#PURCHASE BIAS AMP 1 KEY INSTALL#

After the tubes are hot do a final bias adjustment if necessary and youвЂ™re done! If you have purchased your tubes as a matched set from a reputable source such as Eurotubes, it is only necessary to measure one of your tubes. Leave the amp on in the play mode for at least five minutes because as the tubes heat up the bias will change a little. You will notice that as the current is adjusted up the DC plate voltage will drop slightly, but the difference upon recalculation will be insignificant. If your calculated bias point happens to be 40mA then adjust the bias current up. Adjust the bias to between 20 to 25mA which is a conservative setting for most all amps while you note the DC plate voltage and use the formula above to calculate the bias you want. If the amp has a standby switch then leave the amp in standby for 30 to 60 seconds, then switch to the play mode.

#PURCHASE BIAS AMP 1 KEY INSTALL#

Our recommended procedure: Install the probe under one of your tubes, make sure you have a speaker load on the amp and turn the amp on. The calculation for 80% with a 25 watt tube at 450VDC would look like this. If you want to run them on the hot side we recommend not exceeding 80% but again, you will wear the tubes out about 20% faster. You can run the tube as high as 85% but you will wear them out quite a bit quicker. For example, if you were biasing a 25 watt tube and your DC plate voltage was 450VDC the calculation would look like this. 7 most amps will actually come out of crossover distortion at about 65% but on average sound best at 70% to 75%. All you have to do is make a simple calculation by dividing the dissipation of the tube in watts into the plate voltage and then multiply the result by. The information below is applicable for push pull adjustable bias amps.

Unlike other probes the 'Pro One' uses a direct plate current reading therefore subtracting the screen current is not necessary. The ET вЂњPro OneвЂќ Bias Probe will read out the plate current in the upper readout and the DC plate voltage in the lower readout.

Most all amps will show zero plate current until switched out of standby to the play mode. The ET вЂњPro OneвЂќ Bias probe will power on even when your amp is in standby.

If your amp has a standby switch leave the amp in standby for about thirty to sixty seconds and then switch to the play mode. Make sure you have a speaker load connected to the amp and then power the amp up. Simply remove one of your power tubes, install the probe, which indexes exactly like the tube does with the timing key on the guide pin, then install the tube in the top of the probe. The amount of voltage and current used is in fact so small that you could literally power up one hundred of our ET вЂњPro OneвЂќ Bias Probes with the average guitar amp without any noticeable drain on the transformer. It is phantom powered using an extremely small amount of the AC voltage and current produced by the amplifier it is being used to test. It is unique in the fact that it shows you both the plate current and plate voltage simultaneously and it is completely self- contained with no switches or batteries. In 2012 we introduced the ET вЂњPro OneвЂќ Bias Probe. No switches, no batteries, no knobs! And only $99.00 See it in action in our latest 'How To' Bias Video! The ET вЂњPro OneвЂќ Octal Bias Probe. If you have lost your instruction sheet for one of these probes you can find a copy HERE. We try to keep a carton or two of our $10.00 'Cheap Multimeters' on hand and if you see them in the online store they are in stock. These probes are $25.00 and available in our online store and can be used with 6V6 - Eе…ѓ4 - Eе…ѓ4II - E34L - KT77 - 6CA7 - 6L6 - 6L6GC - KT66 - 6550 and KT88 tubes. We will continue to offer these because in conjunction with a Multimeter this is the most cost effective tool for measuring true plate current allowing you to accurately bias your amp. Since 2006 we have offered a single octal bias probe for use with a Multimeter.

Purchase bias amp 1 key