Choosing a Tube Preamp

Hello,
i need a tube preamp to warm my pc productions and to give harmonic distortion to some of my sounds, but i don't know wich one can be good for me. I'm considering two possibilities:
-Buy a Paia TubeHead (and assemble it).
-Contruct myself an easy project from the net.

Please, if somebody can give me any link of projects for this purpose will help me so much. All i find is designed for guitar or bass.
Opinions about Paia TubeHead or any suggestion about what to buy are wellcome too.

(I have NO experience with electronics, then the project suggestions should be for beginners).

Advanced thanks to you all for your help.
Moce

Hey welcome!

If you are a beginner, solid state (transistors) might be a smart move as the voltages are not as shocking.


And many solid state amps will "warm" up your signal, just like a tube amp.

If you do not care about learning electronics and building a ton of stuff, ebay might be a good way to get something to play with.

Seventh Circle sells a Neve preamp kit, (solid state), or you could buy a discrete op amp from John Hardy, Fred Forrsell, JLM, and a few other people and just wire in and out jacks, in and out transformers, plus a power supply.

How much do you want to spend?

Check the Black Market here for buckets of parts.
(see forum index)

And remember, a bucket of chicken dosen't feed a family, it contains a family.

Thanks Cj!

Well i have only about $250. I know it's not too much...

Yeah maybe you are right, and what i need is to buy an assembled amp.
But anyway if i buy it i would learn about electronics to can make my homemade amps designded for my purposes. (yes i'm falling in love with all this world)

What is an op amp?

Looking on ebay i find lots of nice vintage preamps but they havn't overdrive control (and i need it).

I need more help.
Thanks again!

[quote author="CJ"]
And remember, a bucket of chicken dosen't feed a family, it contains a family.[/quote]

Particularly if you don't finish eating it and forget to refrigerate it.

Once I built a nice discreet dual channel transformer coupled in and out micpreamp for just $50 including ALL. I mean, four audio transformers in there... Rack mounted case made by hand with cheap front panel. Not a beaultiful one, but it sounds way nice!!!








I mean, look at that thing... :razz: Makes me laught.

It´s based on the NTP opam,p posted by Jakob, with a 1:4 as input and a 1:1 as output.

[quote author="moce"]Well i have only about $250. I know it's not too much...

Yeah maybe you are right, and what i need is to buy an assembled amp.
But anyway if i buy it i would learn about electronics to can make my homemade amps designded for my purposes. (yes i'm falling in love with all this world)[/quote]

Right. Be careful -- it's a lifelong addiction.

What is an op amp?

Click to expand...

Broadly speaking, it's an amplifier with a differential input (one input inverts the signal, one doesn't), a single-ended output, and enough gain without feedback that when you hook up feedback elements, they control most of what the amplifier does. These were originally designed for analog computers, and built with tubes, but these days most of them are solid-state, either discrete circuits made with individual transistors, resistors, capacitors etc., or integrated circuits that put the whole amplifier (or two or four of them) on a single chip.

Looking on ebay i find lots of nice vintage preamps but they havn't overdrive control (and i need it).

I need more help.
Thanks again!

Click to expand...

I think a good starter project would be New York Dave's One-Tube Preamp. You may discover that it's warm-sounding enough by itself that you don't need an overdrive control.

Be warned, though, that this and most real-tube circuits (as opposed to low-quality toys like the PAiA) run on voltages ranging from 150 to 350 volts, which can kill you DEAD if you stick your finger in the wrong place, or at least knock you flat on your ass across the room. Been there, done that, was shaky on my feet for half an hour afterwards. The two most important rules are: Never work on something that's plugged into the wall outlet, and always wait at least ten minutes, preferably twenty or more, after you unplug it from the wall before you start messing with it. Power supplies hold their charge a while sometimes. While you're learning, follow these rules without a deviation.

Later, once you have some experience, if you have the occasion to break either of those rules (say, by measuring a voltage), do so while keeping one hand firmly in your pocket. That precludes current going in one arm and out the other, going past and through your heart in the process. You run 3 or 4 hundred volts from one arm to another under the wrong circumstances, and -- well, in the words of Gamble Rogers, one more white shirt'll do ya.

Peace,
Paul

Thanks for your time!!

I think a good starter project would be New York Dave's One-Tube Preamp. You may discover that it's warm-sounding enough by itself that you don't need an overdrive control.

Click to expand...

I've been looking it on the forum and seems to be nice but i have NO experience with electronics and is imposible for me to understand nothing.
I need a step by step tutorial (I found some of them on the net but are designed for guitar).
I produce drum&bass and sometimes i need to overdrive a snare but without tubes it crashes your ears. Is for this that i say i need overdrive control, maybe i'm wrong thinking it and its not necessary.

Be warned, though, that this and most real-tube circuits (as opposed to low-quality toys like the PAiA) run on voltages ranging from 150 to 350 volts, which can kill you DEAD if you stick your finger in the wrong place, or at least knock you flat on your ass across the room.The two most important rules are: Never work on something that's plugged into the wall outlet, and always wait at least ten minutes, preferably twenty or more, after you unplug it from the wall before you start messing with it.

Click to expand...

Do you know any link with an step by step project on the same quality level of New York Dave's?

If i ever follow those two important rules, i have NO DANGER?

Thanks again!

There´s always danger. Make sure you understand where the danger hides, and make sure you ALWAYS measure the voltage across high voltage caps BEFORE touching anything. 10 or 20 minutes won´t save your ass. Sometimes those caps remains charged for months...

You have to discharge it before messing arround.

ehem, if you are in an atomic rescue facility maybe...
(just joking)
just keep care of mains and big loaded capacitors...not following the mentioned rules can definately terminate your life -
i had alot of these shocking moments in live changing kitchen lamps, repairing hifi and guitar amps and stuff... needing almost half an hour to hold a full glass of beer without messing around and another hour to get my hair down...stuttering and feeling *very*nervous about my health.
Seriously, shocking yourself with higher voltages will definately damage your nerves, if you are less lucky it's irreversible damage, if you are out of luck you are dead.
For example theres alot of guitarists up there in heaven because of dumb grounding faults to "reduce hum" and other silly ideas about electricity.
And that's really no joke.

thank you rafa for the clear statement about big loaded caps
- you can take them with you the whole day and weld some steel with the lightbow hours later when shortening ... only funny if you are fifteen, slaughtered a broken TV and don't know how worthy another few decades of life could be... :twisted:

I would say start with the guitar preamps, they will do the job, The frequency response might not be what you want but that can be tweaked. You are going to find the most information and closest thing to a step by step walk through with the guitar stuff. Even if it does not do the job at all, most of the parts will be able to be reused, and the expensive parts will deffinetly get reused, it will get you started. The guitar projects may not be as fancy as some of the preamps out there like NewYorkDaves 1 tube lineamp, but you want to warm things up and maybe add abtt of distortion, which is what the guitar ones are great for. They are simple and you should have a good chunk of that $250 left over when you are done, depending on if you have a meter and soldering iron and the like. When you are done if you do not like it you will have at least learned alot and have all of the expensive parts already at hand and ready for something more complex.

adam

Hi Guys,

I haven't built it yet (on the neverending list of hey that's cool I should build one - 3 projects on the go... none finished yet!) but Dave's one bottle tube pre is one of the simplest & least expensive tube pres you can build: 1 tube, 1 input transformer, an optional output transformer (only really needed if you are going to drive true 600R inputs - most soundcards are at least 10k'ish), a small handful of caps/resistors & a power supply.

I totally second Pauls advice - check it out:

http://www.groupdiy.com/index.php?topic=6711&highlight=one+bottle#img_6

Justin

Be warned, though, that this and most real-tube circuits (as opposed to low-quality toys like the PAiA) run on voltages ranging from 150 to 350 volts, which can kill you DEAD if you stick your finger in the wrong place, or at least knock you flat on your ass across the room. Been there, done that, was shaky on my feet for half an hour afterwards. The two most important rules are: Never work on something that's plugged into the wall outlet, and always wait at least ten minutes, preferably twenty or more, after you unplug it from the wall before you start messing with it. Power supplies hold their charge a while sometimes. While you're learning, follow these rules without a deviation.

Click to expand...

Hardly..Its not the Volts that will kill you ;-)..Its the AMPS !!! and its not the volts that knock you flat out in the room..its the Bloody AMPS !!!

NEVER THE LESS its correct..Be carefull !!!

Kind regards

Peter

There´s always danger. Make sure you understand where the danger hides, and make sure you ALWAYS measure the voltage across high voltage caps BEFORE touching anything.

Click to expand...

Where the danger hide's?
What i need to mesure the voltage?
And to purge it?

I totally second Pauls advice - check it out:

http://www.groupdiy.com/index.php?topic=6711&highlight=one+bottle#img_6

Click to expand...

I think we all are waiting for this step by step! But anyway i think it will be difficult to understand for me. All the people in this forum have at least experience with electronics, and much part are experts i guess. And I have absolutely NO experience with electronics. I need, not a beginner tutorial. I need a for silly's tutorial :sad:

What do you think about this option?
http://www.dogstar.dantimax.dk/tubestuf/miniblok.htm
It is not what i need but is only 1watt (no danger of damage) and can be a good way to start to learn something.

Thanks!

[quote author="moce"]
It is not what i need but is only 1watt (no danger of damage)[/quote]

Output power bears no relation to how dangerous a circuit can be... That's still a >200V supply!

Just be careful when working around tubes. Always put one hand behind your back while poking around with the other, and measure voltages on things before you decide to touch them. You'll get it.

Good luck!

Peace,
Al.

I can't help thinking.. do you really need a valve preamp
Myself - I am scared sh*tless of them.. but then I sweat and cover my eyes when I plug in one of my DIY 18v PSUs... (don't even talk to me about checking the mains voltage going into a Transfomer... I sh*t bricks.. then see 235volts or so come up on the multimeter and get the hell out of there...)

Have a look at the different preamps options around here - (with a possible line in option)... as CJ says one of the Neve options might be easier...

A little word about Volts AND Amperes that will kill you:
- With high voltages you can get killed because of the shock situation that can bring you in a life critical situation. Lay down, put your legs up and decide to call a doctor if you feel like you can get unconcious.
- With high amperes running thru your body there's a good chance that your heart begins to flimmer (can begin somewhere between 1-3 A, depending on your health etc...). That's a situation where you only can beg that it comes to a normal beat afterwards, otherwise you can die in a matter of less than a few minutes in a quite very painful deathfight.
So my brother told me, who works in a hospital for more than 15 years...
A combination of both can be deadly of course, too.
Just to make clear it is not a matter of U OR I, both can kill you... :?

Just be careful...

kind regards

Martin

There is no reason not to start out with tubes, sure it is high voltage but its what everyone used to start with up untill not all that long ago, you just need to properly educate yourself before doing it.

So far I am very happy with NewYorkDaves stuff, but I think it is overkill here, I do not think he will even need an input transformer. He is doing drum and bass and he can just throw the preamp in an FX send of the mixer and it should live there just fine. Other then maybe tweaking the tone controls a guitar style preamp should work wonderfully for the job, it needs to add a little distortion to warm things up and sometimes add alot of distortion. Synths, drum machines, samplers, all are perfectly happy with guitar FX, and will feed almost any gutiar tube preamp just fine.

I was not able to open the link you posted so I can not comment on it, but get some electronics books, pick a preamp to start with and start just get to it. You can always change or rebuild it when it is done, and most likely you will even if it does the job just fine. If you clik on the Meta-Meta link and the top of the page there is a section just for people new to all this, contains alot of useful information. Just do not expect to be able to build the perfect preamp on your first attempt, there is a fair chance of it not working or at least problems with noise and hum, but these can all be fixed, but you have to get it built first.

adam

Yeah, I started with tubes. But just after I was very aware of what I was doing regarding hih voltage caps, discharging, etc. So, once you understand the very very basics of PSUs, you will be probably safe to start.

hey your might also check out cj's v 72 thread
lots of info there and it is said to be a nice beginner DIY.
schematics for these are everywhere on the web.
cj just posted a schematic at the lab...

also i super second and that one hand behind your back trick.
get an insulated alligator clip for your black lead and use the red one in one hand with your other behind your back...
you will be suprised at how many times a hand will drift into a dangerous area while you are in deep contemplation..
just make this your #1 rule... and also make sure the chassis is not hanging over the edge of the table where it could accidentally come in contact with your body anywhere... voltage (more specifically ampreage) wll not have much effect unless the path is completed to ground..
also as stated it's the amperage that kills you but... generally high voltage means high amperage too.. so it is a good indicator to look for... specially since a lot of components do not have the amperage rating written on them.

sometimes if I am in a hurry i will measure some points in the circuit with the power cord DISCONNECTED and the meter will draw a small amount of current and you can watch the measurement fall to zero...
if you do this at several points where you see caps it will give you a better safety ratio... but still check it... double check it... and when you have checked three times well then ... check it again...hehe
better safe than sorry..

and it's ok to figuratively kill yourself but please don't literally kill yourself ...:wink:

later
ts