sick IIC+

[Baconator]

First of all, I'm a noob here so 'hi' to everyone.

I've got a no frills IIC+ (60 watt, no eq, no 'verb, black tolex) that has been my dream amp since I found it used for a good, low price about 3 years ago. I haven't been gigging for the last year or so and don't often get the chance to crank it up. About a month ago I did get the chance and noticed a nasty raspyness that followed the envelope of the notes, especially those around A (multiple octaves). I tried swapping out tubes to no avail and then tried plugging it into an external cabinet which made the noise go away. From this I thought that the Black Shadow was crapping out on me, but after replacing the speaker I noticed the same problem only with different frequencies. Again, the problem goes away when connected to an external cab and doesn't appear until the amp is warmed dup a bit and played at louder volumes (master at 2 or higher, which is plenty loud for most of my bar gigs). I pulled the chassis and found that one of the cabinet's ground lugs was loose and found a lose diode (I think - black thing with a band on one end across one of the power tube sockets), both of which I repaired. This made absolutely no difference.

I've taken my amp into a friend's father that has spent his life repairing guitar (and other) amps and am hoping he'll be able to find the problem. However, when I first brought the amp in to him I wasn't able to get it to make the noise even at loud volumes. I took it back home and (of course) the noise came back after playing it for a minute or two.

I've tried putting a patch cord between the effects send and return on the off chance that this might be the problem, but although it seemed to have some kind of effect it didn't solve the problem.

Does anybody have any suggestions short of sending it to MB? I got it at a low enough price that assuming he can fix it I could probably recoup most of my costs if I did decide to sell at some point, but I really do like the amp and wouldn't want to if I can avoid it.

Thanks for reading!

 

[Dutchman]

Hmmm???? Filter Caps??????

 

[Russ]

Sounds like it needs a cap job to me. I would send it to Mesa and have Mike work on it.

 

[Dutchman]

Nothing like having the Master lay hands on your baby. I'm with Russ send it to Mike B.

 

[Baconator]

Wow - I think I'm gonna grow to love this place quick! I can't belive I got 4 responses in 16 minutes!

I would agree that the filter caps could indeed be due for changing, but I wasn't sure that the problem indicated this. If I can find some time I'll try giving boogie a phone call tomorrow.

Any idea what the shop rates there are? I'd love to have Mike B take a look at my amp, but I can't imagine how much it might cost.

 

[Boogiebabies]

What's your houses wall voltage ? You may have insufficient power.
The only time I have come across ghost notes is bad caps, and infrequent cathode cap failure and 90V from the wall. Maybe your friend is closer to the power grid or has newer wiring or transformers feeding his outlets.

Just my 2 tiny schmeckels.

 

[Baconator]

What's your houses wall voltage ? You may have insufficient power.
The only time I have come across ghost notes is bad caps, and infrequent cathode cap failure and 90V from the wall. Maybe your friend is closer to the power grid or has newer wiring or transformers feeding his outlets.

Just my 2 tiny schmeckels.

Interesting thought, although it's always been played in the same location since I bought it and never had problems like this before. I supposed it's possible that the wall voltage in the house has dropped since we upgraded to 200 amp service last summer. I don't know if I'd call the problem 'ghost notes' though unless the ghost manifests itself as a death rattle. The amp sounds like I'm crossfading in a really, really nasty fuzz pedal following the envelope of the note. The thing that makes me think it's a vibration thing as opposed to bad caps is that it disappears when the amp is put through an external cab, although perhaps there's something else about that particular cab that solves the problem.

I'm stumped - gonna start saving pennies to send it for a trip to Mike B.

 

[Boogiebabies]

Here's an old post of mine to use before trouble shooting.


Your amp should be service every year with a full cleaning of the pots, tube sockets and check of the filter caps, tubes, jacks etc. I do a spring cleaning on every amp I have and get in. In a lot of cases of Boogie's with the SUS-4 mounting they let dust get in from the gap between the chassis and cabinet. It some cases after years of electrical attraction and the fan forcing dust in there the inner chassis can look like a vaccum bag exploded. In these cases I uses a micro fiber cloth and then clean all the dirty circuit traces with PCB cleaner or denatured alcohol and a Q-Tip. I use Caig De-Oxit on the pots followed with Ca-Lube and I use De-Oxit on all tube sockets followed by Caig Pro-Gold. I generally use a curved dental pick to gently scrub carbon and heavy oxidation. A good old fashioned pipe cleaner works great as well. I then use a straight dental pick to tighten the sockets. Finally I soak the grounds with De-Oxit and if they do not look clean enough I remove the star ground washer and scrub it with Scotch-Brite until it shines. Use Scotch-Brite pads to gently clean corroded buss wire and all 1/4 in jack contacts after a good dose of contact cleaner. So spending an hour with your baby once a year will lead to a seriously reliable and trouble free tone monster.

 

[Baconator]

Here's an old post of mine to use before trouble shooting.


Your amp should be service every year with a full cleaning of the pots, tube sockets and check of the filter caps, tubes, jacks etc. I do a spring cleaning on every amp I have and get in. In a lot of cases of Boogie's with the SUS-4 mounting they let dust get in from the gap between the chassis and cabinet. It some cases after years of electrical attraction and the fan forcing dust in there the inner chassis can look like a vaccum bag exploded. In these cases I uses a micro fiber cloth and then clean all the dirty circuit traces with PCB cleaner or denatured alcohol and a Q-Tip. I use Caig De-Oxit on the pots followed with Ca-Lube and I use De-Oxit on all tube sockets followed by Caig Pro-Gold. I generally use a curved dental pick to gently scrub carbon and heavy oxidation. A good old fashioned pipe cleaner works great as well. I then use a straight dental pick to tighten the sockets. Finally I soak the grounds with De-Oxit and if they do not look clean enough I remove the star ground washer and scrub it with Scotch-Brite until it shines. Use Scotch-Brite pads to gently clean corroded buss wire and all 1/4 in jack contacts after a good dose of contact cleaner. So spending an hour with your baby once a year will lead to a seriously reliable and trouble free tone monster.

That's awesome! I guess I need to do some shopping for the Caig stuff. I'm gonna save this post for future reference.

Thanks!!

 

[Boogiebabies]

I get mine at Guitar Center in the Pro-Audio section.

 

[tommyhawk13]

How often do you play? if you are like I am, not even a weekend warrior, not playing it very often will allow the circuits to build up "crusties". I tried to get my amp to our local boogie wizard, but he didn't even want to see the amp. He told me to spray some tv tuner spray (a safe eclectronics cleaner) on the inside of the chassis. It worked. I was ready to send the amp to MB, but fixed it myself for less thatn $10.00.

My symptoms were worse, but it's worth a try before you send it off.

 

[Elpelotero]

there's different kinds...I use the D5 part#D5S-6

 

[Baconator]

I'm pretty amazed at the response this post has generated. I guess you all can sense my frustration and sympathize.

Thanks all for the responses!!

 

[Platypus]

I'm pretty amazed at the response this post has generated. I guess you all can sense my frustration and sympathize.

Thanks all for the responses!!

You've found a great board

 

[Baconator]

Well I finally did what I should have done a long time ago and phoned Boogie tech support. Although it's impossible to diagnose over the phone Mike B suggested that it could be the pull pots failing as he's seen these causing vibration related noises before.

I'm crossing my fingers!

 

[Boogiebabies]

That's easy to determine. Pull the Master Volume and hit an E chord. While the chord rings out, wiggle the Master Volume knob. If it cuts in and out try cleaning it and test it again. If it does not go away, replace the pot. They do this when there dirty and old. The shafts are so long they move around very easily and lose contact with the resistive element in the pot.

 

[Russ]

Oh yeah, hey, Welcome to the Board...