Glow Audio Amp One Hum - Page 2

So I turned the amp up all the way with the phones plugged in. There's a definite hum, but I can't hear it until 2 o'clock or so, which would be eardrum bursting. Typically listen at about 8 o'clock.

- Ed

Well, that would not prove conclusively that the glow is OTL with headphones, but it sure makes one wonder. If it hums with low impedance headphones and IS transformer coupled, that would mean some real design issues.

Because you cannot use European or American Tubes, or Japaneses for that matter, you don't have much choice. Patrick is supposed to fix the issue by next iteration but, until then, these are few of the better choices out there.

There are some pretty decent vintage Russian EL84's - not great, but better than the stock tubes.

And you *can* use 5670/2C51's in place of the 6N3 - some nice USA-made 2C51's would sound a lot better than the stock driver tubes.

Skylab, have you auditioned or own a GLOW? If so how does it compare to the Ming-Da MC84-C07? Id really like to try a newer EL-84 amp with an integrated headphone amp. My listening practice involves switching back and forth between headphones and Horned speakers constantly.
Years ago a friend plucked a wonderful EL-84 amp out of a vintage 50's(?) Hi-Fi console made by Capitol. I believe it had mullards. It was very eye opening when paired with Tannoy dual concentrics. Im wondering now how the designs have improved half a century later.
I must say that between the GLOWs multi colored light knob and the dancing tube of the ming da the flashy factor is through the roof compared to the utilitarian Capitol amp. Can you remove the dancing tube from the Ming-Da?

These hum issues are a bit frightening also.

No, I have never heard a GLOW, so I can't say how it compares with other amps.

The Ming Da is a nice amp, but it does not play nice with low-imepdance headphones either - sounds AWESOME with my 600 ohm Beyers, but hums with my 70 ohm JVC's. No hum with speakers, though.

But no, you cannot remove the "Magic Eye" tube, as according to the manual, it serves as a rectifier tube.

thanks skylab. Im looking very closely at the Ming-Da now. just watched the video on the pacific valve website.

As you'll all note, this is my very first post on Head-fi.

I do not have "golden ears" and am not an expert headphone guru, but I have owned Sennheiser 650's for a few years and 600's before that. I have been in the music reproduction hobby for 35 years, being aged almost 60.

My main music listening is via a near state-of-the-art home theater comprising 7 Thiel speakers with 2 Velodyne DD-15 subs fed from Anthem D2 PrePro and Anthem amps. I listen to a lot of Blu-ray music discs and SACD's (especially love all the Alison Krauss discs). Before the home theater bug, I used to build and modify my own amps (starting with Hafler) and speakers (starting with Dahlquist DQ-10's) fed from all tube Conrad-Johnson gear, SOTA Sapphire turntables with moving magnet cartridges,etc. etc. So while not a Headphone guru, I have heard good sound.

For my office, I wanted to re-experience that warm sweet tube sound and so took the plunge simultaneously with a Glow Amp One and Sennheiser HD-800's fed with Apple Lossless from my MacBook Pro, which I've had for the past 2 weeks.

I must say I am totally knocked out by the combination. I find it very difficult to take the phones off my head.

Naturally it concerns me that another owner of the Glow Amp One and Sennheiser HD800 combo hears hum, 'cause that would be a "deal breaker" for me too. But after probably 100 hours of burn-in, I have not heard any hum unless the volume control is cranked past about 3 o-clock and I never listen past about 8:30.

Just incredibly warm, balanced, nuanced envelopment. I'm listening to my 400+ CD collection burned in Apple Lossless all over again to hear things I've never heard before. I realize the Glow One is an "entry" level tube amp and I suppose the more esoteric and expensive amps like Woo are better, but for my untrained ears, at least so far, my Glow Amp One far exceeds my expectations. And my Sennheiser HD800's are so comfortable! My 650's used to hurt my ears after only about an hour or so of listening, but the HD800's can stay on my head for hours and hours and never, ever hurt.

So all in all, so far I'm very happy!

Chris

In the above, I didn't mean to write the word "hum", because I hear zero "hum" at any volume.

Instead, after the volume control passes about 3 o'clock, I begin to hear what I characterize as very light "gain" or "hash".

Chris