Hi Iam Rafa from Barcelona.

Sorry but I don't speak German.

I have installed the LND 150 kit.

It's working, but I do not like the sound it gives me.
I have installed it in a marshall 2204. I have also installed the switch kit.
When the Loop is bypass, it sounds perfect but when it turns it on the sound becomes treble and GRSSHH.
From the beginning I have not installed the silver mica.

I tried to increase the capacitors and I had not expected the improvement.
I have also tried to remove R5 (feeback) but I have not gotten better either.
I have also installed a TRIMPOT on the input resistance to adjust signal.

Could someone give me an answer?
Thank you very very much

Bon dia Rafa,

you have chosen the right input level?

Input Levels:
InA: 30 - 60 Vpp, max. 65 Vpp
InB: 10 - 15 Vpp, max. 18 Vpp

Please post a schematic of the installation and some pictures of your build. Also some reference voltages would be great. The loop works perfect if used correctly so I guess you made a mistake with the build or the installation or both. Maybe some ground is missing or whatever.

Best regards, Dirk

Bon dia Rafa,

you have chosen the right input level?

Input Levels:
InA: 30 - 60 Vpp, max. 65 Vpp
InB: 10 - 15 Vpp, max. 18 Vpp

yes I put a trimpot in the input level resistor to adjust de level. its Sound treble anyway.

I am drawing the layout to show you Dirk but I use the layout from datasheet of the kit.

(Sorry for my english)

Not the schematic of the kit but where you have installed the loop in the amp, also reference voltages would be helpful, some pictures and a trace of the signal if possible. Also check all ground connections and make sure that the loop has a good ground connection too.

Best regards, Dirk

When the Loop is bypass, it sounds perfect but when it turns it on the sound becomes treble and GRSSHH.

Hi,

maybe you mixed the send and return level pots by accident (one is 100k and one 500k)? I did and in my case it sounded similar to your description.

Best regards

Robert

Hi,

maybe you mixed the send and return level pots by accident (one is 100k and one 500k)? I did and in my case it sounded similar to your description.

Best regards

Robert

no its ok.




This is my Voltage Reading


Algernon Charles Swinburne A Cameo

Hallo,

The voltage seams to be OK.
Do you use the loop serial or parallel ? It looks like that it has a serial connection but hard to tell. There are too much wires on the picture.

Best regards, Dirk

Hallo,

The voltage seams to be OK.
Do you use the loop serial or parallel ? It looks like that it has a serial connection but hard to tell. There are too much wires on the picture.

Best regards, Dirk

Serial


I don't know What I can do it.... it's Sound more treble

The problem is in the SEND.

I conected the output wire of the PCB to SEND jack. And the treble appears.

365V is high?

That means that the Loop itslef is working fine but you have a problem in your chain or with the ground.

Best regards, Dirk