Hi,

thanks for the warm welcome! And yes, AKG for the win!  I love both my pairs.

As for your question regarding sound characteristics … i struggle a bit with it. If anything, i’d aim for the DAC and amp to be as neutral and linear as possible, without promoting listening fatigue which i sometimes encounter with my (slightly less dampened) K240 Studio. I mostly enjoy sax-heavy jazz with my sextetts and love them for their vibrant and dynamic deeper midrange … i think, at least. It kind of just makes the instruments sparkle, which is far too way out into the voodoo range of sound description :-).

So, yes, CMOY. A simple OPA can drive those no problem, with enough supply — right? So especially if i want to go the all-usb route, i’m wondering if the supply is enough to boost to a considerable voltage (say, ±15V?), drive the OPAs with that, and at the same time supply the DAC — with all the lossyness of the other regulators in the setup?

So i think the biggest struggle for building a proper cmoy for the usecase is power supply. More so if i want full-USB supply — with a transformer it’d be simple … but heavy and huge :/.

Thanks so far!
-Dario

I'm curious as to your source currently?  I only ask as the Sextetts are a bit demanding.

This might be one of those times one must choose to hold off on a DAC, and go amp only.  Just because of your limited funds.  No, its far from ideal.  But what can a starving student do.....

My first thought was to check out Garage1217 stuff, as they offer their amps as DIY kits, but most are over your budget.  And the ones that are in your budget might not drive your AKGs to their potential...

I'm looking forward to other's opinions on this matter.

Hi,


my current source is not portable, it’s an old NAD speaker amplifier with a rather nice headphone out  . As a DAC i use my DIYed JeDAC¹, which i’m quite fond of, even though it might seem a bit simplistic compared to all the high-end-high-tech here :-). I also use my JeDAC for my PA100+DIY-ed speakers, and like it quite good!

Sooo, i know that there is plenty of schematic material out there, but one thing i’m missing is a good, small supply. Since i will want a bit more power for my sextetts, especially in voltage(?), a good *small* solution is hard. Most switching boost supplies need arcane ferrite beads or unobtanium smd coils, which are hard to find in small quantities and without 30€ shipping for a 0.05€ part.
If you have suggestions for anything that i could DIY, i’d love to hear! Searching myself i seem at a dead end, not finding anything useful, esp. regarding supply, anymore :/.

China-Fleabay might be a good idea, things i’ve found there include:
http://www.ebay.de/itm/YJ-Assembled-AK4399-SA9227-DAC-USB-decoder-board-support-32BIT-192K-/221802539241?pt=LH_DefaultDomain_77&hash=item33a47628e9#shpCntId
Which seems to be a chinaready version of what i’d probably build myself if i were going transformer-route: ±15V supply from a transformer+rect+linear supply, simple yet nice receiver and DAC, all on one board — connect the transformer, build casing, and off you go.

Also if i were to make an amp — let’s assume i have some kind of magical good clean small modern power supply at ~±15V from somewhere — making a nice CMoy-PCB and grabbing a random chine-fleabay DAC, and throw all three into a good case would be simple i think. The JeDAC would be too large, but there’s many options available. The crux is, again, the PSU :/.

Speaking of casing, so far i’ve always built my own, mostly in-style with my speakers². If saving on anything, i’d most like to save on the enclosure end. Not only are Hammond cases or china clones thereof not that expensive, if it comes to the worst i can DIY something reasonable…

As for the Shiit’s, that’d be a dream. Although i fear one best saved for until i work, the cheapest i’ve found the pair im germay is at around 280€ excl. shipping, which is just way over my budget :/. Same goes for Garage1217, which looks really stylish :-).

Thanks for your recommendations so far.

¹: http://users.abo.fi/jskata/JEDAC/
²: http://pics.kanojo.de/speakers/

I have a power supply PCB with integrated DC protection which is designed around LM317/337 and only needs an external trafo (2x15V)
It delivers regulated DC +/-15V to +/-17V but other voltages can be made.

When the output of an amplifier is connected to the board you also have a power on delay, fast off and DC protection on the amp.

The PCB is 10cm wide and 11cm long.
For now PCB only, standard parts.
Will be available in a month or so (PCB's are ready for production)

There will also be an amp section which is smaller in size (10cm wide 8 cm long) and a powerful amp (inverting) with some nice bonus features.
This can be mounted above the power supply PCB.
Also available in about a month or so....

This amp can easily drive orthos as well as sextets etc with ease and is very cheap in components.

(from the Netherlands)