Gain or master?

[jastacey]

I've had many amps, and that last two ( Subway 800+ & Fender Basan 800 ) really responded well to using the first stage gain, I kinda like a little hair in the signal, but the amount to use depends on if your using an active bass, or passive , also the type of breakup varies, some amps have preamp tubes, and the difference between tube and solid-state can be subtle or aggressive, I found between the Bassman and the Subway, both were subtle, and are very workable, kept the Subway and sold the Bassan ( some passive basses can be borderline active, in output ), what I say, is spend a lot of time with the amp and find your sound, bedroom tone and live band tone are two very different things, play with it till you find your tone

 

[Strane]

Really, are bass amps really that complicated?

Only for dumbs like me. That's why I appreciate all your answers to my question.

 

[agedhorse]

Only for dumbs like me. That's why I appreciate all your answers to my question.

That’s why we address this in our owners manuals, and it has nothing to do with being dumb either.

 

[Strane]

That’s why we address this in our owners manuals, and it has nothing to do with being dumb either.

I had already checked the MarkBass manual, as a matter of fact, but it is not clarifying on this point.

 

[agedhorse]

I had already checked the MarkBass manual, as a matter of fact, but it is not clarifying on this point.

Some manuals are more comprehensive than others.

 

[KenB]

I have always been a bit perplexed by the use of the "Gain" and "Master" designations on the v3 Fender Rumble combos.

I understand completely how the Rumble controls "work", and how to use them, but the "Gain/Master" labeling and the location of the Master control within the circuit are unintuitive to me, and different from what I'm used to seeing in other instrument amps, mixers and audio equipment.

If you look at the block diagram:

The Gain control serves two purposes. It takes the place of the Input Level and "pad" switches in other amps, allowing the use of basses with widely varying outputs. If that was the only purpose of the control I might expect it to be labeled "Input Level" rather than "Gain".

BUT the control also allows fine control of the signal level going into the Vintage and Overdrive sections, to allow the player to "dial in" the desired amount of compression and clipping.
So labeling the control as "Gain" does make sense to me.

The Master control, on the other hand, seems to be located in a really WEIRD position in the circuit!
Very different from what I would expect.

I would expect that a "Master" control would be located at the output of the preamp section, AFTER any EQ and voicing circuitry.
Just before the input of the power amp section.
To me, labeling a control as "Master" would indicate a summing together of multiple stages (like multiple channels in a mixer, or parallel processing stages), rather than controlling volume level in a single-channel combo amp.

From what I've read in the Manual, the Wiki, and on the Forums the Contour and EQ circuitry seem to be designed for frequency tailoring only, with no mention of compression or "dirt".
I have never heard anyone mention the Master control level causing clipping or other problems within the EQ section. The circuitry must be designed with sufficient headroom to pass the incoming signal cleanly, without requiring an additional limiting stage.

So why shouldn't the Master control come AFTER the EQ circuitry?
Or maybe even after the FX Return?

 

[agedhorse]

The gain control is exactly that, a gain control. It’s not a pad, it actually controls the gain of the signal and it makes sense in context of the circuitry following this control., specifically the compression and voicing that follow the gain stage.

The master volume control also makes sense in the context of the Fender environment. It’s post gain, voicing and switching, and just because it’s pre eq doesn’t really matter because the circuitry following the master volume control.

The output limiting has to be post master in order for it to function the way it does, it is tightly integrated within the fixed input sensitivity of the power amp to function as intended.

There could have been the same architecture used with a renaming of the controls to “gain”, “volume” and “master” by inserting a fixed master volume section (it’s actually done this way with a fixed master stage), but that’s not use the designers (and associated “endless” focus group meetings) ultimate decision.

A practical example of the 3 control solution can be seen in the Genz Benz Shuttle 6/9 series.

 

[KenB]

The gain control is exactly that, a gain control. It’s not a pad, it actually controls the gain of the signal and it makes sense in context of the circuitry following this control., specifically the compression and voicing that follow the gain stage.

The master volume control also makes sense in the context of the Fender environment. It’s post gain, voicing and switching, and just because it’s pre eq doesn’t really matter because the circuitry following the master volume control.

The output limiting has to be post master in order for it to function the way it does, it is tightly integrated within the fixed input sensitivity of the power amp to function as intended.

There could have been the same architecture used with a renaming of the controls to “gain”, “volume” and “master” by inserting a fixed master volume section (it’s actually done this way with a fixed master stage), but that’s not use the designers (and associated “endless” focus group meetings) ultimate decision.

A practical example of the 3 control solution can be seen in the Genz Benz Shuttle 6/9 series.

Thanks for the info! Helpful as always.

The Rumble amps are not confusing in actual use. It's just that the circuit Block Diagram surprised me when I first got my Rumble 200.

Looking at the control panel layout,

one (I) would think the Master control would be located AFTER the EQ section, last in the signal path before the power amp.

 

[agedhorse]

Yes, it's not uncommon for the control panel to not follow the signal path, but often it's done that way for ease of use.

The drive section uses both a drive and a level control to allow balancing between the clean and overdrive volumes. IN the case of the Rumbles, there's a lot more going on behind the scenes with regards to the O/D voicing and compression. I think there are either 3 or 4 individual compressors (or limiters) working together to capture in part the feel tat they were going for.

 

[Aloe]

I had already checked the MarkBass manual, as a matter of fact, but it is not clarifying on this point.

it's in the FAQ instead: Support – Markbass

 

[Al Kraft]

it's in the FAQ instead: Support – Markbass

I like their answer for my own personal use.

Since I'm a clean player I tend to set gain along the signal path to optimize my SNR while leaving a little headroom to keep trainsets from overdriving or distorting any of the elements.

 

[Nebadon2000]

Some manuals are more comprehensive than others.

The Manual online is almost useless it does tell you what knobs are but not what they do
And I find this interesting based on another post you were engaged in; the New 58R 500 watt amp has 2 1/4" Speaker outs an 1 Speakon

 

[Al Kraft]

The Manual online is almost useless it does tell you what knobs are but not what they do

Writing a useful manual does take a little work and a lot of thought. IMO a manual should help someone understand the product and its design features well enough that they feel comfortable experimenting a bit and even invited/inspired to try some things out. IME creating a manual that does that equally effectively for a pure artist, a highly technical person, and a total beginner is the trickiest part...but genuinely worth the effort to complement a top quality product.

 

[MYLOWFREQ]

Low gain + High Master = More headroom

 

[agedhorse]

Low gain + High Master = More headroom

Any headroom beyond what’s necessary is headroom not used, and excess headroom directly translates to increased noise floor.

 

[MYLOWFREQ]

Any headroom beyond what’s necessary is headroom not used, and excess headroom directly translates to increased noise floor.

Exactly, and IME bass doesn't need much headroom, and should be at a consistent level in general.

 

[Nebadon2000]

Writing a useful manual does take a little work and a lot of thought. IMO a manual should help someone understand the product and its design features well enough that they feel comfortable experimenting a bit and even invited/inspired to try some things out. IME creating a manual that does that equally effectively for a pure artist, a highly technical person, and a total beginner is the trickiest part...but genuinely worth the effort to complement a top quality product.

Yes I agree I worked in Home Audio from 1980 to 2002 and read a boatload of Manuals very few met your criteria but My Mesa WD 800 Manual is the best overall I have seen
Didn't you have something to do with that?

 

[Al Kraft]

Yes I agree I worked in Home Audio from 1980 to 2002 and read a boatload of Manuals very few met your criteria but My Mesa WD 800 Manual is the best overall I have seen
Didn't you have something to do with that?

That was a collaboration between Andy, Alan (Chef) , and me. We also did the D-350 and TT-800 manuals together.

Andy had a vision for what manuals should be and we tried our best to achieve that. There were a lot of discussions and many drafts, but it was an honor and a pleasure to get to work with Andy and Alan on the projects.

 

[agedhorse]

Writing poor manuals is relatively easy, writing informative, useful and accurate manuals is in fact very difficult and time consuming.

 

[Nebadon2000]

Writing poor manuals is relatively easy, writing informative, useful and accurate manuals is in fact very difficult and time consuming.