Fender Tone Master FR-10 and FR-12 "FRFR" cabs

[jellodog]

The preamp itself is surprisingly old-school analog

Haha. It's funny that you should mention that, because I had the same thought when I saw the preamp board compared to the power amp.

They could have made it a quarter of the size with surface mount components to reduce the area of the preamp circuit significantly.

Shame really; the main reason I wanted this cab in the first place was for a good clean power amp - which seems to be true. "Well done" to Hanser, at least.

 

[aflynt]

Holy cow! That preamp board looks like something from 1983! Maybe that’s why it sounds so good…

-Aaron

 

[jellodog]

Holy cow! That preamp board looks like something from 1983! Maybe that’s why it sounds so good…

-Aaron

Haha. Right?

That's the thing - the hiss is unfortunate, because otherwise it really does sound great. I was playing it again this morning and thoroughly enjoyed it.

 

[Lysander]

No, you have determined the issue, I was just curios to see it

You can stop looking for a speaker crossover; this baby is biamped

There's a small power amp IC on the preamp board itself which feeds the tweeter directly. Makes sense, as these require comparatively very low power, even for a loud amp such as this one.

 

[Lysander]

Mkay, so the bad grounding theory didn't pan out The way the amp is wired makes perfect sense once you figure out how it's working under the hood.

The preamp is an active, opamp based +/- 6db 3-band tone control, with an additional high cut stage. All very simple, using low noise (f.ex. TL084) components. I didn't bother to trace it down, but's quite obvious that the design is what makes it so noise-prone. It's also a very guitar-amp design, which is why the tone controls behave so well.

To sum it up:

• The FR-12 (and i assume FR-10 as well) has an above-average noisy preamp. Can't quite put my finger on why, though.
• The power amp section of the FR-12 is actually very good. Essentially noiseless without an input.
• The preamp slightly colors noise as well. F.ex. cranking up the high cut control substantially reduces the perceived noise volume. Volume, bass, mids and treble don't seem to impact noise at all, funnily enough.
• Was pretty surprised to find out that the FR-12 is biamped, with a separate lower power section just for the tweeter.
• This amp is loud AF, but i don't think it's anywhere near the 1000W Fender is advertising. The class-D power section is likely 1000W, but i presume that's mostly to ensure headroom without distortion. In fact, the back of the amp states a maximum power consumption of 350W.
• I don't think this is caused by loose manufacturing tolerances. Noise aside, the amp is really well built IMHO. My guess is that the inconsistent reports have more to do with different tolerances to noise, or how controls are dialed - for example, the cut knob at noon will be quite less noisy than at zero. Remember, this is a cut control, not a center-neutral one.

All in all, i still think the FR-12 sounds amazing, and it's a lot of fun to play through. But, it's quite noisier than similar FRFRs offerings.

 

[Jkist7]

All in all, i still think the FR-12 sounds amazing, and it's a lot of fun to play through. But, it's quite noisier than similar FRFRs offerings.

Honestly huge props for all the insight you've offered on this. Its clear you know your stuff, and its been very interesting, all the different aspects you've pointed out. Hopefully Fender can nail down whatever is causing the issue and lower that noise floor. Sounds like they built an awesome product at a very competitive price. Think I'll snag one once I have the capital for it.

 

[Stratzrus]

Mkay, so the bad grounding theory didn't pan out The way the amp is wired makes perfect sense once you figure out how it's working under the hood.

View attachment 11976

The preamp is an active, opamp based +/- 6db 3-band tone control, with an additional high cut stage. All very simple, using low noise (f.ex. TL084) components. I didn't bother to trace it down, but's quite obvious that the design is what makes it so noise-prone. It's also a very guitar-amp design, which is why the tone controls behave so well.

To sum it up:

• The FR-12 (and i assume FR-10 as well) has an above-average noisy preamp. Can't quite put my finger on why, though.
• The power amp section of the FR-12 is actually very good. Essentially noiseless without an input.
• The preamp slightly colors noise as well. F.ex. cranking up the high cut control substantially reduces the perceived noise volume.
• Was pretty surprised to find out that the FR-12 is biamped, with a separate lower power section just for the tweeter.
• This amp is loud AF, but i don't think it's nowhere near the 1000W Fender is advertising. The class-D power section is likely 1000W, but i presume that's mostly to ensure headroom without distortion. In fact, the back of the amp states a maximum power consumption of 350W.
• I don't think this is caused by loose manufacturing tolerances. Noise aside, the amp is really well built IMHO. My guess is that the inconsistent reports have more to do with different tolerances to noise, or how controls are dialed - for example, the cut knob at noon will be quite less noisy than at zero. Remember, this is a cut control, not a center-neutral one.

All in all, i still think the FR-12 sounds amazing, and it's a lot of fun to play through. But, it's quite noisier than similar FRFRs offerings.

Since the power amp is quiet, would it be possible to add an effects loop so that a modeler like the FM9 could bypass the preamp section and go straight into the power amps?

Given that it's bi-amped and the power sections have such unequal outputs I can see how it might be hard to do that in a way that's actually functional.

 

[Stone]

Fantastic Work @Lysander, Fender should Offer you a Position in the FR cab Division

 

[laxu]

@Lysander have you figured out what the Cut control does in practice? I thought it might be just a tweeter level control. But is it just another active EQ control operating at higher frequencies than Treble, or just a simple low pass filter?

Also, have you tried powering only the preamp and tweeter, maybe with an external power supply solution if you have one? Still the same noise?

 

[laxu]

Since the power amp is quiet, would it be possible to add an effects loop so that a modeler like the FM9 could bypass the preamp section and go straight into the power amps?

Given that it's bi-amped and the power sections have such unequal outputs I can see how it might be hard to do that in a way that's actually functional.

I think that should be unnecessary if you just leave the EQ controls in the middle (no boost/cut). If it didn't have the noise issues, that is.

 

[Stone]

Im pretty sure that the issue is the Pre-amp and their controls
I mean who did the QC and would not have noticed this ?
and I wonder what their response would have been from upper management and the bean counters
Meh fuck it wont hear it when playing, Ship them out as is ...

 

[Lysander]

have you figured out what the Cut control does in practice? I thought it might be just a tweeter level control. But is it just another active EQ control operating at higher frequencies than Treble, or just a simple low pass filter?

It's just an active low-pass filter - again, i didn't trace it out so i don't have exact details, but looks and sounds like a simple first order circuit to me. It behaves very much like a presence control would on a "real" amp.

It's not controlling twetter level, though. The knob clearly affects both drivers.

Also, have you tried powering only the preamp and tweeter, maybe with an external power supply solution if you have one? Still the same noise?

I considered it, but i was lazy enough not to bother disassembling the front The noise source is evident if plug/unplug the pass-through cables for the horn signal, and amped tweeter. Both are very very quiet by themselves.

I may do this in the future, just to check if the speaker is unusually sensitive. This would explain some of the noise performance, and also how loud the thing can get.

Since the power amp is quiet, would it be possible to add an effects loop so that a modeler like the FM9 could bypass the preamp section and go straight into the power amps?

It's doable, but not an easy mod if you want to retain the tweeter. The preamp and tweeter amp share the same PCB, without any obvious breakout points.

 

[aflynt]

Fantastic analysis @Lysander!

So, the filtering seems adequate? I mean, not a case where maybe filter caps on some units measure lower for some reason and exhibit more hiss? I think I remember people in the other thread measuring a lower noise floor than mine with the tone controls flat, but it’s entirely possible they had the cut up by mistake. That makes sense…

-Aaron

 

[Lysander]

So, the filtering seems adequate? I mean, not a case where maybe filter caps on some units measure lower for some reason and exhibit more hiss?

Doesn't seem like that to me Pretty sure Fender could come up with a revision with reduced noise floor, but i think the hiss is mostly a consequence of how it's designed. The preamp is essentially a chain of op-amp stages doing different types of filtering.

 

[jellodog]

Thanks for looking into this in greater depth @Lysander. I really appreciate you spending more of your time on this

 

[aerial7]

Im pretty sure that the issue is the Pre-amp and their controls
I mean who did the QC and would not have noticed this ?
and I wonder what their response would have been from upper management and the bean counters
Meh fuck it wont hear it when playing, Ship them out as is ...

The same company that just sold my brother a new $2k tele with pickguard static?

Fender: We Don't Hear the NoiseTM

 

[fazer]

So what is the story on these? Do they have a design fault leading to the extra hiss some have been complaining about or not? And is the hiss present on the 10” version as well as the 12”? Does anyone know?

 

[Baba]

Honestly huge props for all the insight you've offered on this. Its clear you know your stuff, and its been very interesting, all the different aspects you've pointed out. Hopefully Fender can nail down whatever is causing the issue and lower that noise floor. Sounds like they built an awesome product at a very competitive price. Think I'll snag one once I have the capital for it.

I couldn’t have put it any better

 

[laxu]

So what is the story on these? Do they have a design fault leading to the extra hiss some have been complaining about or not? And is the hiss present on the 10” version as well as the 12”? Does anyone know?

I think I saw on The Other Place the Fender rep saying they are checking more samples against their "golden" reference models, but they may have deleted that post.

 

[jellodog]

I think I saw on The Other Place the Fender rep saying they are checking more samples against their "golden" reference models, but they may have deleted that post.

Yeah it looks like that comment has been deleted; I just went and checked. You remembered the phrasing perfectly though!