Building a 2A3 DHT SET Power Amplifier

In this video I scratch build a stereo tube amplifier using PSVane Horizon 2A3, 12AT7 and 5AR4 tubes and Hammond transformers. The custom chassis took longer to make than wiring the amp up! Upon some longer listening sessions, I find that this amp has a rich mids, detailed imaging and fills the room well. I did take some inspiration from the Sound Practices article "Build the Baby Ongaku".
The goal of this build to see if I can make a good sounding 2A3 SET amp with commonly sourced components and stay within a reasonable budget. I think I succeeded.

Specs:

Two: 12AT7 tube (one per channel)
Two: 2A3 Power tubes (one for per channel)
Output Power: ~3.5 watts
Input Sensitivity: ~1v
Frequency Response: ~40HZ - ~20KHZ
Budget: $600-$750 (not including chassis)

*** This schematic and build document will be living document as I continue to listen, measure, test and update my findings.

Schematic: https://drive.google.com/file/d/1Jw_9mey1vyRdO5EmT2hbmJwvfHT8lbPl/view?usp=sharing
Parts list (BOM): https://drive.google.com/file/d/1feuYM1qUcAavK-o0OBxximbRsIOR_pMj/view?usp=sharing

Build notes: https://drive.google.com/file/d/19CdhErLL5VjhdWPzh9CRWBh1DLqwbTbX/view?usp=sharing

Upgraded Output Transformers:
Edcor GXSE-15 - 2.5k - 8ohm
https://edcorusa.com/en-ca/products/gxse15-2-5k-15w-2-5k-ohms-single-ended-guitar-tube-output-transformer?_pos=1&_fid=30ddb4e74&_ss=c&variant=41523056509115

Magnequest DS-025 or TFA-204 (used market like Ebay, Audio Asylum or Audiomart)

PSVANE Website: https://psvane.co/

2A3: https://psvane.co/products/psvane-horizon-series-2a3-at-vacuum-tube-amplifier-matched-pair-2-pack

12AT7: https://psvane.co/products/psvane-horizon-series-12at7-at-ecc81-vacuum-tube-amplifier-matched-pair-2-pack


If you enjoyed this video and if you downloaded the build documents, please consider buying me a coffee. I would appreciate your support:
https://www.buymeacoffee.com/MikeFreda

Button Head Cap Screws: https://drive.google.com/file/d/19CdhErLL5VjhdWPzh9CRWBh1DLqwbTbX/view?usp=sharing
Hakko Solder Station: https://amzn.to/3PvQaD7
Kester Solder: https://amzn.to/3aJKNBI
Digital AC Voltmeter: https://amzn.to/3UewrgY
Valve Amplifiers - Morgan Jones - https://amzn.to/43wQjNc

WARNING: Tube amplifiers contain very high and potentially lethal voltages! Drain all filter caps and check voltages before commencing work.

Discharge tool: https://youtu.be/KkBxXtCThNg
Light Bulb Current Sink: https://youtu.be/v66dY6djBlk


Disclaimer: Some of these links are affiliated where I’ll earn a small commission if you make a purchase at no additional cost to you.

About This Channel:

This channel has a wide variety of content. I’m interested in many things and topics. I create videos on things I like and what I feel my subscribers would like as well.
This channel is basically about two things:
1.) Show you how to MAKE things, FIX things, TIPS on how to do things and to give you IDEAS on how to make your life a bit easier! I encourage you to use your hands the to learn something new!
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