Tenor Audio

Does anybody have any working contact information for Tenor? Their phones are disconnected it seems. Thanks.

I heard that Tenor does not exist anymore.
I'm not sure it's true but...
Try Chambers Audio @ 503 221 0465
sad but true. but there is hope and rumors that they will restructure and possibly reopen early in 2005 ... hope this is true for this Canadian venture.
I had heard that Tenor amps chewed up their 6C33C power tubes very quickly. Does anyone know if this is true, or just bulls**t?
They're suppose to make an announcement about their new contact info any day now but they're not they're probably not the quickest in updating their site.

Fatparrot, what do you mean by Tenor amps chewing up their tubes? Are you asking about their lifespan or Tenor's supply of tubes?
No Howie, I am talking about the power output tubes. These are the 3 nipple 6C33C's. I heard that they had a relatively short life span, due to the design of the Tenor circuitry.
Well, replacement tubes is what I want to talk to them about. I guess now that the warranty is worthless anyway I could just get 6C33Cs elsewhere, but I thought I'd try them first.
The so-called restructure annoucement has been coming for 6 week now. Unlikely it will happen. but you never know Von Shiekert came out of bankruptcy.
Don't count them out yet. Someone from Tenor will be posting here as soon as everything is finalized. I have had two pair of OTLs (one of the first and one of the last) and the output tubes lifespan has a lot to do with speaker load. I run mine 6 plus hours everyday and get about 6 months. I am getting a solidstate back up soon. The last pair have been working great. Given the right speaker and front end I have yet to hear anything I like better(maybe the Lamm ML2). I had the hybrid in between the OTLs and just had to have the OTLs back. Although the warranties are gone, service will be available for both the OTL and the hybrid.
I have a pair of 75wi's. One of the amps has a problem with the DC balance. I was told in December that Tenor's service tech, Stephan, would be providing service and would call me around January 12. I have heard nothing as of February 3. Unfortunately, I did not get Stephan's last name so that I might contact him. Does anyone know how he might be contacted ? Any suggestions for replacement 6C33C's ? Thanks.
If 6C33C tubes are Soviet military, I suggest you contact Anton at:


I've now made two purchases from him. Great guy, great tubes. It will take him or Tatyana a bit to pick up your Western Union draft then ship, but it's been less than a month from order to receipt both times and well worth the slight wait relative to US dealers. He lives in Moscow, after all...

Good luck.
Tenors service department should be open for business
in the next month. They will post when there is a firm contact number set.
Will gstubes match tubes? Tubestore doesn't provide matching for large power tubes, and I don't know anybody with a tube tester (except Vlad Shushurin, but I assume he's not gonna test tubes for me).
In the meantime, we'll be happy to help out with service. Its a circuit we're pretty familiar with :)
Bluedevil, just in case you missed the understated post from Atmasphere above... Atma-Sphere certainly can service your Tenor amp, if service is needed. Or they can help you diagnose the problem. The circuit in the Tenor is identical to one used by Atma-Sphere years ago, and they are very familiar with the requirements of this OTL design. It's certainly worth giving them a call to discuss whatever problems you may be having: 651-690-2246. Ask for Bill or Ralph.

You'll find them to be very accomodating and helpful.
Rushton: The circuit is not identical to the Atma-sphere. That is ridiculous.

For all of those who would like service on their amplifiers, be patient and Tenor's service department will be up and running shortly.
Yes, you are right. Rushton was not suggesting that it is identical to what we make now. It is however nearly if not identical to one that we used to use back in the 80s although we didn't use the 6C33 as it was not available in the US back then.

Just trying to help out if it was needed. Of course it would be best if Tenor gets things going again.
Jonathan, calm down, read what I wrote:
"The circuit in the Tenor is identical to one used by Atma-Sphere years ago..."
You're correct that the current circuits are not the same, but that's not what I wrote. Ralph's offer of some assistance is an honorable one, and the fact that the circuit was applied by him years ago is hardly ridiculous given OTL history and Ralph's role in that history.
I considered purchasing one of these amps, after listening to a pair at the Montreal Audio show last year.

Then I said to myself, why should I shell out 30k on a relatively new company, with no track record, and is spending tons of money on marketing. Probably chewing up their cash faster than they can sell their amps.

Lucky Lucky me, I'm glad I bought something else instead !

Phewwww, that was close !
TENOR IS BACK! Updates are finally posted. No need to search for alternate service.
If you want an OTL Amp...Atma-sphere! ' Nuff Said!
Well, not quite. The 2-line post states that they "will finally be in a position to service all products by the end of next week." So I suppose this is an announcement of their intention to be "back" in the near future. My breath, she does not hold, but my hope, she lives.

It seems there are good news for Tenor users. They have placed the following message in www.tenoraudio.com:

 Tenor is back
After many weeks of restructuring, Tenor  will finally be in a position to service all products by the end of next week. Please keep posted for further details.
I have to disagree, the tenor is my favorite
otl! I wish it wasn't. As long as there is service,
I'll keep my Tenors.
Rushton: You calm down. You stated:

"The circuit in the Tenor is identical to one used by Atma-Sphere years ago"

I stated:

"The circuit is not identical to the Atma-sphere. That is ridiculous."

Your statement is very misleading and there is no way for Ralph to even make that statement either. It is a totally irresponsible and you do not know what you are talking about. Are you just repeating what someone told you?

I have quite a bit of respect for you, but in this case you are way off base.
I spoke to the gentlemen at Tenor some years back at CES. Very nice people and very respectful. The designer knew who I was and told me precisely what was in the amp.

Its no secret that the amplifier uses a Circlotron in the same manner that we pioneered. There's only so many ways you can do that. We explored them all years ago. We even published the circuit topology in Positive Feedback magazine about 1992, complete with 6C33s (FWIW we were the first manufacturer in the US to use the tube). It is very definately a circuit that we used.
Jonathan, I sense I've touched a nerve, and for that I'm sorry. Ralph's comments speak to the issue I believe. The only point in mentioning this originally had been to give Tenor owners some confidence that Atma-Sphere truly was competent to provide service support on Tenor OTLs should that be needed. Audiogoner Bluedevil had posted about a current need for some help; Ralph extended a helping hand; I offered what I hoped would be some added confidence for Bluedevil or others to follow-up on that offer because Atma-Sphere is clearly, and I think unquestionably, competent to deliver that assistance if needed. I'm delighted to see that Tenor may be coming back with some facility to support owners of their gear; that's marvelous.

It may be apropos to point out that execution of a circuit design (layout, component and materials selection, construction quality, supporting elements such as power supplies) can have more impact on the sonics than often realized. That certainly can be a meaningful differentiator. For example, I own some of Jim White's gear and he's not shy about saying his basic circuit is pretty classic: it's his implementation and execution that make the difference.
The end of "next week" has come and gone since the message was posted on Tenor's web site about being ready to service products (11 days and counting). Does anybody have any updated information? Thanks. Lou
A lot of people have been trying to contact me in the past few weeks and getting more and more frustrated in the process. I apologize if I have been so scarce.

I am available to help all Tenor owners with technical information and support until a further annoucement is made concerning the actual servicing of units.

Once again I apologize for leaving a number of you out in the cold. I've always been very close to the Tenor owners, in particular to the otl owners, and hope we can re-establish lines of communication.

Best regards, Stephane
Stephane, Good 2 hear from you! As an industry peer, & large supporter of Tenor otl products, its great 2 hear that stead-fast & true Tenor owners, now have the ability 2 get valuable real technical information! Those that jumped off the product (many begrudgingly I may add) may now be reading this thread with a tear in their eye! I must say, the many posts I’ve read laying claim that the “come-back” of Tenor was upon us, and than that now famous “we’re back” post on the Tenor website added nothing but further doubt. This is refreshing news! Thanks for the post!

Kevin Tellekamp – Silent Running Audio Inc.

----- Original Message -----
Hi Stephane, thanks for helping me out. The amps are
great. I hope your OTL customers take a deep breathe and
wait for you to get the shop set up.
Important email change: service@cdfaudio.com is now the email address to get service on Tenor Audio products.

Since nobody else will do it, I think I have to clarify certain things concerning Tenor Audio. I've been getting a lot of email and a lot of people are frustrated as there is continuing confusion about the state of the company.

As some people know, Tenor experienced a bankrupcy early last Fall. The company didn't file under bankrupcy protection so the company does not exist anymore as a legal entity. It was disolved and so was the owner's partnership. In this process, the technical team moved on to find a new home. We have joined Coup de Foudre Audio Video in Montreal, cdfaudio.com to create The Design and Service Center. This new venture is not administratively related to the endeavors of the past Tenor ownership.

This is important because it means that at this time, there is no warranty coverage for Tenor products as we are not the owners of the brand name or the intellectual property (even though it resides in our heads).

Please don't write to me asking for unsold amplifiers. It should also be clarified that right now, at this time, cdfaudio has no leftover NIB units for sale. The only assembled ones I know of, anywhere, are one pair of 15Wi's on sale in the classifieds. If you have doubts on the origin of amplifiers you are considering for purchase then I can help.

I'm sorry to be the messenger of this news. I don't think it was mine to do but it did need to be done.

Regards to everyone.
Ah, $20,000, and no warrantee, because the manufacturer vanishes into the night! I'll stick with Atma-sphere, thank you very much!

As stated earlier. Ralph Karsten of Atma-sphere can service Tenor amps, and his company and his Circlotron design have been around for 25 years!