Having guarantee issues with KR Audio?

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

Dump it asap.

Planning to buy KR845 tubes??

Nagra VPA was launched in 1999 and has an official frequently asked questions site states that KR 845 tubes no longer comply with the original specifications and therefore no longer supply them with their VPA amplifiers. In 2004 Nagra’s news letter reported trying out KR 845 tubes unfortunately quality issues continue to prevent Nagra from using them. Nine years later, in 2013 being cautious I emailed the dealer in Singapore but I was later referred to Ms Eunice of KR Audio. The subject was my question as to whether the latest KR 845 is suitable for use in Nagra VPA which I own. After a few emails back and forth it was confirmed by Ms Eunice that KR 845 is suitable for Nagra design. With that written commitment and assurance, I bought 4 pieces (2 matched pairs) of KR845 tubes and started using them. In my system, KR 845 sounded excellent as compared to Shuguang 845 and 845B that I use prior to KR 845. Ten months into use (from new) clocking around 500 hours one tube went dead. I wrote to KR Audio immediately reporting about the tube failure. Strangely enough KR Audio responded that their 845 tubes are not suitable for my Nagra VPA which contradicts to Ms Eunice assurance to me prior to my purchase. Some emails went back and forth among the Singapore dealer, Ms Eunice and I. Some days later, I was shocked and frustrated to see two new tubes delivered from KR Audio despite of me informing them against sending. I refused to accept since these tubes are not suitable. Some emails went back and forth again but this time only with the dealer in Singapore where those tubes were purchased. I was adamant that there was no point and risky of me to continue using any of those KR845 since they are not suitable. Fortunately my Nagra VPA survived the tube failure as in the past there were quite some cases of the older series VPA being damaged using KR845 tubes. In my situation, there maybe two issues, quality of the tubes and suitability.

I was helpless and at their mercy, eventually accepted the offer of a refund of about 50% of the purchased price from the Singapore dealer on condition to return the existing four and the two new tubes. I was very unhappy and disappointed as I was deceived into buying those tubes. I was expecting 90% of the purchased price if not a full refund.

Devastated and in need of replacement tubes of good quality. I started searching forums after forums about the much talked about Psvane WE845. I decided to take the risk and bought a set of four. It was blessing in disguise that these WE845 in my system sounded close to the KR845 only costing half the KR price. Some forums suspect the reliability of WE845 but I am prepared to take this calculated risk as I can buy 8 pieces at the same price of four KR tubes.

Please make your own judgement of the above matter and hope more Audiogoners and other readers are aware of my unfortunate experience before throwing your hard earned money. I would not have got into this mess had I read this forum about that many Audiogoners are unhappy about their experiences with KR tubes.