Loud pop on shut down. Marshall IBS

[essexbob]

Hi all,

I picked up a Marshall IBS 100w head at the weekend for literally a few quid. It works ok and is quite nice in its own way, but makes  really loud pop sound through the cab when switched off. It sounds like something discharging. It is proper loud, not a normal shutting down sound. Any ideas of a fix? I looked inside and no burn marks - some huge capacitors in there!  

cheers.

[BreadBin]

Pull the speaker lead before you switch off?

😁

[essexbob]

😀 yes, I've been doing that but I'm likely to forget. And I always need something to tinker with (stop sniggering at the back.)

[KiOgon]

A PMR acros the power swich will sort it, for example: https://www.ebay.co.uk/itm/1x-RIFA-Kondensator-100n-100R-X2-250V-SH-PMR209-RC-UNIT-0-1-F-uF-nF-C69k/264043210759?_trkparms=aid%3D1110001%26algo%3DSPLICE.SIM%26ao%3D1%26asc%3D59623%26meid%3D275ba97cd71f4aa899873ac674304144%26pid%3D100010%26rk%3D6%26rkt%3D12%26sd%3D173895418110%26itm%3D264043210759%26pmt%3D0%26noa%3D1%26pg%3D2047675&_trksid=p2047675.c100010.m2109

[essexbob]

Thanks, I'll get onto that. Likely to be resumed  when I get one and realise I haven't a clue how to wire it in. 😀