10 Attachment(s)
Re: Zapco DC Reference 500.1
Now, finish assembling the PCB and make sure everything is secured. It may be a good idea to do a quick power-up before putting everything back together. Yep, amp comes out of protection mode. Green light means go and fans are spinning:
Attachment 11272
Attachment 11273
Attachment 11274
Attachment 11275
This is the noisy / howling fan:
Attachment 11276
Now, clip the leads on the old fans and solder them to the new ones:
Attachment 11278
Attachment 11277
Fans re-installed and ready to go
Attachment 11280
Attachment 11279
One of the toughest parts is to make sure all the indicator L.E.D's are aligned properly when putting the cover back on. They are easy to bend when handling the board:
Attachment 11281
Ge0
8 Attachment(s)
Re: Zapco DC Reference 500.1
OK. Got the lid on tight. Let's power this sucker up and put the juice to it :)
Attachment 11284
Attachment 11283
Attachment 11282
Need to use my old test mule. Can't seem to find my box of 500W load resistors. Trust me, these things are large. How could I misplace them? Each one is about the size of a shoe :(. Well, we won't be testing the amp to full load today. But, we can give it a good burn in within the 300W limit of the sub.
Attachment 11285
Signal generator maxed out at 20V and only applying about 130W to the sub.
Attachment 11286
The jumper settings are too high on my high level input converter. I don't feel like digging out the manual to make the proper jumper connections. It's easier to just switch over to the line level converter:
Attachment 11289
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Attachment 11287
There we go. 30Hz at 9.8V input is giving 300W output. I purposely set my current limit at 30A to protect the sub. Its only rated for 300W. So, ran the amp at 10V and 30A for an hour to burn it in and test it. Fans ramp up and down properly under heavy load. But, most of all they are whisper quiet. If you remember, this was the entire reason I started this exercise in the first place. A noisy / dying fan. Well, mission accomplished...
Ge0
Re: Zapco DC Reference 500.1
Hmm, can't see the pictures for the last posts, that's a shame...
So all the crap you clean off the transistors - is that essentially the same stuff you use to assemble computers, CPU to heatsinks - thermal paste?
What do you use when you reassemble it - is Arctic Silver the stuff, like it is for computers?
Re: Zapco DC Reference 500.1
Quote:
Originally Posted by
geolemon
Hmm, can't see the pictures for the last posts, that's a shame...
So all the crap you clean off the transistors - is that essentially the same stuff you use to assemble computers, CPU to heatsinks - thermal paste?
What do you use when you reassemble it - is Arctic Silver the stuff, like it is for computers?
The photo hosting on this site is hit or miss. Need to re-upload photos again for the 4th time. Makes wanting to post anything here a hassle. But, to answer your question yes. Thermal paste is thermal paste. However, you can buy grades with better thermal conductivity. The stuff I tried is highly rated. But, not easy to apply to weak and floppy transistors. I ended up using an industrial grade like I use at work.
Ge0
Re: Zapco DC Reference 500.1
Quote:
Originally Posted by
geolemon
Hmm, can't see the pictures for the last posts, that's a shame...
So all the crap you clean off the transistors - is that essentially the same stuff you use to assemble computers, CPU to heatsinks - thermal paste?
What do you use when you reassemble it - is Arctic Silver the stuff, like it is for computers?
After my 4th attempt it appears the photos are sticking now. I'm going to go ape shit if I need to redo another post.
Ge0
Re: Zapco DC Reference 500.1
Awesome results. What a can of worms, when you just expected to replace some fans! But you have to be glad you cracked it open, finding all that stuff.
Basically a complete amp restoration, for an amp that's totally worth restoring and keeping going.
Such good work. :thumbup:
Re: Zapco DC Reference 500.1
Quote:
Originally Posted by
geolemon
Awesome results. What a can of worms, when you just expected to replace some fans! But you have to be glad you cracked it open, finding all that stuff.
Basically a complete amp restoration, for an amp that's totally worth restoring and keeping going.
Such good work. :thumbup:
Thanks. I paid nearly $1000 for this sucker new 10 years ago. It was the best of its time. Even though Zapco name brand has been reduced to eBay lately I still like the design of this amp and will support.
Ge0
Re: Zapco DC Reference 500.1
On a related note - do you ever watch Barevids videos?
I'm NOT an amp tech, and I find them super interesting. He's great at taking them up a level so it's not all tech talk, but yet deep dives enough to point out individual components in amps, potential failures, things to inspect and look for, points out which amps are truly manufacturer engineered vs. salad bar contract manufacturer house specialty jobs...
Highly recommended.
I haven't really been paying attention much, and suddenly here we are in a world with... Skar? Taramps? Orion and Soundstream reduced to cookie cutter contract manufacturer brands? Pretty interesting seeing him (and Williston too, for the test side) pick them apart. Wish these guys were around in the 90's. :cool:
Re: Zapco DC Reference 500.1
Quote:
Originally Posted by
geolemon
On a related note - do you ever watch Barevids videos?
I'm NOT an amp tech, and I find them super interesting. He's great at taking them up a level so it's not all tech talk, but yet deep dives enough to point out individual components in amps, potential failures, things to inspect and look for, points out which amps are truly manufacturer engineered vs. salad bar contract manufacturer house specialty jobs...
Highly recommended.
I haven't really been paying attention much, and suddenly here we are in a world with... Skar? Taramps? Orion and Soundstream reduced to cookie cutter contract manufacturer brands? Pretty interesting seeing him (and Williston too, for the test side) pick them apart. Wish these guys were around in the 90's. :cool:
I've seen a glimpse at one of his vidoes but have not followed him. I'm still looking for more documentary videos debating the murder mysteries in Tiger King... :)
Ge0
Re: Zapco DC Reference 500.1
All this work on this amp making sure it would last another ten years. Well, I was testing subs tonight and I think it shit the bed. It heated up rapidly and blew a 40A fuse. Diagnosis does not look good. More on this in a few days...
Ge0