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    VTA ST-120 vs 2a3/300B

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    VTA ST-120 vs 2a3/300B Empty VTA ST-120 vs 2a3/300B

    Post by Guest Sun Jan 19, 2020 9:33 am

    Had a friend over to listen to my new speakers, first we heard them with my ST-120, and he was so amazed, he couldn't get out of his seat. Then he said lets plug in the 2a3 that he paid much more then I did, (Chinese made), he got up at least 25 times adjusting his amp, and even a tube change. He even adjusted the dividing network on my speakers numerous times. He was so confused why his amp couldn't sound NEAR, or as GOOD as my VTA ST-120. My ST-120 sounded excellent!
    Bob Latino
    Bob Latino
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    VTA ST-120 vs 2a3/300B Empty Re: VTA ST-120 vs 2a3/300B

    Post by Bob Latino Sun Jan 19, 2020 10:44 am

    music wrote:Had a friend over to listen to my new speakers, first we heard them with my ST-120, and he was so amazed, he couldn't get out of his seat. Then he said lets plug in the 2a3 that he paid much more then I did, (Chinese made), he got up at least 25 times adjusting his amp, and even a tube change. He even adjusted the dividing network on my speakers numerous times. He was so confused why his amp couldn't sound NEAR, or as GOOD as my VTA ST-120. My ST-120 sounded excellent!

    Consider that ...

    1. A single ended 2A3 amp is only about 3 1/2 watts per channel and your VTA ST-120 is 60 watts per channel. This will translate into much greater "headroom" on musical peaks for the ST-120. Lower wattage amps tend to sound strained as the volume goes up as they struggle to project a good soundstage. Many times single ended amps show a lack of punch and presence that deflates somewhat the "realism" in the music.

    2. Push pull amplifiers can get by with less power supply filtering because they cancel any hum ripple in the output transformer.  Single ended amps (like most 2A3 amps) need much more power supply filtering because they don't cancel out hum in the output transformer. Many times the power supply filtering in a Chinese amp is skimped on. Single ended amps tend to have more inherent residual noise that push/pull amps.

    3. Most 2A3 single ended amps use a "cathode bias" system which can cause many single ended amps to have more of a "mid-rangy" sound. All the VTA amps use a fixed (adjustable) bias system which gives a more balanced sound over the full audio spectrum.

    4. Many (but not all) Chinese amps use cheap parts inside (resistors, capacitors). All the VTA amps use quality 1 % precision metal film, metal oxide and carbon film resistors inside the amp. If assembled correctly by the kit builder, the two channels on a VTA ST-120 amp will be perfectly matched. The electrolytic caps in all VTA amps are Nichicon or Elna caps (Made in Japan). The Authenticap quad cap is made in Germany. There are no Chinese electrolytic caps in the power supply on any VTA amp.

    Bob

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