HL tears the ES9038 DAC down to the bones for a full hardware upgrade! In stage 1 of upgrades, I worked on the analog side of the board, replacing nearly all the stock parts, including: resistors, DIP-8 sockets, and capacitors. The results have been impressive, giving a much more reference leaning tone. (ELNA SILMIC Super Gold included)
A look at the design process for the upcoming HL THD Tester for capacitors. I will be using SPDT or SPST switches to allow a variety of capacitances. Resolution depends on quality of reference arm, but measuring down -160dB, is easily achieved.
Update 8/6/20: Grades for the 5V Charger were posted today. I got a 190/200 (95%) on the final project, giving me an A (overall) in Jr Design. If I hadn’t forgotten to show the PCB partially inserted in the enclosure, I would have made a 100! Update 7/30/20: Revision 2.2 arrived in the nick of […]
Tore down the AU-517 once again, to get at the Power & Protection circuit. I made a mistake in replacing the 10D7C silicon diodes and hoping this fixes the relay issue.
Edit: 7/26/19 I got these molded last night (myself, at home) and must say, I was shocked at the difference (a word I rarely use on this site, except in the literal sense). I was expecting bass to improve, but it improved way more elements than that! Expect a full review in about a week, […]
The first part of my Sansui AU-517/717 restore guide, from recapping to finding those pesky shorted diodes. Not to mention how daunting it is just to remove and then rewire all the PCB’s! Here I hope to help shed some light on the subject.
As you may already know, I started the Hallman Labs Vintage Store a few months back. I am currently using EBay to sell these items and I came across a handful of rules that aren’t exactly easy to find. So, I have created a list of the most commonly encountered EBay rules. 1: You can […]
A look at the Potomac AA-51 Audio Analyzer: schematic, calibration procedures, service manual and more inside. Produced in the 1980’s, the AA-51 is still of great use.
Photo guide on creating custom EL-8 cables using Moon Audio Blue Dragon and EL-8 connectors. All DIY components, non-assembled.