Millett "Starving Student" hybrid amp
Sep 25, 2010 at 12:26 AM Post #5,506 of 7,277
It is definitely wired correctly, just a bad connection at some point.  I am going to redo the whole thing probably tomorrow, with a little more thought put into the placement of parts and a better grounding system.  I just got a little fidgety once I got all the inputs, outputs, and tube sockets placed into my box and started soldering.  It resulted in a cluster****, and you can't really tell what is going on at all.  It is aggravating, both channels are wired exactly the same as far as I can tell, and only one is working, and that one is very quiet.
 
On a side note, my landlord was in the apartment to spray for bugs, and asked me if I was making bombs.
 
Sep 27, 2010 at 7:16 PM Post #5,507 of 7,277
Hi guys!
 
I was really pumped to put together the starving student kit... and I finally have like half a year later. Anyhow, I powered it up, it doesn't seem like anything is running, I'm pretty sure the power is working cause I've been probing around and a few sparks on the board went off... (oops!) However, the mosfets don't seem to be heating up and the leds under the tubes are lighting up so I'm fairly certain nothing is going on there. How would you guys suggest probing around because the top plate is in the way of the probing?
 
Anyhow, I'll keep probing around, but wanted to see if you guys had any suggestions. I used the kit from beezar (which, by the way, thanks to the guys that put it together!). I can snap a few pics when I get home.
 
Thanks in advance!
 
Sep 30, 2010 at 3:00 AM Post #5,509 of 7,277
Ah! I realized the problem was something that someone else had gone over here. The MOSFETs were somehow shorted to ground so they wouldn't turn on! However, my LEDs don't turn on is that an indication that I wired them up backwards?
 
Oct 1, 2010 at 2:35 PM Post #5,510 of 7,277
Thought I'd post some pictures of my recent 12AU7 effort.
 
All resistors are Ohmite carbon composite, capacitors are Vishay axial 'lytics and TAD mustards. Valves are JJs.
 


 
I've used the Hammond case supplied with the Beezar kit and embellished it with teak from and old box and fancy gold bits.
 

 
Chuffed that it worked first time with no problems ~ Cheers!
 
Oct 1, 2010 at 3:26 PM Post #5,513 of 7,277
 
Quote:
Thought I'd post some pictures of my recent 12AU7 effort.
 
All resistors are Ohmite carbon composite, capacitors are Vishay axial 'lytics and TAD mustards. Valves are JJs.
 
SNIP

I've used the Hammond case supplied with the Beezar kit and embellished it with teak from and old box and fancy gold bits.
 
SNIP
 
Chuffed that it worked first time with no problems ~ Cheers!



Nice looking build! Congratulations!
 
 
Oct 2, 2010 at 4:28 PM Post #5,518 of 7,277
hi there,
lovely @ meme, the gold and teak/black fits perfectly imo!
 
I didn't even mess with a possible enclosure yet
smily_headphones1.gif
need to source the parts first hehe.
At first I thought about doing something in engineered stone/marble/granite, but regarding the size... almost impossible for me.
(I work in a small stonemason business, most of the stuff we do is tombstones... , and as we don't have cnc/waterjet...no chance, even drilling would get difficult.. so I'd go for wood or alu too) 
 
I hooked up a BoM , first part is from Conrad.de as Beftus suggested, second part is from Banzaimusic.com, german store ..
Might order most parts there , since they got almost everything. Need to check the total tomorrow.
Maybe you guys could take a look, I made some notes ...
Here's the link : http://frickel.dezern.at/
Thanks for looking,
Marcus
 
Oct 4, 2010 at 3:42 AM Post #5,519 of 7,277
Wow that looks great, meme!
 
So after debugging and fixing the LEDs up - it was just some loose connection. For some reason the left channel is quite a bit softer than the other. I looked at all the connections, but didn't see any connections that weren't soldered completely. I also noticed that when I only had the RCA cable hooked up only to the right channel, there was a ground hum, but when I hooked up the RCA cable only to the left channel, the sound was pretty clean. I'm fairly certain both channels work as well because when I switch the RCA connections inside the box there is sound coming from both RCA connectors.Also, the left channel - which is softer - also has quite a bit of distortion on it. What would you suggest me doing?
 
Thanks,
Ben
 
Oct 4, 2010 at 11:35 AM Post #5,520 of 7,277
Hi Ben,
 
  Good to hear your making progress with your amp. About your problem, try first swapping the tubes and see if the problem 'follows the tube'.
 
If it doesn't then check the connections from the RCA jacks to the board, it sounds like one of them might be inverted (ground connected to signal and signal to ground) or not making good contact at the terminal block or the jack.
 
Good luck!
 

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