I thought it might be useful to share my experience of my β22 build in the hope others might find it helpful, as well as focusing me a little. I don't have a huge deal of electronic experience, but have so far successfully build a CKKIII, mini3 and gamma2 full++. With the group buy of the epsilon 22 I thought it was time to tackle the big one
My intention is to build as reasonably priced as I can 3 channel β22, with the ε22 from the recent group buy and a ε12 to protect my HD800s ... when I get them
. Until then, I'm rolling with HD600s . I'm aiming for no more than £600 for the build but I don't want to cut any corners. Time will tell how close I can get to that.
To start off is the link to my BOM for the build.https://docs.google.com/spreadsheet/ccc ... VFGMldCX1E
This spread sheet covers the parts for the β22, σ22, ε22 & ε12 for the amp, along with a 5V σ11 for my gamma2.
Parts are from the AMB shop where possible (although the sigma22/11 CR devices are in stock with AMB, which I didn't realise when I ordered - they're listed as the Mouser parts in the spreadsheet), as I believe the least I can do for all Ti's hard work is buy all the parts I can from him. Mouser is used otherwise. I'm in the UK, so prices are in GBP where possible. I think the β22 & σ22 BOMs are complete & correct at least for the electronics parts, though I'm not guaranteeing anything so please do double check everything if you use it. The last column on each page contains cut 'n' paste text for the Mouser BOM import tool. The ε12 & ε22 BOMs need a little work.
I'm not going to use 'boutique' components, though it was tempting, but I will probably got for something a little better than the Alps RK27 pot, hence it's not on the order. Hifi-Collective
sell a range of pots that I need to give further inspection. Where I can, I've stuck with the top item on the part list suggestions.
I need to get hook up wire, which will probably just be copper, though silver coated for the signal path isn't too expensive, but I'm not entirely sure I'll be able to tell the difference. I'm thinking 18AWG for the PSU to amp umbilical, possible 18AWG for the larger Molex KK terminated interconnects and 24AWG for the smaller. This is something I need to give more thought but again, Hifi Collective have a large are of cable from the basic to the outlandish.
Molex contacts will be tin. Gold was a possibility I guess, but I don't intend on unplugging and re plugging them once built and my solder is only tin/lead anyway so I can't see the significant extra cost is worth it. I'm not one for warm and fuzzy feelings, but if there is an objective benefit to more expensive parts I'm happy to give them some consideration.
The build will be the PSU in a separate case with SpeakON
terminated interconnects. I'm currently trying to hunt down a suitable price filter IEC inlet so far with out a great deal of luck though I suspect that's lack of inspiration on my part. I also need a suitable transformer, which may end up being a Farnell own brand - even though Avel Lindbergs EU office is just up the road they charge an arm and a leg for single units.
Audio connector wise, Neutrik heavy duty panel mounts
are tempting. The front and rear panel may be from Front Panel Express's sister company in Germany Schaeffer AG
, unless I can find a local firm, and Frontpanel designer already has nice templates for the Neutrik holes. The headphone socket
will probably be locking. I'm not sure I want to limit the voltage swing with higher R34/R35 values, though perhaps that's better than fried MOSFETs. A locking connector seems like a fair compromised. Having said all of that, these connectors and the front panel milling will be expensive. I may just stick to circular connectors with drill bit sized holes and drill them myself!
For the cases I keep going back to Hifi-2000
. I used one for my CKKIII build and it's easy enough to work on, though I don't find them that all that attractive. Otherwise, I'm not sure what other choice I have locally in the UK or EU.
Tools wise, I have a £50 temperature controlled soldering iron with digital display, anti-static mat & wrist band (I've been told I'm paranoid, but better that then fried components), some reasonable quality, though a bit fine, 63/37 solder, flux pen, good side cutters and assorted other tools. Probably nothing much to write home about there, but the same equipment served me well through the Gamma2 & GrubDAC build ( with the help of a stereo microscope
), so I'm sure it'll be fine here as well.
To get a feel for sizings and layouts of the case I'm using Sketchup
. I've found it a useful tool for visualisation the space required.
So that's where I am. The AMB shop parts have been order, so I'm committed now. I'll update from time to time as I make a bit of progress, and any feedback or information on your own build, especially if in the UK, would be appreciated. Thanks for reading