Tonal and volume differences in Fender amp NORMAL and VIBRATO channels

[Leo_Gnardo]

As it's not been noted yet, the trem channel of many twin channel BF non-reverb amps, eg Tremolux http://bmamps.com/Schematics/fender/...a763_schem.pdf tends to be slightly weaker than the normal channel, due to the heavy loading presented by the 50k trem intensity control to the previous stage.
It may be psycological to do with the slightly lower volume, but it also seems to make the trem channel tone seem a touch 'thinner' than the normal one.

That vib intensity pot does load down the signal a bit. A couple years back, maybe 20 or so, there was an article in GP or one of the other popular mags, pointing out that you could put a pot/switch combination in place of the vib depth control, you switch the pot out of circuit when not needed so you could enjoy full frequency response. Of course nobody made or makes a reverse taper 50K pot with a switch attached, and with linear or aud taper you immediately throw out what little advantage the reverse pot gives you and all the action is crammed between about 9.5 and 10 on the control. All the switch does, as far as my ear's concerned, is make the amp excruciatingly bright. Just had an amp in last week that was fitted with this kind of pot. Another fine solution looking for a problem.

[Chuck H]

That vib intensity pot does load down the signal a bit. A couple years back, maybe 20 or so, there was an article in GP or one of the other popular mags, pointing out that you could put a pot/switch combination in place of the vib depth control, you switch the pot out of circuit when not needed so you could enjoy full frequency response. Of course nobody made or makes a reverse taper 50K pot with a switch attached, and with linear or aud taper you immediately throw out what little advantage the reverse pot gives you and all the action is crammed between about 9.5 and 10 on the control. All the switch does, as far as my ear's concerned, is make the amp excruciatingly bright. Just had an amp in last week that was fitted with this kind of pot. Another fine solution looking for a problem.

FWIW it's reported that SRV's Vibroverb was modified with the trem pot disconnected. So there's bound to be some hype around this. What they DON'T tell you is that SRV used the Vibroverb in combination with other amps nearly all the time in the studio. So it's particular sound was only a contribution to the total sound. Guys are going to disconnect their trem anyway.