GS01 Hi-Fi Tube Amplifier with Tubes: EL34,6N9P,5AR4

To me, a tube amp is akin to driving a car with a manual transmission. An automatic transmission gets the job done just fine, but offers little variety or excitement. A manual transmission makes driving exciting. It puts you in touch with the soul of driving as you have more influence in making the car respond to you, and your senses are attuned to everything happening. It is a rewarding experience to tame and control power. Such is the case with amplifiers. A solid state amp does a fine job and lets you enjoy music, but the amplifier is what it is. Tube amps offer a lot of variety in changing how the music sounds and making it more personalized. Like driving a manual transmission, it is rewarding and causes you to more fully tune into what is happening because you have invested time and effort in shaping the sound. I have solid state and tube guitar amps and vastly prefer the tube amps over the SS ones for these reasons. And that shimmering, warm sound of overdriven tubes cannot be duplicated digitally. Oh, yeah, the review...and I apologize in advance for my long-windedness. Short answer: So far, so good! I bought this with a lot of uncertainty about a tube amp from China, but it appears that other users are having good luck with them. I only have about a dozen hours of use after 2 days. I was just happy that sound came through the speakers! But that novelty has worn off and now I can move onto using the equipment for what I intend: listening and tinkering. I have connected it to one set of speakers (more below) and will update as I continue burn-in and auditioning them with various music/speaker combos. Unboxing: Packaging was decent (see pictures), the box has the expected appearance that it has been on a several thousand mile journey. I wish it was double-boxed. Tubes were nicely protected in foam, as was the amp. Power cord and instructions were inside as well, though instructions are for Gemtune's X-1 model. All you need are the pictures from Amazon and you're good. Note: the tubes are keyed so align them properly before installing into their sockets. Appearance: It looks very cool, and warm...inviting even. The wood is well-done and, along with the cool little meters, was the main thing that convinced me to buy this over the X-1 or GS-01M, I think it looks so much nicer! When the amp is on and music is playing, turning off the lights and watching the soft glow of the tubes and meters is the equivalent of watching a bonfire. It's serene and hypnotic. All connections and switchgear are solid in the chassis. Volume knob turns with a nice weight and is incremental, but no audible "tick" as you turn it. No loose pieces in the amplifier either (the instructions actually tell you to check for this). Sound: I think it’s important to mention that when talking about how music sounds, one must realize what they hear is only as good as the recording itself. That goes all the way back to the output signal from the instruments when the song was recorded, to the microphones and preamps used to capture that sound, to the mix itself, on to the recorded album, the format you listen with and finally to the playback system in your home, which itself has at least an input, amplifier and an output. There are a ton of variables at play and any one of them will greatly affect what you hear. When someone says that the music does or does not sound live (as I do below) is not relevant because that standard as a reference point is completely subjective. If a crappy recording sounds live, then the original recording was modified by the listener. Are you after a “live” sound? Unless it was recorded that way, you will have to modify (more accurately – distort) the recording to get that sound to come through. Are you after accurate playback only? Then you will hear the quality of the entire recording signal chain mentioned above. Personally, I don’t want to hear the effects of a poorly mic’d amp, but that’s just me. Someone might appreciate the realism. So everything following that I say is totally subjective, as is any user review. Your ears are *the best* judge of what sounds good to you. Period. Like a fine wine, you must take your time and be intentional about the process and you will be rewarded for your efforts. The instructions suggest 100 hours of tube burn-in, so I'm trying to get as much listening time as possible in case I am disappointed before the 30-day window. I have these hooked up to a pair of Sony SSCS5 (a surprisingly good performer) as my starting point. They have a sensitivity of 87dB and are 6ohm. With the volume at the 11 o'clock position (just under 50%) the music was plenty loud (about 72dB on the meter). At the 12 o'clock position, my wife (who was upstairs) asked me to turn it down because she was going to bed (about 75dB on the meter). You will be surprised how loud 1 watt of tube power actually is. My 60-watt Fender tube amp will make my neighbor’s ears bleed. My impression at only 12 hrs is...hey, the amp works! Seriously, I was pretty relieved that I could hear something. Whew. Based on other reviews I expected rock music to be the worst, so that’s where I started! Listening to Collective Soul’s Untitled album in CD format, my expectations were met. It was muddy in the lower-mids where rhythm and upper bass guitars are heard, and the highs are very thin – cymbals were too muted and vocals sounded compressed. Which is weird because other reviews say their highs were too much, my experience is just the opposite. Vocals didn’t have the airiness that makes them sound live. The next songs were FLAC, streamed via Bluetooth (not ideal, but good enough). Listening to Lorde's Royals was surprisingly good, her vocal range and the deep bass actually came through pretty well. Perhaps unnoticed by some people, the main bassline that plays on the 1st and 3rd beat (actually 2.5 beat...) is not the same bass note. The 1st beat bassline actually has a vibrato effect happening. From other reviews, I expected that this amp would not keep up with that detail. It did alright! I could hear the vibrato. Finger 11's One Thing sounded better, with a wider-than-expected sound stage and nice-sounding acoustic guitars. Billy Joel's Piano Man was the last song I listened to for my first impressions. Perhaps the tubes were starting to hit a stride because it sounded pretty good. I could hear an acoustic guitar to the left-rear that I never noticed before. And I'm pretty sure there's an accordion right next to him. Cool. So if anyone has read this far (thank you and congratulations, btw), I am confident the amp is going to sound better as time goes on, and it appears I’m already seeing it after just a dozen hours. I will update this review with further impressions and speaker combos as time goes on and tubes burn in.

Day 1: About ten weeks ago my GemTune GS-01 arrived. All equipment was intact due to very secure packaging. Tubes were installed, speakers were connected, connection to the pre-amp and GS-01 was made and the GS-01 was powered up. All tubes glowed and the GS-01 was left with the volume turned all the way down for an hour. During this time an odor began to come from the GS-01. It stunk but apparently either the paint or varnish on the transformers or both need heat to cure them. This odor persisted for about two weeks. After an hour a CD was loaded into the player and volume on the GS-01 was turned up to where music could barely be heard. About three hours later volume was turned up a few notches but below normal listening levels. After three more hours volume was turned up to normal listening levels. My modest system consists of an $89 Sony CD/DVD/Bluray/WiFi/Streaming Video Player used as a transport, Emotiva DC-1 DAC/pre-amp, Tekton Design Lore speakers and the GS-01. I have champagne taste but a beer budget when it comes to audio equipment and typically read reviews and do research to find the best equipment that fits my budget. The GS-01 at $400 including freight was selected like all my audio equipment – good price, good reviews and from my research it offered a path to make improvements. My room is small and is in a condo with neighbors left, right and below which limits how loud the system can be played without irritating the neighbors. Normal listening level is not loud enough to create ill will. Speakers are 9’ apart and the center seat is 10’ from a line between the speakers. The left wall is about 4’ from the left speaker and there is no close wall on the right side. Speakers are 22” from the rear wall which limits evaluating depth. CD’s used to evaluate the GS-01 initially and after making tube upgrades included “The Hours Between Night & Day” by Ottmar Liebert, “Expresiones” by Hombre de Barrro, “Creole Moon” by Dr. John, “Live Art” by Bela Fleck, “6 String Theory” by Lee Ritenour and “Get Lucky” by Mark Knopfler. Sound stage width, depth, instrument and voice tone and strength and other parameters were compared by playing the same CD’s throughout the evaluation. Back to the equipment. Now that volume is at my normal listening level I began evaluating the GS-01. In short, it sounded very good with very little burn-in time. Instruments and voices were in the right place. Sound stage width was a little constricted and slightly recessed, low end sounded robust but a little loose (as opposed to being tight), lower midrange sounded good but upper midrange and above was edgy and glaring. Voices (Dr. John/Creole Moon) had a decaying gritty sound. Detail was similar to what I heard with my previous amp but I had expected more detail. Overall, this little amp with less than 12 hours on it was very musical and already I had agreed it was worth the price. Day 2. Power was turned on and with volume down, the amp was left to heat up for an hour. After an hour volume was increased so music could barely be heard and left like this for four hours. After that volume was increase to my normal listening level and continue burning-in for four hours. I was not in the same room except to change volume and change CD’s occasionally during this time. After the second four hour period, I sat in the center seat and began listening. After playing four CD’s it was apparent the upper midrange and high frequencies were a little smoother, less glaring, less piercing. Low frequencies were a little less bloated, a little more focused. Things were shaping up after twenty hours. Over the next two weeks I repeated listening sessions using the same CD’s but reducing the warm up times to about four hours. No large changes were seen. Low frequency and midrange reproduction was good. Upper midrange was not what I wanted. I began researching tubes to replace ones included with the GS-01. In the US the 5Z3P can be replaced with 5U4G or 5R4GYS. The 6N9PT’s can be replaced with 6SL7GT’s. The EL-34B’s are the same in the US or can be replaced with KT77’s. This amp is auto-biasing and the replacement tubes above are working in my system without any bias adjustments. My budget does not permit unlimited tube rolling nor replacing all tubes at the same time. The weakest stock tubes appeared to be the 6N9PT’s. Also, these tubes amplify the low signal coming in so if this area does not do a good job the next stage will amplify the errors. I ordered two Brimar 6SL7GT’s with close matching. They arrived about a week later and were installed as soon as they arrived. I began my typical burn-in and after about four hours I increased the volume to listening level. I planned to not listen for about three more hours but curiosity got the best of me. I sat down and started listening and was really pleased with how much better the amp sounded. I played three CD’s and even with very little burn-in, the differences were noticeable. I went into another room while CD’s continued to play for four more hours and then shut the amp off. Next day I let the amp with new tubes burn-in for eight hours and then began listening. The GS-01 sounded like a much more expensive amp. I have listened to amps costing thousands more than the GS-01 that did not sound as good. Width was wider, stage was just in front of the speakers, low end was more robust and more focused, there was more detail, midrange was smooth, upper midrange was still slightly glaring but better than before the change and then I heard something I had never heard before in my system while listening to the album “Expresiones”. Instruments in this album include what sounds like a piccolo playing a C sharp note. The instrument reaches upper midrange frequencies often and one time at the end of a track the frequency was so high and piercing that I thought the tweeters would fly out of the speaker. The new tubes made a difference from top to bottom and should be the first upgrade for anyone who wants to improve the sound of this amp. Next the PSVANE EL34B’s were replaced with Tung-Sol EL34B’s matched. After about 12 hours of burn-in, I began the evaluation. Sound stage initially was about the same, lower frequencies were a little more contained, high frequencies were rolled off and less glaring. All seemed to be going in the right direction except instruments and voices were not in the correct place. Everything had shifted to the left about two feet. After an hour of troubleshooting I determined one of the Tung-Sol tubes was bad and they were returned. I also noted the Tung-Sol’s were a couple db louder than the PSVANE’s. When I initially received the Tung-Sol’s I decided to replace the 5Z3P with a Phillips 5R4GYS. I thought this would give me a week to evaluate the Tung-Sols and then I could evaluate the Phillips. The order of evaluating changed because the Tung-Sols were returned to the supplier and now the Phillips tube had arrived. Also, when the Phillips arrived I decided to not try another set of Tung-Sols and ordered two Gold Lion KT77’s. More on this later. The Phillips 5R4GYS is a rectifier tube which I did not think would make any difference. If a rectifier tube lights up it and supplies power to the other tubes it should not change the audio performance. Well, that is not true. The Phillips took away the grit mentioned earlier in Dr. John’s voice and resulted in an unusually quite space around most instruments. Each instrument could be heard more distinctly. The bottom end was smoother and the top end was less stringent. After listening for a week to the amp with new tubes but with the PSVANE EL34B’s in the amp, the Gold Lion KT77’s arrived. Reviews were mixed about whether this tube or EL34B’s sounded better. They are two different type tubes. Not just different part numbers and they have slightly different characteristics. Also, the Gold Lion KT77 takes about 200 hours burn-in to reach its potential. The supplier I purchased these from burns-in tubes 72 hours before testing them which speeds up the evaluation period. I could not wait very long to listen to the results of having all tubes upgraded so after twelve hours of burn-in, my evaluation began. The high frequency in the “Expresiones” album mentioned before was much tamer. Very detailed but it was rolled off and sounded more natural. The bottom end was more throaty and sounded more natural. Detail is phenomenal. I now hear sounds and voices that before were not there or if they were they blended into another instrument. Sound stage in wider (6SL7GT’s increased width by 1’ on each side and KT77’s increased width another 1’). Tone is more natural. These will continue to improve but I am completely satisfied with the overall performance of this amp with upgraded tubes. In the past I have owned a Conrad Johnson tube amp which now sells for more than $4000 and this amp sounds as good as the Conrad Johnson did. Is this amp for you? If you have efficient speakers and do not listen at loud levels, it is one of the best for the price. Upgrade tubes (doubles you cost) and it will outperform anything costing three times as much.

I have always wanted to try tube amplifiers,. I Read a lot about how open and natural they sound. So I decided to try this amp as a first toe dipping, after a long research on how they work, what do they require and also reading multiple reviews here and at other websites. First, the shipping experience was excellent, everything arrived on time and well packaged, and well protected for the journey. I started by using this amp on a Pair of bookshelves, Chane Audio A1RX-C, (my computer speakers) rated at 85 db sensitivity. It worked ok on it's own but the volume was low even at volume dial maxed up, however did much, much better after adding a pre amplifier (Emotiva USP-1) . The sound was warm and clear, and very powerful, I set the amp. volume at max, and used the preamp remote to adjust the volume, which got real loud very quickly!. After few days in this initial set up, I moved the amp to power a set of Def. Tech. BP 7006 towers, rated at 92 db sensitivity. I was streaming from Pandora through a Sonos Connect---> Emotiva XDA-2-1 DAC----> Emotiva USP-1 preamp---> GemTune GS-01 amplifier. All I can say is WOW,.....The music has never been clearer or sounded more beautiful to my ears. My Emotiva XPA-200 (rated @ 150 wpc at 8 ohms) sounded nice, but with the tube amp, the music was much more enjoyable to my ears, with more texture, and I really don't know how to describe it, except like if u moved a thin vale off of a beautiful picture. I have not tried any tube rolling yet. I am happy with the sound the way it sits with the included stock Chinese bulbs, although I bought JJ tubes replacement from Amazon, for later may be, and as a back up. It took about 40 h of on/off playing for the amplifier to sound much better then it did on the initial trial, and I feel like it's getting better, to my ears, the longer I let it play. From personal experience, I highly recommend using a pre amp and a DAC with this amplifier, and a speaker set with high sensitivity like 92 db or above. The 8 wpc power rating is plenty to make the speakers sing. I also tried it with my Tektondesigns Mini lore's Floor Standing speakers (rated at 95 db), and boy did I love how they sounded.. beautiful, full, real and very addictive, like they were made for each others,.. Esthetically, the amplifier looks nice and ahs a smaller foot print. The tube glow is real nice as are the ampere meters in the front. Real cute, but don't be fooled by the size. If you use a CD player as source, of course the sound will be better and louder, yet clear. I love the fact that this amplifier is self biased, I am not there yet to do any bias adjustment. So in all, yes it is a chines made tube amplifier, but buying it through Amazon took lots of my anxiety away, and then testing it and seeing and hearing how it performs made me a believer. if you are on the fence, take the plunge, you'll thank yourself later.

Mine came with a giant scratch on the metal casing. The volume knob is held in place by a hex bolt and not attached from the start. There is no real mark on the unit for where the volume should start and should end. You sort of guess when you assemble it. The amp does sound very nice, but I was not a fan of the build quality at all. For a little more money I would recommend the YAQIN NEW MC-13S EL34(6CA7)X4 Vacuum Tube Hi-end Tube Integrated Amplifier Push-Pull Silver. The build quality is vastly superior.

Died after 2 months. No seller support. Don't buy.

I wouldn't consider myself an audiophile, but I really enjoy the sound and aesthetics of this amp. It seems to be well-built and is straightforward to set up. It delivers plenty of volume for input sources like a computer or a radio tuner, but weak sources like an MP3 player (or even turntable with preamp) produce reasonable volume through this amp but in some cases I might wish I had a little extra margin of power. For my small living room this isn't really an issue, but something to be aware of. Customer service was eager and willing to answer any and all questions and really wanted to get me set up for the best listening experience. Update: four months into owning it, the Chinese 5Z3PA rectifier tube stopped working. It never did fit as securely as it should have in the socket, and eventually the heating elements stopped glowing and the amp didn't work. I replaced it with a nicer USA-made RCA 5U4GB and it's back to working great again.

Got my new amp the other day. I'll admit I was a little nervous when I ordered as I wasn't sure exactly what quality of product I'd be receiving. It arrived in plain box, packed well in foam BUT no owners manual, no warranty info and worst of all, NO instructions. Tubes were not installed and had to plugged in. I looked at the picture posted on Amazon in order to figure out what tube went in what spot. I plugged the tubes in the way they were pictured and thank goodness it worked! My nerves were calmed once I got the unit plugged in, up and running however. I've been using with my MacBook Air, running through Audioquest Dragonfly DAC (linked with Zu Audio cable) to the Gemtune. I'm running Zu Audio Omen speakers with this unit and the sound is nothing short of amazing! I had previously been running this system with NAD solid state Amp (80 watts/channel) and this unit sounds much better. More open. Much larger sound stage. Solid bass and clear crisp highs. Honestly, I was shocked. I was ready for slight disappointment from the Gemtune's 8 watts vs. the NAD's 80/channel. Zero disappointment here. I'm a big fan. Looks...in a word...COOL! The VU meters work perfectly and look super cool. The glow of the tubes is nice....but they get pretty hot so be careful. All in all, nice unit. Well built. Sounds great. Worth the money? In my mind....yes!

The Short Review: Nice sound, performs as advertised. Delivered in one day from Amazon's warehouse. So far so good, I'll update this post if anything changes. The Details: Yes, there are printed instructions. They are pretty good except for the tube installation section which appears to be for a different product. Follow the layout in the Amazon photo and you'll be fine. An important note I almost missed is don't power the unit on without speakers connected! This could be why others have had failures right out of the box, not sure. Also I used gloves when inserting the tubes, to keep oils from possibly damaging them. The initial power-on was exciting, I wasn't sure what to expect. Then the tubes slowly started to glow and all was well. Sound was quite acceptable right off the bat. I've only got a few hours on them so far but look forward to them improving over time. My biggest hesitation purchasing this unit was its measly 6W rated output power. But as others have noted you can get surprising performance from a low-power tube amp. I haven't raised the level above 50% yet and it's been plenty loud for normal listening.