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Saturday, September 21, 2013

Back in Black

Hi!

Here some photos of a D3a LCR phono preamp and 10Y line stage in a black/silver color combination.





This preamplifer combination is the very similar to the previously shown D3a phono stage and 10Y line preamplifier. Separate phono (left) and line stage (right):





Phono and line both have external PSUs:




Although the PSUs look a like, they are quite different inside.

The complete preamplifier combination requires significant floorspace:




Each chassis is 27cm wide and 40cm deep. The bodies are 12cm high with parts and tubes extending out of the top. The PSUs reach the largest height with almost 30cm each.





The back sides:




The switches on the back of the phono allow selection of two different step up ratios of the silver MC step up which is integrated (LL1933Ag).

The 10Y tubes in the line stage:




The tube sockets are mounted on vibration damped sub plates.

The D3a in the phono:




Side view of the preamp:





A top view of one of the PSUs, showing the 6AX4 rectifier bridge:





Best regards

Thomas



4 comments:

  1. Very attractive in black :) How much gain does the 10Y line-stage provide?

    ReplyDelete
  2. Hi!

    The line out transformer/TVC has a 1:1 ratio in the max. volume setting. So theoretically the linestage can reach 18dB gain at 5k output impedance. Output impedance reduces by a factor of 4 for each 6dB attenuation. So at 6dB gain and lower the output impedance is less than 300 Ohm.

    One of the inputs has a step up transformer which adds another 12dB if a source with low output impedance (like the D3a phono) is connected.

    Best regards

    Thomas

    ReplyDelete
  3. Hello Thomas,

    as usual a really great work and the black finish looks great, too.

    Why are there two different input paths for the D3a phono (4 cinch adapters)? The pictore does not show the description of the cinch ports?

    Best regards,
    Bernd

    ReplyDelete
  4. Hi Bernd,

    thanks :-)

    The second pair of cinch connectors is for adding resistance in parallel to the primary side for impedance adaption to the cartridge (if needed).

    Best regards

    Thomas

    ReplyDelete