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Saturday, March 26, 2011

Making of a 211 amplifier, Part 3: Listening

Hi!

The 211 mono blocks are finished:





Testing and measuring of the amps delivered results as expected. The power output before clipping is about 25W.

They drive my Haigner Rho speakers to quite remarkable levels and deliver a very deep and solid bass. Everything else is also very nice, beautiful midrange and great highs with fine resolution. Not quite on the level as the big 4 chassis version. But that was expected and is acceptable at around half the cost.

Here some photos of the amps in operation. These 211 tubes give off a lot of heat! They are running at about 75W plate dissipation. In addition their filaments consume another 32W each!

And there are the rectifier tubes at the back which also take their share of power. 13-14W heater power each and a couple of Watts plate dissipation.

These amps guarantee a cosy atmosphere during winter nights! And the sound they produce will perfectly complement this!

Although these amps are meant as scaled down versions, they are still impressive in terms of size and weight. They also sound like this, quite authoritarian. They take control of the speakers. The high step down ratio of the output transformers enables this.


Some more shots of the amps in the dark. The plates of the 211s seem to glow on these photos, but this is only because of the long exposure time. They are perfectly fine. Also the blue glow on the glass of the 6HS5 driver tubes is perfectly normal.

The plate current indicators stay rock steady at just a bit above 60mA.

These amps came out really nice and were worth the effort. But my back hurts from carrying these beasts around. The next projects will be some low power SETs again.

Another 45 is planned as well as an amp with the 46 dual grid tube. Stay tuned!




Best regards

Thomas

14 comments:

  1. SUPERB, Thomas!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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  2. Thomas,

    Fantastic build! Very helpful for this fellow DIY-er to see your process from start to finish.

    What are your findings with other bias options for the 6HV5A? For example, a cathode battery, LED, or grid battery? Your approach is very thoughtful so I would love to get your take on this.

    Thanks!

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  3. Hi!

    Thanks for the comments!

    I don't like battery or LED bias. I prefer cathode bias with a resistor and ultrapath cap connection over these methods. Sounds better and simple to implement. Also saver. fixed bias methods are not really recommended for tubes like the 6HS5 / 6HV5A. Regular cathode bias allows the tubes to settle themselves.

    Best regards ... Thomas

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  4. Thomas, your 211 mono blocks are indeed beautiful beasts!
    Wonderful build quality as well.

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  5. Thomas, where do the panel meters come from? Great work!

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  6. Hi!

    The panel meters are vintage types. Old stock.
    The tubes are also NOS. General Eletric 211s

    Best regards

    Thomas

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  7. Thanks JC!

    Such a comment especially from you means a lot to me. Many of my designs in audio have been inspired by your work which you published in Sound Practices in the 90ies! Hope to see you again soon, probably at the fair in Munich next month?

    Thomas

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  8. That tube is red-plating. That's not normal.

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  9. Hi!

    It just looks like red plating on the photo due to the long exposure time. The tube is fine. It is not red at all.

    Thomas

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  10. Greetings Thomas Mayer.
    Excellent work, it is possible to order you to make similar projects.

    Kind Regards Roman.

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  11. Hi Roman.

    yes you can contact me for custom projects under thomas (at) vinylsavor (dot) de

    Best regards

    Thomas

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  12. nice looking amps ...I think you need some more filter
    capacitors.

    ReplyDelete