The Nola amp is a versatile "gumbo" blend of assorted features without overdone complexity. Including the preamp volume and master volume control is a tone control. It works as a quasi-tone master in conjunction with the tone stack, but it also contains a push-pull DPDT switch. By pulling the pot, the signal bypasses the tone stack and the amp gets an approximate 40% increase in gain while the tone control continues to function.
Near the input jacks there is an ON-NONE-ON toggle switch designated "Punch 1" & "Punch 2". When the switch is in the center position, neither the first or second stage's cathode bypass capacitor is in play. In the upper position, the first stage's bypass capacitor is connected and in the completely down position, both bypass caps of the first 2 stages are engaged resulting in a minor boost then a major boost in gain.
The Reverb circuit of my design can also be bypassed with a push-pull pot resulting in about a 10% increase in gain.
The main unique aspect of this amp is the power tubes. They are American made tubes for television functions that can be also used audio amplifier tubes and the results are surprisingly awesome. There are plenty available and they are less expensive than contemporarily made tubes, yet as NOS American made they are much more reliable and longer lasting.
The plate maximum volts are over 500VDC, but the screen voltage maximum is 220VDC, therefore, a second simple power supply has to be added. This means less stress on the main power transformer and more current availability for more sustain of the signal.
The overall output is 33 Watts RMS.
CHOICE OF CIRCUIT:
Preamp with or without Cathode Follower
Any version of Phase Inverter
Grid biased or Cathode biased Push-Pull Output Stage or Single Ended
Master Volume or none
Tone stack with or without bypass
Tone control or none or with Tone Stack and/or Tone Stack Bypass
Wave control (controls harmonics)
Warp control (warps the signal like a distortion pedal)
Reverb with or without additional Dwell control
Tremolo (Depth and Speed controls)
Volume control is obviously required but still optional if one prefers to control volume with their instrument
CHOICE OF COMPONENTS:
Preamp Tube Choice: Newly manufactured by former Soviet Union countries, etc.
Power Tube Choice : American made NOS tubes made for Television functions but can be used as amplifier tubes (strongly recommended since they are American made therefore last 10 times longer than contemporary tubes and cost less. Plenty available).
Resistor components: Carbon composition, Carbon film, Metal film, Wirewound
Capacitor components: Polyester, NOS paper & oil, Newly manufactured paper & oil
Transformers: These have to be selected based on one's tube & speaker choice.
Rectifiers: Recommended are Solid State diodes, but if one insists on a tube rectifier they need to shell out an arm and a leg for a NOS Mullard or American made rectifier. The contemporarily manufactured tube rectifiers are simply not that reliable and can do some serious damage to your amp when they fail. Either go NOS or with solid state diodes. Sag can still be simulated if so desired.
Note: There may be limitations on certain feature combinations depending on the choice of combination.