Build Thread - A New Take on the Classic Pass Labs D1 with an ESS Dac

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#301
hopefully its one of the surrounding resistors, or you wont have a matched set of mosfets. It wouldnt surprise me, if there was enough power to blow the power resistor it wouldnt take too much to blow a 1/8 or 1/10th watt rated resistor. do any look discoloured? mosfets are pretty hardy, you would think it wouldnt blow without announcing itself. i'm surprised the power resistors blew without some stinky smoke.

getting there though
 
#305
I'll second that... it sounds like the mosfet is dead, especially if those two resistors are measuring properly.

The only other thing I can think of is that the tab is still connecting to the heatsink somehow. Can you see if you get a low resistance when you measure from that mosfet's drain to the heatsink? You'll have to find a spot on the heatsink that doesn't have anodized coating on it to measure (or scratch through the coating).

If qusp noted the mosfet numbers and GM values on his excel spreadsheet, he might be able to send you one that matches the rest of your remaining mosfets closely enough that it'll work perfectly without having to replace the others. Now that would be some impressive customer service!

Cheers,
Owen
 
#306
totally, no problem. all noted down, do you have the measurements for the ones you sold to Felipe Owen? Felipe you dont really need a quad, its nice of course, but 2 pairs is ok if they are close to each other. i have quite a few pairs unspoken for, so wont have to break up a quad.
 
#307
the machined face of the sink isnt anodized but rather heat treated and hardened, so he wont have to scratch anything off. the conrad stuff is actually coated in some sort of Black powercoat/acrylic sort of stuff, but only on all the areas apart from the component side.

oh haha thats right i have the numbers here haha sorry i knew i did the sink, but it was the resistors you didnt get Felipe. ok i'll check it out
 
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#309
no, i was right, opc i think you sold him the fets, i just got the heatsink for him. i have customer folders for everyone still here saved with their name and what fets went to them, but i dont have a folder for Felipe. Felipe mentioned before he got them from you too. so the question is, do you have the measurements still? i can probably find a pair thats close enough.

I could be wrong and Felipe is the only one i dont have a folder for (now that would be a bad coincidence) but i dont think so.

I searched my computer for Felipe with no result apart from his email folder.
 
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#310
Sounds like that fet is shorted to the heatsink after all, so it could be just fine.

Double check the insulators and try again.

Good thing this isn't a power amp, or you would have gotten a pretty good fire and smoke show!

qusp:

I think it may have been me that sold the fets, but I'm at work now and will have to check when I get home.

Let's cross our fingers and hope it works once he gets the insulators in place.

Cheers,
Owen
 
#312
no i remember now, i definitely didnt sell them to Felipe, because i made a mistake and made a set up for him, but he didnt need them, he had already told me this, but i forgot. those ones are gone now, but i have plenty pairs left if we can find out what the gm was on the ones you sent him. otherwise it probably should be 2 close pairs or a quad from me. i'll cut you a deal on a quad though Felipe, its an unfortunate situation and i'm a sucker for a sob story :violin:
 
#313
Looks like you're good to go! All those numbers look to be correct.

Connect up the DAC, and let it get up to full operating temp, then re-adjust each point back to 1.65VDC. They will likely shift a little bit when you hook up the DAC and when the temp changes.

You should be able to listen to it right away though.

I'm glad you got it up and running!

Cheers,
Owen
 
#316
yeah i know (see my last post), Owen just had me thinking otherwise with the customer service bit, made me think i should have records and that he hadnt sold them, but a quick look at the records and vy brain starting to work told me otherwise. i remembered that i made a set up for you by mistake and you had to tell me you didnt need them..twice i think lol
 
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#317
opc said:
Looks like you're good to go! All those numbers look to be correct.

Connect up the DAC, and let it get up to full operating temp, then re-adjust each point back to 1.65VDC. They will likely shift a little bit when you hook up the DAC and when the temp changes.

You should be able to listen to it right away though.

I'm glad you got it up and running!

Cheers,
Owen
Click to expand...

qusp said:
excellent, good work Team D1!! :grouphug: 😎
Click to expand...

THANK YOU guys your are really brave!!!!!🙂:cheerful::cheers::up::spin::worship::emoticon::happy1:
 
#318
Is it making music yet? How did the DAC connection go?

I'm really glad you got it up and running without any major setbacks. Waiting three weeks for a new mosfet to arrive would not have been fun!

I'm glad you stuck with it!

Cheers,
Owen
 
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