Willsenton R-800i Owners & Discussion Thread

[Karma Chameleon]

On 11/02/2023 at 11:04 PM, Karma Chameleon said:

Hi All,

I first had the R800i 805 and loved it.

Then I got the R800i 211 and found it amazing.

Lot of tube rolling. The usual and at the end loved the Melz on the 6SL7 and the Mazda Silver plate on the 12AX7 stage. The 300B is Tronal.

 

Then I got the GE 838, which was wonderful and sounded that much better. Better dynamic, etc.

I also got the GE and RCA 211. Both again  utterly wonderful. Similarly the sound is that much more dynamic, wider soundstage and less noise....

 

I next biamped the two amp to the Tannoy Canterbury, the 211 to the tweeter and the 838 to the woofer. All was wonderful, balancing the sound is a bit of a drag....But then the NOS tubes began to act up (838 and the 211). One of the 838 started to flutter a lot, similarly both the 211 flutters in some difficult orchestral pieces.....So the short of this is that the stock tubes are back in for the power tube, and all is well.

 

Possibly the NOS (Which was pricy) is not electrically suitable.....

I needed to clear up one error on my part. The flutter with the 211 NOS tube was not necessary due to the the power tube, the culprit was the 12AX7.  I was using a JJ 12AX7tube, when I changed this, the flutter went away...

 

[Syncrodelic]

Has anyone done any mods to their R800i? I mean other than tube rolling. Things involving solder.

 

Capacitor changes? Resistors? Interested to see what improvements can be had from simple or complex mods.

[atlvalet]

On 10/03/2023 at 8:57 PM, Syncrodelic said:

Has anyone done any mods to their R800i? I mean other than tube rolling. Things involving solder.

 

Capacitor changes? Resistors? Interested to see what improvements can be had from simple or complex mods.

 

I just have.

Sent my amp to Scott Frankland (https://scottfrankland.com/) to give it a lookover since I had a 300B tube blow and it wouldn't bias properly. For any unfamiliar with Scott, he's the "F" in the old MFA preamps including the Luminescense and the Reference , both of which have cult-like status with some. In short, he's a very experienced circuit designer/tech.

He is upgrading the caps to VCap ODAMs and we switched out a bunch of resistors.

He also saw there was a design issue...there are no bypass caps on the plate voltage nodes near the tubes. Scott said since the two channels share the same nodes, it’s especially important that these nodes are bypassed.

I'll be detailing all of the work he did and my listening impressions when I get it back (hopefully next week).

It will be replacing my R8 with Russian PIO caps that is driving my ProAc Response 1SC's. I like the R8, but can't fit two tube amps in my office

Edited May 14, 2024 by atlvalet

[xlr8or]

On 15/05/2024 at 4:59 AM, atlvalet said:

 

I just have.

Sent my amp to Scott Frankland (https://scottfrankland.com/) to give it a lookover since I had a 300B tube blow and it wouldn't bias properly. For any unfamiliar with Scott, he's the "F" in the old MFA preamps including the Luminescense and the Reference , both of which have cult-like status with some. In short, he's a very experienced circuit designer/tech.

He is upgrading the caps to VCap ODAMs and we switched out a bunch of resistors.

He also saw there was a design issue...there are no bypass caps on the plate voltage nodes near the tubes. Scott said since the two channels share the same nodes, it’s especially important that these nodes are bypassed.

I'll be detailing all of the work he did and my listening impressions when I get it back (hopefully next week).

It will be replacing my R8 with Russian PIO caps that is driving my ProAc Response 1SC's. I like the R8, but can't fit two tube amps in my office

 

Scott is a legend! He helped me tweak the power supply unit for my MFA Magus A2 shown below.

 

@Sir Triode

 

Edited May 18, 2024 by xlr8or

[atlvalet]

Yeah. He came highly recommended, and that's before I realized/learned who he was.

I knew he'd be able to see/address any shortcomings. And I had heard nothing about the plate voltage nodes...which should now be a thing people know about with the R800i.

 

Thanks Scott

[ChMaiwald]

On 14/05/2024 at 8:59 PM, atlvalet said:

He also saw there was a design issue...there are no bypass caps on the plate voltage nodes near the tubes. Scott said since the two channels share the same nodes, it’s especially important that these nodes are bypassed.

I'll be detailing all of the work he did and my listening impressions when I get it back (hopefully next week).

 

Oh no, I was hoping that the R800 was better designed. I have no understanding whatsoever of all things electrical etc. so I hope this is not as serious as the flaws found in the R8.

 

And I'm curious how the changes affect the sound quality.

 

I have a skilled electrician at hand here and might consider neccessary changes and upgrades.

[atlvalet]

On 19/05/2024 at 12:13 PM, ChMaiwald said:

 

Oh no, I was hoping that the R800 was better designed. I have no understanding whatsoever of all things electrical etc. so I hope this is not as serious as the flaws found in the R8.

 

And I'm curious how the changes affect the sound quality.

 

I have a skilled electrician at hand here and might consider neccessary changes and upgrades.

 

To be clear, I don't think the R800i is poorly designed. But I do think with these lower pricepoints that Chinese gear commands, some shortcuts are taken (even though there's a lot of things done right).

The two design issues that Scott saw and fixed were:

• The lack of bypass caps on the shared plate voltage nodes (major)

• Lack of enough filtration for hum (minor)

The mods Scott performed were (in addition to the design issues):

• Upgraded caps (VCap ODAM)

• Upgraded resistors to 1% values (from ~3% with stock)
• Lowered bias so it was within range to be adjusted (had wandered out of spec)

 

I think I'll get it back by the end of this week. I'll take off the bottom to show his work. I had already liked it more than my R8 (which I still really like), and preferred the sound of the R800i with my ProAc Response 1SC's.

Edited May 23, 2024 by atlvalet

[atlvalet]

Received my R800i back from Scott Frankland.

I have attached pics along with Scott's comments:

"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)."

He added 18 "critical" resistors and 4 bypass caps to address this issue along with adding the VCap ODAM coupling caps.

[ChMaiwald]

Thanks @atlvalet, that is very interesting! I'm not sure if I could go to someone here to have the same done (there's a barrier, two actually. Me actually understanding what the changes do and then, being in a foreign country, a language barrier), but I'm soaking up all the information. Do you notice any noteworty change to the sound?

 

A few days ago I installed new Western Electric 300Bs and so far I'm very pleased with the result. Great stage and depth. Warmth – I don't know yet. I guess they have to settle in a bit more.

[atlvalet]

2 hours ago, ChMaiwald said:

Thanks @atlvalet, that is very interesting! I'm not sure if I could go to someone here to have the same done (there's a barrier, two actually. Me actually understanding what the changes do and then, being in a foreign country, a language barrier), but I'm soaking up all the information. Do you notice any noteworty change to the sound?

 

A few days ago I installed new Western Electric 300Bs and so far I'm very pleased with the result. Great stage and depth. Warmth – I don't know yet. I guess they have to settle in a bit more.

From what I understand (and granted, that's very little lol) since the two channels share the same power nodes, there needed to be bypass caps between them with a resistor network to prevent "bad" things from happening. I could go back and ask Scott for more details on this.

As for the sound, I had Scott add the VCap ODAMs and better 1% resistors in the signal path. The Cossor 300B's I bought off AliExpress weren't matched great (I'm glad I have someone like Scott to check them) so I'm sending them back to get exchanged. They did come in a fancy box, so I'm guessing these are factory "rejects." The 805 Cossor tubes I received matched fine, but one had a slight blemish on the black coating inside the tube and the other had a slight smearing of the Cossor logo.

Long story short, right now there are just the Willsenton 300B tubes in there. The amp sounded really good before (I liked it better than my R8...which I really liked), and now there's even more detail/crispness. To be fair, the R800i was already kind of a magical match with my ProAc Response 1SC's...the system has more "magic" than my main system...and the main system has all sorts of fancy-ish stuff. The other tubes are the aforementioned Cossor black bottle 805's, some PSVane globe bottle 6SN7's, a fancy NOS Mullard 12AX7, and a NOS Svetlana 5U4G rectifier.

The cost to fix everything wasn't cheap...I thought it would be around $1,000 for everything, but it was close to twice that (granted, shipping was $300 to $400 of that). I told myself that the work was worth it since I decided the Willsenton was a keeper amp. Of course, I'm sure in a few years there will be some other "must have" SET amp...but this will be enough for my office system...except I want to upgrade my Bluesound N130 node to that new Auralic S1 Vega lol.

[LO-RAN]

A lifelong friend just bought an R800i that he had shipped to my home so I could give it a try. It has the 805 tube option. It was magic. We felt it had so much ease and flow that it made the music sound more human. 
 

a couple of small gripes: The blue meter LEDs obscure the meter movement more than illuminating them. An amber LED would do nicely. The other is the limited range on the volume control. I have speakers that have a 93dB sensitivity and can’t get past 9 o’clock on the volume knob. Did I mention the weight of it?

[Mopardave]

On 22/07/2024 at 7:25 PM, atlvalet said:

Received my R800i back from Scott Frankland.

I have attached pics along with Scott's comments:

"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)."

He added 18 "critical" resistors and 4 bypass caps to address this issue along with adding the VCap ODAM coupling caps.

Thanks for posting that about the R800i.  I am currently looking to order one soon.  Can you post the part numbers and values on the resistors and caps?   I may want to perform this mod if i buy this unit.  Thank you

[atlvalet]

On 21/12/2024 at 10:19 AM, Mopardave said:

Thanks for posting that about the R800i.  I am currently looking to order one soon.  Can you post the part numbers and values on the resistors and caps?   I may want to perform this mod if i buy this unit.  Thank you

Unfortunately I don't have the part numbers since Scott did the work...just what's in the pictures.

He also added more capacitance to adequately deal with the hum (which wasn't audible to me).

[Mopardave]

On 22/12/2024 at 5:12 PM, atlvalet said:

Unfortunately I don't have the part numbers since Scott did the work...just what's in the pictures.

He also added more capacitance to adequately deal with the hum (which wasn't audible to me).

ok, no problem. Just thought you might have a receipt from the work done with part numbers.    Thanks

[Mopardave]

Just now, Mopardave said:

ok, no problem. Just thought you might have a receipt from the work done with part numbers.    Thanks

How is the amp now doing?   Still like it?

[Victore]

Hi guys! I have been a fan of the r800i/845 amplifier for 2 years now. I want to tell you about the problems I encountered after the purchase, as well as the upgrades I made. Unfortunately, I did not save the photo inside the amplifier, as I did the work more than a year ago, and the moderators of the site restrict access to users from Russia. This post will be useful to anyone who is thinking about buying this amplifier. You should be aware of all the risks and problems that you may have after purchasing this amplifier. As I said, 2 years ago I ordered this amplifier and it was delivered to me fully functional. I connected the amplifier to my Spendor s9e and it worked well. However, after a while, I started noticing that I get noise in some musical compositions, especially when the singer hits high notes, I get clipping. Perhaps someone has encountered this problem. This only happened when I turned the volume knob above 10:30.

[Victore]

I'm not going to tell you how much effort it took me to figure out why I get wheezing on high notes at that volume. If we read the user manual of the amplifier, we will see that the sensitivity at the input is 0.3V, and modern signal sources such as CDs and DACs have 1-3v output! The first 12ax7 tube amplifies the signal to 30v, the second tube operates in such a mode that it cannot receive a signal with an amplitude of 30v and simply cuts it off. This leads to distortion. I just want you to know that high power is not guaranteed with a source above 0.3V. This applies not only to Willsenton, but also to Line Magnetic. In addition, when I was exploring the possibility of solving this problem, I found that the amplifier circuit that uses the 805 tube has a better design and the 300B works in a better mode than the 845 design,  300b should amplify the signal by a factor of 3. It only does 1.8! I don't have an answer to the question of why engineers from China allow such a design into production.

Edited February 4 by Victore

[Victore]

I must say right away that I contacted China-hi-fi to get a solution to the problem, and after 2 requests, I did not receive any more feedback. Generally. That's why I don't recommend this store anymore. They refuse to solve the problem and do not provide a service manual. I am not an expert, and most of the work with my amplifier was done by engineers with extensive experience, but I did many things myself. I am not at liberty to discuss the design of the amplifier, but I will only describe the solution to the problem that I found for my amplifier. I used the Triode 300B design, completely removing 12ax7. I only left 6sn7. A similar design uses the Sun Audio 300b, you can use it, these designs are very similar, the only difference is in the capacitors in the cathodes. Now my amp doesn't have NFB. There are no 2 caps that affect the sound. It sounds very good! There is no more clipping (wheezing). I should add that some of the caps were not in the amplifier, although the picture was also in the photo, they also had to dismantle the boards and install new caps.

[Victore]

I got the absence of 1 amplification stage, the absence of a cap affecting the sound and an inverted output signal. Now, for proper connection, you need to swap the plus and minus wires on the speakers (or on the amplifier). I also changed all the resistors to Kiwame, all the capacitors to the best I could find, including the Black Gate in the cathodes. If you want to change the Willsenton caps, then I recommend changing them only to the most expensive ones, I didn't really like the result of replacing them with Mundorf supreme silver/gold. It didn't sound any better to my taste. Willsenton makes very good caps.

[Victore]

I use Linlai e-6sn7 and RCA 6sn7 tubes, I think they are amazing! The first ones are very rich in sound, very high quality. RCA is more detailed and I like them more when I listen to concerts, when I want to feel the space around me more. I still couldn't choose. I hope this information will help someone. I also do not urge you to change anything in your amplifier, but if you want to do it, then contact our specialists. The Willsenton r800i is a very difficult beginner amplifier. If you are thinking of buying the 845 version for an upgrade and are confident in your abilities, then take the 805 version and redo it into the 845, it is not so difficult for an engineer. As I said, the 300B is working in the correct mode in the 805 version (Different load resistors). The difference in the cost of the amplifiers will help you avoid losing money on the purchase of 845 tubes of the best quality. 300b tubes will be the last thing I will change. The 300b Willsenton tubes are not so bad. I really hope that my information will be useful.

[Victore]

I use a translator, I ask for understanding if you see any errors. Thanks!

[muon*]

6 hours ago, Victore said:

I use a translator, I ask for understanding if you see any errors. Thanks!

It reads as being understandable to me.

 

All good.

[dbpgh]

Hello, new to the forum and relatively new to hifi (eh mid-fi).  But let's go!

 

I recently purchased the R800i 450 version.

 

My speakers are

 

vintage JBL L96 (89 dB)

Magnepan 1.7i (86 dB)

 

I received the R800i and she's a true beauty.  But, the sound doesn't yet have me doing backflips at all like it does for many others.

 

Stock tubes.  I fully acknowledge I'm about 1 hour into burn in.   But I have some fundamental questions.

 

The base feels really weak.  And with the Magnepan's especially when I turn the volume up past like 30% there is extreme distortion (guessing the 845s can't drive them well?)

 

Given my speakers, well maybe I made a mistake.  They're both pretty low efficiency yes?  Maybe the 805 would have been a better choice?

 

My source so far is a Cambridge Audio CXN100 streamer and Qobuz.  Vinyl via a Fluance RT85 hooking up tonight.  Not the greatest equipment, but it's what I'm working with :).

 

I'm strongly considering the Wharfdale Super Lintons which are higher efficiency (91db I believe).  Any thoughts on that pairing with the R800i 845s?

 

Can anyone comment on the 845 vs 805 for alt rock, acoustic, modern music listening?  I read the 845 should be smoother and better with vocals.  But not good at low efficiency speakers.  But I read that a bit late .   

 

If the Super Lintons should make the 845 sing then that will be my preferred path vs exchanging for the 805.  But maybe the 805 is better for me so I can use it across all 3 of those speakers.   I'm a bit stumped.

 

Thanks for reading!

 

[Victore]

37 minutes ago, dbpgh said:

Hello, new to the forum and relatively new to hifi (eh mid-fi).  But let's go!

 

I recently purchased the R800i 450 version.

 

My speakers are

 

vintage JBL L96 (89 dB)

Magnepan 1.7i (86 dB)

 

I received the R800i and she's a true beauty.  But, the sound doesn't yet have me doing backflips at all like it does for many others.

 

Stock tubes.  I fully acknowledge I'm about 1 hour into burn in.   But I have some fundamental questions.

 

The base feels really weak.  And with the Magnepan's especially when I turn the volume up past like 30% there is extreme distortion (guessing the 845s can't drive them well?)

 

Given my speakers, well maybe I made a mistake.  They're both pretty low efficiency yes?  Maybe the 805 would have been a better choice?

 

My source so far is a Cambridge Audio CXN100 streamer and Qobuz.  Vinyl via a Fluance RT85 hooking up tonight.  Not the greatest equipment, but it's what I'm working with :).

 

I'm strongly considering the Wharfdale Super Lintons which are higher efficiency (91db I believe).  Any thoughts on that pairing with the R800i 845s?

 

Can anyone comment on the 845 vs 805 for alt rock, acoustic, modern music listening?  I read the 845 should be smoother and better with vocals.  But not good at low efficiency speakers.  But I read that a bit late .   

 

If the Super Lintons should make the 845 sing then that will be my preferred path vs exchanging for the 805.  But maybe the 805 is better for me so I can use it across all 3 of those speakers.   I'm a bit stumped.

 

Thanks for reading!

 

Hi! As I wrote earlier, the problem is not with the power of the amplifier, but with its incorrect design. Modern DACs don't need the first input tube. It creates excessive gain, and I think this will distort the signal even before it is received by the 845/805 tube. If you buy an 805, you'll probably get the same thing. The design of the 805 is more correct, in particular, the work of the 300b is better organized, but they have identical 12ax7/6sn7 cascades and clipping by 30%. In fact, there are only 2 ways to solve the clipping problem. 1. Remove the first tube, replace the 300b load resistor with a 5K resistor. 2. Find speakers with maximum QMS. If you remember, there were times when speakers were powered by a 1W amplifier. This is not exactly the same as high sensitivity, but it is high QMS and coherent speaker performance. Only the new Spendor/Harbeth/ATC (and some other speakers) are able to work like this and only after 10-100 hours of work.

[dbpgh]

11 minutes ago, Victore said:

Hi! As I wrote earlier, the problem is not with the power of the amplifier, but with its incorrect design. Modern DACs don't need the first input tube. It creates excessive gain, and I think this will distort the signal even before it is received by the 845/805 tube. If you buy an 805, you'll probably get the same thing. The design of the 805 is more correct, in particular, the work of the 300b is better organized, but they have identical 12ax7/6sn7 cascades and clipping by 30%. In fact, there are only 2 ways to solve the clipping problem. 1. Remove the first tube, replace the 300b load resistor with a 5K resistor. 2. Find speakers with maximum QMS. If you remember, there were times when speakers were powered by a 1W amplifier. This is not exactly the same as high sensitivity, but it is high QMS and coherent speaker performance. Only the new Spendor/Harbeth/ATC (and some other speakers) are able to work like this and only after 10-100 hours of work.

 

Ok thanks.  Disappointing to hear that as it does seem like a lot of people are having a good experience with this amp. Will try with vinyl and vintage CD sources to see if I have better luck.