I recently started playing the Clarinet again and purchased a much better quality instrument for me.
However I feel I have gone completely backwards playing the clarinet. Over one month ago I could play lots of music, but it all seems to be in vain as I'm finding it incredibly difficult to play for longer than 4 bars as I just simply get out of breath.
Can anyone advise on breathing techniques or ways other than just practising to help. I have heard of circular breathing, I tried it but just cannot do it. I see Clarinestists play and it looks so effortless, obviously its because they've practised, but my cheeks seem to want to puff out when playing. I stop, but I get out of breath so so fast.

Hope you can help.

Don't try to practice circular breathing yet. It is an advanced technique and you need to have a good strong embouchre and good breath efficiency before you try circular breathing.

If you did not have this problem before it could be that the better quality instrument you now have allows more air to go through it, which you are not in shape for yet.

Here are 2 execises that should help you. One is a way of measuring and doing long tones and the other is something you can do while watching tv or waiting in the dentists office, or wherever.

EXERCISE 1
Measured long tones.
The goal is to play all notes the same length. Just like practicing scales you should not play any scale faster than the slowest scale. (I digress). Sit in front of a clock that has a second hand. Play a comfortable low note and hold it for 15 seconds. Rest for 15 seconds and then go up a half step and play for 15 seconds, rest 15 seconds and go up a half step. Continue this until you get to the top of your range.

Do this exercise for 1 week.
On week 2 increase the long tone to 20 seconds, rest 15, play 20 rest 15, play 20, .. . . . .
Week 3 go to 25 seconds of long tone, rest 15, play 25, rest 15
Week 4 go to 30 seconds play, rest 15, etc .
You can go farther later, but this is good for now and will help with your breath efficiency. I know that holding the note will seem boring at first, but listen to your tone closely, it will change, you want to work on it staying full through out while you hold the note.

EXERCISE 2
When you are not playing try this basic yoga exercise. Breathe in through your nose very slowly, pause, and exhale very slowly through your nose. This can be frustrating at first, but with patience you will be calmer and it will help with your breath efficiency.

Let us know how this works.

I find those techniques really interesting.

Just a question though, on exercise 2, why do you breathe through your nose, instead of your mouth?

slap slap,

The exercise is to improve efficiency of breath (and it is incorporating mental calmness as well which will be juxtaposed later when we do fast passages). But, the nose will cause more restriction naturally than the mouth and this will cause the gases in your lungs to change differently and more quickly, increasing the carbon dioxide change over rate. This gas change over occurs when we play and is why many muscians can't play long phrases, we are not accustomed to the gas being generated and are actually starving ourselves from oxygen.

Practicing this will get us more comfortable with the change over, AND will help the body train itself to understand what we want it to do and down the road will produce a slower gas change over rate, which will allow us to paly longer phrases.