Vacuum tube rectification has fewer sharp edges than does a solid state rectifier and thus, lower noise when converting. Or, put another way, when the incoming AC is being switched on and off to separate its direction into DC, there’s a much gentler transition with lower noise. As for regulation I am unconvinced there would be any advantage and quite possibly some disadvantages in noise.
7 Likes
Very exciting, first tube input stage, now tube rectification, next step full tube amplifier. Looking forward to this transformation 
3 Likes
With any design parts choice is all about implementation, so the use of an EZ81/CCA4 was a surprise in a 600 WPC amplifier. From the JJ EZ81 spec sheet its plate current is rated at 180mA DC. Considering the current limitation is this implemented in the BHK600 in a dedicated DC supply for low level signal applications?
Typically found in tube guitar amplifiers their selection is preferred for a modified sound when under heavy load as voltage sag results giving a slightly distorted and compressed sound.
I don’t doubt that within its normal linear operation the JJ Z81 can be quiet and controlled, the term polite comes to mind, when compared to a solid state full wave bridge rectifier. I’d like to think the tube version eliminates problems associated with reverse recovery spike, and the creation of harmonics which need to be addressed by improved schottky or silicons carbide diodes, snubber circuits and filtering networks. Not a criticism, just trying to understand the implementation of a low current rectifier in a high watt amplifier.
Appears to be a novel concept in the making. BTW, thank-you for your response.
2 Likes
Was this something that BHK initially proposed with the BHK300s and is now being fully realized in the BHK600s? Or is this refreshed design?
Thanks
1 Like
The low current tube rectifier is most likely only for the tubes in the input stage.
1 Like
Likely considering it makes the most sense. Still it would be interesting to hear more from PSA staff on the design details. Maybe things are not as locked in as I assumed.
1 Like
Like everyone else, I can’t wait to experience the FR30’s at some point…just from a glance, with the side firing woofers, they remind me of they old AR9 (and later Ken Kantor NHT 3.3) design, which, IMO, was capable of incredible bass performance and pretty accommodating in terms of playing nicely in most spaces.
I’ve been a planar guy for most of my audio journey…Maggie’s, Quads and Carver Amazings. Thing I’ve always found is they are pretty demanding as far as getting them dialed in…but the payoff is worth the trouble.
Anyway, congratulations to the OP!
5 Likes
Thank you sir!
Looking forward to getting to know everyone!
2 Likes
Yes, welcome, Troy! Fancy meeting you here 
I know, right?
What a coincidence!
The Canadian PS Audio distributor is a friend of mine. He just sent this to me from the Montreal Show this weekend. Nice presentation!
11 Likes
Is Nexus the Distributor?
Nice room for those FR 30’s…guessing they sound great in there.
Thanks for posting.
Should see some press coverage coming out of the show soon, which will be of interest to many here of sure…
1 Like
Very nice! What was the black piece on top of the Direct Stream DAC?
Don Rhule of KimberCan is the distributor.
Looks to be the PSA SACD transport.
Paul’s Post about Montreal
2 Likes
This past Thursday I had the opportunity to listen to the FR30 at PS Audio. Very impressive! They were extremely clean sounding with exceptional imaging/soundstaging. Instruments sounded truly like the real thing. There was a true to life relaxed quality to the sound rather than the tendency of hyper detailed speakers like Magico to sound a little sterile. They certainly sounded a lot better than my 20 year old Vandersteen 5s (it would be fun and more appropriate to compare the FR30 to 5A Carbon or Kento). We even cranked it very loud on one or two tracks, not something I normally do, and there was no compression or distortion. A good demonstration of the clarity and lack of distortion.
The only (slight) hesitation to my ears was the ability of the speaker to disappear. On the first few tracks I was aware of the sound source, but I think this was at least partially a psychological factor. There I am listening to these new speakers we’ve all been reading so much about and the anticipation was at a very high level. I just couldn’t ignore their physical presence. This will certainly subside over time. Also contributing was most of the music played I had not heard on my system, though this was Paul’s Picks so they all should have been exceptional recordings. To my point, though, the first song I got to pick was one by Norah Jones and the speakers did disappear just like in my system. Hmmm.
I can’t really compare the FR30 to any other marketplace contender since I haven’t heard any of them since the last audio show two years ago and I haven’t been in a brick and mortar store in years. And we all know how well audio shows give the best demonstrations! Not …. As such I will not say these are the best speakers ever, I can’t possibly make that claim, but my intent on listening to them was to see if Chris Brunhaver’s idea of world class sound aligned with my idea. It sure does!
Will I buy a pair? Actually, probably not, they are beyond my budget no matter how much I stretch it and I do have a small room. What I would buy is the FR30s little brother. Chris is working on a smaller version which could be out in the next year. It hopefully will use the same drivers, just less of them. I speculate two woofers in the front and one on each side, just not sure if that would be floor standing or a low stand mount. Assuming this smaller version shared the same “sound” as the FR30 they will be the one for me.
10 Likes
Thanks, PMOTZ. Here’s another review just posted on Paul’s Posts.
I went to the Montreal audio fest today and I made a beeline for the PS audio room. The setup was very well done, one of the larger rooms, but luckily this morning there were only a few of us in there listening.
The speakers are larger in life than they appear even online, not so much tall and intimidating, but very deep and definitely have a presence. There is a subtle and beautiful PS audio logo on the side at the top, this is so nicely done and one of the nicest design elements of the speakers! They don’t look unstable in person, but I am still not a convert to the overall design of the narrow feet and rounded bottom. The finish and assembly look absolutely top notch though. Then we listened to them… Let me tell you, the stories of the development, and all of the hyperbole that Paul seems to mention about them are absolutely deserved. These are truly world class speakers, capable of awesome dynamics, completely full range, detailed, and really disappear in the room. They were revealed delicate details in the middle of a mix while being powerful at the same time. These are not inexpensive speakers and I for sure cannot afford them now, but after having heard them I have to say I consider them a fantastic value. I haven’t heard much that can do what these do, even for 6 figures. Very well done PS audio, congratulations on a great new product!
14 Likes