Bassman - How do the way the 2 Drive controls interact

unix-guy

Master of RTFM
Can someone explain to me how the 2 Drive controls on the 59 Bassman Bright and Normal interact?

I just got to load up FW19.04 and tried out the new 59 Bassman Normal model. Really digging it!

The 59 Bassman (now called Bright) has been my go-to for a while now.

Just curious how the 2nd drive control affects things.
 
Hi

Generally here is spoken of amplifiers, for me it is a channel strip of an amplifier. And depending on which channel strip (input) I use, I can change something with the associated controls, as in the original.
And in the area of Tone (authenticity) this should also be reflected.
And like in the original, all controls are visible in the area of Tone (authenticity), even if not all of them have a function in the selected channel strip.
 
Refer to the schematic below:
bassman-5f6-a-schematic.gif

Note how the input to the second 12AX7 is a summing node. Both volume controls affect the signal. If you plug into the Bright input the Normal volume control will also control the volume to some degree and change the frequency response.
 
Refer to the schematic below:
bassman-5f6-a-schematic.gif

Note how the input to the second 12AX7 is a summing node. Both volume controls affect the signal. If you plug into the Bright input the Normal volume control will also control the volume to some degree and change the frequency response.
Thanks for the clarification, interesting
 
Thanks Cliff for the note below ,schematic no clue 🤣 there are a few videos on you tube that you can hear how plugging into input one and raising the the second volume affects tone and gain 😎
 
Refer to the schematic below:
bassman-5f6-a-schematic.gif

Note how the input to the second 12AX7 is a summing node. Both volume controls affect the signal. If you plug into the Bright input the Normal volume control will also control the volume to some degree and change the frequency response.
Thanks... That basically describes what I was hearing :)

Can we assume that with the Normal Drive at 5 that the Bright model is the same response as the 59 Bassman model was before this reworked new model (in previous firmware)?
 
I recently plugged into a '59 Bassman Ltd reissue and dialed in the tone for "Channel Blender" (jumping the channels as illustrated) and the sound was absolutely glorious!

I've since tried getting something close to that on my FM9 and have not been successful. I've tried the Bassguy Normal, Bright, and Jumped and despite all of the knob twisting I can think of, I cannot get near this tone.

Suggestions?

59Bassman-Blender.JPG
 
I recently plugged into a '59 Bassman Ltd reissue and dialed in the tone for "Channel Blender" (jumping the channels as illustrated) and the sound was absolutely glorious!

I've since tried getting something close to that on my FM9 and have not been successful. I've tried the Bassguy Normal, Bright, and Jumped and despite all of the knob twisting I can think of, I cannot get near this tone.

Suggestions?

View attachment 112968

You definitely would want the Jumped model...

What IRs did you use?

Of course, comparing a speaker in the room sounds different than an IR.
 
Refer to the schematic below:
bassman-5f6-a-schematic.gif

Note how the input to the second 12AX7 is a summing node. Both volume controls affect the signal. If you plug into the Bright input the Normal volume control will also control the volume to some degree and change the frequency response.
God bless engineers, or we’d have nothing.
 
You definitely would want the Jumped model...

What IRs did you use?

Of course, comparing a speaker in the room sounds different than an IR.
re: Cab (IR) I've been using the Bassguy 4x10, but have tired several others and none are getting me there.

As for is sounding different in the room, I'm well familiar with that concept and have been a FAS user since 2015. In this case, I'm fairly confident that the "in the room" difference is not the issue.

I've tried the Jumped model but have found that the Bright version gets me a bit closer. The Jumped version is much darker sounding with a weird midrange honk I can't seem to dial out of the sound.
 
The Fractal models are based on a vintage 1959 Bassman which has a 12AY7 tube for the input gain stages. Most of the reissues use 12AX7 tubes instead, so they will likely have a bit more gain than the original. It's also quite possible the LTD reissue has other circuit changes from the original as well. You could try turning up Input Trim to give the Fractal models a bit more gain. IIRC the 12AY7 has about half the gain of a 12AX7 all else being equal.
 
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The Fractal models are based on a vintage 1959 Bassman which has a 12AY7 tube for the input gain stages. Most of the reissues use 12AX7 tubes instead, so they will likely have a bit more gain than the original. It's also quite possible the LTD reissue has other circuit changes from the original as well. You could try turning up Input Trim to give the Fractal models a bit more gain. IIRC the 12AY7 has about half the gain of a 12AX7 all else being equal.
Voltages are different too. B+ on a 5F6-A is around 430V. On a reissue it's about 490V.
 
@Nozkcb @mr_fender here's a factory FM3 Bassman preset updated with the information you've posted.
1. Input tubes changes to JJ (they sounded the most "agressive" to me which is what we probably want from the reissue - please suggest if another model should be used!)
2. Input trim set to 2
3. Output tubes changes to GT as https://www.fender.com/en-SI/guitar-amplifiers/vintage-pro-tube/59-bassman-ltd/2171006010.html suggests
4. Scenes 1 to 3 updated with the settings in the photo above, converted using the "fender-to-fractal" sheet (attached just in case, found somewhere here on the forum).
5. Phaser removed to allow IR Lenght set to Ultra, and Reverb to Ultra-High.

No idea how to change the B+ to 490V though - @FractalAudio please advise if this is possible :)

This thing sounds like heaven to me. Can't stop playing.
 

Attachments

  • 5F6-A 2004 '59 Bassman Ltd..syx
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@Nozkcb @mr_fender here's a factory FM3 Bassman preset updated with the information you've posted.
1. Input tubes changes to JJ (they sounded the most "agressive" to me which is what we probably want from the reissue - please suggest if another model should be used!)
2. Input trim set to 2
3. Output tubes changes to GT as https://www.fender.com/en-SI/guitar-amplifiers/vintage-pro-tube/59-bassman-ltd/2171006010.html suggests
4. Scenes 1 to 3 updated with the settings in the photo above, converted using the "fender-to-fractal" sheet (attached just in case, found somewhere here on the forum).
5. Phaser removed to allow IR Lenght set to Ultra, and Reverb to Ultra-High.

No idea how to change the B+ to 490V though - @FractalAudio please advise if this is possible :)

This thing sounds like heaven to me. Can't stop playing.
Thank you for working on this. For some reason, I cannot import the syx file into my FM9. I just get a blank preset.
 
I'm working on a '59 Reissue model. There are quite a few differences between a 5F6-A and the reissue:
1. 12AX7A vs. 12AY7 input tube.
2. Different tone stack (this is a big one).
3. Different presence network.
4. Different B+ voltage.
5. 6L6s vs 5881s (minimal difference).
 
I'm working on a '59 Reissue model. There are quite a few differences between a 5F6-A and the reissue:
1. 12AX7A vs. 12AY7 input tube.
2. Different tone stack (this is a big one).
3. Different presence network.
4. Different B+ voltage.
5. 6L6s vs 5881s (minimal difference).
Excellent!

Thank you very much
 
I'm working on a '59 Reissue model. There are quite a few differences between a 5F6-A and the reissue:
1. 12AX7A vs. 12AY7 input tube.
2. Different tone stack (this is a big one).
3. Different presence network.
4. Different B+ voltage.
5. 6L6s vs 5881s (minimal difference).

I've never understood this. Why would they call it a "reissue" if it's so categorically different from the original?
 
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