Building a Mesa/Boogie Dual Rectifier

[mcorleone]

Hello,

I know this forum is about effects... but i was wondering, maybe somebody here knows anything about this.

I want a Dual Rectifier. But i can't afford even a used one. I found the schematics in this page: http://www.tubefreak.com. I can't locate the PCB for this circuit, nor the specifications of the output transformer.

Can anybody help me? is there a website with this stuff ?.

Thanks a lot,

George

[putrefusion]

After all the time, money, and brain hemorrhages spent trying to do that, you  could just save up and get one.  Unless you're very experienced building high-gain, high voltage channel switching amps, its hardly worth it.  

Not to discourage you or anything  :wink:

[mcorleone]

I've got somebody who can build it  

Thanks

[smashinator]

I'm not trying to be a jerk, but if you can't find the specs for the OT (hint: look at the datasheet for the power tubes), you will probably want to do a significantly simpler build.

At www.ax84.com, there is an amp called the p1 super extreme (or something like that) that is VERY high gain.  It's a higher-gain version of the p1 extreme.  That might be a better approach if you want to build an amp.

Otherwise, save up and buy a real Dual Rectifier.  Unless you salvage parts from other stuff, you will NOT save any money by the time it's actually built.  The transformers alone will set you back a couple hundred bucks.

Either way, good luck!

http://search.ebay.com/dual-rectifier_W0QQfkrZ1QQfromZR8

[barret77]

hi

If you research, you will figure out that DIY tube amps are not - and are not supposed to be - much cheaper than commercial ones. They're supposed to be high quality and completely customized. It's a hobby, not a budget solution...

a P1 basic is the same price of a 70's champ... without the cost of the tools...

anyway, good luck!

[mcorleone]

Thank you both. I'll try to explain why this amp is so expensive right here.

Before 2001, we had 1 to 1 exchange rate with dollars. 1000 $ of the local currency where the same as 1000 u$s. But our !@~#|~@# !!! government, devaluated. The current relation is 3 to 1. What does it means?. Well... imagine that you earn 1000 dollars a month... and suddenly, you begin to earn only 334, which means, you've got to work 3 months to have the same amount of money.

Here a dual rectifier, brand new, is about 2200 dollars. And a used one, 1700. If i want to build it... i can make it for less than 600 dollars.

By the way, i'm from Buenos Aires, Argentina. Beautiful place, but, damn, the exchange rate sucks!.

Thanks you both again,

George

P.s.: I was forgetting. In addition of this 'de-valuation', the government blocked all the accounts in banks. It was a mess. You couldn't take out of the bank YOUR money.

[fikri]

A lot of things to be considered
unless you know what are you doing, (the high voltages danger, etc) I would suggest you to start practice making a tube preamp first, then if you are happy enough, you could try to make the power section. And last but not least, altough a tube circuit have less component compare to the solid state amps, but the price is much more expensive because of its voltage rating and the quality.

[Joep]

have a look here....

http://home.arcor.de/guido.boehne/Boogie%20new.htm

[Mojah63]

That exchange rate does suck

I was building and modding tube amps before i found this site and fx's. To clone the Recto from scratch would be very challanging. What about modding
a cheaper tube amp???  Maybee an older Bassman??  Are you planning on making your own chassis too??  The AX84 site has a lot of DYI info and people that could help better...  If it were me I'd focus on what sound I want to get and not on cloning the Recto exactly... Do you really need the tube rectifier???  I like the low end tightness of a ss rectifier rather that the sag of the tube one...  

http://www.ax84.com/dynpage.php

http://www.ceriatone.com/

An better alternitive to a pc board would be a tag or turrett board. Study how Fender and Marshall ones are done then make one for your Mesa Clone..

http://www.schematicheaven.com/

Good Luck

[mcorleone]

Thanks!!! thanks a lot!!!!

Why a dual recto... that's an interesting question!   . I like the sound of the 'modern' channel. That's why limp bizkit, korn, incubus, rammstein, and **others** sound the way they sound.

Thanks, thanks, thanks!!

I'll study the second alternative... modding another amp!. That sounds cool, and i actually didn't think about it.

[mcorleone]

Sorry, i forgot something. I haven't even thought about the chassis.  If i can get it done... that would be the best!.

Bye  

[GFR]

Besides the exchange rate, there are the shipping costs and the taxes. Here in Brasil the exchange rate is similar and the taxes are ~60% over the total (price+shipping+insurance).

Remember that if you decide to build your own amp from scratch, you'll problably have to buy imported tubes and import tranformers yourself (very heavy ones for a DR so the shipping is very expensive).  You can have the transformers wound by someone who knows how to do it (problably in Buenos Aires it won't be too difficult to find someone) but a custom wound transformer will be expensive.

The best option would be buying a used amp from the 70's, made in Argentina or made in Brasil, restore it and mod it.

Another option would be buying something like a POD that has a Dual Rect model and feed it directly to the power amp input of the best tube amp you can buy.

Remember, for a really heavy tone you'll want a 4x12 closed cabinet.

Yet another option would be buying a similar amp made in Argentina or Brasil.

Some links:

http://www.amplificadoresmeteoro.com.br/site_espanhol/index_espanhol.htm







http://www.warmmusic.com.br/portal/index.php?indice=linha_gt&marca=warm_music

[ErikMiller]

I agree with those who have said that you may do better to modify an existing amp or build a smaller amp that has a similar tone to the DR.

My personal preference would be to do the latter. It would better accomplish your goal of doing it for less money.

The actual DR has a lot of features that are probably superfluous in your application. Most Mesas are like that. Effects loops, channel switching, elaborate tone controls, high-wattage output, etc. Any one of those things might be essential for one person but unnecessary for the next person.

By doing it yourself, you can leave out the features that you don't need or want. That's where you can save a lot of money.

Not playing in cavernous ballrooms with your amp not going through a PA? Then you can probably get away with half the number of output tubes.

Even a single output tube might be enough if you aren't playing out or are mic'ed up when you do play out.

http://www.ax84.com/ is a great place to start.

As far as obtaining the transformers, can you get ones taken from old tube radios? I'll guess that in Argentina, people are less inclined to throw things out than they are in the US, so you might be able to find transformers for tube radios.

Good luck!

[william]

Another benifit for the AX84 site  is the forum there.  They are having a large discussion on the SLO100.  Take a slo100 schematic, and compare it to a Dual Rectifier.  You'll see that 90% of the parts are the same.  The nice thing about a slo100 is it's design is much simpler, and many people have already built them.  You'll save money by not needing 23 optoisolators, and a lower part count.  The major changes can be added into the slo100 easily.  The biggest change from the Slo100 and the DR is the NFB loop.  The Modern/Vintage/Raw setting depends on the amount of NFB in the power amp.  So you may wish to impliment that.

[barret77]

Meteoro, ame-o ou deixe-o...

[sean k]

With the benefit of hindsight,I wouldn't have even started out on the tube amp in Kevin O'Connors book "Tonnes of Tone" simply because it was too complicated for a beginner...even though the build is well set out.The thing is that tube amp building is a whole experience in itself and not one easily given up as soon as you do the first one and because that experience tends to let you narrow in on what you actually like to do with tube amps then its better to start small and work your way into the understanding of what they can do for you.Old radios are definitely a bonus for output sections as this is where alot of expense lies,inc the PT,whereas alot of what you actually want lies in the preamp section and those things are easy to throw together and experiment with.My first succesful amp was made with 12AT7's I got cheap locally,some 6AK6 output tubes in push pull with an OT sourced at another local place and the PT was out of an old radio or stereogram.I hadn't had much succes with others designs so I got some info about reading characteristic sheets and designed my own amp and it works fine.Seeing high gain amps with 220k plate resistors and 4.7k cathode resistors and comparing that to old fender stuff with 100k plates and 1.5k cathodes and the differences in the cathode bypass resistors is all about characteristics and how the input grid is biased and moves accross the grid lines.Thats how you create harmonics and the type of distortion you want...Look up Norman H Crowhurst in a search and find some articles and read 'em.Enjoy the journey!
 has anyone mentioned AMPAGE?

[mcorleone]

Everybody, thanks for every single idea.

I was told that the output transformer is the key to a cool distortion, that's why i was trying to locate the specs of the transformer of the DR.

It's true, i don't need the effect loop, and i probably don't need 100 W, maybe half of that would be enough. But... what i really need... is to feel the distortion of the DR in my stomach!!!  

Thanks, thanks, thanks !!!

[mcorleone]

Williamm, thanks for the tip on SLO100. I've been reading... and well... it seems that it's almost the same thing as DR. Cool!!... =D

[JCM1959]

Build yourself a SLO-100 clone.  The DR is basically a SLO preamp using the MESA power section.  You can find "good" schematics online as well as the PCB layout.  The parts that will set you back the most on the build are the Trannys(approx $300 for PT and OPT) and the Opticouplers($13 ea.).  Prices are current USD.  I am currently gathering the parts to build one myself.

Another amp to look at is the Trainwreck Express.  You can find schematics and layouts for a PTP build online and you can easily build one minus headbox for about $300 USD.  The Trainwreck is one of the most highly sought after amps.  Real TW's easily score over $20k.  They are supposed to be extremely high gain once you tweak it correctly.

[mcorleone]

I found the PCB plus lots of pics. But i'm still finding the output transformer... now... of SLO 100....  

(I mean, the specs to get it done... can you pleaaaaase help me with that? thanks!!!)