Ruby Tuby Sound clips posted!

[slajeune]

Hi All,

well, I didn't have as much time as I wanted, but, I was able to add an opamp in front of the tube to drive it harder.  Boy does this make the poor tube cry

Anyways., here are two clips, one clean and one dirty.  Adding the opamp (1/2 of a TL072) in front of the tube made this little sucker LOUD (for 12v, it is very impressive!!!).  I am suprised at how quiet the amp is!  Anyways, sorry for the bad sound quality of the clip and even more sorry about subjecting the entire internet to my shameful guitar playing.

Here are the links:

http://www.geocities.com/slajeunesse/clean_clip.mp3
http://www.geocities.com/slajeunesse/dirty_clip.mp3

As they are on geocities, there are a few things:

- You need to cut and paste them in a new browser window
- You might get an unavailable message because I exceed bandwith limit

Anyways, once I have more time, I will add to the design and I will post an updated schematic.

This is getting very interesting.

Cheers,
Stephane.

[Lurco]

hey slajeune, isn`t it a bit dangerous these days to play funny names/games on that "puretube" company these days?

Boy does this make the poor tube cry  

[slajeune]

Sorry Lurco, but, I fail to see how that sentence can be taken in a wrong way?

[sarcastic on] are we allowed to use "wrong way" in a sentence, as it could allude to not doing the right thing and therefore alluding to incompetency and therefore being politically incorrect [sarcastic off]

I think that we need to chill a bit.

Stephane.

[puretube]

no fear, slajeune: I love the word-symbology
(or whatever people round the world would like to call it)
between "poor" and "pure" -tube, and how it can cry
(.. maybe `bout the bad-a*sliness of the world?)...

[slajeune]

To clear all doubts (if any existed), I was talking about the 12ax7 tube being pushed into distortion.  Period.  End of story.  Let's move on with our lives people, life is too short to twist what each other says.

Enough said.

Stephane.

For what it's worth, my mother tongue is french and not english, therefore, somethings might be lost in the translation.

[Ansil]

i thought he was talking about ruby tuby ie ruby tubes...  did i miss something here

[slajeune]

Hey Ansil,

hum, hadn't thought about that one.  See, I'm over-reacting...  Classic symptoms of somebody that really needs a vacation.  Ahhh, 2 more days and I'll be on a beach.

Ansil, did you hear the clips?  What did you think of it?  It's a first shot at it, there are so many things that I want to do with it when I come back from vacation.  A simple tone stack is the first on the list.

Cheers,
Stephane.

[Ansil]

sounds cool to me..  you can use a lm386 to slam the input instead of opamps..  gets more bang for your buck..

[csj]

Stephane,
Congratulations on getting that build up and running. I know how hard you worked on it. I admire your perserverance...man, you were NOT going to let that get the better of you.
It also goes to show how valuable Puretube and The Tone God are to this site. That's a great thread that the 3 of you worked through.
I haven't heard the clips yet...the site won't load right now.
Doesn't matter...
I'm very happy for you.
Great job.

[smoguzbenjamin]

Sounds pretty neat for a starved tube! Are you gonna post any schemmo's or not? Or have I missed something :?

[Sic]

sounds pretty good...

i missed the poor tube thing at first too, didn' think there was any negative intentions on that...


what beach ya going to? i could do with a vacation

[slajeune]

Hi all,

csj, thanks for the great words of encouragement.  You also helped me, so a big thanks to you to!  I hope that that thread will help others.

Smoguzbenjamin, there is a priliminary schematic that can be found here:

http://www.geocities.com/slajeunesse/ruby_tuby.pdf

This one doesn't yet have the opamp in front to overdrive the 12ax7.  It is very simple to add, it's a simple non-inverting opamp section with a crontrolable gain.  Very very similar to what you find in a MXR Distortion+ pedal.

Sic, thanks for the nice words!  I'm going to the Bahamas!!!

Ansil,  I like the idea of using another LM386 because I can get rid of the voltage divider for the opamp.  I'll definately look into that when I come back from vacation.

Cheers,
Stephane.

[bobbletrox]

Ansil,  I like the idea of using another LM386 because I can get rid of the voltage divider for the opamp.

...but if you add a TL072, won't that mean you'll have to add the voltage dividing crud?  Although I guess that means you could use 1/2 of the opamp to drive the tubes and the other half to replace the LM386...or am I missing something?

P.S. Finally, something with a tube that's simple enough for me to build!  

[slajeune]

Hi Bobbletrox,

yes, if you use any  ordinary opamp (tl072, lf353, lm741) you will have to use a divider network.  Not a big deal, but, it adds to the total number of components.  Using an LM386, you don't have to use a divider network (it's internal to the LM386).  You can't use the second part of the TL072 because it isn't a power amplifier.  The LM386 is a power amplifier and therefore is a good fit.  I used a 1/2 of a TL072 because I had one lying around.  Any single opamp (even a lowly 741, althought it will be noisy) will work to push the 12ax7 into distortion.

Having said that, be sure to use an LM386-N3.  I used an N1 and the voltage of the entire circuit droped to 9v (which is not enough for the heaters on the tube).

BTW, this is my first circuit that deals with tubes.  My goal was to make the design as simple as possible (hence the use of the LM386 for the power amp portion).  I also wanted to power the amp with a simple wallwart to make it even safer to build (a power transformer is connected directly to 120V).  I think that I achieved these goals with a lot of help from The Tone God and puretube.  Filtering / regulating the power supply was the key to make this thing work!

Cheers,
Stephane.

[bobbletrox]

Oh ok!  ...the 386 is a power amp  :oops:

Btw, those clips sound great.  Did you record them direct into a soundcard or through a speaker cab?

[slajeune]

Hi bolbbletrox,

No problem about the LM386, I thought that it was just another opamp when I started using it.

I plugged the speaker of my Gibson GA-15rvt into my ruby tuby, so, I am using the cabinet of my gibson amp (1x10 inches).  I have a small ZOOM PS-02 (multi-track recorder) that has a builtin mic.  I simply miced the speaker.  The mic isn't the best one, but, I guess it gives an idea of the sound that the ruby tuby produces.

It does sound  clearer in reality!

Cheers,
Stephane.

[Ansil]

you know looking at this a little further it wouldn't take much to add in the voltage doublign ladder paia uses in the siab amplifier

http://www.paia.com/siabsch.pdf

[slajeune]

Hi all,

Ansil, hum, that looks very intresting, I might look into it after my vacation.  What would doubling my B+ to the 12ax7 do?  I guess it would add more 'headroom'.  Might be another cool modification to do.

While I'm on the subject, I tested a few things today:

- Added a volume control right before the LM386 and it is very nice!  Now I can have a cool distortion without the amp being to loud
- Added a very simple tone control

I don't have time to modify the scheamtic for the amp before I leave, but, once I'm back, I'll update the updated schematic.

Cheers,
Stephane.

[Ansil]

well i am not sure theoretically what doubling the b+ would accomplish i assume more headroom.  but if you were to take it to around 50+ volts it is supposed to be pretty cool sounding.  i think the paia uses like 48v or so on the ubes..  and according to a few articles i have read about the evh dropping the the voltage to like 90v on his variac and gave him some seriously creamy brown sound. but i am not sure what the b+ was after this.  he posted values and i tried it once via a home made preamp that i altered the b+ to what he measured his at when he dropped the voltage.

i am not sure if it would hlep ya or not.. of course you could just build a tube amp... lol

or instead of the lm386 add a 20 v power supply and use a lm3886

[smoguzbenjamin]

Whatabout the tube heaters? Do you feed em 12vdc just like that or leave them out alltogether?