UralTone Nos Toaster Deluxe - Guitar amp DIY kit

UralTone NOS Toaster Deluxe is a tube amplifier that extensively utilizes NOS components and sonically sits somewhere between Tweed Deluxe 5E3 and Blackface amplifiers.

Features

• Output power approx. 10 W
• Tubes: 2x6AG7, 3x12AV7, 1x5C4 (5Y3)
• Normal channel volume, Boost channel gain, treble, bass, middle, headroom
• Output impedance: 4, 8 or 16 ohm

Kit instructions

Instructions for building the kit can be found here:

NOS Toaster Deluxe build instructions

The instruction page also includes downloadable layout images, parts lists, and other required documentation. In some cases, the schematic is delivered separately.

Browse through the instructions beforehand so you can see what the building process is like and what kind of guidance is available. The parts list shows the components included in the kit at the time of sale.

We do not include printed instructions with the package.

Links to related products

Head or combo cabinets
Speakers

NOS Toaster NT Kit

The cabinet is the same as in the 5E3 Tweed Deluxe, but the circuitry is very different. The power amp section is based on American 6AG7 metal-can power tubes from the 1930s. Surprisingly, nearly hundred-year-old tubes work excellently in guitar power amps and fit perfectly with the recycling philosophy of the NOS Toaster series. These tubes really were manufactured in 1930s America, at a time when tube quality was extremely high. These tubes have very few applications nowadays, so availability is good and prices remain low.

The phase inverter follows the traditional tweed-era cathodyne design. The preamp has 3 gain stages implemented using NOS USA 12AV7 dual triodes. The tube socket wiring is the same as with 12AX7 / ECC83 tubes, but the electrical specifications are different. Like the 6AG7, these are readily available and inexpensive despite being high-quality 1960s USA production.

The low input uses only two gain stages, making the preamp roughly comparable to Blackface-era amplifiers. The high input adds one additional gain stage, increasing gain and bringing more distortion and earlier compression.

Like traditional amplifiers, this unit sounds best when the volume is turned up a bit more. Although the high input stage has its own volume control (gain), the best distortion character is not achieved with the preamp alone. Instead, it comes alive when all stages, including the power section, are simultaneously pushed to the edge of breakup. Additional volume then takes you into larger traditional overdrive territory.

The best distortion is therefore achieved at higher volume levels. For this reason, we have added a Headroom control to the power supply, which lowers the operating voltages and therefore lowers the amplifier’s power and headroom, reducing the breakup threshold. Under normal circumstances, we recommend keeping this control fully up (normal position) or close to fully up. This usually provides the healthiest and tastiest sound. Other settings allow for wonderful and varied overdrive tones through a “trial and error” approach.

NOS Toaster Deluxe is therefore a combination of Blackface and Tweed amplifiers that delivers rich and highly traditional overdrive.

NOS Toaster Deluxe represents the values of the NOS Toaster family by utilizing components that have been waiting in storage for decades, enabling the construction of a great-sounding amplifier with a slightly smaller environmental footprint.

Capacitors

We have selected slightly different styles of very high-quality NOS capacitors for the signal path. The power section uses Vitamin Q NOS USA Military Paper in Oil (PIO) capacitors. These are perhaps among the most sought-after audio capacitors of all time. The preamp contains one Vitamin Q, one Philips Chicklet capacitor, and several Soviet NOS polyester capacitors. All electrolytic capacitors are newer. The power supply uses German F+T capacitors, while the cathodes use RIFA (Sweden) and Panasonic axial electrolytics.

The above selection has been carefully chosen specifically for this circuit. Is there another device designed in 2022 that actually uses such a wide range of non-Chinese capacitors?

Tubes

The power and preamp tubes are NOS USA production. Both 6AG7 and 12AV7 tubes are still available at reasonable prices. Compared to 6V6 and 12AX7 tubes (which would also work in this circuit), the price difference is roughly €65 vs €450 (calculated using RCA tubes). The rectifier is a Soviet military-grade 5C4 tube, which loosely corresponds to the performance of a 5Y3.

Resistors

NOS Toaster Deluxe uses Japanese carbon composition resistors. The power supply uses more modern resistor types for safety and longevity reasons.

Transformers

The power transformer is custom-made in Italy, and the output transformer comes from Hammond’s factory in Canada.

Metal chassis is manufactured in Finland, like our other chassis.

Mechanical components are all high quality. For example, Korean Belton sockets, Switchcraft jacks, etc.

In summary: All components are extremely high quality and largely Western-made. There’s not much missing here.

The kit includes all the parts required to build a working amplifier except for the wooden cabinet and speaker.

The blog also contains general articles about building, so it is worth browsing the articles more extensively before starting the build.

Combo cabinet and speakers

The metal chassis dimensions of the NOS Toaster Deluxe are the same as the 5E3 Tweed Deluxe, so 5E3 cabinets can be used with the NOS Toaster.

For the speaker, it is recommended to choose a full-bodied and warm-sounding speaker, as the tone circuit is fairly bright like Blackface amplifiers. The WGS Blackhawk or a similarly sturdy AlNiCo speaker is an excellent match for this type of amplifier.

Modifications

The NOS Toaster is easy to modify if you want to tune the sound slightly away from the standard circuit. For example, tone stack modifications are easy, and a useful helper is the Duncan Tone Stack Calculator.

If you want to change the tube type, you can easily experiment in the preamp with any ECC83, ECC82, ECC81, 5751, 12AY7 tube or their derivatives. The power section can be rewired for a 6V6 tube if the availability of 6AG7 weakens (unlikely) or if you want to try a more traditional Fender tube for tonal reasons. The transformers are fully compatible with 6V6 tubes.

If you still want a 5E3 sound, the whole amplifier can be modified to a 5E3 circuit because the metal chassis, tube sockets, and transformers are the same.

How difficult is this kit to assemble?

This kit is perfectly suitable as a first tube amplifier project.

Careful assembly of the device takes 1–3 days. Carefulness and concentration are everything. No electrical engineering knowledge is required for assembly.

What kind of tools do you need to build this kit?

Basic tools are enough, but especially beginners should invest in reasonable quality tools.

Especially the soldering station and solder must be good enough to produce quality solder joints. Always buy a soldering station from a proper electronics store that can guide you to the right kind of equipment for this job.

We have assembled a beginner’s tool kit that makes building easy and gets you far into the hobby. You can choose the tools you want from the package:

BEGINNER'S TOOL KIT FOR SOLDERING

In addition to this, you basically only need screwdrivers. If you are unsure whether your current soldering station (perhaps inherited from your grandfather) is good enough, send us a message and we’ll see whether it is suitable to get started!

How can I get support if I have questions I cannot find answers to?

A properly built device works according to the instructions. So always read the instructions carefully. In problem situations, read through this article and follow its instructions:

DIY tube amplifier troubleshooting

If something still concerns you, you can contact us by email. Unlimited technical support via email is always included in the price. Please note that we cannot provide support by phone or in-store, because our technical support staff do not work in the store or behind our phone numbers.

What does the kit include?

The price includes all necessary parts for building the amplifier. Does not include a speaker or wooden cabinet.

What do I get for the price?

You get at least the following: a fantastic-sounding boutique amplifier that will last 100 years at a truly affordable price. For only a fraction of the cost of the cheapest decent tube amplifiers, less than half the price of robot-assembled failure-prone Chinese amplifiers, and even below the combined retail price of the kit components.

Unlimited technical support is available via email!

WARNING: Building guitar equipment is highly addictive!

NOTE: Component deliveries in the kit may differ from those shown in the product images due to component availability.