GLOW FAQs
Click HERE for our Speaker Compatibility Guide
Click HERE for FAQs on the
2009-2010 GLOW Amp (Series II)
Click HERE for FAQs on the
2011/12 GLOW Amp One (Series III).
Click HERE for FAQs on the
GLOW Amp One Version 1.3 (latest model).
My GLOW Amp won't turn on. Does it need servicing?
Check and make sure the AC cord is firmly attached to the rear of the amplifier. If that is not the problem, more than likely you need to replace the fuse. All GLOW amplifiers are equipped with a fuse to protect against power surges and damage to the unit. We also provide you with a spare fuse, so replacing the fuse is a pretty simple process.
The fuse is in a compartment located on the back of the amp, at the base of the AC receptacle, where you plug in the AC cable. First, remove the AC cable. Locate the fuse compartment, and with a flat head screwdriver, gently slide the fuse holder out from the base of the AC receptacle. Inside the fuse tray you will find two fuses. One is the operating fuse, the other is a spare. Replace the operating fuse with the spare, slide the tray back in place, firmly re-attach the AC cord, and power the unit up. Don't forget to acquire replacement fuses and keep them handy!
How can I tell which version of the GLOW Amp One I have?
Over the years we have retained the classic look and acclaimed sound of the original Amp One. This can make it difficult to determine which model you have, as we have made internal refinements and improvements each time we go into production:
\rThe original 07-08 GLOW Amp One (Series I) has a magnetically attached tube cage; only one switch on the R side for on/off; it can use any EL84/6BQ5 tube; it has "007" in the serial number.
\rThe 09-10 GLOW Amp One (Sereis II) has two switches on the R side, power on/off and light ring on/off; it has a screw down tube cage; itcan only use Russian orChinese EL84 power tubes; it has a strengthened headphone jack assembly, it has "008" in the serial number.
The 11-12 GLOW Amp One (Series III) has a stronger, all steel tube cage and is botha screw down and magnetically attached type; it has 2 switches on the R side; it can use any EL84 tube. It has am improved internal DAC with a custom gain stage, it has "011" in the serial number.
The 2013-14-15 rendition of the Amp One (Series IV, designated Version 1.3) has a number of significant refinements. It utilizes an external DAC allowing for better digital to analog performance. It has 2 RCA inputs instead of one and a side mounted input source selector switch. It has a hi/lo impedance switch for headphones to allow for use of a wider range of headphone types. It has "ver. 1.3" printed on the end plate, and it has "012" in the serial number.
Why is the GLOW sound so detailed and full?
We have eliminated unnecessary "bells and whistles" to minimize the amount of circuitry impacting the signal. The signal has to travel through fewer stages, and requires less negative feedback, than with the typical transistor amplifier (the Amp One has only two gain stages, many transistor amps have 9 or 10 or more gain stages, and must use lots of negative feedback to control distortion). The result is a pure, realistic sound\xe2\x80\xa6. the sound of the music\xe2\x80\xa6. with the detail, resolution and dynamics for which good tube amplifiers are famous. If you want to hear what others are saying about the GLOW sound, take a moment toperuse the testimonials in the "GLOW Community" section.
Vacuum tubes and full range drivers?
We are passionate about good sound. It is regrettable that, while the digital age has brought so much wonderful technology to our fingertips, the sound quality of computers, MP3s and many home theater systems is nothing close to high fidelity. By taking a step back and a hard look at some of the fundamental assumptions in the audio industry, wehave concluded that much of what is marketed to the consumerworks against the goal ofachievingtrue high fidelity sound.
How does the GLOW amplifier make digital music files sound so good?
With use of the optional GLOW DAC 1.3, the GLOW tube amplifiers provide plug and play USB connectivity. And, it is very easy to hook a portable device such as an iPhone or iPad directly to a GLOW amplifier, or wirelessly with bluetooth. When the GLOW amplifier plays a digital source, even a compressed source, something amazing happens... the harsh, flat digitized sound comes to life! No, the tube amp cannot "repair" the compressed digital file. The fact is, much of the originalmusical content may have been lost as a result of the compression process. But, the tube amplifier does bring out the best of what is left, imparting air and depth and space thatotherwise may not be reproduced by a transistor amplifier. You have never heard computer files or even an iPod or smart phone sound as good aswhen it is played through a GLOW system!
The GLOW AUDIO DAC 1.3
Will my Amp One "clip" if the output is too high, and will it damage my speakers?
Tube amplifiers behave differently than transistor amplifiers when driven to capacity. A transistor amplifier if driven too hard will "clip", meaning it will essentially cut off the top of the signal, sending a square wave to the speakers. This can be disastrous; in addition to sounding terrible, it can damage or "blow" your tweeters. But when a tube amplifier is driven to capacity, it simply "runs out of gas". The "soft clip" of a tube amplifier prevents damage to the tweeters and avoids the harsh sound characteristic of a transistor amplifier being over driven. Some transistor amplifiers, such as those made by NAD and Proton, incorporate a "soft clip"circuit in an attempt to replicate themanner in which tube amplifiers behave when overdriven. Because nothing sounds worse than a transistor based receiver being overdriven.
Why do you recommend that users not use some types of EL84 power tubes
with one of the earlier versions of the Amp One?
All GLOW Audio Amp One and Amp Two units are compatible with any EL84, 6P14, or 6BQ5 power tube combination, EXCEPT for the 2009/2010 GLOW Amp One (Series II).
We strongly recommend that you do NOT use power tubes manufactured in Europe in the 09/10 GLOW Amp One. The 09/10 Amp One is specifically designed around the Russian and Chinese EL84 power tubes, and features the Beijing variant of the EL84 designated the 6P14.
European EL84s differ in design from their Chinese and Russian counterparts in one important respect: On all European manufactured EL84s, pins 1 and 2 are connected together inside the tube envelope. Chinese, Russian, and American EL84s do not internally link the pins 1 and 2. Therefore, when a European manufactured EL84 is plugged into the 09/10 GLOW amp, the additional connection within the tube envelope in the European design is likely to cause premature failure of the tube.
It is highly recommended for this reason that you NOT use European tubes in the 09/10 Amp One, as you will likely permanently damage your tube and possibly the amplifier.
All Russian (except the Russian made N709 Genalex "Gold Lion" EL84) and all Chinese and American manufactured EL84 tubes are compatible with the 09/10 Amp One. For all other versions of the Amp One, you can use any make or style of EL84,6P14, or 6BQ5 power tube.
We strongly recommend that you verify that pins 1 and 2 are NOT connected in the tube envelope before trying out tubes in your 09/10 amp. We are aware that some sellers have been known (mistakenly or otherwise) to mislabel tubes as being from one source when they are actually something else.
Why doesn\xe2\x80\x99t the GLOW Amplifier have equalizers or tone controls?
The lack of "equalizers", electronic "sound processors", "bass boosters" and conventional bass and treble tone controls certainly gives our products an uncluttered and artful appearance.But there are two very good technical reasons for eliminating these signal altering devices: 1)