Thanks for sharing as I have been considering of getting one but have yet to decide. Do you own one and if so, what do you have? Any recommendations which one should I get? I guess I would be testing on mostly 6SN7GT, 6SL7GT, 12AX7, 12AU7 and perhaps KT88, EL34 in the future. TIA!!!
I don’t, I am using the tubes that came with my gear, haven’t summoned the courage to play with them yet and this horror story is not helping! If I do start rolling tubes I will probably just check them with a multimeter…
This blown unit is probably just a one off, as I have changed over 4 lots of different KT88 and EL 34 power tubes since I got my R8, also swapped all the pre amp tubes twice -not had an issue.
LOL...I have just bought my first tube amp about 4-5 months ago but have already been rolling tubes from day 1. It is not that scary as long as we take precaution steps like testing with a multimeter for short before first use. BTW, also always check on the interior of the tube on loose parts. I have two tubes with a small piece of broken off mica but are safe to use since mica is not a conductor, just make sure there are no loose metal piece. If you dont roll tubes, you are missing out the fun...
I'm very glad you heard back from them and glad you got it working. I have never had a bad tube take out a component like that so guess I have been lucky. I remember reading another post (possibly on another forum) with one other R8 owner who let the magic smoke out. In that particular case there was a bad board involved and CHA sent the owner a new board to replace it. As someone who enjoys working on my own gear and not shipping my amps around the country or world I really like this approach. I'm hoping to purchase an R8 in the near future...just need to figure out what phono stage I will be purchasing to go along with it!
Right and that’s all you need, just the continuity function. I would not trust the cheaper ones to give very accurate measurements but any of them that have the continuity function should be just fine.
Posted this same information on the StereoNet (Aussie) website. So… I got my R8 back from the shop a few weeks ago, I updated the 4 stocks capacitors for Milfex’s. Right off the bat I noticed an improvement on the high frequency (extension and air). Also, felt more sweetness on the Mids. So far, I haven’t discerned any improvement or impact on the low frequencies, don’t know if the capacitors need more time running. Sorry that I’m not a very descriptive guy, but I will recommend this mod to anyone interested, and I would have never done it without the courage of the folks in this website. BTW. When I picked up the R8, I was greeted by the owner of the shop and complemented me on the amp. The rest of the techs were also very impressed, and the R8 was the talk of the day when they first opened it. They asking me about my decision making and selection of the amp, and I told them about the StereoNet website (main reason I was convinced), and a couple a good YouTubes videos from individuals that I trust. I'm really happy to have the amp back! Peace, Tony
I have just found this tester on Ebay, it seems very easy to operate and compact in size. Thought I would share it here if anyone is interested. Please note that I dont know how well this tester works, I guess I will find out in about 2 weeks time. By the look, I think it has no indicator for short testing, so you would still need a multimeter to check before putting the tube on this tester. New Dummy Tube Tester | eBay
This looks very cool! I wish it would do power tubes as well, but I realize that is asking a lot for such a compact package.
It will measure the current on individual plate when bias to the required grid voltage. There is an operating instruction in the description. How accurate it is, I have no idea. I intend to use two brand new new production EH 6SN7GT as a reference point.
Has anyone thought about getting an acrylic cover for their R8? My regular supplier wants $390 for one, and I found a better deal at another place but they want a minimum quantity of ten. Ideas? Edit: These are some I had made. I really need one for the R8 because I'm using a pillowcase now and somehow it's just not working aesthetically.
Update on the tube tester. Speechless...it is of high quality; great workmanship!!! I can see that the seller is a perfectionist. It is made like a luxury brand gift box Everything is great except one thing that could be better. It is the top panel, a bit flimsy when putting on or removing tubes. It works very well; have compared with couple of tubes, which bought recently, with readings from other sellers. They are super close, within 1-3%!!! Amazing as those tube vendors are using professional or military testers. Highly recommended!!!
Yesterday out of boredom I decided to give my old Bic RTR speakers a go with the R8 and to my amazement, they sound very good with the R8 and much better than the Elac Carina towers that cost 7 times more than the Bic's. I guess it is that synergy thing. The Bic's are 8 ohm 95dB efficient and I guess that's why they pair better with the tube amp.
Howdy all. I just received a second hand R8 yesterday. This particular unit was purchased in December 2020 and the previous owner estimated it had about 200 hours on it. It has the stock Willsenton tubes (EL34 version) except for the 6SL7 which are current production Tung Sol. It sounds fine but I'm withholding my opinion until I do some tube rolling. Either the previous owner or the factory had the tubes biased SUPER hot. Like 72-75mA hot. When I set it up in the afternoon I didn't notice, but V4 was actually red plating. I was using my old Weber Bias Rite tool to measure the plate voltage and bias current. I'm concerned about the accuracy of the bias meter but am reserving judgment until I can get a matched quad in there. I have read that the factory EL34s are very often not matched. For now I have biased them all so that the meter reads dead center. On the right channel that ended up being about 40-43mA. I need to test the left channel again but in dead center for left channel the difference in amperage was fairly different. Like 36 & 42 if I recall correctly. I plan to do some tube rolling in the very near future and am looking forward to the experience. This thread and the stereonet thread have been very helpful so far.
The EL34's are properly biased at about 40mA. To achieve that on my R8, the needle on the R8 meter sits at the very right edge of the letter "S" of "Bias" on the R8 meter. On my R8 and at least one other user, when the needle is in the center on the R8, the bias current is about 28mA which is under biased causing a degradation in sound quality.
