Decware Zen: what can a 2W SET do for you? (Technically Single ended pentode in triode mode) 

Dear Viewer, the link to the coffee-station, or, as I could call it, the Tea-house is right here: www.buymeacoffee.com/RealWorldAudio This is a way to support my channel in a hassle-free manner, and you can contribute as low as 2$ if you feel compelled. If so, I welcome your support with a warm welcome, it goes a long way to allow me to continue with this channel in the future! All your support will go towards improving this channel, and towards the tweaks and components I explore on the channel. János

Thanks for the really good video, enjoyed it. You confirmed many things I was thinking regarding my own Zen clone amp(s) I built from the original Decware schematics many years ago. I for one agree with what you said about pairing the 2W amp with less sensitive speakers, I run Energy 22 Pro, Energy 22 Reference Connoisseur and 1970 Rectilinear 3 all only 86-87 db albiet larger speakers to quite loud volumes no problem. Later I will add a new comment with some notes I made regarding the Russian 6P15P (el84 substitute) output tubes if you're interested. I prefer them to the many el84's I have tried.

I agree with what you have said. I agree with your opinion. Zen Decware hasn't reached my country so I am using a 7.5w per channel old Sony STR receiver (in tip-top shape better than when it was new) driving a pair of 94dB full range speakers wired in series with a parallelled tweeter per channel, a 98dB Coral 6CX-501 and a 103dB Coral 12TX-50 and next weeks to come will be a Fostex 100dB. All speakers are in its prime shape (even the baffles were tweaked to give optimum output) so I can enjoy an enjoyable listening experience. Because I am using solid state equipment, I am using a tube buffer to enhance the signal connected to my mint conditioned 7.5w/channel Sony receiver, this doesn't come close to the Decware Zen UFO yet I am very pleased using a turntable or Bluetooth receiver from an Apple music source. Again this is not a Decware and just imagine if it was. I like your review. Keep up the good reviews.

Somewhere I read the Russian 6P15P tube was a new design back in the 70's , not one just copied from Western tech, although it closely resembled the EL84. A few factories in Russia made them, Reflector, Voskhod (the Rocket brand), and ORZJeP of Orel City. An American Marketing company purchased a large stock of the non-military version and then made up the trademark of Svetlana with their S logo and sold the SV83. Decware discovered this tube and the first Zen amps were designed around them. Svetlana went buy-buy at some time and now Decware uses NOS tubes from remaining Russian stock. 6P15P or 6n15n (crylic spelling) are the same thing. If tube has extension of EV or EB it is long life (5000 hrs) military version, i.e. 6P15P-EV or 6n15n-EB. There is also a military grading system on many tubes marked OTK #. Apparently the lower the number the better i.e. 1 or 2 and I also heard there was a 0 but have never seen that. I have seen them also offered with gold grids, as seen on the great e.b.a...y. Decware writes..." These tubes, SV83, whether mil spec or not, because of their small size and intended use in TV Video applications, are superior sonically to the popular 300B, 2A3, 45's because they lack the heavy signature and are considerably faster. The bandwidth of these tubes is far greater then that specified for audio tubes " The 6P15P are the same as EL84/6BQ5 except for one difference. On EL84 the suppressor grid is connected internally to cathode. On 6P15P the suppressor grid comes out to pins 1 and 6 which are normally unused in a EL84. To interchange it's just a matter of making sure that either of those pins 1 or 6 is connected to pin 3 cathode and that neither pin 1 or 6 is connected to anything else on the tube socket. If you do this either tube can be used EL84 or 6P15P. Decware Zen makes use of the 6P15P unconnected suppressor grid by connecting pin 6 to cathode pin 3 with a 0.1 uf 400v capacitor in their circuit in what they call "The Hazen Mod" after an employee who first tried it. They claim an increase in performance with improved dynamics with increased clarity and imaging. When I did this in my amps I couldn't tell much difference, but maybe the rest of my system at that time was not resolving enough. I kept the mod in never-the-less. In other amps other than the Zen if you want to try 6P15P I also read an amp tech ( which I am not ) claim "the 6P15P will bias up much lower than the EL84, so if you have a cathode biased amp, it would need a much lower valued cathode resistor to idle at the same current as the EL84 (~120 ohm compared to ~270 ohm for EL84), or if it is a fixed bias would need to be set much lower, probably by about half ". Lastly as noted on rutubes.com there is also the 6P14P. 6P15P similar to EL83 6P14P similar to EL84 and same pin out. On Decware forums it was discussed that the 6P14P was a meatier substitute with more balls in bass and midrange presentation but the 6P15P has more detail and refinement. I swear by the 6P15P in my Zen clone amps, have yet to compare to the 6P14P. I hope you find this information useful considering this series of videos is all about the great EL84. Now you know more about his Russian cousin the 6P15P. Marc in Ottawa.

Hello Janosch, thank you for your inspiring videos and very helpful advice. I have rediscovered my passion for HIFI after many years and decided to build the Le Petit. Now I am still looking for a suitable amplifier. Can you imagine that the Decware Zen (2 watts) would be suitable?

I have my Decware hooked up to 99db Tekton. Plenty of power, never go past 2 o’clock on the dial.

Remarkable : while modifying my amp to a lower power SET (and also upgrading components) , the music sounds much louder than before!

Congratulations on your channel! I’m a fan, excellent content, very different from everything else out there, please keep on the good work 👍 I’ve been in this hobby for several years, I love every aspect of it. I’ve owned solid state as well as tube amps (both PP and SET designs), all sorts of speakers, digital and analog sources. I listen to a lot of music, especially jazz, some classical and world music as well. I would now love to start making my own amplifiers. Regretfully I don’t have the know how nor have access to any type of DIY club near my place (where I could learn with/from others). I’d imagine I’m not the only person in this situation. So I have a suggestion for you… there are several channels showing DIY speakers but none that I know of are covering DIY (tube) amplifiers. Why don’t you start a series on how to build a small SET amp, ideally not a kit, step by step, from scratch? What do you think? Best, Joel

could you please tell us the estimation how this decware 25 anniversary sounds compared to audio note amp's ? i used unison research simply two, and i miss that sound because i sold it in the past.

Hi Janos! There is something fundamental regarding single ended amplifiers I have been pondering for quite some time. I do enjoy the sound from single ended amps more than that from push-pull amps, and of course I have been wondering if there is an affordable DIY way of getting slightly more power while my speakers have only 90 dB/W*m. Someone proposed parallell single ended output tubes, like EL84:s or EL34:s. Other very experienced SE-guys on the contrary, said that, while parallelling SE-tubes of course is possible, it very often leads to time-smearing and loss of "airyness" and spatial sound qualities of the amp, because of unwanted interaction between the two not perfectly equal parallell tubes. Do you have any experience of parallell SE-amps , and of the claimed problems with loss of spatial sound qualities I have heard of ? Cheers, Magnus

"the higher the impedance of the loudspeaker, the better the sound you are going to get". Can you go into more detail on this statement? Is this in context to using them with the Decware Zen or in general?

Thank you for the review. What inexpensive preamp would you recommend. I ordered the Decware Zen today. It looks like I have an 8 month wait possibly more before it arrives.

Please provide deets as to what you did to "super charged" the Mirage 760's old X-over. Any details about the Mirage 760 X-over online is scarce since these speakers are extremely rare.

What do you think about Decware zbox tube buffer or tube buffers in general? Thanks

Play & perform, hooked to Decware ZOB open baffles speakers?? (Re: Mr. Bojangles)

The Russian tube has a very different sound signature than the el84 that I prefer

To be nitpicking, the ZEN is a SE pentode (not triode) , run in "triode mode", right?

Ok, I’m going to be That Guy. I know the ZEN Amp sounds good. (But) it sounds good compared to what? There’s no way it can go down to 20Hz with those transformers. Yes the tube synergy is very good. Yes it Looks extremely good, just the right size of the components on top. They were cabinet makers, an they no what looks good, an looks sales. I’m sorry if I hurt feelings, but come on, the laws of physics just don’t support all the hype behind this amp. I was born at night, but no last night.

Go listen and then turn your mic on