Dating silverface deluxe reverb, list of mods
The traditional build materials offer warmth, dynamics, low note articulation and proper distorted harmonic content layering.
Silverface Deluxe Reverb?
You can place your master volume pot anywhere but you may have to use shielded wire to prevent noise or oscillation. If you push your amp hard with boost and gain pedals you may want to stick with the k resistors because they help prevent the power tubes from going into blocking distortion.
Use a 1MA pot with a push-pull DPDT switch and wire one leg of the master volume through the switch so when the master volume knob is down the circuit is completely disconnected. Replace V1 or V2 with a 12AY7.
The Treble and Bass pots change the resistance of the RC audio filters to change the amount of signal filtered out. This speaker is for classic rock, country, and blues.
This extra cab size allows two 8" speakers to fit nicely. Original photo by John Chabalko.
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The trim pot's upper right terminal is soldered to the back of the bias pot for a ground connection. You will need to bias the amp after this mod. If you want to change the Normal channel cap's value then simply remove the original cap and solder in the cap of choice as shown in the layout below.
The stacks' output flows directly into the Volume pot. Pull the knob up to activate the master volume. This diagram shows a 5E3 Deluxe but the push-pull switch wiring is the same. Just put the cap around the ohm Negative Feedback resistor.
This mod is a little more difficult in the 68 Custom Deluxe Reverb because there is no wire, only a trace between the Tremolo Intensity pot and the k Vibrato Channel Mixing resistor R35 so you must cut the trace and bridge the cut with the Tremolo Cut switch. The extra voltage swing will drive the 6L6 harder into distortion and keep the upgraded amp from sounding too sterile.
Using a 1 watt plate load resistor will reduce resistor temperature robots vs zombies newgrounds dating hiss.
Some actually prefer the Sigs to the more expensive 10F and 12F You can buy silverface grill cloth and Fender logos to cover the new board.
Silverface Deluxe Reverb - blackface or silverface circuitry
If you play mostly clean or use mostly open back cabs the. In many silverface amps one of the k grid leak resistors is mounted near the Bias Balance pot.
For a big bottle amp with a 4 ohm output transformer secondary we need to connect an 8 ohm speaker.
The Normal channel original k mixing resistor far left at "X" below is not in the new circuit so it can be left in place or removed. This mod also puts the two channels in phase so you can jumper the channels together for a slightly thicker tone.
You may also need to adjust the bias after installing the 6V6 tubes. To do this you would run the wire from the 2 center pot terminal to the upper left DPDT switch terminal, then run a wire from the middle left DPDT switch terminal to the circuit board's right k resistor.
Dating A Silverface Twin Reverb. Used and Vintage Guitars
You can add whole-amp gain and distortion by changing the two power voltage dropping resistors to the Twin Reverb values which will bump up the phase inverter and preamp plate voltage.
The trim pot is wired as a variable resistor with the trim pot's lower right terminal not connected to anything. For the 68 Custom Deluxe Reverb the negative feedback resistor is R64 at 1. Here's the voltages I measured on my bone-stock AA Bandmaster Reverb schematic values in parenthesis: The V1A k 1 watt plate load resistor will add gain to the channel's first preamp gain stage and make overdrive more likely in the amp's following gain stages.
Installed a slightly tweaked version of the Lead Channel Mod with 2. If you don't use it you should consider voicing it as a "lead" channel by changing out only four components. You can alligator clip the cap in place temporarily to see if you like the mod.
You simply turn the amplifier up and adjust the pot for minimum hum. This method of running both channels through reverb and tremolo does not use mixing resistors so the two channels affect one another which can cause fluctuating attenuation and distortion.
I'm a fan of the.
Silverface Deluxe Reverb speaker - Gearslutz Pro Audio Community
I recommend a 3 watt rating for these resistors for longevity's sake. Trim the wire flush at both ends and you're done. The Original Bias Balance Pot The silverface Bias Balance pot only adjusts the balance between the power tubes, it does not adjust the bias level.
Turned the Normal channel's second gain stage into a Marshall style Cold Clipper with an un-bypassed 10k cathode resistor.
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Silverface Deluxe Reverb
You don't have to use a 1k resistor here, you can chose any resistor value between the original value and 1k to tweak the tone change to your liking.
Two triodes sharing an ohm cathode resistor is the equivalent of each triode having its own 1. It's a good idea to twist the two wires together to the pot to minimize noise twist not shown in diagram above. In a push-pull amp the guitar audio signals on the two power tube grids are degrees out of phase with one another so mixing them together nullifies the signal, kind of like mixing matter and antimatter.
You can use a temporary alligator clip lead to try the mixing resistor bypass. It does this by simply connecting the two channels' second triodes' plates together see schematic below. You will also gain some clean headroom and maximum volume because low frequencies use up a lot of the amps power so removing very low frequencies allows more amplification of the remaining audio frequencies.
By replacing the 1M grid leak with a 1MA pot you will not only cut the amount of guitar signal entering the reverb driver as you turn down the Dwell pot but you will lower the CR corner freq as well which will allow more low freqs into the reverb circuit.
Many people like to use Orange Drop caps in the tremolo oscillator.
I really love the Lead Channel Mod. Desolder and pull the Normal channel's. The frequency response graph on the right will change as you alter component values or move the Bass and Treble pot sliders at bottom left.
You can balance the extra gain from the 12AX7 in one of the channels by swapping out V1 Normal channel or V2 Vibrato channel with a lower gain 12AY7 to make your clean channel cleaner.
Disk cap numbers 1, 2 and 3 match the numbers in the schematic above. As you turn the Master Volume pot down counterclockwise more of the opposite phase signals from the phase inverter are mixed together which cancels the signal out.
This is a great modification and will really make the amp more versatile.
You must consider the power tube plate voltage when running 2 6V6 tubes. If your silverface amp has a Mid tone pot then you don't need the 6. Just use a 4 ohm speaker with the Deluxe Reverb's 8 ohm secondary. The raw tone has a non-scooped mid similar to the no-tone-stack tweed amps such as the 5E3 Deluxe.
It makes setting low bass settings easier and more precise but it does limit you to how low you can set the bass. But since the output transformer was designed to load the current put out by 4 power tubes we need to make an adjustment on the speaker end to load 2 tubes properly.
This mod is also easy to reverse if you ever want to return to the stock Fender circuit.