1/ regularly remove the tubes and have them commercially tested;

2/ replace the tubes with new stock on a regular basis.

These two methods may give the operator a degree of confidence ///but in fact, it can be shown that the faith placed in both methods is misplaced.

It is a known fact that removal of a tube from its socket results in a number of potentially damaging mechanical stresses on the metal to glass seals around the pins. Each insertion of an all glass tube will cause micro-cracking of the glass around the pin. This will invariably cause a small leakage of air into the tube, causing ‘gassing’ and eventually leading to its demise.

Removal for testing will also break the intimate contact between the holder and the tube contact pin, resulting in a poorer contact on re-insertion.

Many tube testers apply unreasonable electrical stresses to the valve internal electrodes and it is not uncommon for a known good valve to be damaged during the test. Tube testers can also give erroneous results depending on the way they perform the tests, possibly allowing faulty tubes to show ‘good’ and the good valves to be rejected as ‘bad’.

The second method of ‘blanket replacement’ with new stock on a regular basis can also lead to problems because if the failure distribution curve for tubes is analysed, it can be seen to follow the classic ‘bathtub’ failure curve. This inevitably means that an amplifier which is regularly ‘re-tubes’ will inevitably be considerably more likely to fail during the first hundred hours service than one which has been left untouched.

TubeSync overcomes these problems by performing an ‘in circuit’ test on the tubes every time the amplifier is powered up. The mutual conductance (gm) of the tube is measured by monitoring the cathode current of each valve whilst adjusting the grid bias in fixed steps. The results are tabulated and the new value is compared with previously stored values. A decision is then made on how far the tube has decayed in emission since the last test. Outputs from the device inform the user of the predicted remaining life of the tube.

“I believe the product is very interesting and definitely nothing like anything I’ve seen or used before. The main advantages of the product are that not only does it give you a valve maintenance feature by displaying a light if a fault is found within a valve, but it manages your valves to run at an equal number of milliamps. This means that each valve is working at an equal rate which in theory gives you optimum amp performance.

Above : TubeSync fitted to a Mesa Boogie F-50

Pics from Glory Days music in Joplin, MO USA. A reporter at CNN saw the orange tolex and took the pics.

We sincerely hope that the company can recover from this, our thoughts and best wishes go out to all.

Checkout the cymbal sliced into the door frame

DIVO will come pre-installed on select Orange Rockerverb 100 MKII heads beginning Summer 2011. The OV4 stand-alone unit, also available in 2011, can be installed on almost any amp that has (4) power tube slots.

”TubeSync DIVO works perfectly and does an excellent job of keeping even the most wayward valves on the straight and narrow. If you want to get the absolute best out of your amp and improve its reliability, DIVO is almost an essential – it’s a real innovation”.

Northern Newcastle Guitar Show

The Lancastrian Suite, Federation Brewery, Lancaster Rd, Dunston, Gateshead, NE11 9JR

on Sunday 6th  March 2011

With Blues Guitarist : Mitch Laddie

In an attempt to guard against this possibility, it is common practice to do one of two things on a regular basis.

1/ regularly remove the tubes and have them commercially tested;

2/ replace the tubes with new stock on a regular basis.

These two methods may give the operator a degree of confidence but in fact, it can be shown that the faith placed in both methods is misplaced.

It is a known fact that removal of a tube from its socket results in a number of potentially damaging mechanical stresses on the metal to glass seals around the pins. Each insertion of an all glass tube will cause micro-cracking of the glass around the pin. This will invariably cause a small leakage of air into the valve, causing ‘gassing’ and eventually leading to its demise.

Removal for testing will also break the intimate contact between the holder and the tube contact pin, resulting in a poorer contact on re-insertion.

Many tube testers apply unreasonable electrical stresses to the tube internal electrodes and it is not uncommon for a known good valve to be damaged during the test. Tube testers can also give erroneous results depending on the way they perform the tests, possibly allowing faulty tubes to show ‘good’ and the good valves to be rejected as ‘bad’.

The second method of ‘blanket replacement’ with new stock on a regular basis can also lead to problems because if the failure distribution curve for tubes is analysed, it can be seen to follow the classic ‘bathtub’ failure curve. This inevitably means that an amplifier which is regularly ‘re-tubes’ will inevitably be considerably more likely to fail during the first hundred hours service than one which has been left untouched.

TubeSync overcomes these problems by performing an ‘in circuit’ test on the tubes every time the amplifier is powered up. The mutual conductance (gm) of the tube is measured by monitoring the cathode current of each valve whilst adjusting the grid bias in fixed steps. The results are tabulated and the new value is compared with previously stored values. A decision is then made on how far the tube has decayed in emission since the last test. Outputs from the device inform the user of the predicted remaining life of the tube.

Click on the link above if you would like to join the TubeSync Revolution

]]> http://tubesync.co.uk/blog/amps-tubes-valves/tubesync-facebook-friends-are-now-2000/feed 0