The state of solid state DIY amps

Gilmore Dynalo and Dynahi (and variants)... PCBs and items available from Amb. Also DynaFET which really isn't readily available come to mind. Szerkeses (sp?) as well on headwize project library. See threads here for any "documentation" on them.

This is pretty new - group buy ends tomorrow.  one board per channel http://www.amb.org/forum/alpha20-line-amplifier-f38/announce-new-alpha20-v2-t659.html

Sjostrom Audio?  The site is being updated right now, but the various headphone amps look excellent and the people that have built them find them to be excellent.

I'd love to see a report or two on the Sjostrom headphone amps. They are scarce as fans of dime store headphones at head-fi.

I have a QRV07 in progress. My experience thus far is that you really have to know what you are doing in the way of electronics if you want to tackle a Sjostrom project. While the designs may be very good -- which I can't judge since I am no board-level techie -- the instructions are incomplete, quite inadequate for beginners. They assume knowledge of basic electronics and familiarity with building devices such as an amplifier.

Technical writing is something I can judge since I made my living as a Silicon Valley tech writer documenting computer software & hardware and semiconductor manufacturing equipment etc. in the 80s-90s. Mostly operations and maintenance or user instructions, not board level assembly.

For this project I've had to learn all about pots, transformers, and a bleepload of other things in order to buy the parts which are not specified or not easy to find. Progress has therefore been fitful.

I will write a final report and post photos when the sucker is done. Still got to design and make a case. Right now I'll just say that the costs are modest, under $200 for PCB and most parts, not counting pot/attenuator and enclosure. The designer's top-of-the line headphone amp, the QRV08, would cost more for parts and be somewhat more ambitious to assemble, but not a lot of either.

http://sjostromaudio.com/joomla/index.php?option=com_content&task=section&id=4&Itemid=27

I built a dual mono/balanced QRV08 and the sound is superb, clean and dynamic. its true the BOMs are not really comprehensive and some contain all the optional alternative parts without designation. the only BOMs that are really complete are his SSR01/02 regulators. also most part numbers included assume you will buy your parts at ELFA. the project was quite straight forward to build, as long as you dont mond SMD soldering, have a good pair of tweezers and have reasonable organizational abilities you'll be fine. the designs are indeed very good IMO, the bandwidth on these beasties is boggling, they are DC coupled with servo, the thing that stands out the most for me is the speed and dead quiet

I did not need a pot as I use mine directly on the output of my sabre dac which I use digital volume on. I made a few changes to the parts selection to taste (one obvious one was the huge stonking nichicon KG caps that tower above everything else), but there are not all that many areas to tweak, as the designs are well integrated and the power supply already superb; in my case 4 x SMD jung type super regulators per channel. these are early pics from before I cased it up; happily it all fired up and worked straight away, troubleshooting such a SMD laiden build would not have been much fun.

I also use some of his regulators ssr01/02 and JSR01, plus his discrete rectifier the RFB03

58 is pretty cheap IMO.

Once you purchase an item from Per Anders his system automatically gives you a login to download all the documentation that you need.

The QRV07 board was about $42 including post, as I recall.

Quote:

Originally Posted by slowpogo 

The QRV08 looks very interesting. But $58 for one PCB?!? That's a lot. And I'm not finding any kind of BOM on the site..

well most of the AMB boards are components, for a B22 for example, you need 1 or 2 sigma22 and 2-5 amp boards, plus backplane, E12 etc, these are fully integrated, once you stuff the board you just plug into AC and off you go, as I said, each board contains 4 x jung type discrete diamond buffers (with or without gain)  actually there is more like 8, as both the input and output are buffered, then 4 x super regulators, 4 rectifiers and smoothing plus 4 x DC servos. pretty damn good value when you look at it like that and the PCB is of very high quality, all you need to do is add a volume control if you need one, as well as case and input/output jacks

Qusp, how does it compare to other head amps you might have tried?

I'd build one just for the fun of soldering surface mount components!

pogo, are you familiar with this list:

http://gilmore2.chem.northwestern.edu/ubb/showpage.php?fnum=3&tid=6339

There are a few people over at Rock Grotto raving about this amp: http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=180579436217&ssPageName=STRK:MEWNX:IT  aka "Panda" .  The only thing you need to add is an 18-0-18 50 VA transformer and a case.  Pink Floyd over at RG is doing incremental tweaks on it to see how far he can take it, but so far everyone who's heard it is saying it's crazy good for the money.. 

http://rockgrotto.proboards.com/index.cgi?board=m&action=display&thread=5700&page=1

I just ordered one myself, and want to compare it to my CTH and a CK2III that I'm collecting parts for..

I've been drooling over the Per Anders amps myself also. They look amazing.  I wouldn't mind building up a Mouser BOM for a QRV07 or 08 or both, but he's not so open about sharing those details, unless you buy a membership at his site.. I'd like to have an idea how much it would cost to build an amp before I buy the board.