Tenor 75 Wi OTL

Just bought this OTL by Tenor.

Living in Destin FL and owning the Atmasphere S30 amp I could remove some power tubes to reduce the heat in the summer. Can this be done with the Tenor?

Kelly High End in Ca. who I bought from said the amps puts off very little heat after being on for a hour or two. BS from the seller?
Great sounding amps. No, you cannot remove tubes.

Yes, BS from the seller.
I will second the BS from the seller as well.
Anyone still using this amp in their system?
Hi Glory

Is the problem the amp or the heat? My guess is the latter. Whatta ya gone ta do? I also live in Florida and can absolutely relate. So far as the seller and what he told you, Cavaet Emptor, you know the rest. The question is are you happy with this amp in your system? you haven't said. I am curious though, for my own personal information, is the Tenor really better than the Atma-sphere in your opinion and how might you describe the differences?
Glory, Love your beaches,Destine and area is just beautiful and one of our favorite vacation areas in the U.S.

Tenor Hmm, I remember the flurry of excitement over these amps a few years ago. The Absolute sound declared them as the very best they have ever heard, well something on those lines, the usual. That along with of course the online buzz over these OTLs. Spread like wild fire though this happens frequently with some of the worst far over priced stuff on the market.
Hope you kepted your Atmosphere amps.
The amps are coming Monday. Sold the AS S30 to a friend down the st so we shall hear if the T is better than the A. The AS has two more space heater tubes than the Tenor so I am hoping that they give off the same amount of heat. The S30 was border line to much heat in the summer.
The plate dissipation of the 6AS7G output tube is 13 watts for a total of 130 watts in the S30. The plate dissipation of the 6C33C is 60 watts for a total of 240 watts in the Tenor. The Tenor will run significantly hotter. It also has a fan which takes the heat away from the amp and spreads it throughout the room. I've been in a fairly large room in the summer with the Tenor and within ten minutes I started sweating. It did sound terrific, however.
I should add that for the Tenor, it's 240 watts of dissipation per monoblock so the actual dissipation in your room is 480 watts.
Gee T thanks for the great news. You made my day. My wide will love this extra hear in the summer.

Looks as if the seller gave me BSHSCS and cat $hit all in one pile.
I got a great price on them shipped to my door for 6K.

Sounds like I should unload them now and not even turn the space heaters on.

I can rebuy the S30. BB why do you think the AS is better?
You have to be kidding Glory 6K? that is a great price from their retail of 17k I believe. This was suppose to be the "it" of OTL amps and among the best period from what I've read and heard, Jtinn was a dealer and major proponent of this amp. I do trust your ears Jonathan. I only heard them once at a show with Pipedream speakers so have no opinion in anything familiar. I certainly would listen first before unloading and if you decide you really love them.....you might want to consider some kind of ventilation system but it seems from looking at your set-up with the staircase directly behind the speakers that it might be a bit of a challenge.
Glory if you must have vacuum tube amplifiers look for a pair of Lamm ML2 for your efficient speakers?but try first if you can.

I borrowed the Tenors at there peak of popularity tenor then floundered shortly there after for many reasons I suppose.
My ML2 are 12 years old and still fantastic. The ML2 changed some parts then later then onto the ML2.1 and 2 and for not the better.

Looking a little deeper at Tenor back then this goes to show you the company they kept at consumer shows and dealer show rooms with the likes of Pipedreams and Karma. Marketing know how of high dollar crap aimed at the gullible with deep pockets, and it works well.

But please give them a good listen to when they arrive just to see for yourself.
I owned these amps for a few years. They put off a huge amount of heat. I live in WA and do not have AC as we only have a few days during the year that really call for it. But, with these the heat in my listening room became unbearable for long listening sessions.

Like others have said try them before you decide to dump them, they are gorgeous sounding and looking amplifiers.
My ceiling goes up to the 2nd floor loft and are 22' high. All the heat goes up there so maybe put a fan in the window and blow it out of the house?

Why did I sell my AS S30. A smart ass for sure. Maybe the seller is right and after an hour they give off very little heat LOL.

What happened to the TRL OTL amp? Never got made?
A miscarriage. Wanted to sell a SS amp to me after the miscarriage but with my 16 ohm speakers not any SS amp will work. Talking to Zu I was told NOT to buy it as it did nor meet their specs.

OTL amps are the best sounding amps on these speakers.

So I will buy a fan and install it in the small door opening that goes to the attic to drive the trapped heat in the loft area that will be generated by the Tenor space heaters.
I`ve been told by some who are familiar with the Tenor that they sound excellent. For 6 grand you may have hit the sonic jackpot.Your plan for a simple fan installation may solve your conern about heat.
Best of Luck,
One other thing Glory fyi. If you can't make the Tenors work for any reason there is another OTL amp option. I recently read on a thread a response from a dealer of these speakers, Audiofeil that the Berning zh270 was one of the best he heard with these speakers brought into is store by an owner auditioning. Unfortunately this amp is no longer made and they are becoming more difficult to come by on the used market as most who own don't want to give them up, yours truly included. However they do have a 30 watt zh230 that is supposedly more refined at less power. Unfortunately the jump in price was quite a bit over the zh270, in the 8k range I believe. Advantages wide bandwidth performance, low heat, extremely low noise, it uses an advanced switching power supply, long tube life, self biasing, OTL clarity and transparency as it uses an impedance converter but no output transformer the best bass control I have heard on any tube amplifier in my experience. I am not in any way affiliated but since you live in Florida you are most certainly invited to my place (Rockledge near Cocoa Beach) for a listen to decide for yourself if it might be an option IF you can't make the Tenors work for any reason. Good luck!

PS The Berning is a no nonsense design if you consider aesthetics important. It will not compete with the beautiful Tenors as it is very simple and unassuming on the outside no exposed tubes which can be an advantage in a smaller space. The advantages are all in the brilliant design by one of the most brilliant amplifier designers in the industry.
I have heard the ZH270s on many occasions over a period of more than a decade, in my friend's system. He has a pair strapped for mono, driving a pair of large Acoustats. They are wonderful, bullet-proof amplifiers. However, to my ears they do not give that last 5% of clarity that one can get from a true OTL. I am specifically referring to my own Atma-sphere amps driving a pair of Sound Lab M1 speakers. I and my friend give the edge to the Atma's. I have a longstanding curiosity regarding the Tenors, and I look forward to hearing what you think of them compared to your S30s. Too bad heat is such a big issue for you.

By the way, the ZH270 was once one of the screaming bargains in audio, when it sold for $2500. Evidently David Berning (one of the geniuses in audio, IMO) met up with a marketer who raised his prices about 10-fold. I think the ZH270 was discontinued just to facilitate the price rise. Of course, there is no crime in that.
So far as the zh270 going up in price 10 fold, i'm not too sure about that Lewm. I wasn't aware that they were ever 2500.00 when they were first introduced but if that was the case I can't imagine Berning doing anything but breaking even if one is to consider that the amps took him 30 hours to assemble. The wiring for the impedance converter alone must be done manually and I can only imagine how tedious that task alone is. Yes indeed, at 2.5K it must be one of the greatest values ever in audio. at its final price with all the modifications I believe it listed at 5.5K

There were some substantial improvements, at least in my experience with several of the mods that improved the amp's performance no less than a wiring change and a few input caps along with some other lesser changes including cryoed outputs. The total net gain was significant. While I have done a direct AB to a Joule VZN80 in my system many years back the Joule clearly was harmonically richer with greater density where as the Berning was somewhat leaner. This was before I performed any of the mods and tweeks including much experimentation with vibration isolation. Sure would love to do an AB with the Atma-sphere in my set-up, I have always been curious all these years. I can imagine your system, great choices!
I live in Destin which is in the panhandle of FL. As my wife says lower AL.

With my open floor plan of my house and the fan thought I might be able to pull it of.


thanks for the offer to hear your amP. When in the area I will look you up.
Glory, I have heard the Tenor's on several occasions and IMHO, they are an excellent amp. They will give off a lot of heat into the room, but that is to be expected with most tube amps. I saw these on 'Gon before you bought them and was tempted to buy them myself. BTW, the same seller has a JR model 8 for sale; this is one of the amps that I currently use and it is also an excellent piece. Perhaps if you don't like the Tenor's, then maybe the seller would allow you to trade them back for the model 8. The 8 has more power than the Tenor's and can control the bottom end better, it's not quite as holographic, however. But if heat is the issue, then the 8 would be a great swap.
I am certainly surprised by the comments of Blackburn. He insults countless people and companies in one statement. Who knows what his motivation is.

Anyone I know that has ever listened to the Tenor OTL has loved the sound. It is certainly, when paired with the proper speaker (impedance), one of the finest, if not the finest, sounding tube amplifiers I have ever heard.

If you have any questions, please feel free to call me and I will be happy to help.

Jonathan Tinn
Glory, Since you have ZU speakers you will not have much advantage in seeking an OTL with more power.

More Power more heat more space more AC cables. Great move yes?
OK so we have 2 hour + on the Tenor amps. My thoughts are a lot of heat and the best amps/sound I have ever heard out of my system.

Jonathan helped set the amps up by phone after the seller caused me to wonder if he knew anything about the amp. You may not always agree with Jonathan but he does have a passion for this hobby called audio. Treated me as if he just sold me the amps yesterday. Thank you so very much J.

I would rather listen to this amp one hour and turn it off for the sake of heat in the summer than listen all night to a lesser sounding amp.

More thought later as I break these suckers in.

Oh buy the way I have the 7th pair made so who are you that first bought these?
Hey Gary, Florida + Tubes = Crank up the AC.
Glory- Agree totally w Tubegroover about the diff btwn Berning ZH-270 and Joule VZN-80. In my system, to my ears, a no brainer. Also a no brainer that those Russian MIG output tubes will dissipate WAY, WAY, WAY more heat than an S-30. In my house, 8 of them (same as the Tenor monos, I believe) gave off WAY more than a pair of the M-60 monos. Even in New England in the winter, they very quickly heated up my 15 x 23 x 8' LR and the adjacent hallway and staircase area. Very interested to hear what you think of the Tenors compared to the Atma amps; the Tenors are beautiful and I've always wanted to try them on my Merlins.
"I would rather listen to this amp one hour and turn it off for the sake of heat in the summer than listen all night to a lesser sounding amp."

Enjoy your amp Glory. I hope you find a solution to the heat from those big 6C33C outputs, keep us posted, love to hear your system!
Congratulations! I know some folks who say the Tenor is the best OTL they`ve ever heard. I hope things workout for you.
"Looking a little deeper at Tenor back then this goes to show you the company they kept at consumer shows and dealer show rooms with the likes of Pipedreams and Karma. Marketing know how of high dollar crap aimed at the gullible with deep pockets, and it works well."

Your comments are interesting Blackburn. At that same show I heard the Lamms matched with the Kharma 2-way, 3.2 I believe? In any case I found that set-up among the best at the show. I was quite taken by the Lamm amps and now completely understand the buzz on that amp. The Pipedream/Tenor set-up was in a large room and in my experience under show conditions it is much more difficult to make a large speaker come together in such a short period of time. While the sound certainly wasn't bad it wasn't magical either. In any case it was quite easy to recognize the transparency and musicality of the Tenor amps, the speakers seemed to be the issue.
I've always been impressed with Tenor amps in friends systems back in the day---if my speaker would work well with them (Zu Def2), they would definitely be a consideration.

Look forward to hearing more thoughts on the sound with the Presences Glory.
Ok so these suckers run hot. A northern amp for sure. My 22' ceilings are allowing me some time in May but JJA I will have wait and see. The 15w would be a better fit for me.

The Tenor OTL is a world class amp and every positive word spoken about It is true.
Hi Glory,
How does the tone and timbre of the Tenor OTL differ(if at all) from your Atma-sphere S30 with vocals and acoustic instruments? Is one more life like or organic? I`m curious, as they`re both well proven designs.
Glory: If I remember correctly, the Tenor 15 watt monos run virtually as hot as they are class a full time.
Have a chance to get the Tenor HP 150 from Tenor.

The Tenor is mind boggling. Far above my AS S30 in every area. Bass has texture and vocals are 3D and real sounding. Duke Ellington's band sounds so natural and organic in the brass section. That is an area I never heard sound so right in my system.
It`s funny you cite the duke. I use the CD Duke Ellington "Dance Concerts California 1958" for system/component evaluations. This sound is so natural, dynamic and just a wonderful live recording. It`s as though I`m right there with them in the dance hall.
It seems you`ve found a fabulous amplifier. Continue to enjoy it for a long time.
05-26-11: Glory
The Tenor is mind boggling. Far above my AS S30 in every area. Bass has texture and vocals are 3D and real sounding. Duke Ellington's band sounds so natural and organic in the brass section. That is an area I never heard sound so right in my system.
I would hope so when comparing a $20,000 amp to a $5,000 amp with half the power.
If there`s one thing thats been demostrated often in high end audio, higher cost does`nt mean better sound.

With the very efficient Zu speakers the additional power is`nt an advantage, it`s sound quality. Often times a lower power amp will have superior sound to a larger and more complex design.

I would think most audiophiles at one time or another have heard quite expensive systems/components that sound like crap.

When I got my 300b SET amp it was less expensive than the 100 watt/60watt triode push-pull I was using, yet the "8 watt" amp sounds better.
Best Regards,
I see a pair of Transcendent Sound SET OTL monoblocks in your future (perhaps even the stereo version given your speakers). Maybe even a stereo T-16. My T-16 does run hot, but not nearly as hot as my S-30.

As previously stated price doesn't always equate to quality, but I get the gist of Darkmoebius's message. In which case you'd find Transcendent Sound amps can play right up there with amps that cost significantly more.
Zu thought a Transcendent amp would sound good on my speakers.
There you go.
Clio09 I don't mean to rain on the parade concerning Trancendent amps, I owned the T-8 prior to the Berning, great amp btw, but to paraphrase Senator Lloyd Benson to Dan Quale during their debate for VP in '88, "Mr. Trancendent you're no Mr. Tenor. In any case Glory, the Trancendent is a great product but I doubt it comes anything close to what you have been listening to the past few days. The Berning is a step above the Transcendent in all parameters or I wouldn't have switched. The issue with the Tenor is dealing with the heat only. I doubt there are any other issues in question based on your observations. The Trancendent is Class AB vs. Class A operation of the Tenor therefore less heat and of course the sonic compromises but it still runs warm, more than the Berning.
05-27-11: Charles1dad
If there`s one thing thats been demostrated often in high end audio, higher cost does`nt mean better sound.
Of course, I was being slightly sarcastic with my remark.
With the very efficient Zu speakers the additional power is`nt an advantage, it`s sound quality. Often times a lower power amp will have superior sound to a larger and more complex design.
Get it, got it, preaching to the choir here. I have similar high(er) efficiency widerange driver speakers and have/had several SET amps(300B, PX-25, 6C33CB, 2A3).
My recommendation was based on the requirements for low watts and less heat. It just may be Glory has to give up something to get something. Not my decision. For Summer months in Las Vegas I have a nice selection of amps to choose from that don't put out a lot of heat. In the other seasons I can use OTL's.
One point about the Trancendent that does bear consideration is that it is a quite inexpensive for its performance. I am not sure what the current pricing is but you DO get a lot for your money. In retrospect, it is unfair comparing a higher priced component that performs at the highest level to one that is really an overachiever at its price point. The T8, a 25 watt stereo amp, idles at 300 watts, not sure how hot it gets when playing but is more than enough juice for those Zu speakers. The Berning idles at 100 watts and maxes out at 300 watts full power, cooler than virtually all tube amps let alone the Class A OTL variety.
Hi Darkmoebius,
I hear you loud and clesr LOL. Sometimes when reading another person`s reply the intended humor is`nt apparent. Based on your system, you certainly appreciate low power /high quality amps also.
The 1.5 watt SET OTL is $1500 assembled including tubes. If he wants 4 watts instead of 1.5 he needs two of them to run as monoblocks. The T-16 is $1599 as a kit with tubes. 15 watts per channel so the stereo version is plenty. There are expert assemblers out there who build these for people who do not have the experience to assemble the kit. I know Ed Schilling at the Horn Shoppe has built a few. He raves how these amps sound with his ~100db horns. For the kind of money we're talking there is not much risk and they do play well above their price point,
So the Tenor OTL is a very quiet amp. Sticking my ear next to PDIFthe Zu Audio Presence speakers & 101 Db I hear no noise/ sound. The Atmasphere S 30 was all about hum/noise in my system.

Running my Lampazator Dac straight into the amps was better than having my Dude preamp in the chain. The Dude is sold and gone.

These amps have placed me in the Zone, a place I have never been in audio in ten years.

Have a fan blowing upward in my fireplace to draw the heat out of the house. Seems to be working. Can not wait for the fall to run fbm all night.

How do I explain to the the wife why our electric bill is so high?

The Lampazator dac is in the same league as the Tenor amp. 7 days to hear it and buy it. When you hear it you will not send it back!
Glory, congratulations on your system. Sounds like you are having a ball. Have you considered installing central air? A window AC unit?