Road King II loop prob

[Dr.Viossy]

Sometimes my RKII has a problem on the fxloop.
When I turn the loop on, in the channel strip, the volume drops down and I hear a kind of "flanger" sound. But the real problem is...that sometimes it does and sometimes it doesn't!!! :-(
Could it be a bad pre-tube? I had them all replaced a couple of months ago, should I try switchin' the tubes?
Thanks for your help.

Cheers from Italy

 

[mrd]

A "flanger" sound indicates that one of your effects is delaying the signal by a hair, and when it gets mixed back in with the dry signal, it's creating a phase issue which would produce the "flange" effect.

Try this, if you haven't already: Put the send knob on the back of the amp (the one near the bold/spongy switch) to 50% or unity gain, at 12 o'clock. Set the output knob on the front to the same, 50%. Pick a channel and turn up, then engage the loop, if you still get a volume drop or signal loss or anything, then it could possibly be a tube.

I think it's preamp V4 for the loop, but I'm not 100% sure with that.

 

[JAZZGEAR]

I just piicked up a RK II Head that is suffering from a similar issue....except for the flanging. But when the loop is active (switch on the back), there is little to no sound.

I purchased it knowing of this problem..and thought it could be a tube. But I replaced every tube in the head with brand new ones and the issue still exists...so off it goes after the New Year to Mesa Boogie for repair.

 

[metalblitz84]

STOP!!! YOU DON'T NEED TO REPAIR IT!!!! I bought a new Road King II a couple of months ago and had the exact same problem. I didn't have a loop in at all, but I wanted to use the master and solo knobs. When that happened all of a sudden I would lose volume and power and it sounding will thin and fizzy. I switched out every tube in it and nothing. It's not the tubes. If you are not using the loop then when you have it selected it causes that. Someone explained it better to me. It's something to do with the power amp not responding correctly or having the signal interrupted by nothing. Each channel has it's own loop switch. Have the master loop on so you can use the master and solo knobs, but if you aren't going to use a loop then turn it off individually for each channel. I was pulling my hair out trying to figure it out but the great people on this board and a little common sense helped me out. Hope it helps you!!!

 

[Spherion]

If it's anything like my Triple Rectifier, the RETURN has to be on 100% or you'll experience phasing issues.

 

[kingster911]

Yeah whenever I unplug my pedalboard and then start putting it all back together at home after playing practicing or whatever somewhere I forget sometimes that I have loops off and whatnot and I always forget.

 

[Dr.Viossy]

I'll try some of your suggestions, thanks.

I use a Lexicon G2 in the amp-input AND loop effects, so I can change fx order in the pre-gain and post-gain path.
I DON'T use the fx loop on the clean channels (only pre-gain effects), I DO USE fx loop in channels 3 & 4. I'll try to set all loops on and see what I get. The problem is that...sometimes it works properly and I don't know why!!! :evil:

 

[JAZZGEAR]

STOP!!! YOU DON'T NEED TO REPAIR IT!!!! I bought a new Road King II a couple of months ago and had the exact same problem. I didn't have a loop in at all, but I wanted to use the master and solo knobs. When that happened all of a sudden I would lose volume and power and it sounding will thin and fizzy. I switched out every tube in it and nothing. It's not the tubes. If you are not using the loop then when you have it selected it causes that. Someone explained it better to me. It's something to do with the power amp not responding correctly or having the signal interrupted by nothing. Each channel has it's own loop switch. Have the master loop on so you can use the master and solo knobs, but if you aren't going to use a loop then turn it off individually for each channel. I was pulling my hair out trying to figure it out but the great people on this board and a little common sense helped me out. Hope it helps you!!!

Oh that would make me giddy of that's indeed the case, cause the guy who sold me the head (8 mos old) sold it at a huge discount (I mean huge.....and no I won't divulge specifics :wink: ) because he did not want to deal with sending the head in for repair and there were no local repair shops.

I'll have to try that after the holidays.