Millett "Starving Student" hybrid amp
Sep 2, 2013 at 5:27 PM Post #6,646 of 7,265

H3nk

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I found a pair of RCA 5963 for a decent price.
After reading a bit it seems like they should be a suitable replacment for the 12AU7.
Searched the thread and I couldn't find any comments on them.
Will they work?
 
Sep 2, 2013 at 7:20 PM Post #6,647 of 7,265

tomb

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Quote:
I found a pair of RCA 5963 for a decent price.
After reading a bit it seems like they should be a suitable replacment for the 12AU7.
Searched the thread and I couldn't find any comments on them.
Will they work?

To be honest, they've always been my favorite tubes in a low-voltage, 12AU7 circuit (like the original SOHA).  They generally have everything a 12AU7 has, but operate at a much lower plate voltage.*  I think they were originally made for WWII walkie-talkies, which needed lower voltage tubes to operate with the batteries at hand.  The data sheets say 67.5V is the typical operating plate voltage.  That's not too far from the Starving Student's operating voltage at the plates.
 
* The closer a tube operates at its data sheet operating voltage, the more linear its response (better its performance).
wink.gif

 
Sep 4, 2013 at 4:59 PM Post #6,648 of 7,265

johng1337

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Hi everyone, 
 
I'm a noob (very much so) and i've been trying to figure this out for an hour or so, and i can't seem to understand. Here's the thing. I thought i'd built a starving student (12au7 version), and it would be great if you guys could explain to me why these schematics http://diyforums.org/SSMH/variants/SSMH-12AU7.gif show 8 pins on the tubes, where as 12au7 have 9. What am i not getting? 
 
Thanks in advance
 
Sep 4, 2013 at 7:09 PM Post #6,649 of 7,265

Fred_fred2004

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Pin nine is the centre tap of the heater and is not used so it's not being shown on the schematics
 
cheers
FRED
 
Sep 4, 2013 at 7:23 PM Post #6,651 of 7,265

Zashoomin

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  Thank you very much, i feel much better knowing that

If you feel unconfortable doing a SS point to point the first time Fred is selling SS PCB's right now so you could PM him. 
 
Sep 8, 2013 at 9:03 PM Post #6,652 of 7,265

johng1337

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It's very nice of you to suggest, but it wouldn't as much fun. The whole point of the exercise, i find, is the challenge of it. To be honest i thought about buying it (i saw it a few days ago), but i'd rather try on my own. I'll keep that in mind as a plan b though.
 
Sep 14, 2013 at 5:44 PM Post #6,654 of 7,265

DrivenKeys

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  It's very nice of you to suggest, but it wouldn't as much fun. The whole point of the exercise, i find, is the challenge of it. To be honest i thought about buying it (i saw it a few days ago), but i'd rather try on my own. I'll keep that in mind as a plan b though.

Also, Fred is shipping from Australia. It's a beautiful little board, I may buy another, but you've gotta wait at least a week (usually more) to receive it in the states.
 
Sep 21, 2013 at 5:04 PM Post #6,655 of 7,265

camdat

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Hey guys, I had a question about the Nichicon 220uf 16v capacitor, Beezar no longer sells them and I was wondering if I could use this capacitor since Mouser is out of stock on the other one. They seem to be the exact same capacitor as far as I know but I just wanted to make sure.
 
Sep 24, 2013 at 2:21 AM Post #6,656 of 7,265

domsch1988

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Hey all,
after reading around 150 of the pages in this thread, i ordered a pcb from fred (thanks for this) for the 12au7 version. I plan on building it like reference. But, since i ordered 2 pcb's (you never know^^) i'd like to ask: is it possible to blow this thing up? Like using other opamps to boost this to like 5 - 10 Watts output?
Background: I'm using a Onkyo suround reciever to power two controll ones. Apart from this being overkill, i just don't like the sound of the onkyo. Since i have the pcb anyways, i thought i might give it a shot.
Adding to this, i would need a sub out (for a active sub). Would i add this before the amp, or after the preamp?

I know that this is all about headphones here, but since i'm using the SS as a base, i figured this might be the right place to ask. Thanks in advance for any input provided.

Rock on
Dominik
 
Sep 27, 2013 at 4:35 AM Post #6,657 of 7,265

Kaaf

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Fellow SS'ers
I finished my SS with the PCB of Fred. Sounds good and fairly happy with it. But fairly is not 100%. Because I have a slight hum on my can's. This isn't bothersome when playing music, but during silent parts it's noticable. 
The volume of the hum doesn't change when using the pot meter. Most likely a grounding issue. But I think my grounding is pretty OK, but there is alway room for improvment. Any clue on where to look/improve? Help is greatly appreciated
 
(update)
I totally rewired it, with shielded cables. works flawlessly right now. Now enjoying the AMP with a internal odac.
 
Oct 7, 2013 at 8:10 PM Post #6,659 of 7,265

Zashoomin

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  I was listening to my MHSS at work and I realized I never did post any pictures of the finished amp...its dead quiet and sounds pretty darn good...
 
 
 
 
 
 

 
That looks sick.  
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