La2a Drip problems

[cifrastudio]

Hello everyone, I’m having an issue with my La2a by Drip.

When I plug in the power cable, the LED lights up even though the switch is set to off. Also, the signal goes through, but it doesn’t compress.

Can anyone help me? I’d like to fix it and then sell it.

Thanks!

 

[pucho812]

Sounds like a problem. Trace snd compare with the drip schematic

 

[cifrastudio]

Sounds like a problem. Trace snd compare with the drip schematic

where can i find the schematics?

 

[pucho812]

where can i find the schematics?

Drip did not provide one? Don’t know how to find one? Best to step away and sell as is.

 

[Rob Flinn]

You might get more help if you post which version of the Drip La2a you are making. I think there were something like 6 different versions.

 

[cifrastudio]

Is the version 2

 

[Rob Flinn]

Did you build this ? DO you have the build docs ? Are all the heaters on the valves lighting up ?
I have built 2 of these version 2 Drips La2a, but this was some time ago & I don't own them.

There is obviously a problem with either the mains switch or the way it's wired up if you can't turn the box off with it.

If you are passing a signal but you get no compression then you have an issue either round V3 or V4 or the T4b.

 

[cifrastudio]

no i bought it from a guy several years ago but i dont have his contacts anymore. it worked fine until last month but now it has this problem (i tried it before putting it on sale)

 

[Rob Flinn]

You can check if the mains switch is faulty with a meter.

As for the no compression it's a little more difficult to track down.

 

[CJ]

T4 module would be the first thing to check. Try unplugging it and plugging it back in. Try removing the cover and see if the EL panel is lighting up.

 

[HoneyBadger Audio]

the mains, should be a simple fix with a multilmeter checking continuity. The power switch should be disrupting either the Live or Neutral from your IEC. If it is not then you'll need to trace where they are wired to and adjust how your switch is connected.

As for the gain reduction. There are 3 places that signal is possibly broken. If your unit is passing signal that means the gain amplifier is working and your only need to worry about the sidechain circuit. Check that you have signal at the following places:

1. Reduction potentiometer pin 2
2. HF adjust/ stereo link potentiometer. When the link potentiometer is full clockwise/counterclockwise (depending on the build) it cuts the signal and you will see no gain reduction.
3. Input at the T4B (pin 3)

To trace the signal in the absence of a scope you can use a multimeter on AC and send a 1k sine wave to the unit. you should be able the then trace the signal. Happy hunting. Let us know your findings.

 

[beatnik]

The power switch should be disrupting either the Live or Neutral from your IEC.

standard safety practice would be a single pole switch on the live connection, or a double pole switch on both live and neutral.
a single pole switch wired on the neutral poses a safety hazard, because even when the switch is in the off position there is mains voltage within the unit.

6AQ5 in the sidechain section would be my prime suspect for the unit not compressing at all, not uncommmon for these to fail.
compare DC voltage readings on the sidechain with the ones in this chart might provide some insight

 

[Rob Flinn]

standard safety practice would be a single pole switch on the live connection, or a double pole switch on both live and neutral.
a single pole switch wired on the neutral poses a safety hazard, because even when the switch is in the off position there is mains voltage within the unit.

I was led to believe that CE compliancy requires both live & neutral to be switched nowadays.