AFI flat.2 Record Flattener by Stephen Yan


StephenYan17.jpgI begin this review with the sound of the component under review – before delving into the rest of the details such as usage, specifications, ergonomics, and the like. I believe many readers, pressed for time in the busyness of modern-day living, only zero in on what they were after in the first place from equipment reviews – how does the equipment actually sound? So to avoid imposing on anyone’s patience or goodwill, please allow me to invert the order of this article. While all the required information for a regular “review” is still there, the most crucial bits will come first. One can always go back to enjoy the rest of the information later at a more leisurely pace.

To set the scene, here’s a quick summary of what this interesting device does. The Audio Fidelity Improvement (“AFI”) flat.2 is, despite its moniker, more than just another record flattener. If only that, my curiosity would not have been piqued enough to want to audition it at home. After all, what’s the harm of a little warp or dish here and there? Do I really need to spend 2 big ones to ensure that every one of my records is perfectly flat? At worst, I would not want to be accused of stepping into audio-fool vanity or obsessive-compulsive territory. 

Over the course of my time with the flat.2, however, I have learned to change my mind on this particular issue. But I don’t want to jump ahead of myself. Without question, the primary raison d’etre of the AFI flat.2 is to flatten vinyl records. I suppose it does as well as any other device on the market. Flattening is a quantifiable, objective target. Either a record is dished or it isn’t. But it is their additional “Relax” function that really made me sit up and take notice. The high-level summary of this function is that Dr. Ulrich Kathe (inventor of the flat.2 system) discovered that during the pressing process, uneven cooling rates of records after being removed from the stamper negatively stress and misshape the molecular structure of the vinyl itself. This, in turn, allegedly translates into sub-optimal sound quality, and cannot be fixed in any other manner except by that as proposed by him through the AFI flat device, which is now in its second incarnation (hence the “.2” moniker). This unique method is accessed through the “Relax” function of the flat.2. Another way of describing this process is tempering the record, in the same way, that one might temper steel or glass. By now, most healthy skeptics’ snake-oil radars are already beeping away. Is this just another example of a manufacturer creating a need out of thin air to sell a product nobody really needs in the first place? Exactly what I wanted to find out.

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Origin250.jpgWithout going into specifics, every 12″ LP (I had only “relaxed” one 10″ record, a mono pressing of a Michelle Auclair album by ERC which will be the subject of a separate article) which I tempered with the flat.2 has demonstrated an audible improvement in sound quality. Every. Single. One. Without fail, these improvements are in the way of the veil-removal, bring-you-a-few-rows-closer kind. The level of improvement varied from record to record, from just audible to drop-your-jaw goodness, but no record ever failed to reveal some amount of enhancement, regardless of vintage, thickness, provenance, or even whether it was cut in mono or stereo. There is no false advertising here. The AFI flat.2 delivers on its promises, no caveats nor ifs or buts.

Needless to say, tempering a record does not turn a nasty 80g pressing into a Mofi One-Step reissue, but that’s missing the point. We all buy records expecting to hear them at their best. A 1960s Columbia six-eye mono sounds different from an early Decca FFSS, which will sound different from a 200g pressing of a modern album. We mentally compensate in advance for the differences from the moment we pay for that record. We innately know it is unreasonable to expect to get anything that is not already pressed into those grooves. What is not unreasonable is to assume 100% of what these grooves can produce, and the AFI flat.2 definitely helps with that. Tempering a record will get one closer to the maximum potential enjoyment that record can provide. The rest will be up to (a) how clean they are (the subject of another review), and (b) the quality of the system and room. In other words, take care of (a) and (b), and the flat.2 ensures the record’s physical condition will not be the weakest link in the chain.

For readers who need specifics, what I get after undergoing the “Relax” treatment are:

darker backgrounds

more saturated tonal colors

ease of presentation

wider dynamic range

individual instruments pop in starker relief against the panoply of other instruments 

cleared nasal passages, drained lymph nodes, and relaxed muscles… (sorry strike that, wrong kind of treatment), and

sonic textures that come closer to real life

Gtt 2018a.gifThat last point is an excellent way to sum up all the changes: the flat.2 makes the music sound more real, less electronically reproduced, radically assisting in the suspension of disbelief. “Relaxing” a record is also true to its name. The record feels freshened up, re-invigorated, re-energized, and re-born after its AFI ministrations. It has come to the point where being in no doubt whatsoever of the flat.2’s efficacies. I now refuse to put a record on my best front-end (Jean Nantais Lenco Reference turntable/Koetsu Coralstone MC cartridge/Fidelity Research FR66s tonearm/Walker Reference Phono Stage/Line Magnetic WE-replica pre-expander) without first flattening then tempering it. 

Why flatten every record? It is a well-known problem that unwanted large excursions caused by warps create subsonic low-frequencies that translate into a phenomenon called “woofer pumping,” which, when it happens, is a sight to strike terror into the heart of the bravest Delta Force operator. For less severe warps, there is often a low-level “whoomph” when a record warp or dish passes under the cartridge. In my system it’s definitely not a pleasant noise, but neither is it particularly egregious. I can usually hear around such interruptions. But why should I? If there’s a way to be rid of it and improve my listening experience, then all bets are off. Plus, I know that I am not stressing my cartridge to track these unnecessarily big-ass movements, altering azimuth and SRA unpredictably along the way. In my experience, a perfectly flat record, or at least one that is as flat as it is possible to make it in reality, gives you fewer extraneous non-musical sounds, but also more music. A win-win if there ever was one.

Which brings me neatly to the next point – some may ask, what is real difference between the “Relax” (tempering) and “Standard” (flattening) functions? After all, arent we just heating up a record and then cooling it down? Well, the practical difference occurs in three areas – the maximum temperature to which a record is heated up (59°C for Standard, a few degrees lower for Relax), the total time of annealment, and how slowly the album is being brought back to room temperature, or around 31°C. This then begs the question, since flattening a record takes it up to a higher temperature than tempering it, wouldn’t the flattening process automatically incorporate within itself a tempering function? The answer is absolutely, empirically, NO. To test this, I have simply flattened a record, played it, and then relaxed it, and the difference is clearly audible. The two processes are different and produce two sets of perceptibly different results. The converse is also true. If I only relax a record, any warps present in the record will somehow remain on the record, even though it’s heated up to a few degrees shy of the flattening maximum.

All of which is the long-hand way of saying that one will need to spend around 10-12 hours per record to get the full benefit of flattening and tempering it. For a record collection that can easily be held in the grip of one hand, it isn’t much of a hardship. Music lovers who possess records numbering in the thousands will take much longer to work through their entire collection. Trust me, the pain and wait are worth it. I have had the AFI flat.2 for about a year now, and the processing count is around 500 (and counting) according to the readout. Yes, there is a useful function that tallies up all the “Flatten” and “Relax” cycles one has initiated, either of which counts as one’ record’. In reality, I would probably have worked through about 250 discrete records in about one year. At this rate, I will need about 5 to 6 years to go through all my vinyl. But am I complaining? Not! I liken this process to having the ability to rediscover every record in my collection. The number of audio components that can do that in my system now, I count on the fingers of one hand.


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esp-stereo-times-ad_250x250_1.jpgEverything is really quite simple and elegant. AFI has obviously taken pains to design the flat.2 to be as sleek and easy to use. Two pieces of very thick rectangular glass, hinged at the short end, creates a clam-shell effect. Open the device and you will find nothing more than two circular pieces of white felt (“special felt,” AFI says), both in the exact shape and size of a 12″ LP record. Place the record in between these felt mats. AFI has inscribed white dots on the surface of the bottom glass piece to indicate where the heating element is located, to precisely guide the position of the record sandwich to achieve a maximum heating effect. A few magnetic buttons are activated using the provided pencil or some other magnetically-charged poking implement. Two of these buttons cycle through the 3 heating options (“Standard” for flattening, “Relax” for tempering, and “Expert” for well, ahem, experts). In all the months I have used the flat.2, I have not used the Expert function nor explored its capabilities. Perhaps in a follow-up article, one day after I have done all my records?

The mechanism for heating is very high quality and precisely controlled. Deviation from displayed temperature is a mere one-quarter of a Kelvin or 0.25°C. This is not your grandmother’s electric tea-kettle. Dr. Kathe is a professional engineer with a doctorate in Chemistry. I would bet my last dollar that he would not just buy any old heating element off Alibaba and stick it into the flat.2 and call it a night. In fact, that the designer is not just a guy in a garage gives me great comfort that the product has been properly researched and tested. Indeed, graphical evidence is available if one needs proof that the flat.2 works. I prefer to simply trust my ears.

There is nothing much else to report from a user perspective, save that I would advise care when opening and closing the unit. When the first sample of flat.2 was sent to me from Germany, it had somehow cracked open near the hinge during transit. I had to send it back, but not before AFI’s excellent customer service (through a dealer and official worldwide distributor Oliver Wittman of HiFi-Studio Wittmann in Stuttgart) decided to send me a replacement. At the same time, they sorted out the return logistics. Three cheers and two thumbs up for Herr Wittmann– and thanks again for your patience!

Finally, I would advise cleaning a record as thoroughly and as completely as possible before putting it through either function. The last thing any self-respecting audiophile wants is to permanently bake in any dirt, grime or dust when flattening or tempering a record. I always put each record through my entire 3-step cleaning regime, painful as it is, before allowing it to be heated by the flat.2. This also helps to keep the “special felt” clean for repeated heating cycles. 


When I first got the AFI flat.2, I was worried that it would end up being an expensive white elephant. As it turned out, it became the most hard-working hi-fi component I currently possess. Day in, day out, it silently does its thing, even when I am working or sleeping. Because it is completely noiseless, I can also let it work inside my music room during listening sessions. Every time it completes a cycle, I get a kick out of hearing it beep clearly and display the word “Done.” No-fuss, no-nonsense, or theatrics. Just a Teutonically stentorian message that the work is complete and urging one to pick it up NOW (“Schnell! Schnell!”) because here is a record whose sonics will surprise and delight in equal measure. Sure, it does not make any sound of its own, nor does it contribute directly to the making of sound, but I consider it an indispensable hi-fi component. 

Equivalent products can be found from Japanese manufacturers Furutech and Orb. These products, the Furutech DF-2 flattener (USD2,500) and the Orb DF-01i (USD1,150), to name but a few, are around the same price as the AFI flat.2 or slightly cheaper.  There are also record flatteners at the other end of the price spectrum. For example, the Vinyl Flat (with or without a heating pouch, sold separately, for around USD250 for both); however, if I just wanted to flatten records, I would go for the last-mentioned product. Hell, you can even DIY the process by putting the record between two pieces of glass together and heating the sandwich in an oven (not a recommended practice, by the way). 

The AFI flat.2 is a more expensive proposition than any of the aforementioned, but it can do everything that these other products can do and more. From that perspective, it justifies its high asking price. Whether one feels that it is worth this amount will depend on how highly one prizes his/her own music collection. I know audiophiles who own single LPs that, by itself, is worth at least the price of an AFI flat.2. How then, I ask you esteemed members of the audio jury, given all the evidence presented before you, would it be unreasonable to consider buying the flat.2 in that context?



Stephen Yan       

Specifications: Technical Specs

–  Power input max. 90Va

–  Maximum temperature 59°C (Standard program), 54-60°C (Expert program)

–  Deviation of target temperature: less than 0.25K

–  Size 400 x 55 x 500 mm

–  Weight 8.7kg

–  Price: US $3,250 


–  No US dealers at the time of writing

–  International distributor:


Brucknerstrasse 17 70195 Stuttgart

Phone +49 711 696774



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