ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

previous: Matthew Springer After looking at the spec again of ... -- 9/1/2000 3:44 PM

Re: Harmonic Tremolo in a pedal?

9/1/2000 9:26 PM
jon	Re: Harmonic Tremolo in a pedal? Hi Matthew, My 'brownface' trem pedal has the oscillator waveform "feel" of a Vibrochamp or an original Ampeg Jet (I have one of the latter)...to my ear a lot nicer than the LDR coupled oscillators. I have a '68 Blackfaced Deluxe Reverb, and several original Ampeg Gemini's; this pedal is way more musical. In the brownface, what's nice is you can hear the shifting between the bass and treble in addition to the amplitide modulation. Still not the vibrato that's in my Magnatones (mono in a 410 and stereo in a 280) but nice. Doing these oscillator based circuits as free-standing pedals required getting gain levels correct and lots of attention to lead dress and shielding. Parasitics were also a bit of a drag initially. Overall, I feel they'r worth doing as I don't care too much for most of the SS trems/vibratos I've tried. Even though O'Connor's SS trem circuit is clean and straightforward, it doesn't have the "feel" of a tube circuit. I'm sure in the right hands, this too can be tweaked; I'm just so much more comfortable with tubes. In reviewing the Vibroverb schematics, I see there was the 6G16 which did have the trem circuit tie into the bias supply. I don't have one of these, I believe my Traynor Guitar Mate Reverb III has a trem tied to the bias supply (been a while since I was in there, don't have the schematic readily available) on a pair of EL84's; this is a very pronounced pulsatile amplitude modulation. Looks like the Vibroverb AA763 (blackface?) had the usual LDR setup. See ya, Jon

9/1/2000 9:26 PM

jon

Re: Harmonic Tremolo in a pedal?

Hi Matthew,

My 'brownface' trem pedal has the oscillator waveform "feel" of a Vibrochamp or an original Ampeg Jet (I have one of the latter)...to my ear a lot nicer than the LDR coupled oscillators. I have a '68 Blackfaced Deluxe Reverb, and several original Ampeg Gemini's; this pedal is way more musical. In the brownface, what's nice is you can hear the shifting between the bass and treble in addition to the amplitide modulation. Still not the vibrato that's in my Magnatones (mono in a 410 and stereo in a 280) but nice.

Doing these oscillator based circuits as free-standing pedals required getting gain levels correct and lots of attention to lead dress and shielding. Parasitics were also a bit of a drag initially. Overall, I feel they'r worth doing as I don't care too much for most of the SS trems/vibratos I've tried.

Even though O'Connor's SS trem circuit is clean and straightforward, it doesn't have the "feel" of a tube circuit. I'm sure in the right hands, this too can be tweaked; I'm just so much more comfortable with tubes.

In reviewing the Vibroverb schematics, I see there was the 6G16 which did have the trem circuit tie into the bias supply. I don't have one of these, I believe my Traynor Guitar Mate Reverb III has a trem tied to the bias supply (been a while since I was in there, don't have the schematic readily available) on a pair of EL84's; this is a very pronounced pulsatile amplitude modulation. Looks like the Vibroverb AA763 (blackface?) had the usual LDR setup.

See ya,
Jon

Replies:

Corwin Is it possible to modify the circui... -- 9/9/2000 2:39 PM