This amplifier is my take on the Ampeg V4, but with a ton of very important improvements. Overall, the tone circuit and topology of the original design is maintained; but more options have been added, obsolete or unobtainable parts have been swapped for parts that are identical in circuit and sound but easily sourced, and tour worthiness or dependability of the overall design and power circuit have been vastly overhauled.
The essential design elements are:
- Enhanced Tone Options
- Power supply stability
- Turret board construction
- Hand Welded Stainless Steel Chassis
- All Preamp tubes are 12AX7 or 12AU7
- All Poweramp tubes are 6L6GC
There are still some changes that will be put into the amp from the photos of the design / build, but overall the prototype is really hitting all the essential marks that need to be hit. It is really well enunciated, the ever powerful active mid controls are as responsive as ever, and the lows are absolutely absurd. I'm overall much happier with this build than I was with the V4; for the overall stability of the parts within and the additional controls.
CONTROLS:
- Input I, Input II, Both (I+II): This is a continuation of later ampeg heads, where people would jumper the leads and use both channels. Here, you don't have to use a jumper to get access to both. The individual inputs are still available if you want you use something like an A/B/Y pedal to be able to swap between the different inputs as a semi-channel select.
- Sensitivity (I+II): Each channel has a sensitivity control. These activate a cathode bypass circuit and create a uniquely tighter sound. Not the best at describing these, but they are cool.
- Ultra Low (I+II): Each channel has an ultra lo switch, that brings in an entire network of caps and resistors into the chain, that give a much woolier / woofy sound to the channel. Great blended with one channel on and one channel off for this switch, or for use in a strictly low end bass sound. This switch does have a significant volume cut, so compensating with gain is necessary. Turning this switch off will return the amplifier to stock V4.
- Ultra Hi (I+II): Each channel has an ultra hi switch as well, this can either add or subtract highs from the channel. This switch is interactive with the gain control, so if you dime the gain, the ultra hi will no longer affect it.
- Gain (I+II): The last control for each channel before they join at the tone stack. Self explanitory, it is the overall volume for each channel, and lets you get decently hot
- Bass / Treble: A simple tone stack for the lows and highs, a reductive circuit that is based on baxandall.
- Midrange: An active mid control that is surprisingly deep and powerful
- Midrange frequency: The midrange knob can be shifted and totally alter the entire feeling of the amp. The most important control to dial in for your sound, to shift its centerpoint and use the knob to add or subtract
- Volume: Master volume control. Dime this to return to a stock no-mv V4, but is really useful when trying to exist in the same room as the amplifier
If you have questions about this amplifier, please send a message.
DETAILS:
- Chassis
- 14 gauge marine grade stainless steel
- Welded mounting nuts
- Corners
- Other corners can be specified and used per request.
- Handles
- Large metal recessed spring loaded with rubber grip side handles
- Leather strap top handles
- Middle single handle can be added on request
- Feet
- Rubber feet
- On request they can be swapped over to wooden slats
- Faceplates
- Aluminum sheet metal in house engraved
- PEC Stainless steel sealed potentiometers
- Turret board construction (this may change to partial PCB for switch routing)
- Inputs modified with third bridged jack
- Ultra Lo modified with independant channel control
- Ultra Hi modified with independant channel control
- 6K11 and 12DW7 replaced with 12AX7 / 12AU7
- Passive FX loop / Slave out / Slave in added to front panel
- Half Power switch
- 7027A replaced with 6L6GC
- Power Choke added
- Heaters elevated to 50v DC