Rothwell attenuators

[Thompsonuxb]

No.

None of those CDplayers have headphones out?

Both mine do, I'm surprised.

Most of those brands use to. Still your focus on the CD players is funny.

And these are not opinions......lol

Lol and the extreme levels some will go...

Bear with me a moment just gonna go lace up my special kung fu kicking boots....

I admit am not familiar with modern players so fair play.

I know the kit I have the output volume is adjustable.

You may even find from that list Vlad the earphone output is connected to the analog output volume like the CD 63.

Doubt it was in the reviews at the time when I bought it - I found out about it myself by accident.

Yes I understand some digital kit will have fixed level outputs - my portable CDplayer Sony Discman D-E3835 (I still remember it's name and it still works) has one connected to my Pioneer sk-757l in the bedroom. Not controllable.

But again I could be wrong - but has stated above my modern devices are controllable.

I mean what's up with you guys..... Is it because I'm a woman?

I went to the WHF reviews section and under CD players I used a filter to choose only the 5 star rated ones. I checked every one of them up to the £2000 range and these are the ones that have no volume control on the CDP gain. Yes, I downloaded the manuals from the official websites.

Pioneer PD-D6-J

NAD C 515BEE

NAD C 545BEE

Marantz CD6004

Marantz CD6005

Cambridge Audio Azur 351C

Rega Apollo-R

Cyrus CD6 SE2

Cyrus CD 6 SE

Cyrus CDi

Arcam DiVA CD192

Naim CD5i (Mk II)

Cyrus CD 8 SE2

Cyrus CD 8 SE

Roksan Caspian M2 CD

Naim CD5 XS

Actually every single one on the list has no volume control. There is a volume control on the remote but it controls the matching integrated amplifier. *wink*?

Why have manufacturers stopped making CD players with volume control like it was the standards 10 years ago, yet they keep selling them as standalone units? I think they are intentionally trying to confuse Thompson. *dirol*

Awaiting for the next rationalisation that explains the good natured intent of our beloved brands.

The only CDP on that list with headphone output is the Marantz. And your proposed solution is using the headphone output with a Y cable? Not very elegant or widespread, is it?

No offense but you don't seem to be familiar with a lot of basic things, yet such an opinionated chap you are. *biggrin*

 

[Thompsonuxb]

The NAD c660 converts analog to digital so I can 'burn' vinyl, tapes or radio to CD.

It also does mp3 etc to CD..... So it's built in DAC/ADC is good.

I enjoy making my own mix CD's.

You answered your own question.

You mean it's been done already????

Lol...oh man, then I take it that'll be the next big thing from the big boys for hifi.

Suprised DACs just go one way.

Only ever concerned with the built in types like the ones in my vs player and amp.

Still, maybe I'm being a little conceited but is there a little back peddling going on in this thread?

I'm not familiar with stand alone DACs never used one or researched them. I would have thought they convert both ways - if I designed one it would.... ;-)

I'm not familiar with external DACs but thought they had analog in.

Hmmm, what does a DAC do?

Thats called an audio interface or a sound card.

?

But what is the point of converting analogue to digital apart from probably vinyl to stream or record?

 

[Thompsonuxb]

I actually think you entertain it to justify the illogical use of attenuates myself.....

But that's just me.

Vlad, I'm not sure it's for the CDP makers to provide a variable output, and even if they did I think many of us would suspect it was an unnecessary step that might degrade the sound.  It is surely for the amp makers to know what has been the published facts for three decades, that players have a 2 volt output.?

My argument is soon lost however, as most make amps too, so they deserve your criticism!

We simply entertain the CDP lack of volume control theme for Thompson's sake (kinda fun). The basic premise remains that amplifiers are too sensitive on their inputs for the standards of digital audio.

 

[Jota180]

I was reading a thread on the Harbeth User Group's forum and the point was made that the specification in CD's Red Book that they output up to 2.1V was to ensure CD's had the wide dynamic range that they do.

I asked there if using attenuators to reduce this volatge would affect the dynamic range but haven't really had a convincing reply.

Anyone know the answer?

Edit...

"Similarly, the use of attenuators in a test system with a spectrum analyzer, for example, willaffect the test-system dynamic range. Since the dynamic range is essentially the difference between the highest-level signal and the minimum discernible signal, the dynamic range will decrease by an amount equal to the total attenuation added."

http://217.34.103.131/app/AN70-001.pdf

The best solution to this would appear to be buying the correct amplifier.

By adding an inline attenuator we are decreasing the amplifier input sensitivity, not reducing CDP output. The CDP remains sending its 2.1Vrms and its dynamic range is not affected by inline attenuators and trimmers.

Lets map out the gain stages roughly with and without added attenuators.

a) CDP outputs 2V for a signal which enters the preamp where gain goes up to 10V (x5) and next is sent to the volume knob set at maximum and next to the power amp where gain goes up to 40V (x4). The end result is without clipping.

Lets double the amplifier input sensitivity to sell more amplifiers.

b) CDP outputs 2V for a signal which enters the preamp where gain goes up to 20V (x5 x2) and next is sent to the volume knob set at maximum and next to the power amp where gain goes up to 80V (x4). The end result is power amp clipping after passing 40V. To prevent clipping, user moves the volume knob back to reduce 50% from the preamp's 20V and return ideal state of 10V sent to the power amp.

Let's half the input signal (reduce amplifier input sensitivity) with an attenuator.

c) CDP outputs 2V entering an input attenuator (or trimmer), which reduces it at 1V, passing it on to the preamp, where gain goes up to 10V (x5 x2 /2) and next is sent to the volume knob set at maximum and next to the power amp where gain goes up to 40V (x4). The end result is without clipping.

"Adding an attenuator anywhere in the chain can only reduce (degrade) the signal to noise ratio."

Is signal to noise not the same as dynamic range?

* The quote is from a retied BT audio engineer.

 

[Covenanter]

"Adding an attenuator anywhere in the chain can only reduce (degrade) the signal to noise ratio."

Is signal to noise not the same as dynamic range?

* The quote is from a retied BT audio engineer.

- The noise contribution of the amplifier's noise source is fixed.

- The Noise Figure of an attenuator is the same as the attenuation.

- The Noise Figure of an attenuator preceding an amplifier is the Noise Figure of the amplifier plus the attenuation of the attenuator in dB.

Source

As previosly mentioned, the noise and sound degradation from just 3 precise 1% tolerance metal oxide resistors is something only an osciloscope can barely measure. Adding a trimmer is a much worse scenario but still questionable if at all audible.

Whilst this last is true, adding anything to the signal path that doesn't need to be there is a bad idea. If your amplifier is clipping, or to be precise if you can hear that your amplifier is clipping, then attenuators could be a good idea. If it isn't, or you can't hear that it is, then do nothing following the "If it ain't broke don't fix it" principle.

Chris

 

[Vladimir]

"Adding an attenuator anywhere in the chain can only reduce (degrade) the signal to noise ratio."

Is signal to noise not the same as dynamic range?

* The quote is from a retied BT audio engineer.

- The noise contribution of the amplifier's noise source is fixed.

- The Noise Figure of an attenuator is the same as the attenuation.

- The Noise Figure of an attenuator preceding an amplifier is the Noise Figure of the amplifier plus the attenuation of the attenuator in dB.

Source

As previosly mentioned, the noise and sound degradation from just 3 precise 1% tolerance metal oxide resistors is something only an osciloscope can barely measure. Adding a trimmer is a much worse scenario but still questionable if at all audible.

 

[Vladimir]

Whilst this last is true, adding anything to the signal path that doesn't need to be there is a bad idea. If your amplifier is clipping, or to be precise if you can hear that your amplifier is clipping, then attenuators could be a good idea. If it isn't, or you can't hear that it is, then do nothing following the "If it ain't broke don't fix it" principle.

Chris

Welcome aboard Chris!

Purism + Conformity. What unique aproach to the matter.

Cheers

 

[Thompsonuxb]

Not sure which is funnier - you making out anyone who queries your 'thing' is a slave to da man or uneducated.....

You and your fake intellect...... :-D

Chris is actually right.

Whilst this last is true, adding anything to the signal path that doesn't need to be there is a bad idea.  If your amplifier is clipping, or to be precise if you can hear that your amplifier is clipping, then attenuators could be a good idea.  If it isn't, or you can't hear that it is, then do nothing following the "If it ain't broke don't fix it" principle.

Chris

Welcome aboard Chris!

Purism + Conformity. What unique aproach to the matter.

Cheers

 

[Vladimir]

You and your fake intellect...... :-D

When all else fails, relly on good old character assassination. Can't blame you, it works rather well.

 

[Thompsonuxb]

You're trying to do it again ..... :-o

You and your fake intellect...... :-D

When all else fails, relly on good old character assassination. Can't blame you, it works rather well.

 

[pauln]

It also does mp3 etc to CD..... So it's built in DAC/ADC is good.

I don't quite follow your logic... but then I never have.

 

[Thompsonuxb]

What!?

It can record mp3 files onto CD from a pc/tablet.

There is no logic to follow.... Just saying it converts all to CD (digital).

Hope that helps.....

It also does mp3 etc to CD..... So it's built in DAC/ADC is good.

I don't quite follow your logic... but then I never have.

 

[pauln]

It also does mp3 etc to CD..... So it's built in DAC/ADC is good.

mp3 is digital, CD is digital, there is no conversion taking place so your statement makes no sense.

Anyway, i'm going off topic, sorry.

Keep up the good work Vlad.

 

[Deleted member 108165]

Oops, looks like I missed all the fun whilst I was at work

So how do you connect your network player?

Is it via DAC - not familiar with them

PC to network player via spdif, (network player operates as a dac - pc sees the network player as an external soundcard).

Network player to amp via phono leads to aux input on amp

 

[Thompsonuxb]

I take it you all went away to try the volume control on your digital devices and they worked.

Well judging by how this thread just dried up!

....... ;-)

 

[spockfish]

After the weekend, in which I had more time to do some proper listening, I can only confirm on my initial findings: these are a definite 'stay'. Having my volume controle just between 9 and 3 makes it very good.

I'm aware though that may also be a question of 'luck': I can imagine that with a different setting it would mean you run out of steam quickly.

Now on the subject of SQ. And I do realize how subjective this is

For starters: no degradation. In fact, I would consider the other way around. Especially when playing at 'low' volumes. The PMC's are very good at that, but it seems that because of the attenuators and thus cranking up the volume my amp 'feels more comfortable' in dealing with this.

Again. This was all a 50 euro experiment based on Vladimir's article. It just makes me wonder: why don't amp builders take care of this gain problem? Even if this is marketing related (let's make sure our amps look very powerfull) why don't they make it switchable? So provide a 'high-gain' for in-shop demo purposes, and a 'low-gain' setting for freaks like us.....

Regards,

 

[Vladimir]

The fact that some add trimmers on the back of their amplifiers I think speaks volumes (pun pun pun pun).