Pre-Amps - Classic 100 Series

Model no: QA-001-Mk3
C$880 Untitled Document [US$ 704]

line stage pre-amplifier with headphone amp

Using the most common 6SN7 (option: 6SL7 / 6SU7 / ECC32/ / ECC33 / ECC35 / CV181...etc) as the amplification section gives you the most warm and easy rendition with such a low price. Once you experience this model of our products superior performance, you will see our higher models are beyond comparison. Compare the sound of 6SN7 with those small tubes like 6922 / 12AX7 / 12AU7, it will be night and day difference in openness, naturnalness and smoothness. You will never go back to those small tubes ever again. That is why those big names need to sky rocket up the price of their pre-amps made with bigger size tubes, otherwise their already expensive small size tube pre-amp can never sell.

This is the most up-to-date enhanced version of our best selling models of Qa-001 pre-amplifiers. Equipped with a variable gain headphone amplifier , which can drive any headphone with whatever sensitivity. Super enhanced power supply with lots of reserve power in order to deliver the effortness handing in the air sonic character. This model is one of our "GIANT-KILLER", It can easily surpass the sonic performance of competitors in US$5,000-$6,000 offerings. There is once a customer even compare our older model head to head with big-names tube pre-amp in $10K range built with 8 x 6922 tubes, and result is just par. Recently another customer bring-in the same big-name pre-amp for comparison with our latest Mk3 , and ours out-perform his by 30-50% in every ways such as openness, smoothness, sweetness , detailness and dynamics.

This pre-amp can use more than 10 different models of tubes to fine-tune the tonal quality as well as dynamics and richness.

With our optional extra tube expansion adapters, even can use 6L6, 6K6, 6G6, 6V6, 6F6, 6Y6,KT66,6550, EL34, 5881, KT88, KT99, KT100...etc (must build with optional super enhanced power supply, cost extra)

The upper photo sets showing regular version with plexiglass top panel chassis design.

The lowest photo sets showing silver aluminum top panel chassis, with optional dual volume control and removed the headphone output


No. of inputs 2 sets of RCA inputs
No. of outputs 2 sets of RCA outputs + 1 headphone output

Max. input level

Max. output level

2Vrms (optional: 4Vrms with no additional charge)

10Vrms typ.

Freq response 2Hz - 140Khz (-3db)
S/N > 85 db
Gain x3- x6 depend on tube types
manufacturing hand-wired point to point for tube section
Phase 180deg inverted (option: non-inverted)
Input impedance 100Kohm (option: from 10Kohm to 1Mohm)

Default tube : 6SN7 or 6SL7 (alt : 6SL7/6SU7/ECC32/ECC33/ECC35/6188 or equiv)

Default chassis : Ultra-low resonance sides with black plexiglass front / bottom / Top / Rear (as shown on photo)

Customer feedback:

From Chieh:

I asked AL if he had a pre amp with either a balance or two volume controls with a budget constraint of $1000. My comparison was my Schitt that uses a 6SN7. This was because my room, and possibly hearing required the right speaker to be slightly louder. He said he could build one based on the QA-001-Mk3. Since it used two 6SN7 I expected the sound to be better or close enough to the Schitt, which was good enough.  I am cautious with special offers because unforeseen issues arise. Anyway, AL was very responsive with emails and estimation of time required. I went ahead. When there was a choice of 6SN7 or 6SL7, AL told me the 6SL7 was lighter and 6SN7 was rich and dark. I chose the 6SL7, to have a greater contrast with existing pre(s). Received the preamp three weeks later (one week for shipment across Canada). The package was well insulated, tightly wrapped in plastic film, surrounded by styrofoam peanuts in a sizable box and text outside saying glass inside. My system is based around a Lowther full range with woofers, single ended, zero NFB tube amps and various DACs such as Topping D90SE, Gustard X26, Marantz, so was eagerly looking forward to a lighter sound. A comment about the two volume controls. Adequately weighted, and sufficient rotation so that it is not too loud or too soft. This was significant because I needed the right channel only slightly louder. Well done, though I hadn't asked. Compared to the Schitt, each note was much better defined without overhang (Bach/Cello suites/Watkins, Bach/guitar transcriptions/Voorhorst, Chopin/Ballades/FouTs'ong, Tracy Chapman collection, Olatunji/Drums of passion). Treble more extended relative to Schitt. Runs much cooler than the Schitt even though it has two tubes. Compared to the NADC165BEE, the treble is smoother, but less extended. Surprisingly, it is more transparent than the NAD with less bloat in the bass on piano. Importantly, my DACs sound different, as they should, ie the pre does not impose character over the DACs. Symphoneis are where the pre shocked me. Berlioz/SymphonieFantastique/Jansons and Stravinsky/Firebird, Firebird suite 1945/Stravinsky revealed that the pre kept instruments and start stop distinct. Timbre was excellent. The instruments were not crushed into indistinct voices. With music that had fewer instruments, I was indifferent between the QA-001 and my existing pre(s), because the QA-001 was cooler (6SL6?), but for pieces with a variety of instruments and large dynamic swings, the QA-001 was more enjoyable. Based on my experience, for those needing customisation on a tight budget, with lots of questions (at one point, I asked if it could have a mono output but maintaining independent volume control, and AL guided me through why it was not), SpaceTech had delivered.


Additonal up-grade options:

0/180deg output phase switch add C$100

solid-oak chassis add C$200

High contrast dual tone solid-oak add C$250

Super high-gloss piano solid-oak add C$500


1 year free parts and labor warranty under normal operation conditions

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