Having guarantee issues with KR Audio?

I had very poor experiences with KR. I had an older KR Enterprise amp that kept burning through 842 VHD tubes (I think that was the name). The tubes died a number of times and I had to replace with no recourse from KR. The amps sound nice, but it's clear that KR wants nothing to do with customers who have issues with their tubes.

I believe their new amps are better designed than the older KR Enterprise stuff.

Sounds like a shady bunch . Thanks for the warning .

Shady bunch is being kind. Stay away and you will be the wiser for it.

I am the US importer for KR. It is hard to know where to begin.

[1] KR Enterprise has been out of business for years. No printed documentation exists about these amplifiers, other than what we have recreated here in the US.

[2] No new 300B balloons have been imported into the US since July 2008.

[3] KR has had issues with dealers selling out of warranty tubes as new. As importer, when these tubes fail, the most I can do is offer new tubes at my cost, because I never received any money for the tubes in the first place.

[4] There were a bad batch of tubes that came through Coincident when I first started, but these were more than two years past the manufacture date at the time they hit customer hands, so these should have been marketed as NOS unwarranted by factory.

[5] The KR 845 does have sensitivity to heater voltage. As the tube heater draws substantially less current than a carbon plate 845, unregulated heater supplies will go to almost double the rated heater voltage. This is a recipe for tube failure. We screen all 845 sales to avoid this issue. Further, we have driven some design mods into KR 845 tubes and KR has renamed them 845M. Their reliability is now world class.

[6] It sounds like there is a lot of concern about the tubes. If you find a KR tube for sale, get the serial number off the crown of the tube, the tube type, and the vendor. Email that info to: tubehist@renaissanceaudio.com with KR Question in the subject field. We will let you know if the tube is legit, black market, or NOS and if the vendor is known legit within 48 hours of the receipt of the email.

[7] Lastly, unless you purchase tubes from me directly, please send in your warranty registration card, with a copy of the the purchase receipt within 30 days of purchase of the tubes. This is required to get warranty service on the tubes.

Unfortunately, by the time that we joined this party in 2008, a lot of damage was done by some importers/dealers with less than scrupulous intentions. This really was out of KR's control because the firms servicing the US and Canada are not owned or directly controlled by KR in Prague.

Since late 2009, we have bi-weekly quality meetings with KR in Prague to advance quality and reliability. The Mark II amplifiers were designed here in the USA and are assembled here in Michigan with the best and most reliable parts we can find.

Lastly, if you have an issue with a KR tube or amplifier, please email me at tubehist@renaissanceaudio.com.

We are trying to clean up the chaos, but trust is easy to lose and takes forever to rebuild.

All the KR 300Bs Coincident received were purchased directly from Eunice Kron in her capacity as owner of KR. From the time or order and prepayment, which was demanded, delivery would take a minimum of 60 days and at times, 120 days. Mrs. Kron stated that all our orders had to be manufactured , therefore the delay. At no time was there any mention that the tubes were anything but current manufacture and up to the latest spec. Coincident ordered and received KR 300Bs on at least four occasions spanning a two year period. On one occasion, delivery after prepayment of the order took 6 months to be delivered.

I took this issue and the reliability problems up with Mrs. Kron when we had dinner at CES 2009. During our meeting she admitted to delays in deliveries and quality control problems which she attributed to the turnover in staff from the very experienced previous workers to new employees who had little or no tube manufacturing expertise. She also admitted to serious financial difficulties and offered to sell the tube manufacturing business to me.

The reliability problems were not solved during the entire time Coincident purchased KR tubes. Mrs. Kron, when sent the defective 300Bs simply refused to replace them or offer a refund, rather stating," if they failed, the tubes must have been used incorrectly". In other words, we offer a warranty, unless the tubes fail.

Coincident has since switched to recommending the Black Bottle Treasury 300Bs, which have in over two years of use in the field , not suffered a single failure and they sound superb.

Israel Blume- Pres.
Coincident Speaker Technology