Bold Vs Spongy

[diamondschwin]

I mostly stay on the vintage mode of channel 2 on my dual rectifier 3 channel, and i love how it sounds, i actually didnt realize till today i had been on the spongy setting even to i swore i had it set to bold, i was thinking tho i want kind of a cleaner sound, which the bold should do, i cant really experiment with it right now because its late at night and the neighbors will complain but im wonder does bold really give more head room, or does it just tighten up the bottom end?

also is it like a post gain contour?

just wondering, because i feel like bold would be best for super heavy stuff which in reality i only play for fun but for my band i stick to the vintage mode

 

[Dale B.]

Yes, the Bold mode will give the amp more headroom. In order to have extra headroom, you need power. The Bold/Spongy selection is a Variac switch. The Spongy mode will have a lower plate voltage compared to the Bold mode. You need a higher plate voltage to create more power and you also need higher cathode current draws to create more power. Volts x's Amps = Power (aka Watts).

For example:

My Triple Rectifier's plate voltage is usually in the 465 area while in the Bold/Silicon Diode mode and the Bias will be right at 25 mA w/ Mesa spec tubes. If I switch it from Bold to Spongy and keep the Silicon Diodes, the plate voltage drops to around 420 and the bias will drop down to about 18 mA. If I swap back to Bold, but I option for the Tube Rectifiers, the plate voltage will be in the 395 to 400 area and the bias will be at about 15 mA. If I swap down to the Tube Rectifiers, while still in Spongy, the plate voltage will drop to it's lowest point to about 350 to 360 and the bias will be at about 9 or 10 mA.

You loose power and headroom if you take the course I described above. If you go in the opposite direction, you gain more power and headroom.

Bold/Silicon Diode - Highest Power
Spongy/Silicon Diode
Bold/Tube
Spongy/Tube - Lowest Power

Hope this helps.

Dale