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Amp builders unite!!!

Discussion in 'Amps and Cabs [BG]' started by Edgy_Gecko, Feb 14, 2005.


  1. Edgy_Gecko

    Edgy_Gecko

    Oct 22, 2004
    I have recently been shopping for amplifiers for my bass. I have realised that I need 100 watts solid state or 60-80 watt in tubes for my band. I will take me over 8 months to gain that kind of cash to get a decent quality amp of that power.

    Is building an amp cheaper than buying one? if so add a link with schematics please.
     
  2. Jack

    Jack

    Sep 6, 2003
    Newcastle, UK
    I think for a band youll need a lot more than 100W, and no, its more expensive, and difficult.

    Sorry to put a downer on things Edgy. :(
     
  3. patrickj

    patrickj

    Aug 13, 2001
    Baltimore, MD
    But it's a lot more fun than buying one!

    (the prerequisite being you like building things and are turned off by instant gratification ;))

    :bassist:
     
  4. DubDubs

    DubDubs

    Aug 23, 2004
    Los Angeles
    Don't build one. It takes a lot of research it won't have enough power (I'd say 20w is about max for a handbuilt tube amp) and it will be more expensive that buying one. You'll also need more than 100w for a band. Look for used you can get some great stuff for not too much money.
     
  5. Eric Moesle

    Eric Moesle Supporting Member

    Sep 21, 2001
    Columbus OH
    Yep, you'll definitely need more than 100 watts to be heard over a drummer. 200 to 300 at a minumum.

    Building yourself isn't always cheaper, in fact it is usually more expensive by the time you are done. Amp manufactures buy components in bulk for a reduced price, and you will pay a premium for one or two specific parts.

    Consider buying a "used" amp that is quality, but not boutique. Peaveys are known to be rock-solid, just not glamorous. The truth is in your playing, you just need to be heard.
     
  6. Kelly Lee

    Kelly Lee Yeah, I'm a guy! Supporting Member

    Feb 17, 2004
    Marana, AZ, USA
    OK, here ya go: Dogzilla 200watt all tube amp Dub Dubs, this amp is definately the exception!

    I have been thinking about building one but just as a fun project and not for gigging. I recommend against building a tube amp as it can be EXTREMELY dangerous. We are talking death here! :eek: If you reall want to try it, you better get some tube project experience under your belt before you tackle this amp. Trust me.

    Otherwise, I agree with what everyone else has said. One like Dogzilla there could easily cost you over a grand and you can find alot of 200watt tube amps for less than that.
     
  7. DubDubs

    DubDubs

    Aug 23, 2004
    Los Angeles
    Yeah I've seen thouse before but I'd like to see someone with average tech experence tackle that one. The poster obviously doesn't have any prior amp building experence so that particular project isn't really an option. In fact the only project someone like me (someone without amp building experence) could and should tackle is that 1w SET. Even that will cost about 120 to build.
     
  8. James Hart

    James Hart

    Feb 1, 2002
    toms_river.nj.us
    Endorsing Artist: see profile
    get an old Sunn tube head... I'd bought one here on TB a while back for $125 plus shipping. It had a pair of 6550 power tubes and was rated at between 60 and 100 watts depending on who you ask. I sold it to another TB member just before getting my 400 watt 100% tube head (and yes it sounds killer at low volume settings too). The current owner uses it through a 2x15 with his band... I think my only real issue with the volume was it didn't like my active basses
     
  9. Building an amp is not for the faint of heart. I certainly wouldn't reccommend it for anyone who doesn't have considerable electronics experience. Even then it can be difficult. It certainly won't be cheaper, especially if you factor in the labour.
    Building an amp can be a very rewarding experience but it's also challenging and doing it to try to save money won't work...:D
    If you're interested in getting into building gear, building pedals and stuff is a good place to start.
     
  10. Blue

    Blue Supporting Member

    Jun 19, 2004
    Central NC
    That is quite an impressive project. Kudos to the builder.

    As for the original topic - there are lots and lots of used gear options .. "go for that" is my advise.
     
  11. The first proper bass amp i got, and am still using is a peavey firebass 700 with peavey 410 cab, i got this for £500 second hand, and now you can get them for about £400 second hand (for the amp and cab), the way the markets seem to work, you could probably get one second hand (amp and cab) for $300 , ive seen the same cab with the lower down amps go for £250 ! , so look second hand for some peavey solid state i say, it isnt tube, but its reliable and will last and they have enough power :)
     
  12. Edgy_Gecko

    Edgy_Gecko

    Oct 22, 2004
  13. fdeck

    fdeck Supporting Member Commercial User

    Mar 20, 2004
    Madison WI
    HPF Technology LLC
    I gigged through a homemade combo amp for a few years, but my goals were modest -- 60 Watts was enough for acoustic jazz gigs that I was playing. I had several National Semiconductor LM12 power op amp chips left over from a project, and I bridged two of them, so it was actually overdesigned by a wide margin.

    Nowadays I see no point in trying to build a power amp, when they have gotten so cheap. There are some issues that the home builder simply can't deal with, such as electrical safety and thermal design.

    Like Mark Reccord suggested, I am now using a commercial bass amp, and only mess around with small-signal electronics such as preamps and the like.
     
  14. Passinwind

    Passinwind I Know Nothing Supporting Member

    Yep, and with a B+ of 750 volts at .8 amps, that's no project for a beginner.
     
  15. patrickj

    patrickj

    Aug 13, 2001
    Baltimore, MD
    You bought it from me :cool:
     
  16. There is a half way house that might be worth considering - buying an amplifier module and putting it in your own box. You can then drive this from a footpedal sized preamp, e.g. Hartke or Boss or sansamp etc.
     
  17. There are getting to be some interesting class D amp chips on the market. Texas Instruments just released one that has six channels for home theatre. 5 at 30 w, one at 60 w. Now my idea was to dedicate a speaker to each channel and run it that way. A 200 w combo with 5x8 and a 12 or 15? You'd have to have some pretty efficient speakers but it might work.

    The real challenge in building amps is not the components or soldering them together, its things like heat sinking them and making sure they component layout won't cause the amp to pick up RF (radio freq) noise and other issues you just don't think when you look at a schematic. Read some articles from the audioXpress web site to get a feel for construction.

    I like the idea of an amp module dedicated to a speaker and then run with a stomp box of some sort. Look at www.partsexpress.com.
     
  18. SirPoonga

    SirPoonga

    Jan 18, 2005
    Funny you should ask this right now. I just asked about this at diystompboxes.com.

    First, check out this thread I kinda over took
    http://www.diystompboxes.com/sboxforum/viewtopic.php?t=29755&postdays=0&postorder=asc&start=0

    To sum up. I've been looking to make an amp because I have to have a project. I figured it would be a fun project.

    There's basically three things to make a amp
    Preamp
    Power Amp
    Speaker Cabinet

    For bass this is tougher than guitar I have found out. There are alot more DIY resources for guitar.

    Preamp:
    Acoustic Control 360 Bass Preamp and Fuzz Unit
    http://www.lynx.bc.ca/~jc/pedals360.html
    http://www.moosapotamus.com/360+/360+.htm

    Flipster
    http://runoffgroove.com/flipster.html

    Speaker Cabinet:
    You know the drill here, find a driver you like, plug the values into WinIDS, tweak, build. I think am choosing the Eminence Delta 12LF. I am going to just make a 1x12 for my needs. For you a 4x12 might be a better solution. Read up on speaker wiring in parallel and series and the such.

    I save the power amp for last.
    This is the toughest part to find anything with power to drive bass. This is the part that why you see so many DIY guitar amps but very few bass amps.

    If you read the thread I linked at diystompboxes.com you can catch up on what's going on. To sum up I found (with help) the right transformer on ebay which for me is the toughest part. I plan on using the LM4780 kit from
    http://www.chipamp.com/lm4780.shtml
    That chip is bassically two LM3886 chips.
    http://www.national.com/pf/LM/LM3886.html
    Read the datasheet and AN-1192 app note.
    What I am going to do is take the two LM4780 assemblies that come in the kit and brige them. That should effectively be the 200W setup from the AN-1192 doc.
    Right now I am looking at how to provide enough power and the right power to that circuit.

    I think what I am going to end up with is make a speaker cabinet. Then I might rack mount the power amp and preamp seperate. That way I can try seperate preamps. Otherwise I'd wire a preamp bypass jack and stick the flipster in with the power amp.

    I will be moving my discussion to diyaudio though.
     
  19. truckin88

    truckin88

    Oct 18, 2001
    Newburgh, NY
    I know everyone is going to hate this rec, but the power wanted, power needed, and budget, buy the behringer head for about 200-230 new, and I think samedaymusic has B-stock (scratch dent) for 150 new, and they go real cheap used on ebay, why even build one.

    By the way sometimes you can find a peavey classic 400 tube for cheap nice, but heavy
     
  20. SirPoonga

    SirPoonga

    Jan 18, 2005
    I beg to differ.
    *IF* you know what you are doing so you can make a quality amp you will probably save money compared to the same quality commercial amp.

    Comparison, the 100W ampeg amp and speaker cabinet combo at my local music store is $300. It looks like I can make this 200W amp and speaker combo for around $250, +/-$30. The most expensive part is the bass driver. Assuming just the amp my guess (thinks out loud), $55 for the lm4780 kit, $25-$30 for transformer off ebay to produce +/-28v with enough power, $20-$40 worth of extra electrical parts, heat sink, enclosure. $20-$30 worth of parts for the flipster preamp. That's a rough guestimate, hence the +/-$30 on the overall price. It really depends on where you get the parts.

    However, you are right that it is difficult. I wouldn't use price as the reason to do such a task. You will be working with dangerous amounts of power.
    So if you want to do something like this *MAKE SURE* you know what you are getting into first.

    For me, I am a hardcord DIYer. I'd rather build than buy. I've built my computer from componants, computer desk, headphone amp for my bass, arcade cabinet, and so forth...

    Edit:
    Also, in building an amp you aren't going to get the features you would with a commercial product.

    A better route to go if you want to save some money is buy a used amp, say off ebay, and build the speaker cabinet. A commercial amp will more likely last longer in your situation since you play in a band publically. Otherwise you have to make sure you make your amp pretty solid.

    I agree with everyone else. Don't do it to save money. If you want to save money get something used off ebay.