[BUILD] FET/500 Official Support Thread

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Hi Mike,

I will definitely do that. Before I do, I want to give a report about where I am with my build just to make sure there's nothing else I might need.

First, the good news: for the most part, the compressor seems to basically be working. I haven't calibrated it yet, but I sent a drum recording through as a test, and it sounds great. The overall level seems to be what it should be, it crunches up just a bit if I drive it, and all the controls do what they should.

Here's what's not working:

  • The 20:1 ratio does not work. In that position, no gain reduction is happening. All other ratios are working as expected.
  • The meter isn't working correctly. The slam LED always stays on, and the only LED that does seem to work correctly is the peak indicator. I've seen some other posts in this thread on this topic and I plan to reexamine my solder joints in these areas.
  • Neither the GR Off or Bypass LEDs illuminate, and the bypass function isn't working. The GR Off function, however, is working.

I plan on double-checking and reflowing solder joints, but if there's anything specific I should be looking about, I'd love to know. Also, I'd still like to know whether I should remove Q6 and install that spacer, or whether I'm OK with it installed as is.
 
Hairball Audio said:
We can send you a new matched set if you like. Send us an email.

Mike

hello Mike!!

Thanks for the Match pair of transistor!!!!

It solved my noise problem on the FET 500 REV A.

But I still got a problem. The gain reduction does not happen...

Everything's fine when calibrating until I have to put GR ON... nothing's happen on the meter board. The green LED (zero in the meter) stays....

I sent audio sample ont the unit and listened.... No compression...

If you have an Idea...

Thanks again Mike!!!!
Have a good day!!!!

Antoine
 
mcrowe said:
Hi Mike,

I will definitely do that. Before I do, I want to give a report about where I am with my build just to make sure there's nothing else I might need.

First, the good news: for the most part, the compressor seems to basically be working. I haven't calibrated it yet, but I sent a drum recording through as a test, and it sounds great. The overall level seems to be what it should be, it crunches up just a bit if I drive it, and all the controls do what they should.

Here's what's not working:

  • The 20:1 ratio does not work. In that position, no gain reduction is happening. All other ratios are working as expected.
  • The meter isn't working correctly. The slam LED always stays on, and the only LED that does seem to work correctly is the peak indicator. I've seen some other posts in this thread on this topic and I plan to reexamine my solder joints in these areas.
  • Neither the GR Off or Bypass LEDs illuminate, and the bypass function isn't working. The GR Off function, however, is working.

I plan on double-checking and reflowing solder joints, but if there's anything specific I should be looking about, I'd love to know. Also, I'd still like to know whether I should remove Q6 and install that spacer, or whether I'm OK with it installed as is.

You have to calibrate it.  I'm surprised it's working at all.

Make sure your LED's for bypass and GR off are in the correct polarity.

Mike
 
antoine00 said:
hello Mike!!

Thanks for the Match pair of transistor!!!!

It solved my noise problem on the FET 500 REV A.

But I still got a problem. The gain reduction does not happen...

Everything's fine when calibrating until I have to put GR ON... nothing's happen on the meter board. The green LED (zero in the meter) stays....

I sent audio sample ont the unit and listened.... No compression...

If you have an Idea...

Thanks again Mike!!!!
Have a good day!!!!

Antoine

Most likely an issue in your sidechain (back corner of the board), or if you have an A you don't have the R-OPT link in place.

Mike
 
Hairball Audio said:
Most likely an issue in your sidechain (back corner of the board), or if you have an A you don't have the R-OPT link in place.

Mike

Hello,

I've re-checked R-opt link so I'm sure about It.

What do you mean about the back corner of the board?!!!

Thanks a lot!!!!
 
antoine00 said:
Hello,

I've re-checked R-opt link so I'm sure about It.

What do you mean about the back corner of the board?!!!

Thanks a lot!!!!

The part of the board where you have the vertical resistors.
 
I'm still having trouble with the 20:1 setting and the metering on my rev A. I was able to calibrate the Q bias and the gain trim on the meter board. However, I couldn't get any of the green LEDs to come on. I wasn't able to perform the GR tracking calibration because the 20:1 ratio isn't doing any gain reduction. All other settings work, but not that one. I've reflowed the solder joints on the switch and the resistor network associated with it, but no luck. In 20:1 mode I do still get makeup gain. The other odd thing is that the slam LED stays lit all the time.

On a possibly related note, I made a mistake when initially populating the LEDs and ended up having to move some around. I couldn't get a reading on two of the yellow ones with my DMM's diode testing function after removing them from the board, so I'm guessing I fried them. At the moment those two aren't installed.

Any ideas where to focus my efforts?
 
mcrowe said:
Is Hairball in the house? I'd very much appreciate any input on this.

I'm a little bit on vacation for a bit.

You have those green LEDs installed in the correct orientation?  Are you saying you can't get an GR drop on your output?

Mike
 
I’m confident about the LED orientations. I do get gain reduction, just not on the 20:1 setting. The others work. I haven’t had the chance to mess with it in a while but I was going to hunt for shorts in the switch connection area.
 
mcrowe said:
I’m confident about the LED orientations. I do get gain reduction, just not on the 20:1 setting. The others work. I haven’t had the chance to mess with it in a while but I was going to hunt for shorts in the switch connection area.

Weird that the others would work, but not 20:1 since 20:1 is at the start of the ladder.

I would definitely re-flow the ratio switch points. Also check the resistor values across that section.

Mike
 
I tried reflowing those points already without luck. I'll continue to try to troubleshoot in that area. I also found this flaw weird, especially considering that the slam mode works.

Does the fact that the slam LED stays on all the time on the meter board raise any red flags?
 
mcrowe said:
I tried reflowing those points already without luck. I'll continue to try to troubleshoot in that area. I also found this flaw weird, especially considering that the slam mode works.

Does the fact that the slam LED stays on all the time on the meter board raise any red flags?

Does the GR meter work?
 
Hi community,

I'm having troubles with the VU meter on my build. Q bias adjustment and peak led adjustment went smoothly.  i see absolutely nothing on the VU meter though (bottom leds) . Solder joints on those leds look pretty good. I will double check resistance values but i doubt it's the cause as i have been pretty meticulous. I don't know where to check at all. Could it be the trim pots on the main PCB ? they were all midway.

Also, i cant get the ratio stepped switch (grayswitch) the turn at all. Did i miss something regarding those stop pins or what?

Any help appreciated.

William
 
WillDuc said:
Hi community,

I'm having troubles with the VU meter on my build. Q bias adjustment and peak led adjustment went smoothly.  i see absolutely nothing on the VU meter though (bottom leds) . Solder joints on those leds look pretty good. I will double check resistance values but i doubt it's the cause as i have been pretty meticulous. I don't know where to check at all. Could it be the trim pots on the main PCB ? they were all midway.

Also, i cant get the ratio stepped switch (grayswitch) the turn at all. Did i miss something regarding those stop pins or what?

Any help appreciated.

William

Hi,

Emailed you about the switch.

For the VU meter check all of your soldering on everything...look close and re-flow.  Check that the diodes, IC, and caps are inserted correctly.

Mike
 
Hey Mike,

    I’m pretty much done with my FET/500 rev D build. I’m in the calibration phase. I’ve gotten thru Q bias & output meter calibration with small corrections. I’ve hit a wall with the gain reduction meter. No leds are registering. I made sure to take the unit out of GR off mode, but nothing changes. Any insight would be amazing.
Thank you,
e
 
eMIX305 said:
Hey Mike,

    I’m pretty much done with my FET/500 rev D build. I’m in the calibration phase. I’ve gotten thru Q bias & output meter calibration with small corrections. I’ve hit a wall with the gain reduction meter. No leds are registering. I made sure to take the unit out of GR off mode, but nothing changes. Any insight would be amazing.
Thank you,
e

To start, make sure your tracking and zero adjust trimmers are dead center.  The are 20 turn pots. Rotate in one direction until you hear a "click", then rotate back 10 turns.

Mike
 
Ok...I turned counter clockwise til I heard a click. Then turn ten times clock wise. Nothing yet, so far. What’s the next step?
 
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