mwl168

Switched from Megatron to the Blue Hawaii this morning. Different sound signature but equally as satisfying. This one is not the BJT version but the one that uses 2SK216/2SJ79 with cascoded CCS and adjustable plate current.

The balanced amp gives twice the voltage swing and slew rate and 4 times the output power. Wether that matters for a headphone like HD650 is debatable. My personal opinion is yes. The motto here at HC is "moar is better" and never pass a chance to go overkill

I bought a bunch of tta004b/ttc004b for this exact purpose but have not tried them yet. Would be nice if we can find something that's also pin-compatible with 2SK216/2SJ79.

I see now that I missed it - I thought you built a SUSY Dynalo and only used one phase of the balanced output. I see now it's actually a single-ended Dynalo. Did you follow Kevin's original Dynalo schematic from many years ago?

Probably not a bad idea to also get the corresponding KSC2690 as well.

Nice review and pics. How would you describe the build quality and durability of the ES 1a compared to the Stax 007?

I also really like my HD800 with my balanced KG CFA 🙂

That's what I am using in my Megatron as well, Philips E180CC SQ. Very happy with the outcome.

Single digit temperature outside. Time to power up this glorious sounding amp. What a treat...

I am in US and figured you are in UK thus the comment on the shipping cost.

I may have spare boards left but, given the shipping cost, it probably makes more sense for you to have them fabricated.

A much better idea is to see if you can obtain one of the pot PCB from a GB (or other sources) some time ago so you don't need to solder directly to the pins on the pot. No need for fancy solder IMO. I have solder from Cardas, WBT and good old Kester and don't believe either one makes an audible difference. Get a good quality solder and solder the joints well is key.

My car has over 400 hp and can go over 150 miles/hour. Even though I don't use all that power nor intend to drive it anywhere near that speed. I enjoy it just as much.

Check out Kevin's (Dr. Gilmore) current feedback electrostatic amp if you are looking for a compact and first DIY project. I suggest it because it's easy to build, low cost with very simplistic power supply requirement and, more importantly, a very nice sounding solid state amp that uses all current production parts.

The original design of Blue Hawaii uses 2SK170 BL grade which has the IDSS grade in the same range of LSK389B. Double check the data sheet to confirm. 2SK170/LSK389 are JFET so using either 10K or 50K volume pot should be fine. 10K pot may be more ideal if your source can drive it.