pin miniature tube socket, top chassis mounts? I am willing to buy them. Just dont have any need to get anything off radiodaze to make my order more than 10 and its faster processing this way seeing time as an issue.
 

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