[n_maher]

Quote:

Originally Posted by shellylh /img/forum/go_quote.gif Unfortunately, I have no knowledge in this area so all I can add it moral support. I would be happy to contribute to a parts fund (via check or paypal) if one was started though.

Have no fear shelly, Steve has friends in low places and will be well taken care of.

Quote:

Originally Posted by naamanf /img/forum/go_quote.gif I am going to say it's either not going to work or the ε12 relay is going to be shot. But I could be wrong.

I'm going to agree here and guess that given the same circumstances something is probably going to die as a result.

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif Thanks Nate for volunteering to help! I'll send you a PM once I get a list of what I need.

I'll keep an eye open and go start sorting parts now. I can probably pick out most of what you need from the pictures later tonight but it'd be good to confirm that with your list.

 

[amphead]

Quote:

So, what is this thread about. Let's show how powerful the DIY community is here on Head-fi. This would be a first, on Head-fi but need not be the last time. Why, swt61? Why not.

LOL, I did a double-take when you started the thread with that phrase.
Looks like Swt61 is being well taken care of by the generous members on this thread.

 

[luvdunhill]

I found two more bad parts that are not visible in the pics. Here's the list:

D9,D11
CR6?-CR7? (not sure how to verify these without removing them, but maybe should replace them?)
Q17-Q25
R28,R32,R34-R35 (not sure what brand these are, Pars may? blue 2W resistors)
TO-220 insulating shoulder washer

In addition to the CRDs, I'm not sure if the capacitors are okay, but I guess we can wait and see. They don't measure a short at least

 

[luvdunhill]

Quote:

Originally Posted by naamanf /img/forum/go_quote.gif By saying I verified this, I verified it can happen when being plugged in and when being unplugger When being unplugged the MOSFETs just fail with out the resistor cooking because there is not place for the current to go. Of course if you then plugged something in....

so, if there were say already a set of balanced headphones plugged in when say this little altercation occurred............

 

[n_maher]

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif I found two more bad parts that are not visible in the pics. Here's the list:

I'll head downstairs to the "lab" and see what I've got. I'll post the results later tonight.

 

[luvdunhill]

 

[n_maher]

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif D9,D11

check
Quote:

CR6?-CR7?

d'oh, don't have these!
Quote:

Q17-Q25

check
Quote:

R28,R32,R34-R35

check
Quote:

TO-220 insulating shoulder washer

check

I'll toss it in a padded envelope and get it headed your way tomorrow Marc.

If you find you need anything else you know where to find me.

 

[Pars]

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif I found two more bad parts that are not visible in the pics. Here's the list: D9,D11

D9 BZX55C12 12V 500mW zener diode, DO-35 (AMB audio shop, Mouser)
D11 1N4004

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif CR6?-CR7? (not sure how to verify these without removing them, but maybe should replace them?)

CR1-CR88Current regulator diode 0.56mA 1N5291
Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif Q17-Q25 R28,R32,R34-R35 (not sure what brand these are, Pars may? blue 2W resistors)

R34-R35 are probably: 282-0.47-RC
R28, R29 and R32 are 75 ohm... RN55s?
Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif TO-220 insulating shoulder washer In addition to the CRDs, I'm not sure if the capacitors are okay, but I guess we can wait and see. They don't measure a short at least

Most of this came from Amb's parts list The β22 Stereo Amplifier The metal oxides I recognize from building a sigma22.

 

[swt61]

I just got back home this afternoon, and there was a work related problem waiting for me. So I'm just now checking in on HF and was directed to this thread from the Houston Meet impressions thread.

Firstly I can't express how much I appreciate everyone coming to my aid. It's always an inspiring event when people do this for others here, and even more so when the recipient is yourself.

Secondly I should have known something was off when I saw a group of Head-Fiers huddled around my amp with marshmallows on a stick, singing Kum Ba Yah with a nice orange glow to their faces.

I have to say that it's usually pabbi1 that has meltdowns at meets, so I guess it was my turn.

The good news is that Marc got my new turntable tweaked and dialed in pretty darn close, and it was making beautiful music... at a less than optimal gain, but that's an easy fix already being rectified.

Marc I just realized I had packed the umbilical for the β22. I'll get it mailed off tomorrow.

Again thanks so much for the support everyone! I know how very busy Marc is ATM, and I'm sure you all have more pressing matters to attend to yourselves, but this will not be forgotten!

 

[amb]

Sorry to hear about the fireworks. Does this amp have the zobel network at its outputs? If not, it should be added as part of the repair. Some speakers represent highly inductive loads to the amp, and cause the amp's output current to deviate in phase relationship than the output voltage swing, which is a difficult load to drive. Also, such a load could cause ultrasonic instabilities which might also potentially damage the MOSFET(s). The MOSFET fails by shorting itself internatlly, and such a failur will ookely take out the gate resistor and other surrounding components.

 

[luvdunhill]

Quote:

Originally Posted by amb /img/forum/go_quote.gif Sorry to hear about the fireworks. Does this amp have the zobel network at its outputs?.

yes, it does actually. They are connected to the speaker terminals at the back of the amp. Just to clarify, the Fostex T50 are actually headphones, not speakers

 

[Navyblue]

Quote:

Originally Posted by naamanf /img/forum/go_quote.gif Was the T-50 plugged into the 1/4" SE Jack? I am guessing it was and the volume was turned up. When being inserted the 1/4" causes a momentary short from ground to the right channel. Poof up in smoke it goes. Don't ask me how I know this but I can say that I have verified it

Can someone please explain this? Is it that mono 1/4" plug is plugged into a stereo 1/4" jack? But of course it doesn't make sense. I'm building mine soon and just want to make sure that this does not to happen to me.

I thought that it is amazing that you guys have so many spare parts. If you guys REALLY need a place to dump those, I'd be more than happy to help.

 

[JamesL]

Quote:

Originally Posted by Navyblue /img/forum/go_quote.gif Can someone please explain this? Is it that mono 1/4" plug is plugged into a stereo 1/4" jack? But of course it doesn't make sense. I'm building mine soon and just want to make sure that this does not to happen to me. I thought that it is amazing that you guys have so many spare parts. If you guys REALLY need a place to dump those, I'd be more than happy to help.

Nope. It's a TRS plug into a 1/4" stereo jack.
Because the left/right/ground channel are "stacked".. one after another, the tip of the plug will short the right and ground channels together, as the plug is being inserted.

This doesn't apply to XLR jacks though, because it has 3 separate pins.

 

[fordgtlover]

Being so far away, it is not feasible for me to offer parts, but I'd be happy to chip in for a new board and parts so that the repair doesn't need to be a patch.

You have a pledge from me, if required.

 

[Navyblue]

Quote:

Originally Posted by JamesL /img/forum/go_quote.gif Nope. It's a TRS plug into a 1/4" stereo jack. Because the left/right/ground channel are "stacked".. one after another, the tip of the plug will short the right and ground channels together, as the plug is being inserted. This doesn't apply to XLR jacks though, because it has 3 separate pins.

Thanks, I always thought that the spacing of the electrical contacts in the jack has taken this scenario in consideration. But, wouldn't it mean that amp has to be turned off when plugging/unplugging?