Vox AC125 HELP!

[cameron]

Does anyone know what the 2N3819 Transistor at the input does? It sounds the same with or without it on the one I have here. I keep looking at the schematic but I still don't get it .

Thanks,
Cameron

[Enzo]

How about letting us look at it too? Got a link? I don't have that drawing, and neither does my dealer site.

The V125 has something that looks like what you describe, I have to think it is the same. The input tube stage to the amp is cathode driven instead of grid driven. I think this is a common grid stage, or is it a cascode including the FET? Smarter people will know. The large cap - 2uf on this drawing - essentially grounds the grid for audio. The FET is in the cathode leg, and it drives the signal into the tube.

[cameron]

How about letting us look at it too? Got a link? I don't have that drawing, and neither does my dealer site.

The V125 has something that looks like what you describe, I have to think it is the same. The input tube stage to the amp is cathode driven instead of grid driven. I think this is a common grid stage, or is it a cascode including the FET? Smarter people will know. The large cap - 2uf on this drawing - essentially grounds the grid for audio. The FET is in the cathode leg, and it drives the signal into the tube.

Sorry Enzo thats the one(it was late last night) I left out the V. I thought cascode too but it just does'nt look right. I'm thinking the schematic might be wrong. Anybody have a V125 to look at?

[Enzo]

Schematic looks OK to me, redraw it vertically and it might look more familiar.

Think of the FET as just another triode, if that helps.

[mykey]

Does anyone know what the 2N3819 Transistor at the input does? It sounds the same with or without it on the one I have here. I keep looking at the schematic but I still don't get it .

Thanks,
Cameron

first stage of the pre amp, blows easily.