12AX7A replacement

zafira1981 · 26th July 2006, 12:20 AM

Hi, I have loooooot of tubes, but I couldnt find 2x 12ax7a for my bass preamp (Bass guitar preamp)

What tube can I use for replacement?

there are some examples of what I have but dont know if I can use them.

6x ECL82
4x 6AQ5
2x 12au7
2x EF86
3x 6B6A
2x 6CG7
2x 6BZ6
2X 6CB6
2x 12BA6
5x 12AV6

thanks!!!

KBK · 26th July 2006, 02:19 PM

12ax7a, 12DF7, 12DT7, 7025*, 7025a*, 12AD7 (filament issues possible), 12AU7 (in a pinch, may not work), 12AU7a (same warning), 12bZ7 (filament), 12DM7(filament).

*=exact replacement-cross

Then the Euro equivalent numbers for a true 12AX7 cross. ECC83*, CV492*, E83CC*, etc.

There is also a Russian one out there, can't quite remember right now.

Depending on how the heaters are powered in the circuit, other crosses are 'potentially' possible.

Be it known, though, that 12ax7's are common as grass and as cheap as it gets. Best to buy the proper tube.

zafira1981 · 26th July 2006, 02:23 PM

Quote:

Originally posted by KBK
12ax7a, 12DF7, 12DT7, 7025*, 7025a*, 12AD7 (filament issues possible), 12AU7 (in a pinch, may not work), 12AU7a (same warning), 12bZ7 (filament), 12DM7(filament).

*=exact replacement-cross

Then the Euro equivalent numbers for a true 12AX7 cross. ECC83*, CV492*, E83CC*, etc.

There is also a Russian one out there, can't quite remember right now.

Depending on how the heaters are powered in the circuit, other crosses are 'potentially' possible.

Be it known, though, that 12ax7's are common as grass and as cheap as it gets. Best to buy the proper tube.

thanks you a lot!!!!!11

I found a place that still sells 12ax7a at u$s11, I will buy them today!!

thanks again!

Giaime · 26th July 2006, 03:44 PM

Quote:

Originally posted by KBK
There is also a Russian one out there, can't quite remember right now.

Hello KBK,

you're refering to 6N2P - 6SS41. But beware heater is different than 12AX7.

http://www.giaime.altervista.org/china_eng.html

Sheldon · 26th July 2006, 04:28 PM

5751 has slightly lower gain specs., but it's close enough to work well in virtually any circuit that calls for a 12AX7.

thyratron · 27th July 2006, 06:45 AM

The 12AV6 double diode triode is regarded by some to be 1/2 12AX7 plus a couple of diodes, and as such, could be used in the circuit you are making. Provided, you allow for the12v heaters, the extra heater current needed, B7G not B9A sockets required, and double the amount of sockets needed.( single not double triodes).

All in all more work..... But if you're desperate.

Dont forget to tie the diodes to ground.

thyratron

zafira1981 · 27th July 2006, 12:37 PM

Thanks for the replies!!

I found a place that sells 12ax7 and i bougth 2 brand-new 12AX7 so there is no need to use remplacements.

thanks again!!

Jorge.

Ryssen · 27th July 2006, 01:26 PM

Is ECC803 an ekvalent?

26th July 2006, 12:20 AM	#1
zafira1981 diyAudio Member Join Date: Jan 2005 Location: Argentina	12ax7a replacement Hi, I have loooooot of tubes, but I couldnt find 2x 12ax7a for my bass preamp (Bass guitar preamp) What tube can I use for replacement? there are some examples of what I have but dont know if I can use them. 6x ECL82 4x 6AQ5 2x 12au7 2x EF86 3x 6B6A 2x 6CG7 2x 6BZ6 2X 6CB6 2x 12BA6 5x 12AV6 thanks!!!

26th July 2006, 02:19 PM	#2
KBK diyAudio Member Join Date: Dec 2003 Location: The Wilds Of Canada	12ax7a, 12DF7, 12DT7, 7025, 7025a, 12AD7 (filament issues possible), 12AU7 (in a pinch, may not work), 12AU7a (same warning), 12bZ7 (filament), 12DM7(filament). =exact replacement-cross Then the Euro equivalent numbers for a true 12AX7 cross. ECC83, CV492, E83CC, etc. There is also a Russian one out there, can't quite remember right now. Depending on how the heaters are powered in the circuit, other crosses are 'potentially' possible. Be it known, though, that 12ax7's are common as grass and as cheap as it gets. Best to buy the proper tube. __________________ "Never forget that only dead fish swim with the stream." -- Malcolm Muggeridge. "Truth cannot be brought down, rather the individual must make the effort to ascend to it." -- Jiddu Krishnamurti

27th July 2006, 01:26 PM	#8
Ryssen diyAudio Member Join Date: Dec 2003 Location: Sweden--> Here	Is ECC803 an ekvalent? __________________ Regards Åke

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26th July 2006, 04:28 PM	#5
Sheldon diyAudio Member Join Date: Dec 2003 Location: San Diego	5751 has slightly lower gain specs., but it's close enough to work well in virtually any circuit that calls for a 12AX7.

27th July 2006, 06:45 AM	#6
thyratron diyAudio Member Join Date: May 2005 Location: yorkshire.	The 12AV6 double diode triode is regarded by some to be 1/2 12AX7 plus a couple of diodes, and as such, could be used in the circuit you are making. Provided, you allow for the12v heaters, the extra heater current needed, B7G not B9A sockets required, and double the amount of sockets needed.( single not double triodes). All in all more work..... But if you're desperate. Dont forget to tie the diodes to ground. thyratron

27th July 2006, 12:37 PM	#7
zafira1981 diyAudio Member Join Date: Jan 2005 Location: Argentina	Thanks for the replies!! I found a place that sells 12ax7 and i bougth 2 brand-new 12AX7 so there is no need to use remplacements. thanks again!! Jorge.

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