Lets build that monster guitar amp for $250.00 or less.

[ivey]

The "Monster Amp" that I have in mind is solid state. A tube amp of this size would cost far, far, more money. And would be too large to move around.

As funny as it may sound "mosfets" are cheaper than BJT's in today's market. But with a little research on the internet and being resourceful can go a long way.

This monster is not my creation, but is a collection of circuits from other sources put together to give us the results that we desire.

First we will use the Fender tone stack, it is easy to build and put together. You can get most of the items that you need from junk electronic that others last thrown away. Radio Shack, Jameco,and Mouser, can fill in the blanks. The reverb tank can be obtained from Antique Electronics for $18.00 part #4FB3A1B.

The schematic for the Fender Tone Stack, is at Red Circuits. WWW. redcircuit.com. It uses 2N3819. You may be able to get them at Radio Stack. If not, do not worry. I have laid out a pcb for the pin outs of both Fets, because I do know that Radio Stack do carry the MPF102. Which most Fets pin out use.

This "Monster Guitar Amp" starts at 200 watts and ends at 350 watts. Any more than that, a cost of the transformer goes up.

We will use only discrete semiconductors, no IC's at all. And will be kept to the lowest part count possible.

So here is the pcb layout using the 2N3819 pin out. I will post the MPF102 pin out next week Thrusday. With the MPF102 pin out, you use such fet's as 2N5457 to the 2n5459 and more. Including most 2Sk units.

Enjoy.

Take Care

Ivey

[mooreamps]

You want a "monster" amp for under $300 dollars.... Go to Fry's and buy something...

-g

[ivey]

Yes you are correct. "Frys"!!!

That is why most of our hobbies and other things we use to use our leisure time on, has gone the way of the dinosaur. Because every one today is looking for that instant happiness.

What does the person do when it breaks and they spent their last to purchase the amp and pay bills.

Besides, most of Fry's items are re-manufactured or "Grey electronic goods. Most are already two to three years old. Or NOS.

In the San Diego area, there three of them here. One off I-15 near Balboa, one in Santee, and the other in Vista.

I know people who purchase computers from them and regret that they did.

I want to show people how to build an amplifier with power, that went it breaks, they themselves can repair it. So that they can say. " I built this".

Our country is becoming a nation of servants. We no longer built things or create things. We just serve pizza's, hamburgers, and fried chicken. We only things we want to do is sit at a desk and push pencils or keyboards.

We need to return to the things and habits that made us who and what we are. We lost so much in the past 40 years. We on and on about how great things are, when in fact, they are all screwed up.

We are finding ourselves always looking for instant satisfaction, that we lose the things that are important. Ourselves.

People no longer build muscle cars, boats, etc., because we are all told that is wrong. We are allowing ourselves to be herded into what direction that those fools out there decide to take.

There is no oil shortage, just a tweaking down on the valve, that is what is taking place.

Do not foolish and believe what the agents of the government, and it clones are feeding you. There is billions of gallons of oil in our ocean areas. They just have not figured out a way to make a profit from it yet.

Building your own amp is food for the soul. It will define who and what you are.

Take Care

Ivey

[custom_amp_30]

Frie's Electronic, Yes a large Mega-market of electronic gadgets. I hoped that the suggestion would be for a larger Electronic supply company in the L.A. Area. Something equal to Mendelson electronic's (Dayton, Ohio) but on the west coast any suggestion. First, id a supply source and the interest in creativity will surface. Surplus electronic's supplier even better. Just believe that we would spend more on our hobbies, even during these hard times. The next idea will come from these sleeping minds..

[Chuck H]

If I weren't lazy I'd tell you about all the things in this post I utterly disagree with. Well, let's just say that all the things in this post I utterly disagree with...

But the question I'd like to pose is, since we build guitar amps here, who want's a 300 watt solid state guitar amp? I know it's cheaper to build with SS devices than with tubes and part of your point is to make the project accessible, but why would a creative and artistic individual squander their time and $$$ on such a pointless venture? If my local farmers supply were having an incredible sale on manure I wouldn't buy any because with no use for it I'll have thrown my money away on $h!t. And if I need 300 SS watts for a guitar it means I'm playing a large venue in which case I'll plug into the P.A. I'll happily keep doing fewer tube amps instead of building SS amps, thanks. I would think that part of the point in building your own amp is to make something special and good sounding. So whats the point in giant, cheap and bland? I never built anything just because it was cheap to build, a project needs other qualities to entice me. A good deal on something of little use isn't a good deal at all.

This might be a good project for a bass or keyboard player though.

[mooreamps]

Yes you are correct. "Frys"!!!

I want to show people how to build an amplifier with power, that went it breaks, they themselves can repair it. So that they can say. " I built this".

Our country is becoming a nation of servants. We no longer built things or create things. We just serve pizza's, hamburgers, and fried chicken. We only things we want to do is sit at a desk and push pencils or keyboards.

Building your own amp is food for the soul. It will define who and what you are.

Take Care

Ivey

Oh, I Like This Guy !!!! You are so absolutely Right On... !! I'd love to see someone build this amp ; Champ 1000 Watt Tube Amp ; plug it in one stage, and then turn it up to "11" !!

-g

[ivey]

I am so sorry..., that I can no longer help people out when it comes to electronics surplus suppliers on the west coast.

I live in California, as well as in Michigan. And I can say with anger, that I do not like some of the business dealings of cut throat billionaires and political people.

There was a business in San Diego, that was known as "Electronic Town". It was located in downtown San Diego. The owner, own the building as well. But when big business and government came calling to build a new baseball park for the San Diego Padres. All those Ma's and Pa's stores disappeared.

You could find almost anything you wanted at "Electronic Town". Now it is gone.

The same for Gateway Electronics of San Diego.

But there are three places left in the San Diego area.

Murphy's Industrial Electronics and Supply in El Cajon, California and California Electronics, also in El Cajon.

Plus, a new smaller electronic surplus store in San Diego, on Ronson Rd, near the UPS company grounds and truck service center.

There is always..., "All Electronics". I suggest that you give them a good look over. They are selling some very, very good stuff, at very low prices.

I order from them often. Just use your imagination, and electronic skills, and you will discover that they have all the parts required to build a 200 watt Mosfet power amplifier; for as little $100.00 dollars.

You see the problem with some people to day is that they feel and believe, that they must have all the right parts to do a masterful job. That is not true.

I built copies of Altec Lansing's A7 speakers out of solid oak planks, that I glued together using wood I obtain from box springs. They use some of the best hard woods available for those box springs. It took some work,and 6 used box springs. But they were some of the most beautiful parkay speakers in the world. And they sounded outstanding. And I bite and kick myself, each time I enter into Carl's home and see them sitting there.

I sold them, for vacation funds to BC.

Take Care

Ivey

[pdf64]

'This might be a good project for a bass or keyboard player though.'
Or pedal steel, jazz or some metal tones that require masses of headroom, eg to get the scooped mid/down tuned tone from a 50 watt amp, at stage sound levels would require a 4x12 loaded with EVM12Ls.
If you don't like the idea, no one is being forced to build one, it seems to me overly negative to question the validity of such a project just because it wouldn't currently have any utility for you.
I remember EVH's stage rig relying on a monster 300+300 watt SS amp at one time (his Marshall was driving a Palmer speaker load/simulator, that then fed the stereo fx then to the power amps).
Just because the project is out of step with the current orthodoxy doesn't mean that it should be suppressed.

[Chuck H]

+
I know the spirit of the post was good. Sorry for being cranky. I picked up a heavy negative vibe about our MO from the post immediately preceding and took offense.

I'll second looking into All Electronics. It's a chain, but a small one. That's if any are still around. In the San Francisco Bay area, specifically Santa Clara there are a few "salvage" type places too. I expect if one were inclined you could find such places near any metropolis. In Santa Clara I use to shop at Halted a lot. They had shelves of big cardboard boxes full of pulled tubes and a tube tester near by. As little as five years ago, which is the last time I lived in the area, you could still go in and find tubes appropriate for guitar amps, test to see if they were good and take them to the counter. IIRC they cost one to three dollars each on average. I still have many of my "finds" like a trio of Mullard 12ax7's, a pair of Tung Sol 5881's, a couple of the old "coke bottle" type 5u4's that look sooo cool and quad of "the Fisher" branded 7591A's that test good but I haven't plugged them in yet. As well as a heap of Sylvania, Bugle Boy, Telefunken and other 'label rubbed off' 12ax7's that I'm still using. Of course the also pulled transformers and other stuff like switches, rheostats, insanely high quality sealed pots, big motor run caps, old school pilot lamps and just a bunch of stuff you might use in a tube amp. I'm a big believer in salvaging electronic "junk" for personal projects.

[Steve Conner]

There's no fundamental reason why solid-state amps can't sound as good as tube ones. Except for:

Experimenter expectancy. People expect transistors to sound bad, so that's what they hear.

Cost cutting. In most cases, the cheap lines of amps are SS, and the top-of-the-range ones tube. In particular, the SS ones get cheap speakers, and that really kills the sound. Compare the speakers in Marshall's Valvestate cabinets to the speakers in their "real deal" 4x12s which are also made of actual wood, not MDF.

Designers that don't understand solid-state. EEs are only just now beginning to understand the reasons why tubes sound the way they do, let alone how to emulate them with solid-state components that vary 200% between batches and with temperature. It's not as easy as you think, if you even have thought about it, which I doubt. Peavey have always led the field in this respect, with their Transtube line of amps, covered by a number of patents.

Last of all, no current feedback in your power amp.

You can probably pick up a used Peavey Transtube amp for less than Ivey's $250, and it'll have a real wood cabinet and a good speaker, and be made in America. The bad news is, it might be a Bandit.

If you want to make your own, Rod Elliott has a number of tried and tested power amp designs, and you can hook up a tube preamp to one if you really want to. I started out building hybrids like this, because I was a broke student and couldn't afford an output transformer. (Somebody eventually gave me an old tube PA amp and I was hooked.)

I've come full circle, in that my last amp was a hybrid again, through choice because after 10 years of thinking about the problem, I thought I finally understood SS enough to be able to make something really good. My next one will be completely solid-state.

[Chuck H]

Peavey have always led the field in this respect, with their Transtube line of amps... You can probably pick up a used Peavey Transtube amp for less than Ivey's $250, and it'll have a real wood cabinet and a good speaker, and be made in America. The bad news is, it might be a Bandit.

Hey!!! Don't dis the Bandit. That was my first amp and it got my vote in the "best SS" thread.

Before I started modding and building tube amps I use to say "If they ever come up with a SS design that sounds as good as tubes I'll never look back." but now after almost two decades at it I realize that I've developed a soft spot (besides the one on my head) for the tubes. I've grown fond of all the nuances of how tube amps are different. Not just the big obvious reasons. I can't imagine SS will ever be the same. But that doesn't mean it can't eventually be good, though different. I still like a good stomp box and I'm pretty sure I could tolerate using a Bandit for a gig if I had to. I played through a new little Roland amp the other day and was blown away by how good the high to uber gain tones were. And of course most people don't complain much about the JC120 clean tones. For most of what I do a good clean and a good uber gain is enough.

I've come full circle, in that my last amp was a hybrid again, through choice because after 10 years of thinking about the problem, I thought I finally understood SS enough to be able to make something really good. My next one will be completely solid-state.

Not long ago someone posted a SS preamp design that they had painstakingly set up to be a Vox AC30. They had emulated time contants, rounded and stepped the square wave forms to be more "tube" like and even simulated the bias characteristics of how some stages clip more in cutoff and other more in saturation. He had scope and spectrumed it and said it was very, very close. It was years ago and I lost the file in a computer crash. The only argument he wasn't able to say he found a solution for was the way the preamp in a tube amp would suffer sag as a result of the power amp. And so ultimately the dynamics of his amp would be different... But not much.

I'll look foreward to hearing what you come up with.

[Steve Conner]

Chuck, I remember the AC30 simulator guy. I was really impressed by his work. He got bought out by Vox/Korg, as far as I know, and they made him take the site down.

I have a few nifty ideas, and good experimental results to back them up, but I've decided not to publish them. I kind of feel bad about that, since much of my philosophy of what constitutes good tone, and my conception of what guitarists want from their amplifiers, comes from here. In the almost 10 years I've been a member, I've gone from Sepultura to appreciating the finer points of Peter Frampton.

But I know 99% of you guys would prefer to be building tube circuits, so they wouldn't really be of any use to you. The only people they would benefit are engineers from guitar amp companies lurking around here in their lunch breaks, and I'd rather they hired me than just got my work for free. But then the AC30 guy published his stuff and managed to sell it anyway.

The Bandit was the amp I wanted in high school, too.

[R.G.]

I have some experience with building amps for 200W - 1kW. This experience taught me that things get much more difficult and expensive as the power rating goes.

It made me rethink how I approach amps. I think my favorite approach to a truly monster amp would be to make it incrementally. This started when I noticed that very few amps over 100W have a single speaker. If you're going to use multiple speakers, why not use multiple amps, too?

One day I'll build this. Take a decent chip amp, like the LM3886. Mess with it a bit to make it have a lower damping ratio and soft clipping, and power one speaker with the amp. Include the power amp and power supply in the speaker cabinet. Odds of this running first time are very, very high, as the odds of a 300W to 1KW amp working the first time you build it are not.

Now do it again. Feed both amps from the same preamp. You have 100W. Need more? Build two more. Now you have 200W. Need a kilowatt? Build 8 more. Each time you build one, it gets simpler and better known how to get it running. Need 5KW? You can do it this way, and be pretty certain that they'll work.

To go to a gig, take along as many 50W sections as you need. You add speakers and output power as you go. A failure in one amp does not stop the show.

[Chuck H]

I like the idea. A simple line out on a Champ or 18 watt build and a few of these would make gigging with your favorite amp easier. This has been tried before and failed though. Fender had their modular powered cabinet bass amp and Mesa had their "Satellite" powered cabinet. Both discontinued in short order due to poor sales. Musicians are a dense bunch. If you've spent much time talking to non amp building pop or rock musicians you know this. Even the concept of adding cabinets confuses them. Modular systems are way too much like math. They want a plug and play, self contained amp that goes from midnight practice to outdoor stadium. It's a real tough biz and only gets more frustrating if you expect people to think.

Since the PA at any venue is usually up to the task I encourage players that need more power to plug the speaker driven line out (already on my amps) into a channel on the PA. This too confuses them. The most you can usually get them to do is stick a mic in front of the exsisting amp cabinet.

[R.G.]

Yep. Thomas Vox had booster amps and the Series 90 powered cabs as well. Probably others.

You're right - it won't sell. Otherwise it would already be in existence. But if you're already talking DIY, doing many small projects seems more do-able than one big, complex one.