Hi Dan

I have been interested in the P1 for a few weeks and have had a few emails from Robert Campbell answering my techy questions etc. He seems like a good guy, with a good product and so I emailed him about getting on some of these forums and getting people like yourself and Harvey Gerst to review the P1, as i think it needs international attention!

He tells me that you and he have been in contact and that you or Warren Dent may be reviwing it in the near future?

Will this be happening and when? Have you read the white paper on their site?

Cheers Dan.

Kane, in the meantime you can read my response to your other query in the Industry News forum.

As cheap as it is, you should pick one up!

Warren

Stuff I mess with...

"Ah, I want to just enjoy this, sip a nice Merlot, dip into my hot tub, and then perhaps stone a kitten to death or something."-Jazzoo

Kane, I just received word from Robert that he is going to modify the power supply and send one on to me. This could take weeks for me to receive, so have patience. I will work quickly to review the unit and get a review up on MojoPie.com.

You're right, Robert is a very nice man and seems like a good guy to work with.

Warren

Stuff I mess with...

"Ah, I want to just enjoy this, sip a nice Merlot, dip into my hot tub, and then perhaps stone a kitten to death or something."-Jazzoo

Cool! With his background (which i did know about due to our email conversations) I'm expecting good things from this little company!

So, do you get to keep the 110v unit he is sending?

The practically invisible and almost brick wall limiting could be just what the digital recording enthusiast ordered, if it works as well as the white paper would suggest! Have you read the review in last months Sound On Sound? They claim the limiting was as good as any analogue device they had ever used. They said the unit is very good in every aspect from pre, to comp to expander and limiter. The expander doesn't take the signal down to nothing, but to -20dB (I think), which sounds like a good approach in keeping a natural sounding signal. The comp section is 3 stage (similar to the RNC I guess), but those who have read the white paper will know all this!

No, I won't be able to keep the unit but if I like it I might buy it.

It does seem like an interesting unit. If it sounds good it will make a fine single channel front end, the limiter is a nice utility for screaming vocalists, kick drum , etc. I can't picture most pc based studios using an expander while tracking cause you can't take it off (kind of...but it's a bitch), but might have its' uses. We shall see!

Patience.

Warren

Stuff I mess with...

"Ah, I want to just enjoy this, sip a nice Merlot, dip into my hot tub, and then perhaps stone a kitten to death or something."-Jazzoo

Yeah, i've always be dubious about expanders and gates for most recording applications, but the design of this expander does seem to have been considered carefully:

Here is the Expander section from the white paper for those who are interested:

The Expander

The decision whether to include a noise gate/expander into the unit was a difficult one. Most commentators warn again using noise gates on source material as what is done, cannot be easily undone after recording. However there are some good reasons for including this stage;

1.The P1 does have potential as an effects processor for recorded material.

2.The quality of many software based noise gates is still questionable.

3.Expanders are very useful for shaping percussion sounds at source.

Having decided to include this stage, the next decision was noise gate verses expander. Noise gates have some advantages in signal to noise separation but the attack and release times have no relation to the audio, so even using a noise gate with multiple control knobs, you can spend forever finding the ideal settings.

Expanders are generally more forgiving because the expander characteristics are always related to the dynamics of the audio material. This was especially important in the P1 design where we wanted a simple to use single knob design. The basic design is shown below.

Although the attack time is nominally fixed at 3ms, this is the fastest attack time permitted in the design. If the source audio is rising at a slower rate then the P1 attack follows this. Attack times faster than 3ms are not a technical problem to design but have a tendency to produce clicks with very fast rising audio edges.

The use of an expander side-chain limiter is a method to reduce distortion when the expander is in circuit. It ensures that when audio level is above the threshold, there is no ripple distortion caused by the audio modulating the side-chain.

In addition to the main expander side-chain, the design uses two additional side-chains which in turn control the dynamic response of the expander drive stage, as follows;

The release side-chain follows the dynamics of the audio sample and measures how quickly the audio level falls when it drops below the expander threshold. This in turn affects the average release time of the expander.

The hold side-chain measures how long the audio has been above the expander threshold. This controls three functions;

1.How quickly the expander goes into its release cycle.

2.The knee shape of the release cycle.

3.Also has an influence on the average release time.

These additional side-chains cause the expander action to compliment the natural dynamics of the audio signal.

Dynamic audio which bursts above the expander threshold for short periods gets the shortest hold and release times with a very hard knee.

At the other extreme, less dynamic audio which sits above the expander threshold for longer periods gets the longest hold and release times and a soft knee transition.

The fairly high expander ratio of 1:3 reflects the main intended uses of the P1 expander for noise reduction and dynamic shaping purposes.

The maximum expander depth of 20dB allows a fairly slow attack time to be used (which improves audio quality) but provides enough depth to have a significant effect on noisy source material.

Kane, I've recieved some email Cc's. If they send one, I'd sure have a look.

Dan Richards
Digital Pro Sound
The Listening Sessions