Millett "Starving Student" hybrid amp
Feb 10, 2010 at 9:42 PM Post #4,681 of 7,277
Quote:

Originally Posted by tomb /img/forum/go_quote.gif
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It's especially clear on the silver cases, because the plastic bezels are still black.
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bezel : that's the word I was looking for
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cheers!
 
Feb 10, 2010 at 11:56 PM Post #4,682 of 7,277
hah ic whaT i did wrong. fixed the bezel thing.. I was so excited about the last step i did it wrong
smily_headphones1.gif

ALso, is there any possibility to try a little tube rolling with these? any recommendations for comparison sake?

Lil knight, thing sounds good with the uDAC huh?
for a 1st project that's a pretty good job man..props
 
Feb 11, 2010 at 12:02 AM Post #4,683 of 7,277
Yes, it sounds really nice but I have to lower the volume on the uDAC. The bass distorts when I set it at full volume.

I will enjoy this little gem for a while before moving to the Mini Maxx. Hopefully I'm capable of building it
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Feb 11, 2010 at 12:19 AM Post #4,684 of 7,277
Quote:

Originally Posted by particleman14 /img/forum/go_quote.gif
hah ic whaT i did wrong. fixed the bezel thing.. I was so excited about the last step i did it wrong
smily_headphones1.gif

ALso, is there any possibility to try a little tube rolling with these? any recommendations for comparison sake?

Lil knight, thing sounds good with the uDAC huh?
for a 1st project that's a pretty good job man..props



No tube rolling on this amp, unless you refer to trying different brands of the same tube (19J6).

cheers!
 
Feb 11, 2010 at 4:06 AM Post #4,686 of 7,277
So I'm looking at the Minimax instruction and see this:

RCA1.jpg


Looks like the grounds are tied together. Is there any difference between this and separate grounds? I mean the 2 ground tabs on the RCA jacks don't touch together.
 
Feb 11, 2010 at 5:26 AM Post #4,687 of 7,277
Quote:

Originally Posted by Lil' Knight /img/forum/go_quote.gif
So I'm looking at the Minimax instruction and see this:

<IMG]http://www.diyforums.org/MiniMAX/construction/wiring/RCA1.jpg[/IMG>

Looks like the grounds are tied together. Is there any difference between this and separate grounds? I mean the 2 ground tabs on the RCA jacks don't touch together.



It's six of one and half-a-dozen of the other, isn't it? The grounds all come together in the terminal block, anyway. The important thing is that both RCA jacks are grounded and that you use two ground wires to lower the resistance of the ground path compared to the signal wiring (IMHO).
smily_headphones1.gif
 
Feb 11, 2010 at 7:15 AM Post #4,689 of 7,277
Quote:

Originally Posted by Lil' Knight /img/forum/go_quote.gif
Gotcha. Thanks.

I'm very interested in the minimax but have no idea how to do the tube bias so I guess I have to stay away from it for a while
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Biasing the tubes is the easiest part of building the MiniMAX, really. Being able to carefully follow the BOM and the board layout to sort out the sheer number of components, put each one in its correct location in the board and all the soldering you have to do are the hardest parts, IMO. Biasing the output diamond buffers would come in a close second.

Sharpen both your soldering and DMM usage skills and you'll be fine building a MiniMAX. Just get a scrap PCB or a RadioShack protoboard (part no. 276-0150) to practice your soldering. In the DMM front read a good tutorial (google: DMM tutorial) and you'll be set.

You might also want to follow the MiniMAX thread here and read as much as you can before you delve into that build.

cheers !
 
Feb 13, 2010 at 12:21 AM Post #4,691 of 7,277
Got a bit of a shielding question I didn't see answered - I've recently started using my Starving Student with my ER6i and/or RP-21, as opposed to my 80-ohm DT770s. This combo of lower impedance/higher sensitivity has led me to notice a quite obnoxious rendition of my college's FM radio station in the right channel (as the 1,300w transmitter for the station sits about an 1/8th a mile from my dorm).

Is there anything I can do to help reduce this? I'd thought of lining the insides of my wood case with aluminum foil and then tieing that to ground, but then I remembered that the interference is only in one channel, which seems to suggest there is a flaw in my construction somewhere that is allowing for excessive noise.

Any hints?
 
Feb 13, 2010 at 1:04 AM Post #4,692 of 7,277
Alright guys, get ready for a really novice question.

I noticed that TomB specified what wire he used for the LEDs, but I didn't see any mention of the wires used in the other part of the project. I just bought an obnoxious amount of something called 'hookup wire' {stranded, 22-guage} from RadioShack. I also have some left over, stranded silver cable from earlier projects.

Would any of these work for the full project? Or should I return the RadioShack wire, and look elsewhere?
 
Feb 13, 2010 at 1:32 AM Post #4,694 of 7,277
Quote:

Originally Posted by Chipp /img/forum/go_quote.gif
Got a bit of a shielding question I didn't see answered - I've recently started using my Starving Student with my ER6i and/or RP-21, as opposed to my 80-ohm DT770s. This combo of lower impedance/higher sensitivity has led me to notice a quite obnoxious rendition of my college's FM radio station in the right channel (as the 1,300w transmitter for the station sits about an 1/8th a mile from my dorm).

Is there anything I can do to help reduce this? I'd thought of lining the insides of my wood case with aluminum foil and then tieing that to ground, but then I remembered that the interference is only in one channel, which seems to suggest there is a flaw in my construction somewhere that is allowing for excessive noise.

Any hints?



I'd say shielding will definitely help. Still, I've found some 19J6 tubes to be more susceptible to picking up hum and noise. Maybe swap the tubes and see if the radio follows the tube? If it does, I guess you'll need to shield the tubes.

My first build using 19J6 tubes hummed like crazy in one channel when using sensitive phones (not only IEM's, it happened with my Denon cans, for example). When I slipped a shield from one of the preamp tubes in my speaker amp over the offending channel tube, and making sure the tube-shield touched the tube-socket screws (which were grounded) the amp was as silent as can be.

cheers!
 
Feb 13, 2010 at 11:01 AM Post #4,695 of 7,277
Just started to test mine after building thisevening. Took a bit more than I expected, maybe 10 hours all told. I'm new to DIY audio stuff and literally had to wipe the dust off my soldering iron from highschool.

This is my first experience with tubes so I wasn't sure if i'd seated them hard enough or not. Turned on the amp - LEDs lit up nice and green - turned on my old discman (ready to be sacrificed if I'd wired something up wrong) and plugged in some el-cheapo headphones (again incase something went wrong). At first...silence....then a gentle glow from the tubes! ALL WAS NOT LOST! faintly at first, then slowly louder it came - the music!

I popped the earphones in for a moment to see what sort of volume this beast was going to give me...and I was almost in tears. I have never heard a soundstage like it. My post count and join date are probably very good indicators that I am damn new to this, but what an eye opener. If this is what's on offer from a relatively cheap amp, cheap source and cheap headphones...I know where all my money will be going soon
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Thanks Tom for making the kit available and getting it all the way out to Australia for me
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