Hi all , i have the above amp and on using Voice No7 amp sim (early brit combo) I'm getting a loud 'clack' through the speaker on every note played (only on No7 sim) any ideas, i have swapped the 12ax7 for a 12 ay7 valve, thanks keith

Could be a defect in the signal processor itself. I thought of the switch, since a dirty or defective switch can cause clacking or other noises. But usually, that would be intermittent. If it was the power tube, then you'd hear it on the other settings. So the final question is: how long have you had it? If this is a new XD, probably best to get another.

Hi Phil, i have just bought it (3 months) and I'm second owner, its approx 4 yrs old never gigged.

It still sounds like a fault in the effects chip since most of the rest of the amp (pre-amp, power section, speakers, etc.) would be in common with the rest of the settings.

It's possible that the original owner didn't know about the problem. I've had an SCXD for around 4 years but I only use 3 of the settings. I probably clicked through the rest at some point when new, but (especially for the more aggressive rock type settings) may not have sat on them long enough to hear a problem.

Has the clack been there since you first tried the setting, or did it start recently? I'm not sure how those chips are wired together, but I suppose if it started recently, it could be some circuit board trace that's used only by some component needed for that setting? (And that's really reaching because I'd guess the entire effect is generated in one place.)

only just started using it (Sold my AC15tbx) as i have serious back/leg probs, i was wandering if it could be the strings slapping against the pic, but only seems to be happening on No7 sim

hi, I've had my SCXD for about 3 years now and had no probs, in fact it sounds a lot better now that the speaker has been broken in. Anyway what your describing sounds like a problem with the chip. Does it happen at low volume as well? If it is the chip, the good news is that it is replaceable fairly cheaply. If you go onto the amp forums there's a great guy named Bill who hangs there that has a website showing some incredible mods he does to Fender amps and I do recall him showing with pics how to replace the chip in an XD. So maybe that would be your best plan of attack HTH. and good luck with the amp...I love mine

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Thanks dharma, i do use bill's site thats where i found out about the 12 AY7's, I'll try your idea and get a new chip.