Category: turntable

LL1943 / LL1933 SUT PCB V02 – Balanced option

After a long time, decided to update the PCB of the LL1943 SUT to provide extra flexibility on the grounding connection. This is in essence to ensure no ground loops and noise when either using balanced or un-balanced cabling from the cartridge into the PCB:

LL1943: note the additional jumpers added

The additional jumpers are in line with the recommendations from the Datasheet. Here is the diagram:

For a fixed connection (like in most of the cases once preamp has been tuned/optimised) you can replace the jumpers by solid core wire jumpers soldered to the pad for best connection and performance.

This PCB is also for the LL1933. Basically is the same SUT but with 1+1:8+8 instead of 1+1:16+16 windings.

I made a small batch (I won’t need more than 2 or 4! myself) so the remaining will go on first-come-first-serve basis.

LCR Phono: design notes (Part III)

My previous design wasn’t good for two reasons:
  1. Input capacitance was too high due to Miller effect.
  2. Overall gain wasn’t enough: 55dB was marginal as 60dB would be ideal for an MC stage. Obviously this doesn’t apply to an MM cartridge where 40dB should be more than ok.

Continue reading “LCR Phono: design notes (Part III)”

Merry Christmas!

20121220-202553.jpg

It is so great to have another Christmas. It gives us an opportunity to wind down and spend proper time with our loves ones. The ones who are physically with us, and remember the ones who are no longer here, but still very present in our memories.

In fact, we all look forward to the holiday period to crack on with our projects. We all have a pile of endless projects and ideas and no better time than Christmas to start working on them.

Continue reading “Merry Christmas!”

Lenco arm board

20131026-184830.jpgThis is a great new arm board made by Carl to fit my Lenco plinth. I’m planning to add a second plater so needed to raise the tonearm and therefore a new board was required. Carl can make this arm board to fit any requirements. Just get in touch with Carl if you need a special arm board for your plinth.

Lenco turntable (Part II)

Great thing about bank holiday weekends is that you have more time to work on your projects! At least I had this time round.

After doing the initial calibration to the Lenco idler mechanism, I got the turntable finally assembled on the new plinth. It runs very quiet and smoothly despite having not dampened the idler wheeler  as recommended in the Lenco Heaven forum. I need to look into it but so far the turntable runs really quiet.

The arm board is a bit lower than it needs to probably. I can adjust the VTA with the micrometer but I should look at raising it to allow the arm to be rotated to the right for best placement. The micrometer is preventing this to happen. Will refine later.

GL75 now on its final place
Audiomods tonearm
First test
Clearaudio virtuoso cartridge

Ok, impressions so far after all this work then. I did many upgrades this time to my system so it is hard to quantify which part contributed the most to the sound improvement. Overall tone and clarity has improved. I suppose that the heavy plinth makes a big difference to the bass clarity. The overall tone improvement and detail is quite likely to be the Audiomods tone arm as well as using the Clearaudio Virtuoso Wood MM cartridge that Tony kindly give me to try.

Lenco turntable (part I)

A rare occasion in my hi-fi life is too see me switching from electronics to basic mechanics. I’m not either good with woodworking or mechanics :). Either way, the GL75 rebuild is coming along quite fast. I sealed the original arm holes in the top plate and painted it yesterday. Today, I spent all morning waxing the plinth. The afternoon was devoted to rebuilding the Lenco turntable mechanism and testing the re-lubed motor and spindle. I still need to do further calibration, but so far so good.

Here are some pictures of the building steps:

plinth and arm
top plate ready for paint
painted top plate
waxed plinth