What are the most under-appreciated products?

What brands of audio gear have you come across that were great, but that most of us haven't heard of?

I'll start with Cayin. Ever heard of them?
Mod Squad “Soft Shoes.” This inexpensive footer is my most used tweak over the last twenty years. I currently have at least 25 of them in my system.

For hardware, the Sound Valves Stereo 70 amp. This late 1980’s modernized version of the Dynaco has provided good sound and no repairs for more than 14 years. Two pair of these bi-amp my B&W side channel speakers for home theatre.
1. Foundation Research LC-1 and LC-2 dedicated passive in-line power conditioners. Foundation Research is a small mfg'er in Ontario, CA.

Marty DeWulf of Bound for Sound recently reviewed the LC's as perhaps the best line conditioners available, sold his old line conditioners, and now uses these in his Big Rig.

2. McCormack DNA-2 Revision A amp. The revision A means it has been rebuilt by Steve McCormack with some of the best aftermarket parts available. An excellent amp using single-ended connections. An awesome amp using the XLR connections via the 2 additional volts.

3. AudioPoints from Star Sound. Installed them under my components, on my rack, and under my speakers. Could not believe the improvement after the mechanical break-in period.

Thor amps and preamps.
The Taylo reference monitors. Nothing touches them - at any price.
Interesting so far, but I've heard of all of the above :)
C'mon, somebody stump us!
Thor indeed! But damn, big money!!
Any budget contenders in the electronics category?
Albert Porter's cryo treated outlets. Talk about bang for the buck!
You want obscure...

ASR - You may have heard of ASR because Stereophile did review their phono stage recently. But before this, their availability and press in the US was minimal. Their gear looks like Burmeister crossed with MBL. I heard their 150wpc integrated amp not long ago and it was some of the best solid state sound I have heard at any price. The ASR integrated amp sells for like 10k Euros.

A lot less obscure, but people do not realize how good these products are:

Krell KRC-HR preamp - Other preamps may be different... But getting objectively better I think is very difficult. This is the most resolving preamp I have ever heard, and people dump them at Audiogon for $2k to $3k.

Audio Logic 2400 DAC w/latest mods - Best dac I have heard under $10k or so. Not far behind the best dacs out there at any price.

Sony SCD-777es w/Superclock mods - Used as a CD or SACD player it is so-so. Used as a transport, it is simply AMAZING.

Music Metre
Aural Symphonics

Front End:

The Perch

Malodorous Wind / Audio Canine Rectum Armagedon Reference

Speakers: Gallo Ultimates
Wires: Omega Mikro
Phono stage: NYAL SuperIT
Tweak for tubeophiles: Mapleshade tube anchors
Llano amps. I have one in my main listening system (a 100S). And I understand the newer versions are even better. Also, I think any of them, such as mine, can be sent back to Randy White, owner and founder, and they can be redone or brought up to newer specs.
AK speakers by AudioKinetics company located in St.Louis, MO. All of the eficiency and accuracy of horn spekers but none of the hurshness. Very musical from top to bottom with very dip tight bass.

Are those speakers casually known as the Fart Winds and the Dog Asses?
I have had great success using Aurios under my Dynaudio Temptations. Also under my SA-1 Front end and DVD player.
Super tweak!
I think Emission Labs tubes are not as well known as they should be. I use the Emission Labs 45 Triode tubes in my amp, and they are the equal or better of any NOS 45 tubes that I know of. You can get them perfectly matched, and brand new with a warrantee, instead of getting 50 year old tubes that are used, not matched, and uncertain lifetime. I love 'em. Not cheap, but very well made, and sound fantastic.
David Berning products, way ahead of their time. I have never before seen such advanced tube circuit designs, utterly impressive engineering and sonics.
My speakers seem to be very obscure, at least un the U.S., check out www.sehring-audio.de
Eico tube amp kits. Comparable to Dyna Kits (later Dynaco) for less money. Ah for the good old days when matched KT 88's went for $25.
Canton Speakers.

Sar Labs or Scientific Audio Research Lab...
A one man operation and his flagship power amp ..the Mos 400
is produced at the rate of two a month.
Great sound at half the price.
No, I'm not related, just a satisfied customer.
Herbies Hal-O tube dampers. I was amazed at how they increased the 3 D spacial characteristics, plus tighter and deeper bass. It was like getting an amp upgrade.
Ever since I owned a pair of Sequerra Pyramid MET-7 speakers in the mid-1980's, I've had a special appreciation for them. While they got some positive press from The Absolute Sound some 20 years ago, they've pretty much dropped off the audiophile radar screen. Dick Sequerra continues to modify and improve this speaker, and even at its current price of around $1200 per pair, they offer a lot of performance: imaging, midrange accuracy, and musicality.
Hey TWL, does your Emission Labs tube recommendation apply to 6DJ8 and 12AX7? Or how about EL84? Thanks.
Now this is getting interesting. ASR, Sehring, Scientific Audio Research Lab. Those stumped me!
Sugden gear, especially their Masterclass Pre-amp.
Biggest bang for the buck...
Ear wax removal
Pulls in detail like you've never heard before.

Happy Thanksgiving!
OHM ACOUSTICS In 1988 The Audiophile-File placed the 4-XO in the ranks of Martin Logan Monolith, Apogee Duetta II and Snell Type A. Here what the MK-2 series sound like now.
We should never forget the late Lirpa Labs...inventors of such great audiophile delights as:
Steam-powered turntable
Compact Disk Washer
Stationary record player...the disk was stationary and the Stylus ran around the record
And many other great items untill the demise of Audio Magazine...
Cambridge soundworks speakers - as good as Bose for a lot less. Stereo Review said they are the best speaker value in America and the price has dropped since.

Have a listen - for the money, it is a great deal for a small space somewhere.
whipped cream
I think Clements Audio speakers are great for the money but seem less known than they ought to be. To a greater extent, however, would be JJ Electronic tube amps. My 243 preamp is work of art...stunning sound...has a very nice tube phono amp...compares favorably with some very expensive and well respected company...and damned affordable at around $1600, to top it off. Very little known in the US...but just damned good!
In response to the original question re Cayin amps.
I saw a Cayin A265i advertised (used) and was impressed by it's presentation. I figured since it looked so good I'd try to find out more about it. So I did my due diligence and found NADDA. A couple of links to a german website but since I don't speak the language useless. Then I happened to find the distributor for them in Canada and so with my brother who is also very knowledgeable we made the trek (in a blizzard no less) to audition the amp. It was a disappointment. The listening room for this dealer sucked. There were many things the amp did well but the presentation overall was dark and a bit flat. Still with the things it did right I thought I'd buy it with the proviso that if it didn't like my equipment I could return it. No problem from the dealer. So with great anticipation I brought it home, hooked it up warmed it up and again was disappointed. I listened to our everday music, no particular genre just listened. The sound was "Clinical" not involving, everything there ( soundstage, articulation,separation,slam,bloom),just not involving. I couldn't put my finger on it. My brother came over and we started to isolate possible weak links in the chain. I was using Kimber silver streaks between the amp and dac Ead T1000 transport and Ead 7000 Series3 dac. I use the Focus Signature Series 78's as my listening speakers.We swithched to Cardas and WOW,WOW,WOW. HOLYSHIT!!!!!!!!!!! The reason that many of the CD's sounded lousy is because this amp brings out ALL, good and bad. Put on a true well recorded CD sit back and marvel at what you get for what you paid.
This amp and I don't care what you pay would rate as a 7/10 stacked up against anything I've heard.
My wife and I listened to Linda Rondstat's Winter Light Cd last night. The wife had tears in her eyes. That alone is worth it's cost. Previous amp (still have it) Perreaux PMF2350.
If you've not heard Cayin, you may, if you wish, continue to live in blissful ignorance, BUT, you'll be denying yourself a true audiophile experience.

My take.
Records and Guiness on draught.