Wich valve to start?

[samsagaz]

hi guys, i want to build my firstvalve amp, in my country i foudn the following valves.

18USD Sovtek 12AX7
18USD Electro Harmonix 12ax7
28USD Jj Ecc832 12dw7

wich one you recommend me?


othe stuff that the seller told me that have are

12b4a
Cv4043-M 8098
0a2
E90cc
Ck 5651wa
E91h
Og3
Ecc82 - 12au7
6au6
6u8a
E80l-E80cf
E130l

[azazello]

E130L & ECC82

[samsagaz]

any recommended schematic for those?

cost like 20USD each one.

[Gordy]

What is your application? Do you want to...
...select and amplify a small signal (for example from a CD player)?
...or drive a loudspeaker?
...or do both?

The application will determine the choice of tube.

I agree with azazello that E130L & ECC82 seem like good choices. The E130L for power (possibly connected as a triode), and the ECC82 as a driver.

[samsagaz]

well i want to drive some speakers,

Use the PC as Source, and drive my speakers.

[Gordy]

Examples of circuits with e130l output:

http://www.ys-audio.com/e130l_pp2.htm

http://www.jogis-roehrenbude.de/ (on the left click Leser~briefe, then search for e130, there are two amps there with e130l)

Just a thought... if getting vacuum tubes is difficult, then maybe getting transformers might also be difficult? If so, the available transformers might dictate the choice of circuit.

If this is your first build then maybe buying a kit might be a better place to start? Maybe it is possible for you to import Decware or Bottlehead...

http://www.decware.com/
http://www.bottlehead.com/


Good luck.

[stocktrader200]

I am looking at a 12AX7 to run as a "conditioner" to get the tubey sound out of my class D amp I just finished.
The rails are +- 42 volts which should run the tube.
I have no experience with this, but the 12AX7 appears to be a popular hi gain tube.
idea is to run tube at a gain of 50 -80 and then cut back the output to about 2v p-p for the amp.
How much plate voltage does this tube require to be optimal?

[analog_sa]

Originally posted by stocktrader200
I am looking at a 12AX7 to run as a "conditioner" to get the tubey sound out of my class D amp I just finished.
The rails are +- 42 volts which should run the tube.

12AX7 won't run at 80v. Why not choose a proper tube?

The idea of introducing high gain and then cutting it back is quite silly. Even at appropriately high rails the tube will either be clipping or close to clipping most of the time. Not to mention it will really distort.

[Gordy]

stocktrader200; 12ax7 was introduced as a cheap, high gain, small signal amplifier. At useable bias levels (example: -2V) it has characteristics that are not so linear. It also needs lots of volts to work, and the internal resistance is quite high. I am not sure this is the best choice for you.

Also remember; adding a vacuum tube does not automatically add a 'tube sound', because 1) sound quality just does not add in a linear way, and 2) there is not a specific 'tube sound'.

Perhaps your amps do not need a tube in front... maybe try them without !

[azazello]

Gordy:
What is your application? Do you want to...
...select and amplify a small signal (for example from a CD player)?
...or drive a loudspeaker?
...or do both?

The application will determine the choice of tube.

I agree with azazello that E130L & ECC82 seem like good choices. The E130L for power (possibly connected as a triode), and the ECC82 as a driver.

Abs. NO in triode! I burned one tube!!
Gride 2 E130 L needs stab. 150 v. from stab. tube !!
This is my ampl:
http://www.flickr.com/photos/12596932@N02/1318954378/
My first tube is EF86, but use ECC82 isn't big problem!
http://www.jogis-roehrenbude.de/Lese...130L/E130L.htm