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Fratus-Amplification.com Custom-Built Amp Price Estimator

Choose the features of your new amp!

You must include your name and phone number or your email address to get a response from me!

All amps are designed by me. I start with the traditional circuits that the manufacturers published back in the 60's. I won't clone someone else's amps. First of all, it just isn't right. Second of all, mine just might sound better!

All amps are all-tube*, hand-wired, point-to-point, tag or turret-board construction, or my new modular board method. They are built right here in Houston**. I use parts from known parts suppliers.
All amps are built in a head-only format on an aluminum chassis, and are usually built with ceramic sockets. All variable controls are 24mm Alpha pots with 1/4" solid shafts.
Circuits are usually simulated first on LTSpice, a really great program for analyzing frequency response and phase distortion, and then verified with real hardware. They are built using the best practices of current and safe electrical manufacturing. The AC supply and HV circuits are both fuse protected. Fuses are user-accessible from the back of the amp without tools. Only grounded AC cords are used.

With a Plain, Fancy or Exotic Case: They are housed in a beautiful solid wood cabinet that is sanded and painted with clear polyurethane (or other covering as ordered) finished edges and a handle on top. There is a metal mesh on the back that is removable for access to the tubes, and a fabric (or other requested material) cover for the front like most amps.

For Audiophile amps, choose an appropriate level of casing. They are in anything from a painted metal chassis with wood trim, up to stainless steel, etc. Please include a link to a photo of the "look" you are considering. If you want an Audiophile amp, make a note.
For Audiophile amps, I use completely different designs which provide more headroom and low distortion. I have made Audiophile amps, but have no sound samples of them.

You can also request a rack-mount amp, but you have to do that directly as it is not implemented here.)

It is pretty much your choice of colors and materials.

Look at my Products Page for an example of what I have been building. Read the text with the amps to read a more detailed description.

You can request a certain look or colors, or a certain fabric for the front. I can leave it unfinished as well.
Chassis-only amps can be made in tubes-up (like a Marshall JCM800) or tubes-down (like a Fender Twin) or to be mounted on the back of the chassis like most tweed amps. I prefer the tubes-up style.
Of course, we will have to work out all the details, and only then arrive at a price.
When you are finally satisfied with the results, and if you have included your email or name and phone number, I will contact you to finalize the details. When we are agreed to the final design, I will then write an invoice for 50% of the cost as a down-payment so we can get started!
Amps usually take anywhere from a month to two months to finish, depending on the complexity.

Everything is already pre-selected for the most common choices. Change it to what you want!

New formula on 2/12/2016.

The most important question of all:

Are you human? Please answer yes or no.
Leave this empty:

Describe the sound of your new amp:

Do you have a certain sound in mind, like a certain brand?

Would it sound like a certain model?

Try to give me an example of the tone or a description of the tone you seek.
If you have a track that demonstrates the type of sound you are thinking of, an artist whose tone you like, or if there is a song that you can think of that has that tone, please name it, describe it, or paste a link here.
Some people find a track on Youtube and indicate how many minutes into the track the sound starts. That is really helpful.


Stereo or Mono? Most Guitar amps are mono. Audiophile amps can be either.
Mono Stereo


Output Watts
Note: Non-standard combinations of output power and tube type will result in non-accurate calculations.
For example, a 45 Watt amp using EL84's will calculate wrong. If you insist on that, I'll figure those cases by hand.
1 2 4 8 12 18 24 32 40 45 50 60 100
Type of output tube
This is more about the power and description of the tone you are looking for. Some people have already decided they want a certain tube.
If you have no preference, just leave this choice alone, and I will choose the best one for the watts and tone.
6L6 - American tube often used for audio amps
EL34 - European output tube, slightly different sound
6V6 - small American audio output tube
EL84 or 6BQ5 - used for small amps and table radios
KT88 - "Kinkless" higher-power design from Europe
6550 - American higher-power tube
12AU7 - HiFi preamp and output tube often for headphone amps
12AT7 - more power and less fidelity than 12AU7
Do you want a tube type that is not listed? In that case the estimate will not include the cost of tubes until I add them manually.

Type of output stage
Push-pull is the most common, but for certain applications Single-ended sounds better. Ultralinear is used if you want lots of clean power.
Push-Pull Single-Ended Push-Pull Ultralinear.
Type of output stage bias
Bias type sometimes makes little difference in the sound. Self-bias is commonly used on lower-power amps, such as those 30 Watts and below. It is also usually used on Single-Ended amps. Fixed bias is much more common. Switchable is used for a choice of type, but Regulated bias keeps your tubes at optimum bias without the heat and waste of tube power that Self-bias causes.
Fixed Bias (adjustable internally) Self-Bias or Class-A Fixed Bias (user adjustable) Fixed Bias (regulated) Switchable

Power Supply

Type of rectifier
Tube rectifiers "sag" and respond to higher volumes by causing output compression. Solid-State rectifiers provide more clean power but there can be a large difference in the sound. Choose Tube for Vintage sound, Solid-State for modern, or Both for a switchable choice.
Solid State Vacuum Tube Both (switchable)


Number of Inputs
This is really how many input jacks there are to plug into, per channel. One or two is most common.
1 2 3 4
Number of Channels
Each channel would have its own controls, commonly Gain, Tone(s), and Volume. Please leave a note if you want this Foot-pedal-switchable.
1 2 3 4

Channel Details - comments about the channels
Here you can describe in more detail what you want. Examples could be:
  • One Input, One Channel Out
  • Two Inputs, One Channel Out
  • One Input, Two Channels Out
  • Two Inputs, Two Channels
  • One Input, Three Channels
  • Three Inputs, Three Channels

    Number of Tone Controls for each channel. If you want something special, like Parametric Tone controls, leave something in the Tone Control Notes.
    None One Two Three

    Note: A Blackface would be 2, a Silverface would be 3, for example. Tone Control Details (per channel) - Examples could be:

    Tone Control Notes - comments about the tone controls:


    4 Ohms 8 Ohms 16 Ohms

    Notes: Output Notes - comments about the outputs, like:


    Reverb (solid state or traditional spring reverb)
    Tremolo (solid state or traditional tube-type)
    Echo Module (solid state)
    Variable Attenuator (pure resistive)
    Effects Loop OUT and IN

    Cabinet, Case and Quality

    Chassis (open metal chassis - customer install in their own cabinet)
    Plain (lightly sanded wood with rounded edges and corners)
    Fancy (painted or varnished, or other standard amp covering)
    Exotic (very special wood, covering and/or custom hardware)


    What is your idea of how much this amp should cost? $ (US Dollars)
    Optional: Your Name & Phone or Email Address (Required if you want a response from me)
    You can hit the BACK button when you get the result to adjust your values and re-submit them.

    * Exceptions to "all-tube" are in your choice of solid-state rectifiers and also diodes in the bias supply if you chose anything but self-bias (which is like Class A).
    ** Exceptions to "built in Houston" are with the solid-state accessories, like the echo, reverb, and the delay modules.

    my name and phone number graphicCall, but please not before 9AM.

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