March, 2010: Quote from "NUTS AND VOLTS MAGAZINE"
"...Where the domestic kits market is apparently alive and well, I like to sample the offerings of overseas kit makers. One of my favorite kit suppliers is AnalogMetric (http://www.AnalogMetric.com), a Hong Kong-based firm that caters to the high-end DIY audio market. I’ve purchased several tube audio amp kits in the past with great results. My most recent purchase was a TDA1541A digital-to-analog (DAC) kit that takes a digital audio signal from a CD player, computer, or music synthesizer, and outputs a clean analog audio signal.
The unpopulated 2.5 mm PCB for the DAC kit is shown in Figure 1. As you can see, the labeling on the bullet-proof board is so extensive that kit building is virtually paint-by-numbers. It took an afternoon for me to assemble the kit and a few minutes for setup. Performance of the 16-bit DAC is comparable to my commercial recording gear, and the board layout is so clean that it’s a shame to hide it in an aluminum enclosure.
AnalogMetric kits — which range in price from $15 to well over $1,000 — aren’t for novice kit builders. While the boards can probably handle a few failed attempts at soldering, there is little handholding for the construction and testing process. It’s assumed that you can read a schematic, identify components, know when to observe component polarity, and know how to connect a power transformer to the line and the circuit board.
If you’re uncertain about the difficulty level of a particular kit, take a look at the photographs, full schematics, and documentation available on the AnalogMetric website. With many of the kits, you can either order an upgraded kit or order the base kit and add your own upgrades. For example, I ordered the basic DAC kit with an NE5534 op-amp, and replaced the amp with an AD797AN op-amp that I had purchased for another project..."
June, 2008: Quote from "NUTS AND VOLTS MAGAZINE"
"...In the end, I decided to forgo the expensive custom amplifier project and take a chance on one of many DIY tube amp houses that advertise on eBay. I went with AnalogMetric (http://www.analogmetric.com), a Hong-Kong company that offers dozens of tube-type DIY kits, from unpopulated PCBs and full kits to professional looking aluminum enclosures. I studied the schematic and photos on the AnalogMetric website and decided I’d rather spend my time modifying a clean, relatively simple amplifier rather than hunting for hard-to-find parts and paying more for shipping than components.
The DIY preamp, which consisted of a PCB and all the components except the power transformer, was $168, not including shipping from Hong Kong. The preamp sports three 12AX7s and solid-state power supply. Add one HV power transformer — also available from AnalogMetric — and you have a complete tube preamp that can feed a power amp. In all, I was pleased with the kit. The PCB was well designed, clean, and the parts fit easily. Inexperienced builders might be upset by a lack of instructions, though. I had to rely on a parts list keyed to a schematic because there was no step-by-step instruction manual. My only complaint with the kit was that the company shipped the incorrect power transformer, but readily replaced it with the appropriate model after an email. The components seemed first rate — except for the high voltage output capacitor, which I replaced with a capacitor with a higher capacitance and much higher ripple current rating. Although $168 may seem expensive for a preamp kit, the cost of parts and shipping from the three vendors for the original design would have cost more, and I would have spent a weekend designing a circuit board..."