21

LA502 Optical Compressor / Re: Release time feels bit fast

« Last post by Slembones on August 11, 2026, 04:49:08 PM »

My construction quality is world class. that being said what happens is with vocals its very good but with bass it swells to fast as the note dies. it feels like with a bit more release time it might compensate for the swell

22

LA502 Optical Compressor / Re: Release time feels bit fast

« Last post by JPK on August 11, 2026, 09:27:39 AM »

Do you also find the release time too fast with the 10mS attack?
Check the value and solder joints of R32, C17, C18.
If still too fast try increasing R32 to 4.7M. You could also add an additional cap in parallel with R32. It will also slow down the attack time but you can compensate by decreasing R29.

23

LA502 Optical Compressor / Release time feels bit fast

« Last post by Slembones on August 10, 2026, 08:03:50 PM »

Is there a way to slow the release time down a bit. it feels a little non linear. the unit sounds good and is set up per the manual so everything works and is in the right place.

24

MP566-II Tube microphone preamplifier with HPF / Re: Green LED (LD2) does not light

« Last post by guenter1910 on August 07, 2026, 12:59:14 PM »

After reflowing the solder joints it seems to work now. This is a bit of a surprise to me because measuring the connections alway showed that everything is fine. Thank you for your help!

25

MP566-II Tube microphone preamplifier with HPF / Re: Green LED (LD2) does not light

« Last post by JPK on August 06, 2026, 04:47:16 PM »

Check that R46-L is connected to the 0V. Check on the resistor leads, not the PCB pad.
Reflow the solder joints of R45, R46, R47, R48.

26

MP566-II Tube microphone preamplifier with HPF / Re: Green LED (LD2) does not light

« Last post by guenter1910 on August 06, 2026, 07:08:42 AM »

what should I check next? 

27

MP566-II Tube microphone preamplifier with HPF / Re: Green LED (LD2) does not light

« Last post by guenter1910 on August 03, 2026, 06:35:16 PM »

the connections are all ok

28

MP566-II Tube microphone preamplifier with HPF / Re: MP566-II Phantom Power problem - signal fades to zero

« Last post by guenter1910 on August 03, 2026, 06:00:31 PM »

So I guess the reason was a somehow defective microphone that finally died during the testing phase. Thank you for your support and fast feedback!

29

MP566-II Tube microphone preamplifier with HPF / Re: MP566-II Phantom Power problem - signal fades to zero

« Last post by JPK on August 03, 2026, 05:43:17 PM »

No, that's very unlikely. The microphone is isolated from the preamp circuitry by the input transformer, so the preamp itself cannot damage it. The only parts directly connected to the microphone are the 48 V phantom power (through R1 and R2), the pad relay, and the input transformer. Under normal conditions, none of these should damage the microphone.

30

MP566-II Tube microphone preamplifier with HPF / Re: Green LED (LD2) does not light

« Last post by JPK on August 03, 2026, 05:34:53 PM »

You have a broken connection.
Check that R47-Right is connected to
- R46-R
- R45-L
- U4-pin2
Check that R47-Left is connected to
- D11-L
- R48-R
- U4-pin6
If one link is missing, repair it with some wire.