Nope. Oddly enough, these don’t do mids at all, and glow a lot, and distort a lot. I guess I got two good ones and two bad ones.
I feel like this tube buffer makes everything “airy” and really “close” to you, lifts the veil off everything – but maybe too much. You can actually control how much “air”, and “veil”, therefore how much soundstage you want, with this little 90$ Class A amplifier.
The SMSL SAP-1 is bass and mid-focused and lacks “air”. This is the perfect match.
And to continue with that, yes, apparently, the higher the volume, the more the little Tube-03 works. I said “more tubes” or “more Class A” without realizing what it meant.
It’s a tube pre. Leave the volume at max.
Sometimes it’s as if I can hear the reverberations coming from the wall at the back of the studio.
Have you tried any other tubes beside the Voskhod 6J1P-EV? I’m considering picking one of these up. I’m also planning to pick up a Bottlehead Crack 10 months from now when it probably goes on sale. But 10 months…
Has anyone compared one of these cheap tube buffers (tube swapped) with a nice amp like the Crack?
How 'bout 1000 too many words comparing a tube buffer to a Darkvoice?
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What GE tubes specifically did you use for the preamp? Are those still the best one’s you’ve heard? I think I may give this thing a try since it’s so cheap.
The link to the Amazon page where I bought those tubes is in that post. I don’t know if they’re the “best” but there seems to be limited options for that tube type. These GE tubes are much better than the stock tubes.
Yeah all I know is the Voskhod sound better than the stock tubes. I said they sound “classier”, which might be a new one for audio descriptions, lol. But yeah, it means good mids and a ton of clarity, good soundstage. Stock tubes also sounded… muddy, or just lacking detail, compared to these.
So I own a Hagerman Tuba. But the Tuba lives in the bedroom (where I would use it more) and I wanted tubes in office. So I decided to give one of these tube buffers a try. The one I got was from FX Audio and it was about $30. The tubes were GE JAN 5654W and were $25 for the pair. I set up the tube preamp between my RME ADI-2 DAC and THX 789. Because the ADI-2 and 789 have two outputs and two inputs respectively, I could set it up so that I could instantaneously switch between having the tubes and not. I did the testing with my HD600 and here are my impressions:
- It didn’t make the 789 sound worse. At least as long as you didn’t turn preamp knob too far past 12 o’clock. It gets really distorted if you do.
- It brought up the lows up a bit and it relaxed the upper mids and highs some.
- It helped improve sound stage a little.
Overall the change in sound more subtle than I was expecting. But depending on the sound I’m looking for, it’s still an overall improvement. So I will continue to use it some of the time in my system.
If anyone else wants to get into tubes, I don’t really recommend this unless you’re on a super tight budget. I’m sure anyone new would want something more substantial. Although it is possible the other brands might be better than this one.
Update:
It turns out the extreme distortion at high volume was the result of the preamp clipping. This can mostly be remedied by reducing your DAC volume. This is worth doing because the tubes have greater effect at a higher volume setting. So in conclusion, I can recommend this particular setup more than before. But it’s still worth investing in a proper tube amp.
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Might be that the tubes haven’t burned in too – or you got bad tubes. Something like 50 to 100 hours of burn-in is recommended for tubes (literally “burn-in” this time: gets rid of unwanted stuff in the tubes).
With my Tube-03 my volume is set to max and there’s no distortion whatsoever. I got two pairs of (6J1P-EV) tubes, one starting to distort at 10 o’clock 
, and the one I use now, zero distortion.
Well that’s interesting. I did let them burn in but not for quite that long. Do you get a better tube sound if you max out the volume as opposed to having it half way?
Yes 
“volume” should be labeled “tubes +/-” really. It’s like “how much tubes do you want in your sound”.
Also, it’s chi-fi and tubes and these get hot, don’t leave it on at work at night. Fire hazard. 
(Like all tubes I’d say – whatever the price).
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I’ll try letting them burn in more. Although the particular tubes I have don’t get that hot. I can touch them without too much issue. Maybe I should have got different tubes? The GE tubes were well rated and recommended for this thing on amazon so I’d figured they’d be decent choice.
I can’t keep my fingers on mine after a few minutes. Maybe move em around in the socket and push em a bit to be sure they’re 100% well connected, too. Better connection might equal better sound.
I bought Voskhod 6J1P-EVs because someone on Amazon said they got impressive soundstage from em. Perfect for me because I got more bass (warmth), more smoothness (sounds “classy” lol) and still decent detail and “air” (10khz+).
Edit: 25$-ish for the pair too. I want to try GE tubes too… even if I’m pretty sure nothing will make it sound better than what I hear right now.
I let the tubes burn in longer, but that didn’t seem to make a difference.
So I went on Amazon and submitted a question to other users with the same preamp and tubes on whether they experienced significant distortion if go past around 1 o’clock. 2 people said they had the same problem while 1 said he has “'no problems with distortion cranked up.” He also suggested my amp could be clipping if the amp input voltage is greater than 2 V. So I decided to take some measurements my multi meter.
RME ADI-2 RCA Output at 0 dB: 3.3 V.
RME setting to get 3.3 V out of Preamp: -14.5 dB
RME setting for getting 2.05 V out or RCA: -4 dB
Tube Preamp outputs 3.3 V at about 10 o’clock
Preamp max output is about 6.7 V at around 3 o’clock
Preamp output voltage will start decreasing after going past 3 o’clock.
So in conclusion, it’s pretty clear that preamp is the one clipping for one reason or another. If I lower the volume of the ADI-2 enough, I can max out the preamp volume without getting major distortion. The “tubiness” of the sound also does appear to increase with preamp volume based on early tests
Oh, crap.
Well, yeah, that was one of the two possible problems. I did not knew the Tube-01 did this too. iWii reviews found this in the dac-tube-amp combo, but I think he sait 5 volts. 6.7 is… more than the double? 
I do not have this problem with my tube-03 either plugged straight into my AVR or my amp (and my multimeter isn’t here). Sorry anyway.
But… you can “lower the adi-2 preamp” and max the “tubiness” now? Sounds better?
Yes when I’m using the preamp, I will be lowering the DAC volume. Although I think I’m still getting a little distortion when maxing out the preamp volume. So I will keep it around 3 o’clock.
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Hope you enjoy it!
FYI I found out it makes… like, many times the difference with speakers versus headphones. For me anyway. My inexpensive speakers were a bit aggressive, and too bright for me at times. The tube buffer fixes this – also adding a ton of depth/width versus the “2D” soundstage I had before.