Hi All,
Can someone describe the gain in terms of peak-to-peak voltages at each stage of a typical high gain tube preamp like a Marshall JCM2000:
http://www.drtube.com/schematics/marshall/dl40-60-02-iss9.pdf
For example, if the input is 1 Vpp and the first stage gain is 60, that's 60 Vpp at the anode. Then the insertion loss from the filter network that follows would probably cut that down to around 1/3 or 20 Vpp (of course this is frequency dependent but lets say at 1 KHz). If you really bang on the guitar you might get 4 Vpp giving 240 Vpp at the anode and 80 Vpp after the filter. If the second stage is another gain of 60, that's 1200 Vpp which of course will start to clip to the supply which we'll say is 350 Vpp and so the level of clipping mgiht be described as 3.4 x the supply (or 13.7 x if the input is 4 Vpp). If the filtering that follows is again around 1/3, that's 117 Vpp times 60 which is 7000 / 350 = 20 x the supply and so on ...
Can someone describe the Vpp, gain and attenuation at each stage in a typical high gain amp in this way?
Is the typical gain of a triode stage in an amp like this 60? Is that under load or is the gain with the load more like 50?
How much attenuation is there before the next stage? I realize this is highly dependent on frequencies but I just need a vague idea.
I want to get some idea as to how much clipping occurs at each stage.
Mike
Can someone describe the gain in terms of peak-to-peak voltages at each stage of a typical high gain tube preamp like a Marshall JCM2000:
http://www.drtube.com/schematics/marshall/dl40-60-02-iss9.pdf
For example, if the input is 1 Vpp and the first stage gain is 60, that's 60 Vpp at the anode. Then the insertion loss from the filter network that follows would probably cut that down to around 1/3 or 20 Vpp (of course this is frequency dependent but lets say at 1 KHz). If you really bang on the guitar you might get 4 Vpp giving 240 Vpp at the anode and 80 Vpp after the filter. If the second stage is another gain of 60, that's 1200 Vpp which of course will start to clip to the supply which we'll say is 350 Vpp and so the level of clipping mgiht be described as 3.4 x the supply (or 13.7 x if the input is 4 Vpp). If the filtering that follows is again around 1/3, that's 117 Vpp times 60 which is 7000 / 350 = 20 x the supply and so on ...
Can someone describe the Vpp, gain and attenuation at each stage in a typical high gain amp in this way?
Is the typical gain of a triode stage in an amp like this 60? Is that under load or is the gain with the load more like 50?
How much attenuation is there before the next stage? I realize this is highly dependent on frequencies but I just need a vague idea.
I want to get some idea as to how much clipping occurs at each stage.
Mike