Tell me about the upgrades

You can read more about the kit in general on the AE1 page. In addition to the awesome upgraded color scheme and beautiful hardwood maple base, below are the details of what's different about the AE1-C.

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Upgraded Transformers

Nothing makes a tube amplifier better than the iron, so the most important upgrade of the AE1-C is the output transformers. These USA-made Transcendar single-ended output transformers are extremely well-made and larger than the EdCors used with the AE1, which results in wider frequency response and lower distortion, in particular for the lowest frequencies.

The power transformer is rated for higher current, which makes it run a bit cooler and ensures strong voltage under load.

Finally, the AE1-C has a 7 Henry choke, instead of a 6H included with the AE1, for even more power supply filtering so it is stone silent.

Mullard  EL34 and 12AT7 tubes

Mullard new production tubes are among the best in current production and are an upgrade from the JJ tubes included in the AE1.

Auricap XO Coupling Capacitors

These are audiophile-grade coupling capacitors made by Audience in California. They have incredible clarity and ensure your audio signal has the greatest purity as is passes through the signal path.

Audio Note Speaker Binding Posts

These high quality silver-plated binding posts ensure the best finishing touches to your amp, front and back!

Alps Blue Velvet Potentiometer

Smooth, high quality volume control with this top-of-the-line dual-gang logarithmic taper potentiometer.

Solid Aluminum Volume Knob

A perfectly fitting design touch, this solid aluminum knob feels just right as you turn up the volume and sip your gin and tonic while you listen to your amazing tube amplifier!

Other modifications and flexibility

  • The circuit has been tuned a bit for the transformers, so you will notice a few different resistor values.

  • There are several other larger power supply and cathode bypass capacitors used for highest quality.

  • The output transformers have taps for 4, 8 or 16 ohm speakers for greater flexibility for your audio system.

Tell me about the performance

Maximum Power Output:  7 Watts per channel

Speaker Impedance:  4, 8 or 16 ohms

Total Harmonic Distortion (THD):  0.4% at 1W (1kHz)

Input Sensitivity:  850 mV

Frequency Response:  20Hz - 20kHz (<1dB)

Commentary on sound and design:

The AE1-C sounds fantastic, I believe primarily due to the upgraded transformers and coupling capacitors. These Transcendar output transformers have full range across the audio spectrum so you ensure great, tight bass response and sparkling treble. The Auricap XO coupling capacitors ensure incredible clarity in the signal path. And the fit and finish with solid aluminum volume knob, Audio Note binding posts, and color scheme with maple feet really make this amp look amazing. Yes, kit amplifiers can look beautiful!

Some who have followed my pages may know I originally planned for the AE1-C to use a constant current source (CCS) for the plate load of the input stage, which typically provides lowest distortion and highest possible gain for the tube. I built a prototype of this design using a 10M45 regulator and it was testing really well. All my graphs and measurements would say it was a great amplifier. But an important part of the process is the listening test. As I played song after song in different genres, listening to the amp, something was just off. Full music passages were just a bit too harsh in the mid-range. I kept all the upgraded components but switched the circuit to a resistor load on the plate and it all came together to sound just right. This is the magic of a tube amplifier and why sometimes our measurements look right, but we need our ears and just the right amount of natural tube behavior to bring about the perfect sound. I hope you enjoy it, too!

Reviews

Customer from Maryland

7/9/2021

This kit was a lot of fun to build and is a gorgeous design. Perry was great in responding to questions I had as I never built anything like this before. The amp sounds amazing. The music sounds like it’s reaching out and wants to give you a hug. Very rich and warm soundstage.

Customer from Nevada

1/1/2021

Don't be afraid to ask questions about the amp. Perry knows his circuit inside and out and provides thoughtful answers. I felt like he wasn't trying to sell me his amp kit. I felt like, instead, he was trying to explain his amp's strengths and where those strengths may serve me best. In other words, I made an informed choice, rather than feeling hustled.

Customer from California

9/13/2020

Fantastic comprehensive kit with detailed instructions of how to build and how it works of top quality components that sound phenomenal. I've soldered very little previously and it was a fantastic learning experience and so satisfying to now sit back and listen to the creation.

Customer from N. Carolina

11/28/2020

The AE1-C amplifier is exceptionally detailed and handles jazz, particularly horns and vocals with an amazing amount of detail and clarity. The imaging and instrument placements on the soundstage are quite remarkable and life like. I'm hearing new details in familiar recordings I've not heard before. Love the amp... Sonically, the AE1-C is a 5. I would give it an overall rating of 4.5 due to some of the detail I thought could have been a little better.

An amplifier kit like no other. Build one yourself.

To get a preview of additional details, download the AE1-C instruction manual here:

AE1-C

Single-ended EL34 HiFi Tube Amplifier Kit

The AE1-C is a fully-loaded upgrade of the AE1 Kit. While it shares the same basic circuit, the AE1-C has multiple upgraded components for builders looking for top quality, performance and flexibility.

Plus, it comes in this awesome Cape May Beach House color scheme! (Also can be ordered in white like the AE1)

Yeah, it's special.