So I bought the Willsenton R-800i

@jbhiller he is in San Jose, CA.

Here is Scott's info: https://scottfrankland.com/

My previous post about my "unbiasable" R800i: https://forum.audiogon.com/posts/2493681

So, in searching for someone who can update my Audio Research LS-5 mkiii, I have also found someone who can take a look at my r800i...Scott Frankland...who came highly recommended by a member here who has an LS-5 and said Scott worked some magic on his unit: https://scottfrankland.com/

I have pinged Skunkie a few times, but she’s not fond of either the weight or the 1000V. So, off to Scott it goes (in January). He’ll be upgrading any resistors and/or caps that need it and giving it a full go through. I’ve also alerted him to the issues Skunkie pointed out with the R8 (which I have currently sitting in as a replacement for the R800i) in case there are any commonalities.

Once I get it back, I’m probably selling the R8. It has upgraded Russian PIO caps...but I’m in a slightly smaller space. If I sell the R8, my Bluesound N130 w/Teddy Pardo LPS, and my Gustard X26 Pro (along with a few Hafler DH500 amps I’ve lost interest in modding), I can upgrade to a used HiFi Rose 150B, which I’ve had my eye on for a bit. I’ll assume the DAC in the 150B is at least comparable to the Gustard. This gets me a better piece of kit to pair with my R800i, which I like better than the R8 (even though I really like the R8). But the R800i makes the ProAcs magical, whereas the R8 is simply great.

I’ll probably pick up one of the newer R8’s at some point down the road, but my urge to get the R800i fixed and upgrade to the 150B basically trumps everything else.

@jbhiller wrote:

"I wonder if the 800 has the same design issue as the R8--Skunkie Designs found that it was missing a resistor on the bias pots.  If the pot wiper gets sticky or otherwise malfunctions, it could let full bias hit the tube and blow it.  

This is giving me incentive to flip my 100lb beast over and open her up to have a look.  I have been lazy. I don't want to lift it and I'm not motivated to find my little tool I use to bleed volts off of the capacitors before poking around."


So, I have an R800i in my office system and I just realized a channel was out. One of the Gold Lion 300B's (right channel) went bad. Put the Willsenton stock 300B's in and went to adjust the bias and...wow...both channels are super high. In fact, the left channel won't go below where the Dolby symbol is. I am assuming that's above 120ma. (I used to be able to adjust them to where the "0" is).

Could this be that pesky resistor/bias pot issue? I've reached out to China HiFi for advice.

Also, has anyone opened one of these up to look at cap upgrades, etc? I'm the kinda person who wants to do everything as long as someone is in there.

Also, I live in a mid-sized city and have no idea if the techs are any good here. Anyone have a reco? Willing to ship the amp.

@smodtactical see my post above.

@jbhiller not sure if my post above addresses any of the issues you were having, but Scott said no bypass caps for the shared power nodes was a big no-no.

I posted this on StereoNet, so I figured I’d post it here too.

My personal R800i blew a 300B tube (Gold Lion) and wouldn’t bias correctly (no matter how far I turned the adjustment down for either channel, it wouldn’t get within the proper range on the blue VU meters). So I sent it off to Scott Frankland.

When Scott got to the amp (he’s very busy) he noticed a few design issues. The biggest was that both channels share plate voltage nodes, but that there are no bypass caps for this. He added 18 "critical" resistors and 4 bypass caps to address this issue.

A smaller issue was that there wasn’t enough filtration to account for all the hum, so we’ve added more.

He also mentioned this was a curious design for audio, but it wasn’t unheard of:

"The Willsenton R800i operates the 805 as a power grid tube, which is allowed for rf transmitting tubes but not often seen in audio amps. This means that the operating point is below the diode line on the plate curves, in the area of positive grid bias. This causes the grid to draw a certain amount of current continuously. It’s a technique in rf that allows the tube to be pushed to deliver more power. Of course, that grid current has to be supplied by the driver stage, which in this case is the 300B. The R800i operates the 300B as a cathode follower direct coupled to the 805 grid. This is certainly unusual in audio, but not unheard of. I recall that the early Wavac amps used this (or a similar technique)."

I also had Scott modify/upgrade the amp. The mods Scott performed were (in addition to the design issues):

• Upgraded caps (VCap ODAM)
• Upgraded resistors to 1% values (from ~3% with stock)

The amp was burned in and then I got a follow-up email from Scott:

"Clearly the Willsenton 300B’s and 805’s were designed to work together, and clearly other brands don’t. I set the bias range to be just below 100mA so that the full range of bias would be available as the tubes age, but I’m concerned that the Gold Lion’s may not bias down with the current adjustment. I recommend that you send me the Gold Lion 300B’s (or have them shipped here) in case a further adjustment is needed."

So, I have had a set of PSVane 300B’s and 805’s shipped to Scott so he can swap those in and see how the bias needs to be adjusted. Right now the amp has the stock Willsenton 300B’s and a set of LinLai 805 DG’s in it (the original Willsenton 805’s were not included with the amp when I bought it from the previous owner).

Perhaps some of this info will help other R800i owners. I like the sound of the R800i enough that I’ve sold my R8 (even though I like the R8). I am hoping these mods deliver the performance and reliability I’m looking for.