The ST-70 is a classic amp designed by David Hafler of Dynaco that dates back to 1959. This VTA kit is similar to the original in all the right places, but features some modern updates. Can I build it in ten minutes? Let's find out!

0:00 Introduction
1:02 Painting the transformers
1:40 Building the PC board
2:00 Bias trimmers
2:10 How I organize components
2:55 Cleaning flux from PC board
3:28 Protecting the chassis with masking tape
3:45 Building the chassis
4:25 Reassembling the transformers
4:50 Installing the transformers
5:00 Let’s learn about chokes
5:30 Installing the choke and output transformers
5:42 Installing multi-section capacitor and chassis wiring
7:54 Faulty expensive Russian capacitors
8:20 Finishing PC board and installing it on the chassis
8:53 Installing front panel hardware
9:44 Level control modification
10:12 Rocket Sockets
10:42 Uh oh, there’s a problem
11:19 Installing AC power cord
11:35 Correcting the faulty capacitor
11:44 A new world record!
11:52 Initial startup and tests
12:32 Bench testing
12:44 The finishing touches
12:50 Protective shield modification
13:15 These feet stink
13:30 Crank up the music!

Check out the videos Dave of My Own Devices made about this project:
   • I Screwed Up Buying a Tube Amplifier!...  
   • The Dynaco VTA ST-70 Review. My First...  

My Weak-End Update video with info about Rocket Sockets:
   • Weak-End Update With Flux Condenser •...  

Some videos I've made showing amp bench testing in detail:
Kenwood Jumbo receiver:    • 1971 Kenwood Jumbo Receiver • Noisy T...  
Eico HF-52 tube amp:    • It's Done! 1957 Eico HF-52 Tube Amp •...  
Dynaco SCA-80Q amp:    • Dynaco SCA-80Q Amp Kit P9 • Bench Tes...  
Kenwood KA-76:    • Kenwood KA-76 Amp. Let’s fix it. Let’...  
Heathkit preamp:    • Let’s Test A Heathkit Preamp • P6 How...  
McIntosh MC2105:    • McIntosh MC2105 P8: Let’s Test Power,...  

To learn more about VTA (Tubes for Hifi) kits visit:
http://www.tubes4hifi.com

To visit my Amazon Shop, please click:
https://www.amazon.com/shop/fluxconde...

#stereorepair #stereoamplifier