Tube Amp Archive

thanks for the replies, I'll give it a try and see if I like it

Hi all, looking for some technical insight here.. I've been wondering about this for some time. Would changing the value of V3B cathode bypass cap effect the amp's negative feedback circuit? Schematic attached, cathode bypass cap in question is circled in red. I've experimented with different cathod...

Hi all, one of my amps is a single channel AB763 build made by a reputable builder here in Nashville.. it’s more or less a single “normal” channel Vibroverb with a Bassman style OT. Sounds fantastic. The circuit appears to use vibroverb values throughout. However the choke is something different.. i...

awesome! thanks! very much appreciated

If you turn the Vibro Champ tremolo off with the foot switch and turn the Intensity control up, it fouls-up the bias on the pre-amp tube which causes distortion reminiscent of Clapton's tone on certain recordings. If you don't like this distortion, and I don't, you can minimize it by wiring the foo...

Is your main reason for wanting the Champ tremolo is because how slow it can go? Hi Stevem, ab763 tremolo is just too square wave for me and I never vibed with it. I really love the sound of vibro champ tremolo.. also Princeton reverb trem.. I dig slower smoother tremolo tones. I really don't want ...

thanks sluckey, updated schematic attached, look correct? Do you think ~ 460v from the B node would present any problems for the vibrochamp trem circuit? The vibrochamp schem shows ~360v to the trem circuit, would a voltage dropping resistor be required there? Or could I use the C node? Not really s...

Hi all, I'd love some input on this - can I delete the tremolo section on an AB763 circuit and paste in the tremolo from a Vibro Champ? I've attached a modified schematic for reference.. the red highlights are where the old circuit is cut, green highlights are where I've attached the Vibro champ cir...

thanks for the replies! this is very informative and will take some time for me to consider all this. I guess I'll just need to try a couple of OTs and see how they sound. R.G.I'm using 6v6 tubes in my Princeton Reverb. The volume level is good (I use this amp for studio work with the volume typical...

All else being equal (and I guess it never is..), how does primary impedance on output transformers affect output level and tone? I’m considering putting an oversized output transformer in my Princeton reverb build.. something like a 20w 6.6k deluxe reverb OT or oversized Princeton OT at around 8k (...

Thanks all for the replies.. I’ll try rotating and nudging the tank position to see if that fixes it. Might not be an issue after all. Would pulling the reverb driver effect the dry tone at all? I know pulling the tremolo tube on blackface trem amps can effect the dry tone by allowing additional cur...

Hi all, I have a Princeton Reverb style amp that I'm considering putting into a head cab for session work. The issue that may well arise, I'm told, would be excessive hum from the spring reverb tank's proximity to the amp transformers, if in a head cab. I don't really need the spring reverb on the a...