Slightly embarrassing newbie type question.

[Chr1]

I have recently inherited my dad's speakers. A pair of B&W 603 S3s. As I already have way to many speakers myself, I was going to give them to my girlfriend who currently only has a small Bose soundbar. Unfortunately she is very against large hifi components, so I was hoping it might be possible to pair them with a Denon RCD-M39 Micro System that I have.

The relevant specs are as follows...

B&W 603 S3: 90db, Nominal 8Ω, minimum 3.0Ω
(Recommended amp power: 30W-200W @8 Ohm)

Denon RCD-M39: 30W + 30W, @6 Ohm

I realise that this is far from ideal, and the B&Ws should really have a fair bit more power. However, thankfully they are going into a relatively small room and my girlfriend doesn't like her music loud.

My only concern is for the speakers. Am I right in thinking that the low minimum impedance of the B&Ws could cause issues for the Denon, but the only risk to the B&Ws is if the Denon is pushed into clipping?
ie. Their low minimum impedance only risks damaging the amplifier?

The Denon is expendable, but I really don't want to cause any damage the speakers.

Thanks in advance.

 

[Mart68]

My only concern is for the speakers. Am I right in thinking that the low minimum impedance of the B&Ws could cause issues for the Denon, but the only risk to the B&Ws is if the Denon is pushed into clipping?
ie. Their low minimum impedance only risks damaging the amplifier?

The Denon is probably quite robust, there's more risk of damaging the speakers if it is pushed into clipping.

 

[Chr1]

Okay, thanks.

Guess I will just need to see how they work together, and be careful to ensure that clipping is avoided. I actually have a slightly bigger Teac A-H500i plus matching tuner, which would be a much better match. Unfortunately I would need to add a CD player to it though.
She doesn't really care about the Teac being superior soundwise and prefers the minimalist Denon unit. Ho hum.

 

[Chr1]

Following up from this:

Can clipping occur anywhere within the sweep of the volume potentiometer? Or does it only happen higher up in its range?

Thankfully it's been many years since I have had any experience of this.
(Being that I have long since been running easy to drive, relatively robust, high sensitivity speakers with clean and plentiful amplification.)

 

[Mart68]

Following up from this:

Can clipping occur anywhere within the sweep of the volume potentiometer? Or does it only happen higher up in its range?

Thankfully it's been many years since I have had any experience of this.
(Being that I have long since been running relatively robust, high sensitivity speakers and clean, powerful amplification!)

It can happen at any position on the volume pot as they are totally arbitrary. All the power of the amp could be reached in the first quarter turn.

 

[Chr1]

OK, thanks. This is what I thought, and a bit of a concern. So from what I can gather I will just have to see how it sounds and be sure the volume control is not going into clipping early.

I really wish clipping indicators were standard. Particularly on small amps where clipping is likely. Like this wee Denon.

Kind of ironic in a way, that they're usually only standard on very powerful pro audio types.

Got a couple of old, good, more powerful NADs with their "Soft-Clipping" circuitry, but unfortunately they won't be visually compatible with her tastes. Doh. No accounting for some people's tastes!

 

[Chr1]

It can happen at any position on the volume pot as they are totally arbitrary. All the power of the amp could be reached in the first quarter turn.

This is the bit that I have a problem understanding. What is it that dictates this?

I guess that I was under the assumption that clipping would only occur higher up the volume control scale, given a standard voltage signal at the preamp input.

 

[Mart68]

This is the bit that I have a problem understanding. What is it that dictates this?

I guess that I was under the assumption that clipping would only occur higher up the volume control scale, given a standard voltage signal at the preamp input.

How the gain staging is set up in the amp which depends on number of variables.

The amp could clip at low volumes if the speaker load is extreme, or it is a very cheap / poor design and cannot maintain voltage as impedance reduces. Denon are usually competent though.

 

[Chr1]

Nice one. Thanks for your help. Much appreciated.

Guess I will just need to see how they work together and be sure to avoid clipping.

If it seems like clipping occurs low on the volume control, or the control is too course, I will be either removing the system completely.

Or doing this, I guess...

 

[Keith_W]

It can happen at any position on the volume pot as they are totally arbitrary. All the power of the amp could be reached in the first quarter turn.

Yep, I am convinced that some manufacturers deliberately do this to make the amp seem more powerful than it actually is.

It's a bit like old Alfa Romeo's. 90% of the throttle is engaged in the first 10% of travel. So you barely push the throttle and off she goes. It makes the car feel eager.

 

[Chr1]

Yes. When I was younger, me and my pals used to joke about putting a 1/8 turn racing throttle from a speedway bike (normal = 1/4), onto our road bikes. (Plus nitrous. Obviously.)

Fact is that it would be pretty dangerous, unless you had the skills of Valentino Rossi. Fine on a dirt bike, but not so much on a sports bike. Throttle control is important!

Though the consequences are less severe, it strikes me as being equally stupid doing similar things with the volume control of an amplifier. Logical intuitive control is surely a good thing.

 

[Mart68]

Yep, I am convinced that some manufacturers deliberately do this to make the amp seem more powerful than it actually is.

It's a bit like old Alfa Romeo's. 90% of the throttle is engaged in the first 10% of travel. So you barely push the throttle and off she goes. It makes the car feel eager.

No question about it, and it works too. The number of times I've seen people amazed how loud the 30 watt amp goes 'And it's only using a third of the volume! Plenty more in reserve!'

 

[Chr1]

Wow. Didn't know this.

Very stupid.

They should really also have volume controls marked going up to infinity then...

(A dumb take on the Spinal Tap thing.)

Here's hoping Denon have more sense.