Review: Space-Tech Lab VP-1001 Tube amp

Category: Amplifiers

Review of Space-Tech Laboratory QA-115-Reg Preamp and VP-1001 Power amp.

Associated components:
CD: Opera Audio Consonance Reference CD-2.2 (tubed output stage)
Speakers: Joseph Audio RM25si MkII

I purchased this pair from Albert at Space-Tech Laboratory ( about 3 months ago and after some tube rolling and lots of listening, thought I should write a review. I am placing this review under both the power and pre-amp sections because these are being reviewed as a pair. I have no other separates to use in a comparison. I ordered both pieces in the oak case for a small extra charge. They are quite attractive and are set off by the custom oak and walnut cabinet I built a few years ago. I also ordered an extra biasing circuit on the model VP-1001 power amp so that I can use 6550/KT88 output tubes as well as the standard EL34’s by simply changing tubes and flipping a switch for each channel. The amp is completely self-biasing, so there is never any need to manually bias the tubes. You can look at the website to get the specs for each piece. The model QA-115-Reg preamp can take either 6SL7, 6SN7, or 6SU7 types in the main amplifier section and a variety of tubes in the buffer section. Even the power supply is tunable by changing tubes. There is not a transistor in either amp. This coupled with the fact that the power amp can take either EL34 or 6550/KT88 output tubes allows for tremendous flexibility in tailoring the sound to suit your musical tastes, associated equipment, and room acoustics. Try that with a transistor amp….

A bit of background. I have been into this hobby for about 37 years now. Changing one piece at a time every few years as the budget allowed, you know the drill. I had never owned a tube amp because I grew up in the age of transistors. Then about a year ago I replaced my Krell integrated with a nice Jolida JD1000a tube integrated amp. What a revelation! Anyway, shortly thereafter I happened to be in a used record/CD shop and was talking to the owner about amps. We shared a fondness for the tube sound and he mentioned that a friend had just bought a beautiful tube integrated from this little shop about 5 minutes away that builds custom components. So I went over and discovered Space-Tech Labs. Albert invited me to bring in my Jolida and compare it to his amps. When I did this it became apparent that I was going to own some of his stuff when I could swing it. His EL34 integrated that cost less than the Jolida completely blew it away in every regard, and his higher priced separates…well a different league altogether. After a few visits to his shop and some saving up for the better part of a year I bought the pair in this review. Albert talked me out of an integrated for all the usual reasons. The separates are better in every regard if you can afford them. What I have is his lowest cost preamp that has fully balanced inputs and outputs and a tube regulated power supply (model QA-115-Reg). I also have his lowest cost power amp that has fully balanced inputs with level controls for each channel (model VP-1001). This duo probably gives about 70 - 75% of the performance of the most expensive equipment Albert makes at maybe half the cost. This is the usual spot on the price/performance curve most of us with real budgets shoot for.

So how does it sound? Well, in 37 years of stereos, I have only owned one other tube amp. However, I have heard some VERY expensive solid state gear. I would take this pair over any solid state gear I have ever heard. Period. As for comparisons with other really high quality tube gear, that is hard for me to say due to limited experience. However, Albert’s designs use AC filament and the more expensive amps in his line such as these two use no negative feedback whatsoever. This results in an openness with air and detail like I have never heard on any system in my life. Everyone who has heard this pair has been impressed. According to Albert, the AC filament and no negative feedback are more difficult to implement in a mass manufacturing setting because they are noisier if not done well. Clearly he knows what he is doing! With the usual judicious separation of power cables from signal cables I can detect no hum in the system. The tube noise is negligible. If you are more than 2 –3 feet from the speaker you can’t hear it. Tube noise seems to come mostly from the pair of 12au7’s in the power amp. If you use a good NOS tube it is much quieter. I currently have a pair of Mullard CV4003 in there and they sound great. I listen to a wide variety of music. Everything from Bach to Zappa. This pair sounds great with all of it. On a good recording the image extends at least 2 feet beyond each speaker. Everything is three dimensional. Vocals are to die for. The resonances in acoustic instruments and percussion sound amazingly real. Cymbals sound like cymbals, not tizzy at all, you can hear them resonate like never before. You can hear subtle nuances and shadings that you never knew existed in familiar recordings you have owned for years. I upgraded from some pretty good equipment and I was amazed at the difference. Great recordings sound fabulous, but what is really surprising is how fine the older, marginal recordings sound. For example, I have all three of the “Old and In the Way” bluegrass recordings. I have owned these for years and enjoyed them for the music, if not the actual sound quality as they were recorded in the early 70’s live at a club. Sort of a very good quality bootleg. I can’t believe how they sound through this system! It’s like being there. I haven’t quite decided if I like the Mullard EL34’s better or the EH KT88. Each has their strengths. I could easily live with either and it is nice to change the sound now and then for a week or two by swapping tube types. To me it was well worth the small extra cost for the dual bias circuits and an extra set of tubes. My Joseph Audio RM25si MkII speakers have aluminum cones and in my room they are just a bit bright (but they sure are imaging champs). Using a 6SN7 type in the preamp instead of a 6SL7 works best for me. I have ended up with a pair of Mullard CV181 (a 6SN7 variant) in the preamp and they are my favourite. If I could afford a pair for the power amp I would use them there as well. Both of these amps really allow the tubes to shine. If you change any tube type from the power supply in the preamp on through the output tubes in the power amp you can immediately hear the difference in sound. This allows a huge degree of flexibility in tuning the system. The separate level controls for each power amp channel are very useful because they allow for precise balancing when preamp or power amp driver tubes are not exactly matched in output.

Undoubtedly, some of you reading this have some amazing gear, fabulous monoblocks and the like – probably better than these pieces. I am not out to try and trash anyone’s system or taste or play that ridiculous “my system is better than yours” game. Nor am I going to write detailed notes about every recording I have listened to on this system while trying to impress you with my audio vocabulary. My aim in writing this is just to let anyone considering the Space-Tech Lab products know that Albert makes really fine equipment. It is not cheap, but is very good value in my opinion. It will certainly rival anything you have ever heard at twice the price point. I have no affiliation with his business. I am just a satisfied customer. I have never seen anything on any site that was critical of Albert. He is honest and a gentleman. He is extremely knowledgeable about most any area of audio as he also makes fine speakers, DAC’s, etc… When you are considering a purchase, the first thing he asks you is what kind of music you listen to so that he can steer you into the proper type of amps. We listen to most everything in our house so he tuned this pair to be “medium” sounding. If you were solely into classical music or opera he would tune the sound for that sort of music. The point is that you get an amp or amps that are designed for your tastes and needs. Let’s face it, every amp has a characteristic sound. There is no such thing as a straight wire with gain, and if there were, we probably wouldn’t like it! Here is a chance to get a custom amp or amps to fit your budget and your taste in music and associated equipment. Albert makes a dizzying array of models, and each one of these is customizable as well. He will build what you want. I am now saving up for one of his DAC’s. His $1400 US DAC is quite a bit better than my CD player. You should hear it as well!

Associated gear
Space-Tech Lab AQ-115-Reg preamp
CD: Opera Audio Consonance Reference CD-2.2
Speakers: Joseph Audio RM25si MkII
DiMarzio M-Path speaker cables and interconnects

Similar products
Krell KAV300i integrated amp
Jolida JD1000a integrated tube amp

Showing 1 response by listener57

Thanks for bringing a relatively unknown custom manufacturer to everyone's attention. Your unit is very beautiful to look at, and it's great to learn it makes beautiful music, too.