Noobie question: which amp is best for me?

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Hi everyone
i am a noobie and i wish to build my first amp
i have a limited experience in electronics but i am able to solder, read the values of components and etch a board.
What kind amp do you suggest i start from?
i want something that has a decent power (>20W) that is not too critical to make (shouldn't burn my speaker), that doesn't use components that are almost impossible to find, that is "cheapo", and that sound like tubes (possibly with even armonics, i love that tone).
please advice me what should i consider (i was about to start a gainclone mod some days ago, but then i tought better i ask here 1st, the clone is My_ref_A rev 3)
Thanks all!
 
Check the latest schematic in the "my simple class a approach" thread. Very simple and can be scaled easily to more power although theres not a large difference in sound between 10 and 25 watts. And of course there is the tried and true JLH which is a very good amplifier. Class a is the way to go if you want an amplifier with 2nd harmonics and tube like sound.
 
I think that if you are a beginner.. you should definately build the Gainclone. As pretty much all of the critical circuitry is on the chip, it is less difficult to make something that will blow up when you turn it on.

LM3886s will give about 50W into 8 ohms with 35v supply rails.
 
jerluwoo said:
Check the latest schematic in the "my simple class a approach" thread. Very simple and can be scaled easily to more power although theres not a large difference in sound between 10 and 25 watts. And of course there is the tried and true JLH which is a very good amplifier. Class a is the way to go if you want an amplifier with 2nd harmonics and tube like sound.

Hello
i saw the post, interesting indeed, but i need also a pcb or it will come out a mess...
where is this JLH?
i found only this
http://www.diyaudio.com/forums/showthread.php?s=&threadid=3075&highlight=
which is too "short" in power :D
Thanks for your answer!
 
Go way back in time: Death of Zen.

You'll find all the info on Rod Elliot's site.

I wouldn't try the simple class A thingy, it's not reached maturity yet.
The circuit also uses 2N3055, those are TO3s.
Mounting TO3s is a PITA !
Try something with lower rail voltages than 50Vdc or higher !
 
jaycee said:
I think that if you are a beginner.. you should definately build the Gainclone. As pretty much all of the critical circuitry is on the chip, it is less difficult to make something that will blow up when you turn it on.

LM3886s will give about 50W into 8 ohms with 35v supply rails.

I AM a beginner..
i have limited experience in electronics (i mounted around 25 electronic kits but never an audio one) especially regarding tubes.
I was thinking maybe the Gc is interesting, but i don't know how it sounds, and if it really sounds like tubes, i saw My ref rev C, looks nice, but i don't know what are those Z protection nets that are missing..
i also saw on the website of the author that a new version is out, an improved Gc..but i couldn't read any feedback about it.
What i wanted to know is this: can i directly go from CD to Gc or i need a preamp? and if i need it, what kinda preamp should i use in order to keep a tubelike sound (maybe a simple tube preamp)..
moreover i read about tube buffers or solid state buffers for GC, are they needed? does it sound better with them?
50W are too much for me, 20-25 would be enough, the important is the sound :D
Thanks!
 
jacco vermeulen said:
Go way back in time: Death of Zen.

You'll find all the info on Rod Elliot's site.

I wouldn't try the simple class A thingy, it's not reached maturity yet.
The circuit also uses 2N3055, those are TO3s.
Mounting TO3s is a PITA !
Try something with lower rail voltages than 50Vdc or higher !


i gave a look at DoZ
seems very nice with nite tubelike sound..
but i am scared at the massive amount of heat generated..
how did u deal with it?
 
BIG heatsinks, as with the Zen, and every SE after that.

I've also used watercooling, with special semiconductor fluid coolers.
But you'll need access to wholesale shops, unless you are good enough in mechanical work to make one yourself.

Big heatsinks are easy to find nowadays, especially with the web around. Building the amps is dead easy, you don't even need a ready made PCB.
Personally i find these easier to construct than PP designs.

If you like something that resembles a VT amplifier you'll end up with SE and class A. Definitely not GCs !
 
Hi,
50W is 3db louder than 25W.
20W is 3db louder than 10W. You will hardly notice these differences.

You will probably listen between 10mW and 200mW most of the time. When you turn it up really loud it will probably be about 1W or 2W with the extra to 10W leaving headroom for the peaks.

If you use very efficient speakers you will need a lot less power than with low efficiency speakers.
Something around 90db/W is pretty good for a house system and lower power.
87db will need twice as much power for the same volume and 93db will need half the power.
96db will need only an eighth of the power that 87 db would require.

So if low power valve type sound is more important to you, then selecting efficient speakers will allow you to get the same volume as someone else using 100W to 200W of brute force.

Make your choices to suit your requirements.
 
assasukasse said:
i have bose acoustimass 5 speakers...
they sound nice at me, but i don't know about the Db..
btw, do i need a pre with those class A amps?

Those are 85db speakers and many would consider them to be quite poor quality but you like them and that's all that matters. Because they are so low eff I would suggest an amp with a lot of headroom which small class A amps don't have. I would reconsider a peppy chip amp or something like the P3A kit. And since you're going to need a preamp anyway build yourself a simple tube linestage pre and you'll have all the tube sound you want.
John.......
 
I don't carry the schematic to mine around but it is a very simple 6sn7 linestage that uses a 5y3 for rectification. The most expensive part was the fancy pants volume control. An Alps stepped ladder pot probably would have been just as good and cost $100 less. I have piles of used trannies and made my own chassis so they were free and everything else couldn't have cost more than $25. I found the plans on the web so I'll see if I can find them again and post the addy here.
John........
 
My rev c rawks, I have one and will vouch for it.

I think if yuo search this site you could find the boards we developed with Digi and Franz Gysi...

Its is in the chipamp section, is probably from about the end of last year... maybe search for ecc88 , it was my first valve project and comprises an integrated valve buffer and 2 chipamps...

It is super simple, has no hum or his, and sounds awesome too...

The hardest part is the power supply, but if you copy the basic design, and know how to assemble a kit, then this will be easy too... I build mine in modular pieces of pcb, with a coki pen and swimming pool acid at the time...where there is a will...it allowed me to pair the preamp stage with my rev c (for wich I bought the pcbs)
 
As for heat sinks just think about all those dead car amplifiers cut short by some teenager bumping away. I use the shell of a dead 1000 watt car amp to build my class a projects in, 10 x 20 slab of inch thick aluminum with mounting provisions already there. B y the way the output trans I have been using for my simple class a project are mje3055t's, 70 watt to-220 package.

Whatever you decide to build you'll always like it more than anything you can go out and buy because you made it which is the greatest thing about diy.:D
 
The schematic is in the "my simple class a approach" thread, I just built one this morning that runs on 40v at 3 amps idle squeezing about 20 watts to 8 ohm and nearly 30 into 4. Mine are built point to point on vero boards very simple. There have been several people on the boards that could do some good pcb's if you really need them if you ask nicely. Will have to get a cam one of these days to post up some pics. The case is simply the amp shell with a wood bottom to house the transformer and supply caps. If you really want to build one I will help you all I can as the actuall component values(well the only things that have to be changed are R8 which can be swapped for a high power pot for adjustment and R9 may need to be a 1.5 meg pot depending if the input trans. used has a very high gain) depend on the transistors used but is simple to figure out once you get a circuit together and measure actual voltages and currents.
 

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