Chorus issues.

[Richie_B]

Hey guys, Due to work I've been kept busy. Alrighty... a little while back I was having a few issues regarding drops in volume. I do think that's either the guitar lead or jack. The issue that is really bugging me is the chorus or lack there of.

I notice that on chorus patches it either sounds like it clips or there is no effect at all. An example would be 26 Sparkling Chorus where it just sounds completely clean. On 6 Clean with Compression is where it clips and distorts. There is no red light type clipping, it's just the wait it has been sounding.

I put new tubes in yesterday, the Mullard long plates which apart from what is going on right now sound good. Could it be the trimpot, I don't know. Hoping for a solution from the experts :)

[Harley Hexxe]

Hey Richie,

    Did you try plugging in your guitar cable into the other jack to see if it still drops the volume?

    I don't believe the Chorus issue is with the trimpot, it sounds more like an op-amp, but I'm only guessing at it. MJMP might have a better idea where the issue could be.

      Harley 8)

[MarshallJMP]

Hey Richie, can you send me a soundclip?

[Richie_B]

Hey Harley, The rear jack has never worked, I'll have a go at repairing it one day. MJMP, Ive attached a clip of the issue. Sorry about the quality, recorded it on my phone.

[MarshallJMP]

The trimpot of the chorus bias should be set at around 11 o'clock, is that the case?

[Richie_B]

I just went and checked, I think I had set it before. It looks pretty close to 11 o'clock. Here's a pic just to be sure.

[MarshallJMP]

try to turn it a few times and set it back to it's original setting. Just to make sure it's not a bad contact in the pot.

[Richie_B]

Ok, will give it a try now. Just to be sure, its the trim pot on the far right. What IDid notice while i was in there was that the trimpot on the top left was turned down, i havent touched it. Other pictures ive seen have it up a bit. Finally is it safe to adjust while the unit is on? Cheers.

[MarshallJMP]

yes you can turn it with the unit on. Just be careful

[Richie_B]

I turned the pot a few times then reset it. Am still having the same issue. turning it to the right, turns the chorus off, to the left give more break up.

[MarshallJMP]

So when turning it you hear a difference?

[Richie_B]

Yeah when i turn the trimpot to the right, the sound is clean. At around 1to 2 o'clock and onwards its a clean sound, no effect.

[vansinn]

The clip sounds to me like it's the active electronics, not a defect trimpot.
Richie's comments doesn't indicate scratching sounds produced by the trimmer itself, when changing it's viper position; but merely that the intensity of the cracking goes up in one direction, and goes down in the other direction.
Thus, I - cautiously - conclude it's likely the associated electronics being at fault.

@Richie: try spaying the opamp and bucket brigade delay chip, i.e., the near-by chips, with cold spray when you have signal on, and report if/how this changes the cracking.

[MarshallJMP]

So if I understand correctly,after 2 o'clock the sound is clean but no chorus effect, lower the sound distorts and no effect?

[Richie_B]

There's an update. After again adjusting the trimpot I've found that between 10 o'clock and a fraction after 12 o'clock is where the noise happens. Anywhere from all the way to the left to just before 10 and anywhere from just after 12 to all the way right is clear but still no chorus affect. I'm pretty much flying blind here but want to understand what it is and how to fix it.