I bought a pair of these about a year ago and the bass extension is remarkable, looking at the FR at the Inner Fidelity review shows that they are flat to 20 Hz. There's a lot of hyped up in the bass source material so I'm thinking of adding a gentle, switchable, LF rolloff filter. I'm going to...

Some info on 6L6 variants: http://audiokarma.org/forums/index.php?threads/6l6gc-vs-7581a.603043/page-2#post-8622975

Do you know what the plate voltage is on the 6L6GC's they used to really push them hard in some guitar amps, probably not in a jukebox.

Nice work, maybe someday I'll build one!

Looks like a banana hanger would work with a larger hook:

Junior Wells "Use Me" Warning this is a Telarc recording with very wide dynamic range: This sounds good and there seems to be a claim that they worked on it with a DAW, not sure: Wish I could get a high quality version of this:

I agree that the crossfeed is an excellent implementation. @Markj What did you upgrade to?

The input switch is more for setup to select XLR vs. RCA inputs.

There are several posts here about the Ohman crossfeed circuit: https://www.innerfidelity.com/content/crossfeed

These were imported to the US from Sweden for a short period of time by a friend of mine and I happen to have one that I've been using for several years. A bit about the company: I mainly use it with my Sennheiser HD650's and they've never sounded better, the bass punch and extension seems to...

Some pictures here: http://techtalk.parts-express.com/forum/free-classifieds/1368275-new-old-stock-and-demo-holographic-riaa-line-and-headphone-amps-ct?p=1368289#post1368289

Unfortunately he didn't review the Ear One.

Review by the same youtube guy:

The Holographic story:

I have the Holographic Ear One that I use with my Senns and love it, very transparent and clean, will output 10 V RMS easily into the Senns. Here's info on it: https://www.holographicaudio.com/produkter/headphone-amp-ear-one I have a few of these from the importer, that were shipped to the US...