Anybody with RWA Isabellina and JKeny Hiface MK3?

I have a Mk 3 and a hpa what is the question?

I came across the same problem. It would not play with the 20db attenuator in place. But I never even tested it with battery mode. Only did a few test's with ac mode. I contacted John Kenny and he said try a different cable. I was using a radio shack BNC 75ohm. Then I got a Canare Double shielded 75 ohm BNC, but it still did not work with the 20db attenuator. He told me after the cable swap to try a 10 and 6 db together. But I have not tried them.

I have a couple of questions as well since you have a similar set up.

In battery mode did the 20 db attenuator sound better or different?

Do you like the Mk3 hiface does it sound better ? In what ways does it effect the sound? What usb and bnc cables are you using?

I was really exited when I got it and wrote a review to quick. (newbie excitement) My HPA was not fully burned in, which really effects the overall sound. In turn my test and review. Once everything settled in, I actually preferred just using the usb cable the hpa came with, without the mk3. It had a better placement of instruments and more relaxed detailed sound. With the MK3 in the signal chain the sound-field was better, but it became veiled and the bass was way to boomy and over emphasized. Using the denon 7000. It was a little better with the Canare bnc but I was disappointed. I did not want to cut my losses and I invested in a kimber select 2020 bnc and wywire usb. My first impression was what is wrong with you! Spending this much money in hopes to fix something, that by itself had a inferior sound. Now you have a REALLY EXPENSIVE dust collector. After very little burn in the sound has completely transformed. The bass is extremely defined and textured, in comparison to any other set up with the hpa. With or without the mk3. It has more detail and the best placement and that deeper wider sound field I liked. The cables have a long way to burn in. So I will wait this time to do a review. But I am now impressed with this setup.

Please let me know your experience.

Thanks for letting me know about your expieriences. I will try the 20 db attenuator in battery mode. Keep me posted about the 15 attenuator or the cable swap. For me the cables made a huge difference in details, clarity, and definition when using the Mk3.

I got the Kimber select 2020 a couple of days before the usb cable. But the BNC cable definitely makes a huge difference. It was getting better each day. At first I was not impressed at all. This cable really needs burn in, they recommend 150 hrs. Others have commented that it needs a lot of burn in. From what I here silver in general takes longer. I am a STRONG believer in cables and burn in. At least with "most" of my gear. When I put in the wywire usb cable I did notice a change in sonics. But it was harder to pinpoint. The next day I noticed a big upgrade in sound. However when I was going to a/b and better isolate the changes with each cable to evaluate, my hpa stopped working. On a side note Vinnie at RED WINE AUDIO is awesome. He was extremely helpful in trouble shooting with me. I sent it to him and he fixed the problem immediately and shipped it the next day They really have EXCELLENT customer service. I should get it monday. Then I can resume my burn in and evaluations of each cable . Even if they don't  change  anymore, it sounds much, much, MUCH, better then my old cable's. Well I can say this for certain with the Kimber 2020. But they both don't really have that much time burning, only a few hours. Because the battery's on the mk3 need to be recharged. Which really slows the burn in process. I am excited to try the attenuator on the battery mode as well. Any sound improvement is appreciated.  I'll keep you posted!

What tube are you using?

I should get my HPA back today hopefully. I will try it then.

I have only personally used three different cables. A radio shack 75 ohm, a dual shielded canare and a kimber select 2020. Which were all Bnc to bnc connections. There were only slight differences between the $ 10 radio shack and $40 dollar Canare. But definitely an audible difference. Using the Denons 7000, I preferred the Canare and the radio shack with the seinnhesier 280hd pros. The radio shack had more bass but was WAY to boomy and drowned the mids on the denons. The Canare had tighter bass. But  both cables  lacked detail and sounded very veiled. Thats why I liked  going straight usb vs the Mk3. Both cables are made of regular copper, not ofc or occ. I decided to not give up on the Mk3 because of all the reviews about it and read it needed the best BNC cable to see it's true potential. So I did a lot of research and I was going to get the stereovx Ultra which had a lot of great reviews and was praised for detail retrieval. Then at the last minute I read on audigon a cable for sale praising the kimber 2020 and it was amazing in comparison to the stereovox ultra. It is VERY expensive but he choose it anyways based on it's sound. I decided to get the bnc connection as I read that the adapters effect the sound and rca is not truly 75 ohm. The kimber cable is made of a high purity silver. It did not sound any better after I hooked it up but after a few hours of burn in it started sounding a lot better. The bass is very tight and has a lot of definition, there is a LOT more detail and the vail was lifted. The first two cables were subtle but enough to make me see the benefit of a great cable. The Kimber puts these two cables to shame! Im glad I could invest in it. It really comes down to ones budget to determine the value. But not all cables are created equal. I read the black cat velocie is a good value with good sound. If budget is a concern. On a side note what tube are you using?

Yes I use a dario Miniwatt tube. It sounds better in every way over the JJ. The soundstage is the biggest improvement. The sound is much wider and deeper with better instrument separation. The mids, highs and bass are better defined as well. I have a 1950's Siemen  CCa tube coming soon. 

Just tried the 20 db attenuator it works with battery mode and A/c mode. I guess different cables effect more than just the sound. They effect the signal strength as well. The Kimber 2020 lets everything through. The radio shack and Canare do not. I am going to let the cables  burn in before I comment regarding the sound.