SS Bass amp problems...

[Low_fidelity2100]

So, the other day at band practice our bass amp developed some oddness...after being on for about 45 minutes, there was a bit of crackling, and then the amp cut out completely. We turned it off for a few minutes, then tried it again...and same problem occurred. Tried using a different bass, different cords, etc...all the obvious things.
Basically, the amp works 100% ok every time we turn it on after its been off for awhile...it'll work totally fine for 15-30 minutes...then cut out, and stop working...occasionally sound will come back for a minute here or there...but over all, once it cuts out, its out regardless of what we try. When its doing this, the Pilot light stays lit, and other than the first time there was no crackling before it died.
I pulled the chassis earlier today, and "investigated", didn't see anything that was obviously fried, no burnt up components, no scorch marks on the PCB, I even smelled the inside, just to see if there was that "burning electronics" smell...theres no smell at all, haha....So I have no idea. Anyone got any suggestions? What should I be looking for?

Its a Fender "Rumble 100" 115 btw..

 

[tone4days]

Re: SS Bass amp problems...

are you cranking it at its max output during the time it works?

i am guessing heat related protective shutdown ... does it have good ventilation?

 

[Low_fidelity2100]

Re: SS Bass amp problems...

are you cranking it at its max output during the time it works?

i am guessing heat related protective shutdown ... does it have good ventilation?

We generally have it a bit above 1 o'clock on the volume (i.e. bit more than half way up)...it does seem to have good ventilation. Cut outs in the back, etc, etc...never really seems to get too hot, thats the first thing I thought of too. But I dunno. Maybe you're right? Its just odd cause it never did this until recently.

 

[astrozombie]

Re: SS Bass amp problems...

its heat. ive had 2 solid state amps do the same and it was heat. fan it.

 

[Rich_S]

Re: SS Bass amp problems...

Definitely heat. There are three basic things that can go wrong due to heat:

1. Thermal overload. A sensor designed in on purpose to shut the amp down if it overheats. In this case, the amp would stop working for a time until it cooled down. I seriously doubt it would crackle.
2. Borderline bad component. In this case, some part in the amp is on the edge, and heating it up pushes it out of spec far enough to prevent the amp working. The heat could come from the defective component itself, or just be general heat from the entire amp, heating up one overly-fussy component.
3. Faulty connection. Either a solder joint or a mechanical connector that's less than perfect, and heating it up causes it to fail.

You might be able to find #3 by probing around in the amp with a wooden chopstick until you find something that makes the crackle and cuts out the sound.

Otherwise, I wouild recommend making sure whatever cooling passages/fan/heatsinks it has are clean. Vacuum them out or blow tham off with one of those computer-cleaning cans of compressed air to make sure there's no dust interfering with air flow. Then, observe it for a few days.

If the problem continues, get it to a tech. The best way to track down an intermittent problem like this is to burn it in on a bench (preferably through an attenuator), then probe for voltages and signals while it's heating up and the problem is known to be occuring.

Blowing on it with an external fan is a stop-gap measure that will get you through a gig, but the amp was designed to run without it. If it won't, there's something wrong. SS bass amps are getting smaller and smaller while getting more and more powerful. Mechanical design and heat transfer are becoming increasingly important, but are not always engineered well.

 

[everdrone]

Re: SS Bass amp problems...

prolly heat overload, hopefully it was auto shutdown; that is what my bass amps have, also maybe a fuse. I would take the lil bugger to a tech for periodic maintenance.

 

[Funkfingers]

Re: SS Bass amp problems...

Periodic maintenance includes vacuum cleaning the PCBs and air vents.

 

[Low_fidelity2100]

Re: SS Bass amp problems...

Alright, kool, thanks for all the info everyone...I guess for now we'll stick a fan behind the amp, and hope for the best, haha...and then I can force my bass player to actually take the thing into a tech and get it fixed, haha.

 

[guitfiddle]

Re: SS Bass amp problems...

Alright, kool, thanks for all the info everyone...I guess for now we'll stick a fan behind the amp, and hope for the best, haha...and then I can force my bass player to actually take the thing into a tech and get it fixed, haha.

I have to ask what kind of amp it is, and how much wattage it has. If you have the volume on 1 o'clock, then TBH, you're having to run it to high. If your bassist gets an amp that has double the wattage, you can run it louder at a lower volume, so it'll hold together.

 

[Low_fidelity2100]

Re: SS Bass amp problems...

I have to ask what kind of amp it is, and how much wattage it has. If you have the volume on 1 o'clock, then TBH, you're having to run it to high. If your bassist gets an amp that has double the wattage, you can run it louder at a lower volume, so it'll hold together.

Its a Fender Rumble 100 115. An yeah, You're probably right, she probably does need to buy a larger amp. Specially considering we're gigging alot lately. Luckily, we're playing venues with really good PA's, and that have all had they're own backline for us to use if we choose (she generally just uses whatever amp the venue provides when we gig, I use my own **** though)...But she definitely needs to score a better/louder amp of her own...
Funny thing is, the current amp isn't even hers...its mine. haha...I bought it cause our last bass player had a tiny ****ty amp, and I got tired of not being able to hear him. He quit, we found our current bass player, and She once again, doesn't own her own amp. I'm starting to wonder if theres some rule that any bass player under 25 can't own all the equipment they need. haha.

 

[everdrone]

Re: SS Bass amp problems...

ya, Fender Rumble 100 115 has been prolly cranked at the edge of destroying it at practice and shows, its dying dude. I know, I used to crank a 115 peavey tko 300watt AT PRACTICE and the red light is always on showing that I have abused it past its limit. my competition at practice was a big room and a guitarist using a combo amp, so it was not very loud even lol

 

[guitfiddle]

Re: SS Bass amp problems...

Its a Fender Rumble 100 115. An yeah, You're probably right, she probably does need to buy a larger amp. Specially considering we're gigging alot lately. Luckily, we're playing venues with really good PA's, and that have all had they're own backline for us to use if we choose (she generally just uses whatever amp the venue provides when we gig, I use my own **** though)...But she definitely needs to score a better/louder amp of her own...
Funny thing is, the current amp isn't even hers...its mine. haha...I bought it cause our last bass player had a tiny ****ty amp, and I got tired of not being able to hear him. He quit, we found our current bass player, and She once again, doesn't own her own amp. I'm starting to wonder if theres some rule that any bass player under 25 can't own all the equipment they need. haha.

Yup. At those volumes, that amp is just barely holding on for it's life. The one I recomend ya'll look at is the Acoustic B-200 1x15 combo. Used, they roll for $200 -$250 all day. These have 200 watts, plus an extension speaker output, so you can add another 1x15 cab. There is a DI output on the back for a line out to the PA, so you can hook in and be loud as you please.

It thouroughly shakes my guts with the volume and gain on 4.

 

[Low_fidelity2100]

Re: SS Bass amp problems...

ya, Fender Rumble 100 115 has been prolly cranked at the edge of destroying it at practice and shows, its dying dude. I know, I used to crank a 115 peavey tko 300watt AT PRACTICE and the red light is always on showing that I have abused it past its limit. my competition at practice was a big room and a guitarist using a combo amp, so it was not very loud even lol

Yeah, we practice pretty loud, and in a small room...so I'm guessing you're right...time to make her buy herself a bigger/higher wattage amp. haha.

Yup. At those volumes, that amp is just barely holding on for it's life. The one I recomend ya'll look at is the Acoustic B-200 1x15 combo. Used, they roll for $200 -$250 all day. These have 200 watts, plus an extension speaker output, so you can add another 1x15 cab. There is a DI output on the back for a line out to the PA, so you can hook in and be loud as you please.

It thouroughly shakes my guts with the volume and gain on 4.

Thanks for the recommendation...We actually borrowed one of those from a friend of my drummer for a couple weeks awhile back, an yeah...totally louder than ****! I'll definitely keep an eye out for one of those (+ a 210 cab to go with it)...The line out is a HUGE plus to me...a mic'd bass amp sounds like wet dick to me.

 

[guitfiddle]

Re: SS Bass amp problems...

Yeah, we practice pretty loud, and in a small room...so I'm guessing you're right...time to make her buy herself a bigger/higher wattage amp. haha.



Thanks for the recommendation...We actually borrowed one of those from a friend of my drummer for a couple weeks awhile back, an yeah...totally louder than ****! I'll definitely keep an eye out for one of those (+ a 210 cab to go with it)...The line out is a HUGE plus to me...a mic'd bass amp sounds like wet dick to me.

If you ever find yourself in need of mic'ing a bass cab, you can use a Sure Beta 52 kick drum mic. It is voiced to pick up that low end unlike a 57 or 58.