Re: MiniWatt N3 tube rolling
I think my MiniWatt is still breaking in. I found that changing to the 6 ohm speaker outlet instead of the 8 ohm gave it more get up and go. I looked at the Stereophile test results for my speaker and they showed that it dips to 5 ohms.
I'm just listening to Kepa Junkera's Bilbao 00:00h, and it is sounding stunning - so much detail via the HRT Streamer II+. With the Glow Amp One it didn't have quite the same treble resolution, but the bass was slightly better. So with the Glow I thought the system sounded like electrostatic speakers in miniature, but the MiniWatt sounds more like electrostatic headphones. My head is needing to adjust to all the detail, and I keep wanting to move my chair further away from the speakers. I am sitting 2.3 meters away from the speakers, and they are 1.3 meters apart - so it isn't really near field listening. I am a big fan of the Tandy LX5s and the Linaeum tweeter, and I have never heard the tweeter sounding so good.
I will listen for another couple of weeks and then 'downgrade' to the stock MiniWatt valves/tubes. I won't being doing any more tube rolling as I think the TJ 12AUXs and Genalex reissue EL84s are about as good as you can get - the only question is whether it is worth it in the context of the system that the MiniWatt is likely to be used in.
Create Audio Tube upgrade
I've just found this tube upgrade for the MiniWatt from Create Audio:
Create Audio Hi-Fi tubes are made with special nano materials and electron beam welding fixed to control the electron current. The vacuum of the tubes is 10-7 Torr which increases their life span and quality. High performance Hi-Fi tubes from Create Audio.
So I wonder if that is the ultimate upgrade, and how it would compare with my TJ/Genalex combination. It would be great to find a review of them.
MiniWatt N3 vs Glow Amp One
Ultralight: "I'm currently looking at the Miniwatt and the Glow One (along with the MP301).
Both amps seem sensitve to changing the valves/tubes. I would say the stock MiniWatt is a bit better than the stock Glow Amp One. The MiniWatt is quieter and the treble is more transparent. The MiniWatt comes with higher quality valves than the Glow, and I think many people would be happy with the stock sound. The Glow is really let down by the stock valves, and it is worth replacing them straight away.
I first changed the Chinese valves in the Glow amp to Russian ones. I bought the Glow from Audiomagus and they were offering an upgrade for about $45 dollars which was pretty good value.
The next step was changing the Reflektor EL84s to Genelex Gold Lion reissues. The Genelexes are sweeter than the Reflectors and have better resolution. However, on the Glow web site they warn against using these valves with the 2009 and later versions of the Glow:
"*POWER TUBE INFO: 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 and Russian EL84s do not internally link the pins 1 and 2 (witht he exception of the Russian made Genalex Gold Lion). Therefore, when a European manufactured EL84 is plugged into the '09 GLOW amp, the additional connection within the tube envelope in the European design is likely to cause premature failure of the tube.
For the above reason, it is highly recommended that you NOT use European tubes in the 2009 Amp One, as you risk permanent damage to your tubes and possibly the amplifier. All Russian and Chinese manufactured EL84 tubes are compatible with the Amp One, xcept for the Russian manufactured Genalex Gold Lion."
So with a newer Glow the challenge would be to find the best EL84 that is compatible. Maybe the Create Audio ones that ALO offer as an upgrade for the MiniWatt would be a good choice. Or the platinum matched pair of Sovtek EL84s that the stock MiniWatt has for a little less money. I tried those in the Glow and they sounded pretty similar to the Reflectors to me, and a little less sweet than the Genelexes.
Looking to upgrade the 6N3s in the input stage I bought a pair of General Electric JAN 5670Ws. These valves were disappointing - the bass was a bit strange and unnatural sounding and the treble was un-dynamic and boring. After a week or two I reverted back to the Russians. A couple of months ago I bought a pair of Raytheon Windmill Getter 5670 tubes, and these were a large improvment and I finally heard what the Glow was capable of. They have much tighter bass than the other valves, and the Glow is more dynamic and detailed.
The final upgrade for both my Glow and MiniWatt amps was to use EAT Cool Dampers and these improve the resolution further - the sound becomes more 'solid'. Here are the upgraded valves with the dampers fitted:
http://www.computeraudiophile.com/fi...ow Amp One.jpg
The Glow amp no longer sounds warm and valve-like, it is still nice to listen to, but is just a lot more accurate.
Ultralight: If you had to keep only one, which would you keep and why? I'd love to hear your comments now that have had both for a while. The Glow one is higher power by rating- do you find this reflected in actual usage?"
They are both great little amps, and I'm very happy to own both. In my system the Glow is better at the moment after the surprisingly large improvment from the Raytheon input valves. On the other hand, for a desktop system the MiniWatt is probably better as it is smaller, has a lower noise floor and wonderful sweet detailed treble.
The Glow is a bit more expensive to start with and you need to upgrade it to make it achieve its potential, and so really it is a more expensive amp than the MiniWatt. The build quality of the Glow is superb - it has a hand wound output transformer and beautifully down point to point wiring. It looks a lot better inside than my Puresound P10 phono stage which is also built in China. I haven't opened up the MiniWatt to look inside yet, but I don't think it is in quite the same class.
Richard, Wow! What a long
Richard, Wow! What a long extensive response. I am very grateful for your time. Very detailed post - I'll have to look into the tubes.
After doing a lot of reading and conversing with a number of people, I believe that I'll pick up the MP301 first and see how that goes. Your comment is very valuable as I'll look at some of the tubes you used and perhaps roll it in the future. Grateful thanks!
Any updates on tube rolling?
To revive a thread, anyone else done some tube rolling with the N3?
I will eventually be able to report back on the Psvane tubes (12AX7 and EL84), as well as 12AX7s from Telefunken, and hopefully a few others. Just need to find time to A/B them...
I would be very interested to
I would be very interested to hear about the Psvane tubes.
On my Miniwatt I upgraded the Sovtek EL84 to EL84M (military version) after reading what the vendors were saying (eg Tube Depot). I haven't looked back - these tubes are musical and basically get out of the way.
You get big sound differences when swapping the 12AX7, which allows for system tuning as you change equipment upstream and downstream. The stock Tungsol re-issue is very good, and I liked it with my tube DAC. But I am now experimenting with a solid state DAC and find the Tungsol too bright on top - a vintage Tungsram sounded very sweet, but went too far the other way. I have currently settled on a platinum grade Mullard re-issue, cryo-treated by Kevin Deal at Upscale Audio. This is just right - tight and tuneful bass, open highs without sibilance issues.