Tone stack placement in Rectoverb....

Blaklynx · Jan 25, 2011

Hi guys,

Would like some info as per topic. I've searched but couldn't find what I was after.

In relation to the tone stack, where is it placed? I've read it's before the preamp stage. Does it mean it's placed before the gain dial? I'm trying to figure out the tone dial's relationship in respect to gain (dial) level.

Also, does anyone know what the centre frequencies are for treble, mid, bass and presence? Q curve values?.....

This will help me understand this amp better so I can tailor my EQ pedals out front and in the loop as required.

Thanks.

b0nkersx · Jan 25, 2011

Blaklynx said:
Hi guys,

Would like some info as per topic. I've searched but couldn't find what I was after.

In relation to the tone stack, where is it placed? I've read it's before the preamp stage. Does it mean it's placed before the gain dial? I'm trying to figure out the tone dial's relationship in respect to gain (dial) level.

Also, does anyone know what the centre frequencies are for treble, mid, bass and presence? Q curve values?.....

This will help me understand this amp better so I can tailor my EQ pedals out front and in the loop as required.

Thanks.

The EQ in rectos is post-gain. Marks are pre-gain. There was a post somewhere a while back where somebody called Mesa and asked them but I don't know where that post is.

As for the frequencies, I have no idea.

screamingdaisy · Jan 25, 2011

Blaklynx said:
Hi guys,

Would like some info as per topic. I've searched but couldn't find what I was after.

In relation to the tone stack, where is it placed? I've read it's before the preamp stage. Does it mean it's placed before the gain dial? I'm trying to figure out the tone dial's relationship in respect to gain (dial) level.

Post gain... like a Marshall. The pre-gain is how a Mark is setup.

How they differ from a Marshall is that the tone stacks feed into each other. So turning up the treble reduces the amount of midrange, and so on down the line. Generally, it's best to set the voice of the amp using the treble knob, then adjust the mids two until you get the sound you like. The midrange knob also controls how stiff or squishy the amp feels. If the amp sounds too scooped, experiment with lowering the bass rather than adding midrange.

The only thing that's kind of different is the channel 2 presence knob. In Raw and Vintage modes it's in it's normal position in the power section, however in modern mode the power amp's negative feedback loop is bypassed and the presence pot's position in the amp is adjusted.

Also, does anyone know what the centre frequencies are for treble, mid, bass and presence? Q curve values?.....

I find the centre frequencies shift slightly depending on how the other knobs are set in relation.

94Tremoverb · Jan 26, 2011

Nearly!

The tone stack is post-distortion on the 2-channel Dual/Triple Rectifiers/Tremoverb on both channels, 3-channel Dual/Triple Rectifiers on channels 2 and 3, and on channel 2 on the Single Rectifier and Rectoverb - but pre-distortion on channel 1 of the 3-channels and the Single/Rectoverb. (I'm not sure about the Road King/Roadster but I would assume pre-distortion on at least channel 1.)

There is no difference in the way the controls interact compared to a Marshall, the circuit is identical in layout. But it does use different values, so the result isn't quite the same and the Mesa one does *seem* more interactive. It's correct that the center frequencies vary depending on the other control settings - it's an interactive passive tone stack, not an 'EQ'. There are some rough figures (although I don't have them), but they're not very precise.

Another difference with the Mark series (and in common with most Marshalls) is that the distortion channel tone stack is driven by a cathode-follower stage, which gives it a different sound from the Fender/Mark-type plate driven tone stack.

Essentially the Rectifier distortion channel is a descendant of the '59 Bassman > Marshall > Soldano lineage, whereas the clean channel (except for on the 2-channels) is a descendant of the Blackface > Boogie lineage.

Blaklynx · Jan 26, 2011

Thank you all for the replies.

I was hoping it was post gain on ch 2. Now I can tailor the EQ out front and in the loop with due consideration.

Interesting that it's pre-gain on ch 1; no issue for me on the clean ch.

screamingdaisy · Jan 26, 2011

94Tremoverb said:
Nearly!

The tone stack is post-distortion on the 2-channel Dual/Triple Rectifiers/Tremoverb on both channels, 3-channel Dual/Triple Rectifiers on channels 2 and 3, and on channel 2 on the Single Rectifier and Rectoverb - but pre-distortion on channel 1 of the 3-channels and the Single/Rectoverb. (I'm not sure about the Road King/Roadster but I would assume pre-distortion on at least channel 1.)

Did not know that.

Is it like that for all of the modes (I'm thinking about Brit mode specifically)?