tube tone control?

[JojoD818]

Hi,

A friend pointed me to this schematic. It uses 2 12AX7 per channel so 4 is needed. I have the tubes and I also have a power supply that I can use for the circuit.

Has anyone tried it already? Any comments?

Best Regards,
JojoD

[ray_moth]

The schematic can be found on Max Robinson's "Fun with Tubes" web site, with a detailed explanation.

You can see it at: http://www.angelfire.com/electronic/.../Amp-Tone.html

Max says he has built it and was quite impressed with its performance.

Regards,

Ray

[SY]

I'm abit far away from my library so can't post a schematic, but... in Glass Audio a few years back, there was a circuit for a tube version of the tilt circuit that Quad popularized (this tube version was adapted from a Reg Williamson circuit). Of all the tone controls I've used, the tilt control has been the most effective.

In the adaption, a pentode (5879?) was used, but there's no reason one couldn't use cascaded or cascoded triodes.

[JojoD818]

Originally posted by ray_moth
The schematic can be found on Max Robinson's "Fun with Tubes" web site, with a detailed explanation.

You can see it at: http://www.angelfire.com/electronic/.../Amp-Tone.html

Max says he has built it and was quite impressed with its performance.

Regards,

Ray

Gee, thanks for the link! So that's where it came from.

[JojoD818]

Originally posted by SY
I'm abit far away from my library so can't post a schematic, but... in Glass Audio a few years back, there was a circuit for a tube version of the tilt circuit that Quad popularized (this tube version was adapted from a Reg Williamson circuit). Of all the tone controls I've used, the tilt control has been the most effective.

In the adaption, a pentode (5879?) was used, but there's no reason one couldn't use cascaded or cascoded triodes.

I would be very happy if you could please post a schematic of that circuit. I don't have a 5879 tube but only 12AX7 and 12AU7 I have readily. I guess it can be reconfigured to accept this tubes.

JojoD

[benny]

That circuit looks a hell of a lot like a Baxandall tone control.

I would highly recomend this circuit. I have used a passive version of the Baxandall circuit before, and it has very impressive results, offering a very wide range of tonal variations considering just two controls, bass and treble... and set bass and trebble both in the middle, and in theory you're getting a completly flat frequency response from the circuit.

i attached a schematic from an old article i have that is acutually about anode followers... but it discusses Baxandall's tone control in there as this utilises an anode follower, so therefore, in the article, there was provided this highly simplified version of a Baxandall tone control.

I say you should build it... my 2 cents

cheers

[SY]

Originally posted by JojoD818



I would be very happy if you could please post a schematic of that circuit. I don't have a 5879 tube but only 12AX7 and 12AU7 I have readily. I guess it can be reconfigured to accept this tubes.

JojoD

I hope someone else can- I won't be back home until the first week in July...

You can't substitute in directly a 12AX7, but a pair in cascade should give you sufficient gain for the circuit to work properly.

[JojoD818]

Originally posted by benny
That circuit looks a hell of a lot like a Baxandall tone control.

I would highly recomend this circuit. I have used a passive version of the Baxandall circuit before, and it has very impressive results, offering a very wide range of tonal variations considering just two controls, bass and treble... and set bass and trebble both in the middle, and in theory you're getting a completly flat frequency response from the circuit.

i attached a schematic from an old article i have that is acutually about anode followers... but it discusses Baxandall's tone control in there as this utilises an anode follower, so therefore, in the article, there was provided this highly simplified version of a Baxandall tone control.

I say you should build it... my 2 cents

cheers

You are absolutely right about the Baxandall. I have built circuits with Baxandall but using opamps, and now I am into tubes, I want to build one that has tubes as the amplifier.

I bet those articles would be interesting read, can you please send me a copy?

jojod818@yahoo.com

Regards,
JojoD

[benny]

I bet those articles would be interesting read, can you please send me a copy?

yes, it's pretty interesting... and i've just sent it then... enjoy.

cheers

[JojoD818]

Originally posted by benny


yes, it's pretty interesting... and i've just sent it then... enjoy.

cheers

I got the file, it is very helpful, thanks a lot!