Amplifier ideas.

[LSemmens]

I let out the puff of smoke on my Behringer ACX1000 last week. I was using it as a Bass amp.... Anyway, getting the thing apart is becoming a problem so I am investigating just purchasing some off the self components and making an amp up that would connect to the speakers in the dead box. My idea would be to make an amp that could handle acoustic, electric, and bass. Now to the questions.
I'm thinking along the lines of this for the power stage coupled to a pre-amp like this and use a 4 channel mixer to feed into it.

Each instrument would likely require different pre-amp stages to deal with the different harmonics.

Would the power amp stage likely to be different? Class A? B? AB? D?

I'm wondering how a subwoofer would handle Bass.

The ACX1000 has two 60W into 8Ω speakers which I would like to use.

Is it worth the effort? Given that I am on a tight budget (Pensioner) and I don't like to throw away something if it still useable.

[Wyllys]

No, it's not worth the effort. You'll spend as much in the end for likely inferior results. You blew it up being too cheap to buy a proper bass amp...

Save money?

Buy used.

Amps can be had for the cost of a case of beer.

[dannyg1]

You'll need to figure out what kind of cross-over network is built into the amp and whether it's an analog, after the amp cross or a digital one. Ideally, you ought to figure out what you blew exactly and work your options from repair first, to other later. The repair tech will be in the best position to offer advice on what you can do to minimize the cost. Might just be a power supply thing.

[dannyg1]

Originally Posted by Wyllys

No, it's not worth the effort. You'll spend as much in the end for likely inferior results. You blew it up being too cheap to buy a proper bass amp...

Save money?

Buy used.

Amps can be had for the cost of a case of beer.

Go easy on the poor guy, it is an older Behringer and reliability is not their virtue, independent of any which way you use it.

[Paultergeist]

I have signifianct experience building my own tube-based guitar amplifiers, so I feel I have some basis for rendering an opinion.....

Wyllys is absolutely correct. There is a significant learning curve associated with repairing amplifiers, and based on your post, I do not believe you have that experience. Moreover -- and again, in complete agreement with Wyllys -- even if you had the knowledge and skills, you would most likely spend more money purchasing individual parts a la carte to fix this one than it would cost to buy a decent but budget-sensitive replacement. My advice is to let this one go, and find a replacement which is suitable for your intended purposes.

[dannyg1]

Well excuse me but, are you actually suggesting that he forgo even looking into the cost of having it repaired?

Originally Posted by Paultergeist

I have signifianct experience building my own tube-based guitar amplifiers, so I feel I have some basis for rendering an opinion.....

Wyllys is absolutely correct. There is a significant learning curve associated with repairing amplifiers, and based on your post, I do not believe you have that experience. Moreover -- and again, in complete agreement with Wyllys -- even if you had the knowledge and skills, you would most likely spend more money purchasing individual parts a la carte to fix this one than it would cost to buy a decent but budget-sensitive replacement. My advice is to let this one go, and find a replacement which is suitable for your intended purposes.

[myersbw]

Hey LS,

I am a tech and here's my take on it. The behringer amp is certainly not one that ought to be used as a bass amp. Acoustic...well duh...electric? Depends on what you're playing...bass? Not at all.

I'll also take a guess that playing bass is when the amp went belly up...? (Or, heavy overdriven electric? )

That amp is designed to do acoustic work..thus, light duty. If it blew playing bass, you likely hosed the preamp section. My guess is it might be a $100-200 AU repair? Not at all sure.."could be power supply related" but I doubt it.

What would I do? If mine and I could not repair it myself, I'd divert the money toward purchase of a bass amp IF you still want to do all instruments through it. Something like this.... http://www.ebay.com.au/itm/Ashdown-1...MAAOSwCGVX-XiH

Decent price...decent performance. You can play your electric and acoustic through it, too. Want some cool preamp selections for acoustic/electric work? Use or get an older iphone 4 or iPod touch and use BIAS Fx or JamUp Pro as your preamp for an amazing array of amp/pedal models. (acoustic sims included).

As for the ebay posting you referenced...I'd avoid it. You don't know if that's 55peak-to-peap, peak or rms. If it's really an rms rating, you STILL need a hefty power supply to run it. I don't trust the limits info the bay site posted for the amp or the preamp. The preamp is designed for line level audio work, not bass or guitar extremes. That just won't cut it.

With an iPad, iPod, iPhone etc, you still have an interface to buy (about $60-90 USD) but its a great platform in that it satisfies any pre or amp you'll need. I use mine every week in church. Guitar->interface ->iPad or iphone-> BiaxFX-> out of interface into amp...bass amp works fine. Take a used bass amp and outfit it with a modest priced horn on a switch and now it serves an acoustic in a pinch!

From Behringer pics, I see 4 top screws...removing those, disconnect the speaker and I'd guess it can be pushed out the back of cab...? ....check for an internal blown fuse for starts. If you really "smoked it"...might or might not be worth fixing.
Cheers!

[dannyg1]

>>designed to do acoustic work..thus, light duty. If it blew playing bass, you likely hosed the preamp section.<<

Unless the bass has active electronics, why would you suspect the pre-amp? There's nothing hotter about the signal a bass puts out vs a piezo or a magnetic acoustic pick-up. Especially considering many acoustic pick-ups are active systems.

The amp in question was probably built pre-2006, so more than 11 years old and has a fan driven power supply.

So?.........

Well yeah! Or 'duh', as you like to say. It's more likely that it's a power supply problem. More likely to be a power supply or power amp section problem than a pre-amp problem.

[LSemmens]

Thanks for the advice.
I was being lazy. Rather than cart it with me to Church every week, I left it there and didn't bother to bring the Bass amp which, incidentally, is underpowered for the job. I honestly thought I'd blow the cones on the speakers first. No, power wasn't blown, it started out with an earth hum, which rapidly turned into a brown smell. I turned it off at that point.

My background is telecommunications, so, had I the tools, I probably could fix it, but most of my experience is electro-mechanical, though I did some electronics as part of my job. I probably could cobble a working amp together but, I don't have the recent experience (at least 20 years ago) or the time to spend on too much. I have pulled the PSU which (visually) looks ok, I've yet to be able to break the adhesive they used on the screws on the front panel, so have yet to inspect the pre & power amp. At this point, I'll probably look at a new amp.

[LSemmens]

An issue I have with buying a second hand amp is finding one at a reasonable price point within a couple of hundred Kilometres (120 miles) Most of the good ones are on the eastern seaboard which is nearer to 2000Km away! Anyway, I'll just have to make do, it's not as though I don't have other amps to play with, problem is, like the Behringer, they are all practice amps. The Behringer, at least, had a balanced output to plug into FOH.

[Paultergeist]

Originally Posted by dannyg1

Well excuse me but, are you actually suggesting that he forgo even looking into the cost of having it repaired?

Yes, that is exactly what I am suggesting.

I realize that you are trying to be helpful, but so am I. Consider this:

That amplifier -- which I believe is discontinued -- sold for around $200-250 US when it was new. I found a used one on EBay just now before I composed this post: perfectly functional for $150 US.

Now, consider the cost of having the OP's non-functional unit looked at by a competent amp pro (and there are not that many of those around). In my neck of the woods, an examination / estimate for repairs costs about $60-80 US dollars. That is NOT for the repair -- that is how much it will cost to get an estimate for the repair. The OP mentioned "smoke," so this does not sound like a simple loose connector or blown fuse -- there are almost certainly going to be parts involved. Then there are the unknowns, and while some amps lend themselves to being repaired much more readily than others, this is a Printed Circuit Board (PCB) design, and those little trace pads do not always cooperate when one is trying to de-solder / solder components. A lifted trace or warped PCB can add to the challenge. I know this because I have been there and done that.

Unless there is special sentimental value associated with this amp, my advice is to not spend any money on this, and instead use the money to get a more appropriate amp.

[dannyg1]

That's fair enough so long as he has to pay to get the diagnosis. My main objection all along this thread has been to the tone of it. Seems that, just because the guy has little money to put towards this, and was upfront enough to say it, he get's called 'Too cheap to use the proper amp' and nobody objects.

It is an older friggin' behringer and it was going to explode someday anyway. I'd be right with him, using it for whatever I could use it for until it smoked. That was destiny.

Originally Posted by Paultergeist

Yes, that is exactly what I am suggesting.

I realize that you are trying to be helpful, but so am I. Consider this:

That amplifier -- which I believe is discontinued -- sold for around $200-250 US when it was new. I found a used one on EBay just now before I composed this post: perfectly functional for $150 US.

Now, consider the cost of having the OP's non-functional unit looked at by a competent amp pro (and there are not that many of those around). In my neck of the woods, an examination / estimate for repairs costs about $60-80 US dollars. That is NOT for the repair -- that is how much it will cost to get an estimate for the repair. The OP mentioned "smoke," so this does not sound like a simple loose connector or blown fuse -- there are almost certainly going to be parts involved. Then there are the unknowns, and while some amps lend themselves to being repaired much more readily than others, this is a Printed Circuit Board (PCB) design, and those little trace pads do not always cooperate when one is trying to de-solder / solder components. A lifted trace or warped PCB can add to the challenge. I know this because I have been there and done that.

Unless there is special sentimental value associated with this amp, my advice is to not spend any money on this, and instead use the money to get a more appropriate amp.

[Wyllys]

Cheapest kludge might be to find an old tube radio and adapt it to drive the speaker(s).

[myersbw]

QUOTE->>designed to do acoustic work..thus, light duty. If it blew playing bass, you likely hosed the preamp section.<<

Unless the bass has active electronics, why would you suspect the pre-amp? There's nothing hotter about the signal a bass puts out vs a piezo or a magnetic acoustic pick-up. Especially considering many acoustic pick-ups are active systems.-unQuote

Danny, mostly because of "how" we tend to play at our typical gigs in respective mixes -and- because of personal experience I've had with some Behringer products.

It's not a secret bass frequencies "for the same perceived volume level" will require more power from the same circuitry than an electric or acoustic guitar counterpart. If playing a gig and switching instruments, my assumption is the bass will get audibly pushed to the same level if playing with the same players.

So, bass output will be likely maxed (don't we always?)...the gain setting will go up somewhat to push the SAME level of audible signal (more power mind you) to the house system. BUT, likely the master would be kept lower (somewhat?) to keep from blowing speakers obviously not intended to be used for bass reproduction.

The experience? Behringer is not a manufacturer consistently noted for prime quality equipment...they're hit or miss and usually the latter. My guess is they design (by copy) and on the edge of acceptable design.

Since the bass freq's do require more power per same audible level, the signal may do well in stage 1 and maybe 2...but, before too long, transistors or chips at the tail end might reach the peak of their power performance and..."out goes the lights", as Pat Travers so elegantly put it. :O

If he'd pushed it to the point of a power supply failure, my guess is the speakers would've ripped apart first from the excursion being exceeded for that range of notes.

That's what makes sense to me...my 2 cents.

[LSemmens]

Originally Posted by myersbw

........
Since the bass freq's do require more power per same audible level, the signal may do well in stage 1 and maybe 2...but, before too long, transistors or chips at the tail end might reach the peak of their power performance and..."out goes the lights", as Pat Travers so elegantly put it. :O

If he'd pushed it to the point of a power supply failure, my guess is the speakers would've ripped apart first from the excursion being exceeded for that range of notes.

That's what makes sense to me...my 2 cents.

I agree, in that I'd have thought the speakers would let go before the electronics. What I am having difficulty coming to grips with is what the actual differences between, say, a Bass amp and an Electric amp, apart from the speakers and enclosure design. I'd consider the only real difference between the output of a Bass guitar, and an Electric, are the frequencies. The actual signal should be the same, hence, an amplifier should only be designed to pass different frequencies depending on the task. Obviously, a Bass amp, to compete in the real world, may need to produce more sound (i.e. more power) than the equivalent guitar amp. But, in effect at component level, what are the differences, and why? My thinking is an amplifier is designed to do ONE thing, make noises louder, regardless of the type of noise.