How do I bias a Peavey Windsor Head

[Wonker]

I have a Peavey Windsor head and would like to check the bias.





This isnt like the Marshalls I biased before. The Windsor only have one adjustment pot and a nipple looking test area?

[ahamay79]

My guess is that you would hook your black lead to ground, red lead to the test point, and read the total of all the tubes. Try it out and see if it looks right. You can always call Peavey to find out.

[Enzo]

Like a number of other Peavey amps, the test point is for bias VOLTAGE. It is not a sample of tube current. The factory spec is -55v for 6L6s and -42.5 for EL34s. What that sets in terms of current is up to the tubes installed, but it will be cool enough that most any tube will be fine.

If you want to adjust by tube current you will have to get a bias probe or go inside and use the shunt method.

[Wonker]

If you want to adjust by tube current you will have to get a bias probe or go inside and use the shunt method.

So this knob doesn't adjust bias?

[ahamay79]

Yes it does adjust the bias.

[Enzo]

ALL bias controls adjust the bias voltage - that is their job. You bias control adjusts the bias voltage too. It is the bias voltage that determines the amount of current flowing through the power tubes. Most guys here are concerned with the current through the tubes. You use that plus the B+ voltage to determine powr dissipation, and they set the voltage to achieve the desired level of current. What exactly the volatge winds up being is not all that important and won;t be the same tube after tube anyway.

What is different here is that the TEST POINT shows the bias voltage, not the tube current. If you set the bias voltage at the test point to -55v for 6L6s, you will have it set the way the factory recommends.

However, if you intend to adjust the bias to the common (around here) 70% of dissipation, you will need to use some other method. The test point won;t help you. The bias adjust control will still adjust the bias, but the test point won;t tell you anything useful.

SO you would still use the control, but you would not use the test point, you would instead use a bias probe or the shunt method with an ammeter to take the readings.

[gobigjeff]

Peavey Windsor 100 watt head bias procedure

I just got off the phone with Peavey. You can run either EL34 or 6L6 tubes in the Windsor. Connect up the red positive lead of your multimeter to the test point, and the black to ground. Get yourself a matched quartet of either EL34 or 6L6 and use the bias control knob to set the voltages accordingly:

EL34 = 44 volts
6L6 = 54 volts

This is straight from Peavey repair. Hope this helps.