Dynac ST-70 Amplifier - $700 (Cedar Rapids)

condition: excellent

make / manufacturer: Dynaco

model name / number: ST-70

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I am selling this recent Dynaco ST-70 amplifier that I assembled. The chassis is a new stainless steel replica of the original Dynaco chassis. The transformers are new and the power transformer has the more appropriate 120 volt primary. The other components also are all new. The driver board follows the Dynaco design and is a drop in replacement for the original. The only modification of the diver board from original is that it uses the very available 6GH8 tubes instead of the hard to find and expensive 7199 tubes.

This amplifier functions perfectly. The tubes have not been tested and if I was keeping the amp I would replace them. A copy of the original instructions for assembly and operation will be included.

Warning. The older Dynaco tube amplifiers, including the ST-70 should never be used with a sold state preamp and or preamp section of AV receivers, etc. There would be an impedance mismatch. Tube amplifiers like the ST-70 have high input impedance ( often >300K ohms) Low-impedance solid state preamps or AV receivers can load down the input causing distortion and or reduced performance. Solid-state preamps, can induce (hiss, hum,buzzing) that the ST-70's sensitivity tube circuity will readily amplify, ruining the listing experience.

$700 cash Pickup only, no shipping.

post id: 7908287835

posted: 2026-01-12 20:13

updated: 2026-01-15 07:33

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Dynac ST-70 Amplifier - electronics - by owner - sale - craigslist