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  1. What size heatsinks do you have? I want to build a stereo set up which I presume will need to dissipate about half the power.
  2. Soren, 

    Firstly, thanks again for the group buy - I am sure it was a lot of work to cut and pack all those SMD resistors. As the 50k kit did not fly, I was wondering if you had another 10k kit that you could spare? I bought 2 boards and 16 relays, but only have one 10k kit. As a very first surface mount board, I am pleased with the result. 

    Any progress on the Überamp? I dod not manage to get the transformer (ebay). 


  3. I can't believe I just soldered this - it's unbelievably tiny. Seems to have gone well, though.
  4. Yes, it weighs 15 Kg (33lbs) - 200 x 110mm. It's from a swedish company, but I can't find specs on the internet. Two would be preferable for monoblocks but I can get this one for a good price.
  5. I have found a transformer with the following spec: 2 separate 36v secondary 30A (seller states 60A, I presume 30A per winding). I will need further transformer(s) for the lower voltages. Is one transformer for both channels OK or better one for each channel ?
  6. Kerry, 

    I'm new to programming the arduino and I intend to build the digital attenuator boards. I would appreciate it if you could comment whether the code you/Kevin have posted would also work with the 4D Systems display if I use the right serial library ?.

    If I want the 4D display to be used as an input, presumably it just needs to pass one variable back to the controller and to increment the volume parameter up or down irrespective of whether the variable change comes from the 4D display or the  encoder? The 4D display has commands to write values back to the display and I have used the 4D systems software to create code. What is the general approach to merging the 4D code generated and what you have produced?  

    Do you have a list of the variables used in the code and what they do to assist? (if not, I will work through it).

    I am wondering whether I might be better off just buying the oled dispay and forgetting the 4D, at least for now.


    Guy Wilson, Bremen, Germany

  7. Is anyone (apart from me) intending to use the 4D Systems dispay and to amend the code from Kerry?
  8. Soren, All arrived thanks. Have to stay off the coffee to have steady hands for this one
  9. I would like to echo that and thanks to Kerry for the explanation. Thanks Søren
  10. I seem to have solved the problem. The instructions state that the directory should be saved as a subdirectory of library - it has now worked with a subdirectory renamed genie and just the file genieArduino.h in there without the other subdirectories and files. The genie library can now be included in the Arduino sketch with #include <genieArduino.h>. I hope this is of help if anyone else plans to use a 4d display for the digital attenuator
  11. I am having issues with the 4d display (uLCD-24PTU) and Arduino. I am trying to intall the 4D systems library in the arduino software, but it says it is not a valid library. The Arduino software is the latest from www.arduino.cc and the library is https://github.com/4dsystems/ViSi-Genie-Arduino-Library. I have tried unzipping the downloaded file to /documents/arduino/libraries and also the menu install a zip file from the arduino software. Both give error messages. Any help would be appreciated.
  12. Hi - I am in the attenuator group buy and want to use the 4D systems display and arduino. From your comment, it sounds as if you have it working. Do you have arduino code? I have the 4D display and arduino shield. Any help would be appreciated

  13. Hi, 

    I see that you have got the digitial attenuator going with the 4d display. Are you using an arduino to run it, or something else? I have ordered the 4D development kit and all the bits on the group buy. Any tips would be appreciated - like the code or hints on using it, anything you needed that you were not expecting.

    Kind Regards, 

    Guy Wilson 


  14. I want to put together a spreadsheet to check the attenuator values. I have replicated figures from Kerry, For 0.5dB attenuation The voltage ratio K = Vin / Vout (L attenuator) for 0.5dB = 10 to the power -0.5/20 = 1,0593 For Z = 50k , R Series is 2797 Ohm, (50.000 x (K-1)/K R Parallel is 843829 (50.000 x 1/(K-1) (These values match Kerry's and also several web sites) Now taking these two values V Out / V in = Rpar / (Rpar+Rser) = 1,0033 dB attenuation is 20 x Log10 (1.0033) = -0,03 Where is the mistake?
  15. Soren - thanks - please put me in for combined shipping attenuator and Überamp
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