LOMO UP27 – Racking

Lomo UP27 / ЛОМО УП-27 racking project. Recently bought four UP27 microphone preamps + PSU unit. Documentation so far:

The 6HE 19″ case has been bought here. Their website doesn’t list a 6HE model at the moment but if you ask they’ll be able to deliver. The base plate also comes from this shop. Side panels are regular 6HE eurorack rack-ears put in a 90 degree angle screwed on the base-plate (see 3rd pic). On that eurorack rails were screwed (see first pic).

Aluminum bars hold connectors in place. This way the preamps can be removed by pulling.

Original Lomo PSU schematic and two versions of the UP27 schematics:

LOMO PSU schematic

First test:
– one unit completely non-working
– one unit having issues
– two units working properly
Because I’m not a tube expert all units have been checked and restored by a professional.
Both recordings have been mad after this restoration:

4 thoughts on “LOMO UP27 – Racking”

  1. Hello

    I found your page with the LOMO UP27 project. I’ve had 4 LOMO units myself for some time, which are still waiting to be put into working order.

    I see that you have the original LOMO power supply and I’m wondering if you could tell me its specifications because I will have to order the power supply myself. So, I’m interested in what its power is at 220V and 6.3V or what voltages it uses.

    I have plans that indicate that B+ is 250V and I would like to check if this is with or without load. I’m not an expert on vacuum tubes, so I would like to confirm before continuing with the project.

    Thank you in advance for any information. It would mean a lot to me as it’s hard to get accurate data.

    Best regards,

  2. I love the sound! Just love it
    Would love to buy one from you, if not i will also try to convert one into working order

    1. Hi Raquel,

      I have x3 Lomo UP27 preamps that have been gone through by a technician.
      If you are still interested in purchasing, drop me a line.

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