Yet another Velleman K8060 Amplifier - YAVK8060A

Marcel27

Member
2017-07-02 6:16 pm
Hi,

This is another K8060 DIY amp from Velleman. Yes, I've read all the good advise here about this amp. :D

However I had already the components before I read the experiences on this forum and I must say they are true.:)

The K8060 is a very delicate lady and if you do not handle this amp properly you will have to change the TIP's a lot, especially in my situation. I have a Denon CEOL RCD-N9 and am not satisfied with the class D amp in it. This amp cannot drive my ASW Genius 300 speaker (4 Ohm) properly. Another problem is that is has not a proper output for a power amplifier and therefore I use the headphone output. With the 0.6V RMS sensitivity of the K8060 unit you can overload the input very easy. Which I did. The next step is to put the pre amp in front of it with with an attenuation of 11. So 5 V will be downsized to 0.450 V. A save value.

At the moment the power rails are 40 V, Transformer 2 x 30 V AC. That is too much for the amp with a 4 Ohm load. So I will lower the power rails to 28 ~ 30 V. by putting 2 x (10 x BY500) diodes in series and anti parallel in the AC power lines for each amp. A bit pity but safety first. Don't want to burn more Tip's or fry my speakers although there is an K4700 speaker protection unit installed.;)

The units are mounted in a wooden casing and I found out that this is very sensitive for hum and noise. If I put the unit to close to the CEOL you hear the hum. A meter beside the CEOL and the amp is dead silent.

At first I had the inputs, outputs and mains on the back of the amp. You can still see the holes. But that gave a hum and noise. After reading the information about ground loops I decided to rearrange the wiring. Now the mains wiring are on the back and the in- and outputs are on the front. The amp is dead silent now.

The next step is to assemble the pre-amp. Also a Velleman unit K8084. This is not all state of the art but it will suffice. The point is that you have fun and see a positive turn towards a better sound.

I had already a listing moment with my iPhone as source and it sound good, better than the dull D-class amp of the CEOL. There is nice bass, the mid and high are clearer.

Marcel
 

Attachments

  • img_0642_small.jpg
    img_0642_small.jpg
    208.6 KB · Views: 137
  • IMG_0644._smallJPG.jpg
    IMG_0644._smallJPG.jpg
    169.7 KB · Views: 131
  • img_0645_small.jpg
    img_0645_small.jpg
    206.5 KB · Views: 128
  • img_0646_small.jpg
    img_0646_small.jpg
    219.3 KB · Views: 134
Last edited: