360 bass preamp with home built cabinet?

[SirPoonga]

I was thinking of making a 360 bass preamp.  I love the samples on moosapotamus's site.  I went to jc's site through the link through moosapotamus's site, however that link just shows pics, no schematics     After about 20 minutes of searching the web I finally found the schematics on jc's site.

Being that I don't have a steady job right now I don't have a bass amp for my bass.  What I am doing now is playing my bass through my home theater system which has speakers I built.  It sounds good but since it is just a straight, no preamp, bass signal it gets a little boring after awhile  :roll:

I was wondering if I could make, for now, a 360 preamp to feed the bass through before it goes to the home theater system?  If so then in the future could I make a dedicated bass cabinet all I need to make is a speaker cabinet with power amp and sit the 360 on that?  Any good bass cabinet/power amp DIY sites?  My assumption is I'd build a cabinet like my I did for my home theater speakers with calculating the correct internal volume of the encolsure, etc... and find or make a power amp.  I'd prefer if I could find a decent power amp kit versus building one from scratch.

If so I can gradually get a dedicated bass amp this way as the money rolls in  

[nofretsplz]

The weakest link in the chain might not be the preamp, but rather the speaker. One time I plugged a bass into a very nice home stereo, and kept the thing on low volume. In spite of the precautions, one of the rather expensive woofers had to be reconed. I think that a home stereo/home theater rig has speakers that are designed more for clarity than ruggedness.

Perhaps a workaround for this would be to use headphones. Bass guitar is rough on these as well, but cheaper to replace.

James

[Ben N]

Yeah, I'd say make sure that whatever you build includes some kind of compressor/limiter, to keep from spiking your home theater speakers to heck.  AFA a power amp, I don't think there are any special requirements for bass--as long as it has the watage and can drive your speakers, it'll do.  So look for a decent used PA amp of at least 100 watts on ebayor wherever-sometimes you can get one for <$75.  I got an old but functional Traynor amp like that for ~$40, IIRC. Your biggest expense wil be a proper bass cab & speakers.  There are some DIY projects that may be helpful at Shvano Music (can't locate the url just now, but it is around).
Ben

[Mike Burgundy]

If you've already built speakers, constructing a good bass cab shouldn't be a problem.
There are a lot of brands that sport great speakers, at low prices. Eminence, RCF, Dayton (know only the name, tho)...
Look for adequate wattage, high SPL (and high efficiency, at least 100dB@1W), and a largeish Xmx - this gives you a little leeway in the low end if youre using a low-B
I've had very good experiences with Eminince Kappa 10's and 15's.
Not too expensive, total costs will be significantly below that of a commercial unit, and tuned lower too (most are tuned to 45-50Hz)

[SirPoonga]

Oh no, I am not complaining about my home theater system.  My bass sounds awesome on it.  You can definately tell the crossover between my mains and my sub are setup right when playing my bass.  Volume wise there is no difference as you start the switch over in frequencies.  But it is what I am using now while learning bass.  I'd like to move away from it.  But, for now, I was wondering if running the bass through the 360 preamp then to the receiver would be a good idea.  And then as a next step to make a bass cabinet  to put the preamp on top off.

Yeah, I figured making a cabinet shouldn't be too hard.  I don't know what specs I'd want right now (1 or 2 drivers, watts, etc...).  I am curious if any of you know any good websites to goto about building a bass amp or cabinet.  Now, I built home theater speakers and sub, I wonder what type of speaker I need to go after for a guitar amp.  I'm going to surf around partsexpress.com and see what's there.  My home theater speakers sound good but that's many speakers and crossovers working there.  I'd need to compress that into a single or two speakers and figure out what the best setup would be.  Along with putting a power amp on it...

[SirPoonga]

Now that it is after christmas and I have my expenses back in order I am thinking of doing this project.  However I think I will make my own practice amp.

I am thinking of using the LM3886 GGG amp circuit.  That should work well with bass, I'd think.  Looking at the GGG schematic it is very simular to the one int he datasheet which says it can handle 20-20000Hz.
I'd use a 360 preamp then.
I'm in search of a speaker(s) for this.  I will probably stick with 1 speaker though 2x10/12 would be interesting

I'd like to do what some combo amps do, have a headphones out that shuts off the speaker when plugged in.  That requires the right stereo jack which I have.  However 68W I'd think would be way too much for headphones.  I have to limit that down.  Any suggestions?  Also then I'd probably want to have a CD/AUX in so when I use headphones I can hear music with it.  Actually, a better idea would probably have a preamp out and get a Cafe Walter HA-1 headphone amp

I'd probably make this has a head and cabinet instead of a combo thinking about it now.  Everything will be modular.  Maybe event he preamp and amp.  Hmmm. Sound like I should have a rackmount head witht he amp and preamp (and possibly HA-1) ontop of the cabinet???

I'd need to power this.  Can the GGG schematic take 28V as the lm3886 specs say the chip could do.  I'd need a heatsink for sure then.