[BUILD] FET/500 Official Support Thread

[JoelCoteBergevin]

It's the pad for the cathode. So just solder one end of a wire to the lead and the other end to the via under C21, that's it ?

 

[Echo North]

It's the pad for the cathode. So just solder one end of a wire to the lead and the other end to the via under C21, that's it ?

Should work.

 

[JoelCoteBergevin]

Hi !

I did what you told me and it works ! However, I have a question, is it normal that the PEAK LED (led210) lights up even though the signal is definitively not ''clipping'' ? I used it on different sources (mono room, snare, vocals) and it's working perfectly for room and vocals but with the snare it lights up quickly. But I think it's normal since the peaks of the transients on a snare track are pretty strong...

Yes I did follow the calibration steps by steps.

Can you confirm I'm not going crazy ? haha

Thank you

 

[Echo North]

Ya the peak picks up transients.  You're fine!

 

[Tiotever]

Hi, I'm just about to start my first FET/500 Rev A build.  I can't seem to find components sorting sheets anywhere on line.  Has anyone posted some already or do i need to make my own?  Thanks!!

 

[Echo North]

Hi, I'm just about to start my first FET/500 Rev A build.  I can't seem to find components sorting sheets anywhere on line.  Has anyone posted some already or do i need to make my own?  Thanks!!

I didn't make any sorry.

 

[mnats]

I can't seem to find components sorting sheets anywhere on line. 

Sorting sheets? Do you mean the Bill of Materials (linked from the first post)? Or were you looking for something in spreadsheet form?

 

[Tiotever]

Hi thanks for the response.  I Made my own. I would share them for other users but they're  not very well done and might cause problems rather than help avoid them. I was looking for files I could print out that I could literally place the resisistors on after testing to help keep them organized and properly identified before stuffing the PCB. Hairball has done them for the Lola pres I built awhile ago. And another DIYer named chunger has done them for other builds I've done. I'm still a newbie so I need these things. But I'm all good and really excited to build this compressor you've designed. Thanks again!

 

[t_carvalho]

Hi.

Just finished building my stereo pair and i just seem to have a small problem with the grayhill ratio pots. Once i insert the knob, the ratios dont align with the pointer in the knob. I followed the instructions in the build guide (set flat side to 7 o´clock and inserted the pins at 12 and 6). In my case, once the knob is inserted, Slam is at 6 o´clock and 2:1 is at 12 o´clock, instead of Slam 9 o´clock and 2:1 at 4 o´clock. I´m also putting the screw of the knob on the flat side of pot. Am i doing something wrong?

Best regards

 

[Echo North]

Sounds like you just need to flip the knob around.

The switch has 12 positions.  6 are used and the other 6 are just duplicated.  You probably have your switch on the other side of the switch which is no issue except you need to flip the knob.

Not sure if that all makes sense.

 

[t_carvalho]

Sounds like you just need to flip the knob around.

The switch has 12 positions.  6 are used and the other 6 are just duplicated.  You probably have your switch on the other side of the switch which is no issue except you need to flip the knob.

Not sure if that all makes sense.

If i flip the knob, the screw wont be secure on the flat side of the trim pot shaft. Even if i remove the pins and and switch the flat side of the shaft to the other side, the pointer in the knob still wont match with the faceplate.

here are some pics:

https://dl.dropboxusercontent.com/u/109310897/Hairball%20FET%20500/Flat%20side%207_oclock.jpg
https://dl.dropboxusercontent.com/u/109310897/Hairball%20FET%20500/2%20to1%20with%20knob.jpg
https://dl.dropboxusercontent.com/u/109310897/Hairball%20FET%20500/Slam%20with%20knob.jpg

Thanks

 

[Echo North]

Sounds like you just need to flip the knob around.

The switch has 12 positions.  6 are used and the other 6 are just duplicated.  You probably have your switch on the other side of the switch which is no issue except you need to flip the knob.

Not sure if that all makes sense.

If i flip the knob, the screw wont be secure on the flat side of the trim pot shaft. So i need to remove the pins, switch the flat side of the trim shaft to the other side and insert the pins again?

Doesn't really matter where the screw hist the shaft.  I think it's best not on the flat of the switch pot for setting it dead on but that's just my experience.

Flip the reducer to the other screw.  Whatever works.

Mike

 

[JoelCoteBergevin]

I have a Rev D pair and when assembling the faceplate of my second unit, the yellow GR led broke in half.. I want to buy a couple through mouser. I was wondering what is the part number for the LED ? I'd like to have the exact same thing. Thank you !

 

[Echo North]

I have a Rev D pair and when assembling the faceplate of my second unit, the yellow GR led broke in half.. I want to buy a couple through mouser. I was wondering what is the part number for the LED ? I'd like to have the exact same thing. Thank you !

WP710A10YD

 

[Tiotever]

A few probably stupid questions regarding a REV A build;
1) While populating the meter pcb i encountered some extra resistors and one missing resistor from the set.    So I began triple checking values of resistors already soldered into the pcb.  Several of them were reading 5-20k ohms less than their value prior to being stuffed.  Is this normal or indication that I have stuffed an incorrect resistor along the way?  In particular R206 reads 82k outside of the pcb and it reads 64k when its stuffed.  Also note this is midway through populating the board.  Many holes are still empty. 

2) R222 is 1.2k ohms resistor.  My set came missing this value.  Can I get a Mouser Parts number so I can order the exact intended resistor for R222?

3) Where can I buy extra Grayhill Graphite Stops?  I can't seem to find them sold separately on mouser.  Perhaps you have a Mouser parts number for them or have any suggestions for where I might find them in Los Angeles.    Thanks in advance for the help!

 

[Echo North]

A few probably stupid questions regarding a REV A build;
1) While populating the meter pcb i encountered some extra resistors and one missing resistor from the set.    So I began triple checking values of resistors already soldered into the pcb.  Several of them were reading 5-20k ohms less than their value prior to being stuffed.  Is this normal or indication that I have stuffed an incorrect resistor along the way?  In particular R206 reads 82k outside of the pcb and it reads 64k when its stuffed.  Also note this is midway through populating the board.  Many holes are still empty. 

Parallel resistances.  You can't measure resistors in circuit without doing the math of what is in parallel with it.  So it's normal.  To measure something in circuit you either need to a) desolder on leg or b) look at the schematic and calculate the resistors in parallel with it.  For the same reason meters are inaccurate at reading high R resistors.  Especially meters with low input impedance (1M).

Sometimes we mess up the kits and include extra resistors or miss some.  Email us if you're missing some.

2) R222 is 1.2k ohms resistor.  My set came missing this value.  Can I get a Mouser Parts number so I can order the exact intended resistor for R222?

Send us an email.

3) Where can I buy extra Grayhill Graphite Stops?  I can't seem to find them sold separately on mouser.  Perhaps you have a Mouser parts number for them or have any suggestions for where I might find them in Los Angeles.    Thanks in advance for the help!

Send us an email.  We'll get you squared away.

Thanks!

Mike

 

[pearl]

I have a problem with Calibration step 3(Gain Reduction Tracking) on my rev a. The first 2 steps(Qbias Adjustment and VU Meter Calibration) works fine but when im trying to adjust the “Tracking Adj” to led -9 it doesnt work it, stops on led -5.  I have built 2 units and its the same problem with both. any ideas?

 

[Echo North]

I have a problem with Calibration step 3(Gain Reduction Tracking) on my rev a. The first 2 steps(Qbias Adjustment and VU Meter Calibration) works fine but when im trying to adjust the “Tracking Adj” to led -9 it doesnt work it, stops on led -5.  I have built 2 units and its the same problem with both. any ideas?

The two trimmers (0 adj and tracking adj) can be finicky.  Start by getting them both in the middle.  Turn until your hear a little "click" which is the end, then rotate the other way 10 times.  Do that to both to center them. 

They kind of interplay with one another, the zero moves quick and the tracking slow so if you get the tracking over rotated, you'll never get it right.  Try again going back and forth in small rotations.

See if that helps.

Mike

 

[Echo North]

Email Question:

Hi,
I finally plugged in my two fet/500's rev D
One is working very well except for the metering. I can't seem to calibrate the VU or the peak.
The peak and vu are way to high when set to the output level specified.
The GR seems about right. It sounds great. Should the slam led turn on in slam mode? It doesn't at the moment
My other unit passes audio but doesn't compress at all, the is no difference with GR on or off even with the input cranked.

Slam works like the original.  The unit will peg hard right so the top red button will light and the meter will show GR erratically just like the original.

Often the trimmers can be set way off.  Turn the 0 adjust and GR trimmer till you hear a slight "click" that is the end of the trimmer.  They are 20 turn trimmers so rotate them each back the other way 10 turns and they will be centered.  Now try to calibrate starting with zero adjust.  As you make the adjustment go back and forth make small adjustments.  If that doesn't work, you need to check the metering sections for errors.

For the non compressing one, did the qbias adjustment go well?

Mike

 

[mysticmerlin]

Email Question:

Hi,
I finally plugged in my two fet/500's rev D
One is working very well except for the metering. I can't seem to calibrate the VU or the peak.
The peak and vu are way to high when set to the output level specified.
The GR seems about right. It sounds great. Should the slam led turn on in slam mode? It doesn't at the moment
My other unit passes audio but doesn't compress at all, the is no difference with GR on or off even with the input cranked.

Slam works like the original.  The unit will peg hard right so the top red button will light and the meter will show GR erratically just like the original.

Often the trimmers can be set way off.  Turn the 0 adjust and GR trimmer till you hear a slight "click" that is the end of the trimmer.  They are 20 turn trimmers so rotate them each back the other way 10 turns and they will be centered.  Now try to calibrate starting with zero adjust.  As you make the adjustment go back and forth make small adjustments.  If that doesn't work, you need to check the metering sections for errors.

For the non compressing one, did the qbias adjustment go well?

Mike

Thanks for that, On my first unit the lowest I can go to get the peak to turn off is 1.2V , at 4.88v (16dbu) it never goes off
Likewise when I set the output at 0.388v I can only adjust between the 2dn and 3rd yellow led
I set the 20turn trimmers to halfway. The sound is good but the metering is way off

On the other Unit I get compression only with the 20:1 ratio and the GR OFF switch doesn't do anything. I am able to the Qbias and 0.388v output the first green led lights up but I can't adjust to the 2nd. The sound is quickly distorted when I turn up the input. Also the GR leds stay on in bypass/ GRoff .
Any ideas welcome