Sound Skulptor forums

Build help and troubleshooting => LA502 Optical Compressor => Topic started by: Kliozotis on November 03, 2021, 07:55:16 PM

Title: La 502 0 VAC ON OUTPUT
Post by: Kliozotis on November 03, 2021, 07:55:16 PM
Hi, 
I finish my first la 502.
When start to setup, the voltages dc are fine.
I read 1VAC With bypass but, when i put in the IN position, 0 VAC, no matter the gain pot marker. 
I try to measure in the R17, same result with 100% gain. 
The voltage 0V with TP1 are 14vac, no voltage at dc meter. 
The ohm are 5r at this points. 

I try to find the issue but, i can't.
Maybe someone can help me. 

Thanks in advance. 
Eduardo Norte 

Title: Re: La 502 0 VAC ON OUTPUT
Post by: JPK on November 04, 2021, 06:23:57 PM
Do you hear the bypass relay clicking when going from BYP. to IN?
With power off:
Measure the transformer secondary resistance (about 23 Ohms) on the output, between hot and cold.
Measure the transformer primary resistance (about 5 Ohms) between TP1 and 0V.
Check the solder joints on the relay.
Title: Re: La 502 0 VAC ON OUTPUT
Post by: Kliozotis on November 07, 2021, 10:21:14 PM
Hi. 
I check the values and they are fine. 
23ohms on output and 5 on tp1.
This means that the tranformer are fine?

The relay i dont hear nothing with power off but hear when engage the power. 

When compressor in, i increase the GR and leds work, if i turn the ratio the Gr ups, it's like everything Works but, no signal on output. 

The relay, how about the last pins, need or not ti be solder? 

I dont know, everything looks fine. 
Title: Re: La 502 0 VAC ON OUTPUT
Post by: JPK on November 08, 2021, 09:08:07 AM
Quote
This means that the tranformer are fine?

Yes.

Quote
The relay, how about the last pins, need or not ti be solder?

No, the last 2 pins are not connected.

If you do get the AC voltage across R17, then the only possibility is a defective relay.
Send me an email here (http://www.soundskulptor.com/en/content/6-contact) to get a replacement part.
Title: Re: La 502 0 VAC ON OUTPUT
Post by: Kliozotis on November 16, 2021, 10:52:28 PM
Hi
Unfortunately, it's not from the relay.
I change it, and nothing happens.

I bought the extension cable to check outside the box.

By the way, thanks for the help.