Please Help! OOps... IIC+ boing boom pop hiss buzz

[Masterof1angel]

well.... boom might be a little extreme but it seems these things always happen when you are getting back into music and getting your life straight. I put some new tubes in my baby and was really diggin the sound (tung sols, wing c) and was like (yeah!) But it needs bit more. So I tried on a standard boss eq pedal in the loop and was like (yeah, that's it), So I'm playing around with the settings and crankin the sliders down in 15 watt mode, just loud enough to stand in front of the amp or sit in front of the 1x12 at night, when I decide to see what the eq can really do to my bottom end. I start with the 80 on the face and boost the 100 in the loop and all it brings out is this deep boomy endless open bottom that sounds like the speaker is distorting. So I'm listening to it flop and thinkin, "Aw Man, that doesn't sound goo.. Pop Huummmmmm" :shock: So now I've got a great sounding amp with a deep hum and sometimes random clicks and pops like a confused clock. :wink: So anyway, the hum is almost a OHM! like a Monk meditating but has more of a OOOOO sound like a vacuum cleaner is in the other room and it's bleeding through the power. it is most prevalent in the 80 hz region and less obvious going up in frequency. It's very natural and clear and powerful - almost like a sine wave, but it strikes me as a very dangerous sound (note I have been electrocuted) - it sounds like electrical hum?

 

[Masterof1angel]

Anybody?

 

[Masterof1angel]

I'm just going to burn it...

 

[Freefall]

Wish I had the tech skills to even render an opinion. Perhaps a phone call to Mesa is in order. If there's a likely cause with a simple fix, they might point you in the right direction.

 

[zodiac272]

sweet, that will give new meaning to the flame maple cab! post pics


could be tube, capacitor or LDR related... or anything else. unless you are a good tech, I'd send it to mesa. mike b. will have it perfect for you.

scott

 

[Masterof1angel]

yeah, thanks. :lol: that would be so epic! Flame maple, Baby! As the amps became more and more highbrow and rare, people could look back and laugh, cry and marvel at how simple we were. I would send it to mesa but the shipping on a 80lb? combo has got to be outrageous. As for Calling Mesa, Since it's a bit late, (now that I think about it, California is 3 hours back) I didn't.

So, I called my step dad(record head) and he said it might be 60 cycle hum and had me check all the outlets and the power conditioner, since we had thunderstorms lately, as well as checking the send from the effects loop to see if the hum originated before loop. I Went FX send to my marshall jcm 800 - that didn't work too well haha! had the IIc+ down at whisper volumes and the marshall at 0 and 0 and put the master up to 1 and cranked the preamp to all of .5 and heard a CRACCKAPOWWWWWW!! and realized that there was a dirty pot. Dang amps as old as I am! So I made a mental note to clean her out later next time I wish to risk life and limb and turned it off.
I'm thinking it might be a loose wire or something that would explain the random clicks and pops. Maybe it's the rectifier, I don't know.

 

[zodiac272]

if you do ship it, you should just ship the chassis... smaller and lighter, probably 35 lbs packed. I'm not trying to have you spend $$ but if it hasn't been serviced in forever, that may be a good idea. your issue sounds like a failing component rather than a loose wire, though you could get lucky. either way, it may be due for a cap job.

got any pics?

scott

 

[Masterof1angel]

if you do ship it, you should just ship the chassis... smaller and lighter, probably 35 lbs packed. I'm not trying to have you spend $$ but if it hasn't been serviced in forever, that may be a good idea. your issue sounds like a failing component rather than a loose wire, though you could get lucky. either way, it may be due for a cap job.

got any pics?

scott

Well, I had a cap job when I bought it over a year ago and I think I had the tech look over all the caps and resistors+ he give it a clean bill of health... you mean remove the speaker? I'm gonna have it checked here, and maybe one day when I get some extra mony give it to MB.

 

[zodiac272]

cool if you have a local tech that you trust to look it over.

if you ever ship it, just take the metal chassis out of the combo shell. there are 4 screws and then the chassis slides right out. very easy. then it's much smaller and lighter to ship.

scott

 

[Masterof1angel]

cool if you have a local tech that you trust to look it over.

if you ever ship it, just take the metal chassis out of the combo shell. there are 4 screws and then the chassis slides right out. very easy. then it's much smaller and lighter to ship.

scott

Local tech is Dave Sarge. I trust him to look it over and he knows a lot about older amps and teaches here at penn state (electrical engineering prof. i think). Anyway, he's a good guy and I'm looking forward to it with him. I always seem to learn something new. Only thing is the IIC+ is a bit different and I've heard things about shaky diagrams. I think he got the one from mesa when I had him look over my mark IIC+ when I got it, but I'm not sure it's the best one. I know you guys have been researching a lot on that.

 

[fishyfishfish]

Might be a defective tube or tube socket not making good contact. I had one of a new set of tubes go south and did the same thing. (Only one tube was bad.

 

[Masterof1angel]

Might be a defective tube or tube socket not making good contact. I had one of a new set of tubes go south and did the same thing. (Only one tube was bad.

Good point. I swapped out the preamp tubes and put some mesa tubes in, and it was not humming, so I put the tung sols back in and low and behold it was only humming a bit! I figured maybe it was that the tubes were in a different position and that's what caused less hum, so I went through and swapped the tung sols 1 by 1 until it took most of the hum out (only took one out and it's still humming and clicking very softly) I was like "Cool"

Next thing I noticed was that when I switched the amp off standby, the Hum (big and bold) was there for a second and the speaker jumped. When I switched cabinets to see if the speaker was messed up, it happened again, and since I was behind my amp, I noticed that the tube (power) on the far right flashed blue as i switched the standby off. I then Swapped the power tubes to another set and it did it with the new tube again in the same place.

Help?