tube preamp for metal

[Fossilshark]

can someone point me in the direction of a simple tube preamp with alot of gain and can get some overdrive out of it? preferably not too complicated as im new to tubes. yes i am going to start with a single 12ax7 preamp build but im doing research for an amp im designing (to eventually build) and i need a preamp for metal.

[J M Fahey]

You'll need 2 x 12AXy/ECC83 for that kind of gain:
Marshall JCM800/2203 preamp


or some of its derivatives (still about the same as you'll see, it's a tried and true formula):

Peavey Butcher, build preamp from input until master volume, here called post volume (same thing)

[Fossilshark]

Thanks this helps alot. Ill try the marshall

[phatt]

Sounds like this:
Can someone point me in the direction of a simple F1 racing car design? Something that has a lot of horse power (gain).  I'd like to start with a lawnmower.

Sorry chum but your request a bit fanciful. If you want to build these things you have to crawl
before you can walk let alone run with the best.

I've been at this DIY game for a long time and I've only just started to understand enough to design and build a really good amp.

I urge you to build a kit first to get you started, preferably something small. It's painting by numbers
but gets you used to how it goes together before you embark on a serious DIY project that will take years to perfect.
The chances of pulling off a fist time wonder are next to zilch.
Meantime lots of research and reading.

Just because an amp has a valve does not automatically mean it's going to be good.
If you want an easier way to go I'd test drive some pedals before you waste years learning Valves
only to find there is little benefit.
Some of the AMT pedals do a fantastic job of producing the metal sounds you desire and that will
work out faster and cheaper.
Phil.

[Fossilshark]

I understand that. Ive built a distortion pedal (not a complicated one) and ive designed and built some solid state amps. The closest thing to amplifier tubes ive worked with is nixie tubes. I was really just seeing how complicated something like a twin 12ax7 preamp would be compared to the single 12ax7 preamp im going to build first.

[phatt]

Just know that 2 Ax7's will not magically make the sound you desire the whole circuit has to be made to work together,, just grabbing a bit of some famous amp circuit and wedging it into a box of DIY ideas is not a good idea. These circuits are made up of many stages and each part has to work with the other parts and that takes a lot of R&D to get then all to talk nicely to each other. just the way the High voltage is setup for each stage can be a nightmare, not to mention that grounding layout with Valve circuits is a big problem for the novice.
Even more so with Hi gain rigs.
Phil.

[Enzo]

Two tubes are not substantially more complex than one tube is.  Just as cooking dinner for five people is not much more complicated than cooking for three people.

The idea of building a kit amp first is a great one.  Designing amps is not the same as building them, and building a kit tube amp will get you some experience working with tube circuits.  it won;t teach you much about the electronics of it, but it will show you all the details and considerations.  it will save you later trying to build something, getting all your parts together than finding out you need to order something else you had not considered.

I would suggest finding a preamp you want to build for preamp reasons.  Don;t build something based on the number of tubes.  SO what if it has two tubes, you just have to wire 18 socket pins instead of 9.  Soldering parts together is soldering parts together, it doesn;t get harder just because there are more parts.  Driving to Pittsburgh is no harder than driving to Cleveland, it is just more driving.  (I am starting from Michigan)

[J M Fahey]

Agree.
That said, if you want to start step by step, which nis fine, then start a single 12AX7 preamp ... just don't ask High Gain Heavy Metal from it
Which is not wrong by itself.

Or split the difference:
make a test chassis where you have ample space to mount the whole preamp, provision for 2 sockets, etc. ... just build a single tube one first.

Which can be as tasty as a single channel of an Alembic F-2 .... which in turn is a stereo version of a classic Fender Blackface preamp:


The transformer you buy should have enough filament winding rating for more than 1 tube ... for example 1A is ample for 3 of them; HV is usually not a problem, each triode needs ~1 mA each, piece of cake.

[Fossilshark]

Thank you for all the help. I will definitely take your suggestions seriously as you guys are alot more experienced then me. Cost also happens to be an issue here so kits may not be the best option, i havnt looked into it yet though. My electronics teacher in school is helping me with this project and is getting me the tubes and tube sockets. Im going to be working construction half the summer to get money for this build to hopefully have it done before the summer is out. Thank you very much guys

[J M Fahey]