Greetings from Louisiana. I just wanted to introduce myself and show a few images of my last build. My name is John and have been coming to this awesome site for probably over a year now. I really appreciate all the information and guidance that is is freely given by folks that have been there before and that experience shows.
I work in the medical imaging field but rarely do any component level work. It is mostly board swap, software, calibrations and mechanical tweaks. School and electronic training was decades ago. It has been a fun sidetrack addition to my recording studio. This site was a huge help considering my training was so long ago
This is my second build with my first being a Hairball 1176. As you can see this build was using Martin Adriaanse’s EZ 1290 board and design. The usual suspects of Carnhill transformers, JLM Power Plant and Go Betweens with the frontpanel from Frontpanels.de. I used BC547CTA and BC549CTA transistors. I measured the 549’s for hfE over 600.
Some of the issues that I ran into were the large Dale resistors that were just too large for the board for them all to fit neatly, but I got it to work . I was off on my initial measurements for the front panel and the boards would not line up so I had to redo the design and sent it back to Frank for another panel. This time I decided to leave off the trim pot.
Two big issues were that I left off the jumpers on the power supply and that I initially used non shielded wire for the 24v and 0v connections. The jumpers were an easy fix and I just used shielded wiring for the 24v and 0v connection. The later took care of the hum that I had started with and now the pre is very quiet. The Bias came out to 22.84 volts and I am very happy with the sound.
All in all it was not too difficult but it took much longer than I had anticipated. As careful as I though I was and as much research that I had done, I still had issues that I had to troubleshoot. Still, it was a lot of fun. This stuff is quite addicting.
Thanks again to everyone. Happy Holidays.
John
I work in the medical imaging field but rarely do any component level work. It is mostly board swap, software, calibrations and mechanical tweaks. School and electronic training was decades ago. It has been a fun sidetrack addition to my recording studio. This site was a huge help considering my training was so long ago
This is my second build with my first being a Hairball 1176. As you can see this build was using Martin Adriaanse’s EZ 1290 board and design. The usual suspects of Carnhill transformers, JLM Power Plant and Go Betweens with the frontpanel from Frontpanels.de. I used BC547CTA and BC549CTA transistors. I measured the 549’s for hfE over 600.
Some of the issues that I ran into were the large Dale resistors that were just too large for the board for them all to fit neatly, but I got it to work . I was off on my initial measurements for the front panel and the boards would not line up so I had to redo the design and sent it back to Frank for another panel. This time I decided to leave off the trim pot.
Two big issues were that I left off the jumpers on the power supply and that I initially used non shielded wire for the 24v and 0v connections. The jumpers were an easy fix and I just used shielded wiring for the 24v and 0v connection. The later took care of the hum that I had started with and now the pre is very quiet. The Bias came out to 22.84 volts and I am very happy with the sound.
All in all it was not too difficult but it took much longer than I had anticipated. As careful as I though I was and as much research that I had done, I still had issues that I had to troubleshoot. Still, it was a lot of fun. This stuff is quite addicting.
Thanks again to everyone. Happy Holidays.
John
