To Treble Bleed Or Not?

jaymenon

I recorded four equal volume clips on my Strat

- Mojo Alnico 5-2 pickups
- No treble bleed

Two clips each on neck and bridge pickups

Neck 1
Neck 2
Bridge 1
Bridge 2

- Volume at 7 and 10 (input sensitivity adjusted accordingly)
- Tone controls at 10

Identify please - which one is volume at 7 and which one is volume at 10

I'd be interested to hear your thoughts on any tonal differences.

Funkfingers

Wot? No link? 

jaymenon

Just added...!

Funkfingers

In your Stratocaster circuit, is the lower tone control connected to the bridge/Treble position pickup?

jaymenon

That's right. 
1st Tone: Neck
2nd Tone: Bridge
Both at 10

Funkfingers

Examples 1 and 3 sound thinner than examples 2 and 4. This difference could be explained by either the treble bypass in the guitar or the adjustment made to the amplifier controls.

jaymenon

There is no treble bypass in the guitar Funkfingers...

But thank you for your observations - and also for having the honesty and courage to commit yourself by expressing an opinion.

Shall we wait until a couple of other people comment before revealing what each recording is?

SunDevil

Clip 1 has more top end that clip 2, so if you have no treble bypass and 'modern' wiring, I'd say Clip 1 was on 10 and 2 on 7
Clip 3 & 4 are the other way around, but clip 4 you hit the strings a little harder (or it could be where you're volume matching?)

p90fool

The treble pass caps on my log volume pots don't really come into their own until I get below halfway. They're certainly not doing much on seven, so although I'll have a listen later I'm not expecting a huge and obvious difference. 

Also, you haven't stated the value, there's a vast difference in the effect between say a 180pf and a 1000pf cap. 

Funkfingers

Maybe I am being too pedantic about terminology? 

A passive treble roll-off control is a bleed. The term bleed is often erroneously applied to a bypass. 

To my ears, some of your audio examples have an unpleasant trebly edge. This is why I asked about a tone control in circuit for the bridge position pickup.

ICBM

Do you mean treble bleed (what a tone control does) or treble pass (a small cap on the volume control to let top-end through and reduce treble loss as you turn down)? I ask because almost everyone calls a treble pass "treble bleed", which is exactly what it does *not* do...

The other complicating factor is that the treble loss is not caused by the volume pot, it's caused by the cable to whatever the guitar is plugged into, and the input impedance of that - so it varies. If you're using a short cable into a high-impedance buffer, you may not notice much at all.

1 and 3 sound brighter than 2 and 4, so they will be the ones on 10 if there's no treble pass cap.

jaymenon

I mean a treble by-pass circuit - designed to avoid the loss of treble associated with lowering the volume control. This guitar doesn’t have one...

Funkfingers

jaymenon said:

This guitar doesn’t have one.

This has registered, already, my life.

ICBM said:

1 and 3 sound brighter than 2 and 4, so they will be the ones on 10 if there's no treble pass cap.

I specifically (and pedantically) used the adjective "thinner" because I hear examples 1 and 3 as lacking in lower frequencies rather than having additional high ones.

Think of the way that a studio sound engineer might equalise an acoustic guitar to work better in a full band arrangement by removing low end to leave space for bass guitar and kick drum.

jaymenon

On many fora, the ‘big boys’ will never commit themselves - respect to you all.

And you gentlemen got it right -I’m really impressed...! 

Clips one and three have the volume control at 10.

Clips two and four have the volume control at 7.

I was however very struck by how subtle the differences are when the volumes (input gain on my amp) are equalised.

So when turning the volume down on my Strat, the associated perceived loss of treble is perhaps due to the reduced loudness itself - and might therefore to some degree be a psychoacoustic phenomenon.  

And that means that treble pass circuits compensate for this psychoacoustic phenomenon, rather than any really significant loss of treble...

jaymenon

Funkfingers said:

jaymenon said:

This guitar doesn’t have one.

This has registered, already, my life.

That was in response to ICBM and P90Fool’s comments

ICBM

jaymenon said:

On many fora, the ‘big boys’ will never commit themselves - respect to you all.

And you gentlemen got it right -I’m really impressed...! 

Clips one and three have the volume control at 10.

Clips two and four have the volume control at 7.

I'm always willing to have a go - you can often learn as much by being wrong as being right . But in fact this one was pretty clear, even if subtle. I should probably say that I do these kinds of listening exercises through proper hi-fi speakers at head height.

jaymenon said:

I was however very struck by how subtle the differences are when the volumes (input gain on my amp) are equalised.

So when turning the volume down on my Strat, the associated perceived loss of treble is perhaps due to the reduced loudness itself - and might therefore to some degree be a psychoacoustic phenomenon.  

And that means that treble pass circuits compensate for this psychoacoustic phenomenon, rather than any really significant loss of treble...

That is also a factor I think - but not the main one. The main effect is real, but is cable-dependent. If you're using a decent quality cable under 10', into a 1M input impedance, it doesn't make a huge difference. Replace that with a 20' cable - or worse, two 20' cables with a bypassed true-bypass pedal in the middle, into the same 1M impedance and you will start to hear much more treble loss.

It's simply caused by the capacitance of the cable, which is in parallel with the lower part of the volume pot track, and to some extent the amp or pedal input impedance, which is also in parallel with that at the other end of the cable. This acts like a small tone control turned down.

Funkfingers

Good valve amplifier input/gain stages respond dynamically to the signal strength sent to them. Players like me exploit this phenomenon to control overdrive saturation.

There is definitely a psychological component to the phenomenon. Some players desire that the volume should remain constant even when the amplifier's contribution increases. (i.e. The harmonic overtones created beyond the onset of signal clipping.) IMO, maintaining constant levels are what compression, limiting and compansion processors are for.

gringopig

.

p90fool

jaymenon said:

Funkfingers said:

jaymenon said:

This guitar doesn’t have one.

This has registered, already, my life.

That was in response to ICBM and P90Fool’s comments

Ah ok, sorry, I misread the OP. 

guitars4you

gringopig said:

I'm not a fan of treble bleed. I have it on a Telecaster but like the tone darkening with the volume turned down.

I agree - with a good guitar and a good taper on the pots the variation is subtle but effective and certainly controls the gain on the amp as per @Funkfingers comments earlier - And such variations is where the soul and emotion is

Sassafras

Turning volume down is a concept I'm unfamiliar with.