Project files: The Borbely non-hybrid headamp

To supplement the original Borbely tube hybrid headphone amplifier are here the files for the solid-state version as described previously here. Have fun!

Read more of this post

MQ preamp…

Yet another ebay-purchase, partly to feed the shopping habit and partly as an excuse for some relaxation with the soldering iron :D.  This one is a ”cousin” of the BP26 project as it was made by the same people who designed that board.

It is a discrete preamp circuit with a discrete regulator PSU, an output delay circuit and a four-input relay selector on the board as well. It’s (supposedly) based on an (unspecified) Mark Levinson circuit design, although I usually take these things with more than a grain of salt. If nothing else because there are usually component replacements and tweaks to the original schematic, but sometimes even the basic topology deviates from the original. Anyway, I thought the board looked interesting and as I already had some of the more expensive parts I could keep the initial investment on a reasonable level.

Apart from the somewhat questionable ethics of cloning and selling brand-name circuits I have to commend the ”designer” of these boards, because they are good quality, they seem well thought-out and they are delivered with full documentation. I’ve actually received less comprehensive information with commercial boards and both of these boards have gone together without any problems and worked the first time they were powered up. The confidence that I am going to be able to put something together without too much trouble actually weighs more and more when I decide to buy something, because I dislike troubleshooting and always end up leaving non-working projects for far too long, so going forward I am going to keep this in mind (is “buildability” even a word? 🙂 ).

As I did with the BP26 I’ll try to listen a little bit to the amp first before deciding how much to splash out on the mechanicals, but impatience may get the best of me still. The missing transformer is already in the mail though…