(Not Orange) Series FX Loop Dry Bleed

[OU818]

Hi guys,

Sorry that this isn't Orange related however there tends to be a lot of tube amp knowledge here so I thought I would ask.

Lately I've been experiencing some problems with my Series FX Loop. I have started noticing that certain effects such as delay have been seeming a lot more subtle than I remember them being. It all came to head however when I tried a Trem, Tuner and Volume pedal through the loop. The Trem was rendered useless as between each pulse there was an evident 'out of phase' sounding dry bleed which just destroyed the effect. The tuner would mute the signal however it would once again leave a terrible sounding 'tinny' distorted signal coming out of the speakers. This is more or less what happened with the volume pedal except it more or less killed the fx signal before it was even half cocked, leaving only the bleed.

I have read many reports of people who use Volume and Tremolo in their loops so I know it isn't just that these sort of effects don't work well. I used to run a tuner through the effects loop of my Rockerverb 50 and it would mute the whole amp every time.

At first I thought it may be the fx loop buffer tube dying so I replaced the whole pre-amp section with 60s Mullards in the PI, Reverb and Loop and Mullard 7025s in the V1 and V2. This however only seemed to make it worse as now the dry signal is more clear and dominant than it was before.

Does anybody have any idea what this could be? I am going to take it to a tech but thought I'd try and do some troubleshooting here before I lay down my hard earned to have him tinker around trying to locate the issue.

I have spoken with Cornford and all they can do is agree that it sounds like something is wrong with the loop. Not being in the UK kind of hinders having them look at it.