“Excellent tube, very quiet. I put them in my Manley Chinook phono pre to replace the stock tubes which were EH 6922. Vocals are clearer and more up front in the soundstage without causing any excess brightness in the treble. This was just what I was looking for. A bit pricey but worth it.”

Helpful Report

Posted 2 years ago

“Picked up a set of these to replace the EH6922 that had begun to fail in my M3. My immediate sense was that the tube wasn't obviously sweet but very open sounding and neutral compared to the EH6922 that always seemed a bit dark and slightly lackluster. I trust the folks at Upscale and their recommendation was spot on. Thank you!”

Helpful Report

Posted 6 years ago

“These tubes are quiet to start with and quiet longer than any 6922-type replacement that I have tried (and I have tried many). With the 6922-type tubes, even those sourced from CJ (EH), about 1/2 of them would be too noisy to use at all (microphonic, single channel noise) and the other half would develop tube rush within a month or two (or less). I've had a 6H23 in my ET5 since last October and it is still very quiet, tho' there is just barely a hint of tube rush developing; I've NEVER had a tube last this long before and I have the stack on *a lot*. As others have said, the 6H23 has a bit of a forward mid range and good overall extension. I've found it to image/layer very nicely and easy to listen to for long stretches. Treble is a bit less tizzy than the 6922s in my system and that is fine with me. My all time favorite sound was from the EAT EC88 tube, but those are very hard to find and very expensive. Also, about 1/2 were too noisy to use. Highest recommendation!! Try one out and you just might, like me, be ordering enough for a long-lasting back stock.”

Helpful Report

Posted 7 years ago

Michael Poullos

Unverified Reviewer

“The 6H23 / 6922 TYPE 3 tubes work superbly in my Sonic Frontiers preamp. I use platinum grade cryogenically treated tubes that I bought from Upscale Audio. I am a classically trained organist. I've spent weeks listening to these tubes with several genres of music: Queen Absolutely Best 2009 Remastered J..S Bach "Complete Works" Andre Isoir (La Dolce Volta) The Bill Evens Trio "Live at the Village Vanguard" (Riverside) The Oscar Peterson Trio "We Get Requests" (Verve) Miles Davis "Kind of Blue" SBM Super Bit Mapping Peter Hurford "Romantic Organ Music" (Argo) Environments 1 Psychologically Ultimate Seashore (Atlantic) and Delius "Violin Concerto and other orchestral music" Symphony Nova Scotia (Naxos) Bottom Line: very quiet, harmonically accurate, not the warmest tubes I've used in the midrange (compare Siemens CCa which I brought from a Vancouver High End Dealer) sonically neutral, fast well packed International Shipping and so on. Trust Kevin, he won't steer you wrong. What an excellent business to deal with. These tubes will likely out live me. Thanks so much Upscale Audio.”

Helpful Report

Posted 7 years ago

“First things first. Kevin is correct saying these are the most robust 6922 equivalent. My first pair were powered-up in standby or playing music nearly continuously from 2007 through 2015. When I scored a brand new pair in 2016, the sonic deterioration of the used pair was tiny vs the fresh pair. (I was using tube coolers, but that's still a great run) (mine are Reflektor brand from the late-'80s, 6H23N-EB) Second, these do sound great, like an excellent transistor amp, meant as a complement: fast, detailed, dynamic, clean, great extension at both ends, and a 'bold' midrange (articulate and maybe a little forward, but the mid-mids, not the upper-mids). They don't have quite the dimensionality, dynamic gradation, absolute purity of tone or harmonic saturation of the very best, but they're at least 'average' in all areas and will complement your uber-tubes in multi-stage applications, and outlive the pricier units too. Buy these now and you won't have to worry that there aren't any more cos these will outlive your preamp. And likely you too.”

Helpful Report

Posted 8 years ago

“If had one of these in my Conrad Johnson ET3SE Pre for 6 Months now. Like the gentleman before me I am very happy with it. I find it very musical with an impressive soundstage. I had to give it at least 60 hours break in before it settled down in my ET3SE. It has been smooth sailing ever since so don't be to harsh on it early. Looks like I am going to have to beg one or two out of Kevin for backup. I mean: If not this, then what?”

Helpful Report

Posted 9 years ago

“Very quiet and musical tube, has the musical character of the stock EH6922 that came with my Conrad Johnson ET3SE just without the noise and distortion you get at times. The 6H23 produces rich premium sound and is by far a keeper for my tube hungry preamp!”

Helpful Report

Posted 9 years ago

“I bought a platinum pair of these tubes to replace the stock input tubes in a brand new Schitt Valhalla 2 headphone amplifier. These tubes have more mids and treble than the stock tubes, which seem to have more bass. In reality, I've never put the stock tubes back in, because although they sounded good, these sounded better right away with my Sennheiser HD 650 headphones. I think these headphones react well to tubes that are a little brighter than the stock Valhalla 2 tubes. I'm extremely happy with the Valhalla 2 with these input tubes and the Sennheiser HD 650 headphones. I've been using these tubes for five months with no problems. I would buy these tubes again. I'm long past the wallet hit, but I'm still enjoying the sound every day.”

Helpful Report

Posted 9 years ago

6H23 / 6922 Type 3 Gold Grade / No Cryo Reviews