New at building amps, need suggestions on what to build for a high wattage

[coreythompsonhm]

Hi, Im new at building amps, and Im in need of a fairly high watt bass amp, somewhere around the 300 range. I play fairly large venues, and am using a 8x10 cab. And, like everyone else here, I have the "I need to build it myself" disease 

I have a fairly good understanding of the concepts behind building amps, and have good wood and metal working skills. I guess my main problem is figuring out the layout with a schematic as a reference.

I would really like to build an ampeg svt, preferably the svt classic.

Any thoughts, suggestions?

[navdave]

The SVT classic is one hell of a beast for a first build so maney toooobs it's silly. You could build a bass amp that would swing a lil over 200 watts using Marshall Major iron.
You can buy the OT and PT from Heyboer transformer for around 400 bux. I cloned channel one minus the midrange control and fed it into a cathodyne phase inverter with
great results nice loud and stable.

[phsyconoodler]

Having worked on many of the older and newer SVT's,to hand-build one of those would be a daunting task indeed.They are complicated.

  If it were me,I'd build a simpler amp with less EQ intrusion,less complicated preamp structure and about the same voltages.

Like a Sunn Amp.Simple and effective and great tone.Sure an SVT sounds great but it's as heavy as a Volkswagen and isn't as loud as some on the new feather-weight switch-mode power supply solid state amps out there.
 To me building bass amps that weigh a ton is really un-necessary. I would also look at the most efficient speakers and cabinet design so maybe 300 watts would sound like 500 watts?
  The new Markbass amps and cabinets are really intriguing.But then again,I'm not a bass player and I do see most stages at big concerts having SVT's and 8-10 cabinets on hand.Must be for some reason.

[bakerlite]

perhaps a dr201?
http://www.vintagehiwattconvention.com/forum/viewtopic.php?f=5&t=1111

a few watts shy of your request but still pretty loud - but man oh man are these heavy

i have a 100watt version and it is awesome for bass (dr103) - if i play a venue that requires more than the amp can put out i just DI into the desk using an FANTA which emulates the speaker out on the amp (it plugs in between amp and speaker and gives you xlr out)

300 watts all tube is a lot of iron.

in saying that the guy who did that thread above just finished a 400 watt version - it made me laugh:


bear in mind - that is a dr201 in the background and that is alot of amp!!

[kagliostro]

The only 200W Bass Amp schematic with layout that I remember to have seen is this

https://taweber.powweb.com/store/ab200_layout.jpg

https://taweber.powweb.com/store/ab200_schem.jpg

the Kit price is $ 750,00

About the schematic I think also Hiwatt is a good source of inspiration

see Mark Huss pages

http://hiwatt.org/tech2.html

I like the DR201 - 6 x EL34 200W head

in the DIY page you can find interesting info, but not about a so big amp

http://hiwatt.org/DIY/

Kagliostro

[Ritchie200]

Welcome to the disease!  This question has come up several times over the years.  First, a build like this would be a VERY expensive labor of love.  Let's say you copied a SVT, Major, Hiwatt, etc., design.  Huge $$$$ for the iron.  Then consider the power section.  Probably at least 6 GOOD matched KT88/100/120, 6550's - again, huge $$$$$.  I would sit down and add up the dollars to make sure your bank is ready for this kind of commitment.  You also mentioned that you are new to building amps.  We are talking pretty high B+ in these amps to get the output you are looking for.  You only have to read a few posts from experienced builders and repair techs to see that even they are nervous around these voltages.  Safety would certainly be a consideration.

Have you thought about maybe taking a preamp design from one of your favorite bass tube amps and building that?  Then run it into a big wattage SS power amp to give you the dB?  Watts are MUCH cheaper in SS!  And who knows, if you dial in the perfect tone in your tube preamp, then you tackle a big tube power amp later on.  You will have more time under your belt on the bench tweaking and your skill level will be higher.  Besides, you spread your investment out this way!  Much more palatable to the significant other, trust me.....

Good luck!
Jim

[Willabe]

+1 on everything Ritchie200 said!

If I wanted to get into building, lets say boats, I wouldn't start with a battle ship.       

Like Ritchie said, maybe start a little smaller, till you get your sea legs?       


          Brad                  

[tubeswell]

What all these other guys have said. Start with something simpler. The more complicated it is the more troubleshooting you will have to do, and the more frustrating it will be for a 1st build. This is a disease all right, but its a sickness that you want to nurture, bit by bit, building gradually on your addiction over time so you can get yourself well and truly hooked.  Its never going to be a cheap disease, so you may a well resign yourself to spending much more than you ever thought you would. So you may as well start with a tweed princeton or deluxe or something like that.

[coreythompsonhm]

"Like a Sunn Amp.Simple and effective and great tone.Sure an SVT sounds great but it's as heavy as a Volkswagen and isn't as loud as some on the new feather-weight switch-mode power supply solid state amps out there."

yes, heavy as a volkswagon, but in my honest opinion all tube amps are the way to go. Anything SS just doesnt cut it. I also have a road case that has space for a head and rack effects and has good size casters on it so it saves a lot of lifting when i do gigs playing guitar. Well heres an interesting thing... Ibought amp plans from Dan Torres that is a sunn clone with a couple mods. only problem is that its running two kt88's. It comes with a layout and everything, i would just need to figure out modifying it to get the wattage i need and run 6550's.

I already have a decent ss amp, so Im not in a hurry with this build, and am taking the time to do research and talk to as myany people as i can.

Sorry i forgot to mention, I used to be an electrician so i understand safety around high voltages, and tend to be more cautious than necessary because i am paranoid Im going to fry myself someday.

[samato]

In my novice opinion you should definitely build what you really want.  That might change as you continue to research and plan but so be it.  To me even a simple amp like a 5e3 or something is too much work to do just to get some experience.  I know I wasn't interested in building anything other than the amp I wanted.  Of course, mine was much simpler than what you are planning.

You sound like you are patient and careful enough to get this done so just take your time, especially with the planning.  Don't start buying or building anything until it all makes sense in your head and you have it all documented on paper (or on the computer I guess).

It won't be easy but I don't think you'd be talking about building an amp if you wanted easy.

[coreythompsonhm]

Thank you everyone who have replied so far, you all have been a great help.

Bakerlite, that is a really interesting layout, Im looking at it now, and more research on it is being done 

"I do see most stages at big concerts having SVT's and 8-10 cabinets on hand.Must be for some reason."

I definitely understand where you're coming from, as a guitar player I didn't understand it until I started playing bass. When playing in a band with a loud drummer, two guitarists using 100w tube full stacks, and a large venue with pretty dead acoustics, your bass amp needs to move a lot of air to cut through enough on stage to really get forward in the mix. That means large cabs, or a combination of cabs. Bass frequencies have a harder time cutting through guitar and drum level frequencies, so the right combination of power and cab is a must. 300 watts is a number I threw out there because thats what svt's are running at.

[phsyconoodler]

300 watts of SVT power is sometimes necessary.A good thump from the bass is what drives the band.
  It needs lots of tubes at high voltage and huge transformers.But I'm not sold on the complexity of the SVT to get a good bass tone.

[tubeswell]

300 watts of SVT power is sometimes necessary.A good thump from the bass is what drives the band.
  It needs lots of tubes at high voltage and huge transformers.But I'm not sold on the complexity of the SVT to get a good bass tone.

I think he could get it with a B15N (and maybe, but not necessarily, twice as many output tubes and a bigger OT)

[coreythompsonhm]

kagliostro provided a good link to a 200 watt amp, and its really not that bad of a price for the parts

I was expecting maybe 1500 to 2000 for parts by the time i was done, so this is actually a relief to me.

I believe Im going to build the weber speakers ab200, but im going to order parts as i need them from weber, because they have fairly decent prices, and im planning on building my own chassis and head cabinet anyways, so ill save a little money.

Im goint to save that svt clone for a later date so i can do it right 

[Ritchie200]

Corey,

The reason we are all here discussing your options is by the grace of Doug Hoffman.  If you are going to order parts a little at a time, might I suggest you go to Doug's parts catalog?  His prices are great and you will get your parts delivered before you even hit the order button!  And when you have problems trouble shooting (and you will!), you supporting Doug will keep this site up for you to enjoy and ask questions!  We all owe Doug a great debt of gratitude for all the (FREE!) information he has posted on this site and the opportunity for kind folks to come here every day.  Please support him.

Jim

[coreythompsonhm]

yes, i should have been more specific on Im ordering as many parts as I can from Doug, and what parts that I need that he doesn't have I'll order from the other site. Lol I had said it in my head when I was typing out the last post, but it didnt make it to the key board apparently 

Almost everything I know so far about tube amps has been from his site, and greatly appreciate everything he does. Ill be ordering my circuit board material and turret lugs from him within the next week I hope 

I also greatly appreciate everyone's help, this is by far the friendliest forum for tube amps I've found.

When I start getting parts and building, I'll definitely keep this updated with photos as I progress

[andrew_k]

6x KT88 @ ~700V plates = ~300W. Exceptionally dangerous territory for a first build. Be safe.

[Willabe]

And how much current?  1.2A? or more? Should be enough to put down a large horse.       Maybe I've got that wrong?

Not that I know that much or have a lot of experance, but I did a cap job on a Sunn bass amp, 4x 6550, 550+dcv. It was a little nerve wracking. I put one hand in my back pocket, used a chop stick to turn on the amp after I changed the filter caps and used clips on the meter probes on everything I measured.    


        Brad      

[Tone Junkie]

+1 on ordering from Doug man sometimes ive recieved my stuff 2 days after my order no one else is that fast. Bill

[coreythompsonhm]

I modified my multimeter so now it has longer leads with alligator clips 

I found a small variac for $65, brand new. Worth the money? Or should I look for better quality?

[Bub]

Possibly a Traynor YBA-3 Custom Special with 4 x 6550s. All the info is in TUT 3. This was my first build and I used the pre-amp from the Ampeg B15 in the same book. Big bass-O-matic, loud and clean.

Rob

[Frankenamp]

...
Like a Sunn Amp.Simple and effective and great tone.Sure an SVT sounds great but it's as heavy as a Volkswagen and isn't as loud as some on the new feather-weight switch-mode power supply solid state amps out there.
 To me building bass amps that weigh a ton is really un-necessary. I would also look at the most efficient speakers and cabinet design so maybe 300 watts would sound like 500 watts?
  The new Markbass amps and cabinets are really intriguing.But then again,I'm not a bass player and I do see most stages at big concerts having SVT's and 8-10 cabinets on hand.Must be for some reason.

They are there for two reasons: 1) they look impressive (I submit Heaven&Hell's backline prima facia); and 2) the bass player has roadies to move his stack(s).

I would recommend a Sunn (Conrad has posted here occasionaly) or a Hiwatt clone both great topologies that sound excellent. with a couple hundred watts and a pair of these: http://www.billfitzmaurice.com/Jack.html or these if you have the woodworking chops: http://www.billfitzmaurice.com/DR280.html   You would need a kilowatt+ if a conventional cab could take it to be louder.
If you are into complexity, you could always add a sub. You might want to explore 811's or 813's ( http://www.triodeel.com/tubedata.htm ) if you got the Tim Allen disease!

[gldtp99]

I'm going to suggest building two Hiwatt DR103-type clone heads--- one a normal full featured head and the other a Slave unit---you wouldn't need two preamps---- wire the 8x10 cab so that each head powers 4 speakers each.
Parts are easily available, voltages are in the normal tube amp range, schematics and layouts for the build are excellent, current production EL34's (or 6550/KT88 if you prefer) can be used also keeping cost down. Might cost the same or less to build two 100 watters rather than one 300 watt tube bass amp.
Sometimes two heads are better than one------ just a suggestion.
FWIW---- i lent my '72 DR103 for a memorial jam for bass duties w/2x15 bass cab---- the several different bass players liked it very much---- vol levels were such that this rig could perform well for bass guitar.....................gldtp99

[toomanyslurpees]

I'm a fairly novice builder but I though I'd chime in with my thoughts as I've been a bass player for a lot longer and do much more gigging than amp building. I've had an SVT classic for a decade now and though it's got an awesome tone, my search for a better sound took me elsewhere, though an extra plus of ditching tube poweramps are how much lighter solid state is and not having to live in fear of the day my power tubes wear out and I have to dish out another $300 in tubes... I'm on my third set.

I've found what I'm looking for tone wise (yeh, at least for the time being) in running a solid state power amp with a tube preamp (warmth and some dirt) in parallel with a solid state preamp (sterile and boring, but I just use it to bring up the volume to match the tube pre, it brings a tight low end punch that I haven't found in a tube bass amp) The tube pre is the Ampeg SVP-PRO and I've found I can get the tube warmth in a lighter, less maintanence rig, plus I have control over how dirty or clean I want to sound, whereas a cranked SVT only sounds like a cranked SVT, not a bad thing if that's the exact sound you want. I've been thinking about building my own version of that preamp for the heck of it, but I have way too many half built projects on the go.

For the record, I found a pignose 100W tube bass head in a pawn shop for a fraction of what I spent on the SVT-CL, (it weights a fraction too) it has 4 6L6s (read that it's closer to 200w) It can't do what the SVT can do but in a lower volume setting it comes very very close. I gig it for most shows where we're not playing with a full drum kit and we're recording at the end of the month, I'm bringing the rackmount getup and the Pignose, not bringing the SVT....


So my thoughts would be build an awesome tube preamp, save your wallet amd your back, but that's just my thoughts, not right or wrong.

[coreythompsonhm]

...
Like a Sunn Amp.Simple and effective and great tone.Sure an SVT sounds great but it's as heavy as a Volkswagen and isn't as loud as some on the new feather-weight switch-mode power supply solid state amps out there.
 To me building bass amps that weigh a ton is really un-necessary. I would also look at the most efficient speakers and cabinet design so maybe 300 watts would sound like 500 watts?
  The new Markbass amps and cabinets are really intriguing.But then again,I'm not a bass player and I do see most stages at big concerts having SVT's and 8-10 cabinets on hand.Must be for some reason.

They are there for two reasons: 1) they look impressive (I submit Heaven&Hell's backline prima facia); and 2) the bass player has roadies to move his stack(s).

I would recommend a Sunn (Conrad has posted here occasionaly) or a Hiwatt clone both great topologies that sound excellent. with a couple hundred watts and a pair of these: http://www.billfitzmaurice.com/Jack.html or these if you have the woodworking chops: http://www.billfitzmaurice.com/DR280.html   You would need a kilowatt+ if a conventional cab could take it to be louder.
If you are into complexity, you could always add a sub. You might want to explore 811's or 813's ( http://www.triodeel.com/tubedata.htm ) if you got the Tim Allen disease!

i wish i had roadies