Millett "Starving Student" hybrid amp - Page 231

ok guys i figured out what the problem was. it wasn't the pot that was done right. (only wasn't sure when putting it together) the problem was i messed up resisters 14/15. (im using the pcb) i didn't have a single resister for those locations so i used 2 to add the ohms together, SO...... it was different ohm loads there and threw off the balance.

finished pics i call him "Old Happy Man"

Well done bobfig, i love it!

So how does old happy man sound?

gumpy as ever lmao
pretty good

Is that me or Beezar.com is down ?

I think it's you, I have no problem visiting beezar from belgium.

WTF ??

Everything is ok except beezar... I checked my Hosts file and no restrictions concerning beezar...
PC has been cleaned... Always the same...

Damned !

P.S. : I am from France...

This is a handy tool for Tritonpad's situation:

Down for everyone or just me?

Thank you for your answer and the tool you propose. It says that beezar is up
Seems that it is my ISP that doesn't like beezar ^^ Trying to tell them not to block it anylonger...

the BOM lists a standoff, is it the same as the one listed for the minimax?

Attempt 2: still not working.

Alrighty, so when it was recommended that I take pictures to post to help with trouble shooting I looked at the jumbled mess that was my project and decided I needed to redo. Whatever.

So having redone the whole thing, it still won't work! This time there are new problems:

I measured no voltage from the mosfets onward (if you follow the path from power to out put. Well, I didn't get anything from the audio ins either... I think I may have fried the transistors at some point. I'm going to get new ones and see if that helps anything.

Other issues:
-Instead of a constant voltage it spikes at regular intervals. In addition, when my phones are plugged in I can hear a clicking, almost like a heartbeat, that matches the voltage spikes. Why is this?

-There's a silvery build up on the inside of my tubes near the top (in the same place on both) right where the decal is. If no one's encountered this I'll post a picture, I'm just too tired now. What is that? Is it a problem?

I think that's it. I'm hoping new transistors will fix my issues, if they don't I'll post pictures.

NO. I've had a little trouble packaging a solution that works in all cases, but I expect to have a SSMH Standoff Kit posted on beezar shortly.

The issue comes in with the washers. One washer is needed between the PCB and the standoff to provide the final spacing needed. However, all available English washers are too big - they impinge on the back lead and pad of the tube LEDs resistor. Since the standoff makes contact with the PCB ground plane (desired), this will result in a dead short. Instead, I will probably be packaging some metric washers for this use with the standoff - they are much smaller diameter. I should have the kit available tomorrow.

Likewise, the heat sink kits will be something special for the SSMH. Two extra screws, with corresponding washers, lock washer and nut are needed for the back mounting hole of the TO-3 heat sinks. Also, since the screws used on the MOSFETs go through the MOSFET, the case lid, and the TO-3 heat sink, they have to be longer than the other screws. These will all be socket-head cap screws, stainless washers and lock washers, and genuine polysulfide-filled shoulder washers for the MOSFETs. Bergquist pads will be used to complete the kit. These should be available shortly, too.

BTW, when using the Hammond case and these TO-3 heat sinks, one should apply heat-transfer grease to the bottoms of the heat sinks where they contact the case lid. I did this on both of the ones I built, but will be detailing it, along with the proper mounting holes and orientation of the heat sinks, on the SSMH website.

That voltage is being applied to your headphones through the headphone jack. It could be damaging, so don't let that go on for long. If your tubes didn't have it, it would be a problem. That's what's known as the "getter flash" and pretty much every tube everywhere has one. The getter flash is a catalyst chemical designed to react to the gas molecules of air that may have infiltrated into the tube. The getter itself is usually a small loop, square, or D-shaped wire near the getter flash. The getter has voltage applied to its loop, which hopefully ionizes any gas molecules so that they'll react with the shiny chemical "getter flash" painted on the inside of the tube. This is how a tube maintains a clean vacuum over the life of the tube. When you see the getter flash stop being mirror-silver and start to turn white, the tube is worn out or worse - the glass is broken somewhere and the vacuum has been irreparably ruined.

Still no dice.

Replaced Mosfets, no luck.

Current situation:

-that same 'heartbeat' spike when the switch is on. Except this time instead of jumping from zero up high it's got a constant voltage and then jumps a little. It's also more frequent.

-I read no voltage at the output jack, yet I hear the clicking sound (associated with the voltage spikes)

-Other than that weird clicking there's no sound.

-Every voltage I measure (with the exception of the power input) is pretty weak. Under 10V usually.

There's a picture of the whole thing and here are some links to some closer shots. Picasa Web Albums - Matt - Starving Stud...

By the way, those two green bundles are connecting the grounds.
Speaking of which, I'm using a Rat shack chassis and grounding to the metal bottom plate. I can't get anything to solder to it though, any hints?

You might be better to get a board and start again
that looks a little scary
good luck

Yeah I'm sorry to tell you this, but it looks like a bug explode in there.
I'd say try thing over, check every wire before continueing.