Willsenton R8 Owners & Discussion Thread

[echorec]

51 minutes ago, Candan said:

Thanks a ton Echorec!  Very helpful info to get me started.  Just the answers I needed!  

 

Once I get the amp (still about 30 days away I guess) I'll report my findings from stock after a hundred hours of burn in or so.  Then I'll look to start rolling the 6SL7s.  

 

It is interesting that when I look at the China Hifi site where I bought it, it's suggesting the purchase upgrades on the preamp side are the 6SN7s upgrades, and keeps the Willsenton 6SL7s.  Which about-faces what you and just about everyone else is saying LOL.   Yong Lee at China Hifi emailed me to say to switch the 6SN7s, but also admitted "he thinks"    

 

Looking forward to hear your experiences!

 

You'll definitely want to keep your expectations in check when it comes to preamp rolling. The differences between even the 6SL7s are going to be fairly subtle to many ears; mostly small refinements in top end, midrange, or separation. For me, anyway, it requires deep listening. Personally, I've found it is better to listen to one tube for a week or two before switching it to another. My memory of the previous tube's sound seemed to last longer this way and the differences were much clearer at the swap. Also, many tube's sound can change subtly over that first week, so best to just leave them in and enjoy them for at least a week before you swap.

 

Also, where you will notice bigger changes is when you switch between the two power tube classes. If you are getting the KT88s, definitely buy a quad of EL34 so you know what they sound like in this amp, and vice versa. I thought I was a KT88 kind of guy until I tried EL34. I did not expect that. And I'm sure there are some EL34 people that could prefer the KT88. All preference, of course, but you won't know unless you try.

 

More important - Have fun with it! Rolling tubes in this amp has kept me happy during the pandemic. That, in itself, is worth the money.

[2Dculture]

2 hours ago, Candan said:

For the 6SN7 in the V5 middle front position.  Preamp Power supply filtering tube.  Some say it doesn't need to be rolled, others say it's the most important.  Which is it?

 

 

Welcome! I'm sure we take full responsibility for your choice=)

 

I hear you and I got confused too. Not too long ago I came across the Prima Luna website on tube rolling and website said that the gain preamp tubes have more effect than the driver preamp tubes. https://www.primaluna-usa.com/tube-rolling

 

Anyway.. I changed it as part of a set from China Hifi. Maybe I should try rolling the middle tube. Previously I always rolled all. 

 

Do try it.. if it works for you. Why not?

 

Edited December 4, 2020 by 2Dculture

[2Dculture]

New Thomas video but no discussion on tubes. Maybe its not coming.  

 

 

 

 

[08Boss302]

Thought I'd post up the numerous reviews of this amp in here too. 

It can serve as a good reference for anyone choosing between this and the other talked about and  regarded Tube Amps ...

 

 

 

 

 

 

 

 

 

[xlr8or]

I might chime in here and share my experiences on tube rolling power toobs over 12 years now. If in triode mode look no further than EL34's. In UL mode, it's a neck to neck contest between 6550's and KT88's. The 6550's win hands down when it comes to fullness. The KT88 is more extended and vertical in tonal character. As Thomas mentions, once the 3 hole grey perforated plate Tung-Sol 6550's from the 1960's go in there you're in heaven. His quad set is from 1968. There are variants to this vintage 6550 tube including black solid plates with 4 revisions all with different getter configurations, solid grey plates and then the 3-hole perforated plates. These sound nothing like Russian or Chinese tubes.

 

Now something separate to share. The realm of going backwards with tube rolling to get more bass slam is restricted as this is primarily controlled by the design of the circuit topology. I would seriously get the R8 if this feature is inherent in the tonal character of the circuit design by default. You can always work forward with tube rolling and fine tune it if it's too overwhelming to start with.

Edited December 6, 2020 by xlr8or

[Candan]

Just pulled the trigger on a quad of Mullard EL34 tubes and a pair of Brimar CV1985 6SL7s.   

 

Guess I'm now on double burn-in duty.

 

Wishing I'd paid for faster shipping now 

[echorec]

10 hours ago, xlr8or said:

If in triode mode look no further than EL34's. In UL mode, it's a neck to neck contest between 6550's and KT88's. The 6550's win hands down when it comes to fullness. The KT88 is more extended and vertical in tonal character.

 

While I'm not using NOS power tubes (yet!), I've found the same to be true with new production power tubes in the R8 - EL34 = Triode Wins. KT88 = UL Wins.

 

Definitely keen on getting a quartet of NOS power tubes for my collection. Just waiting for the right one to pop up...

 

40 minutes ago, Candan said:

Just pulled the trigger on a quad of Mullard EL34 tubes and a pair of Brimar CV1985 6SL7s.  

 

Nice! Russian "Mullards"?

 

I bought a couple more new production quartets to try in the R8 - Both Russian "Tung Sol" 6550s and "Mullard" EL34s. I've been using the Russian "Mullards" for a few days. I think they sound good and are very balanced in the R8. Compared to the TS EL34B, they are more more neutral sounding, with a tad smaller soundstage. They don't have the richness in midrange that the EL34Bs have, but will match better with a wider range of speakers, IMO (EL34Bs really pair better with metal dome tweeters due to their darker highs in this circuit). While these are nothing like real Mullards, I was honestly surprised at how good they sound. For the R8, I think they are a great starter tube because of their more neutral character in this circuit. Very affordable too.

 

The 6550s should be here next week.

[Candan]

22 minutes ago, echorec said:

 

Nice! Russian "Mullards"?

 

I bought a couple more new production quartets to try in the R8 - Both Russian "Tung Sol" 6550s and "Mullard" EL34s. I've been using the Russian "Mullards" for a few days. I think they sound good and are very balanced in the R8. Compared to the TS EL34B, they are more more neutral sounding, with a tad smaller soundstage. They don't have the richness in midrange that the EL34Bs have, but will match better with a wider range of speakers, IMO (EL34Bs really pair better with metal dome tweeters due to their darker highs in this circuit). While these are nothing like real Mullards, I was honestly surprised at how good they sound. For the R8, I think they are a great starter tube because of their more neutral character in this circuit. Very affordable too.

 

The 6550s should be here next week.

 

Yes, Russian reissue ones.   I figured for the price, it is was definitely worth grabbing some to get an idea of comparison against the stock Willsenton KT88.   Then I know if I get NOS later, it'll likely be better still.  But at least I'd have heard the characteristic differences.  

 

I'm a bit concerned the EL34s might drive the speakers a bit too bright.  I have Focal Kanta #2 speakers.  The beryllium tweeters are already very forward in mids and highs.  Perfect now with my Rega Ellicit-R, but don't want to add much more.  We'll see!

 

The Brimars are NOS.  Looking forward to those as a pre upgrade to the stock Willsentons too.

 

Let us know on the 6550s. if there's a solid diff between them and the KT88 !

[echorec]

21 hours ago, Candan said:

I'm a bit concerned the EL34s might drive the speakers a bit too bright.  I have Focal Kanta #2 speakers.  The beryllium tweeters are already very forward in mids and highs.  Perfect now with my Rega Ellicit-R, but don't want to add much more.  We'll see!

 

I think they'll be fine. They seem pretty neutral, so I don't think you'll be doubling down on any aspects, plus you will be "taming" the R8 with the Brimars, which are often described as a being a bit smoother on top. IMO, anything is better than the stock 6SL7s, which by the way, are actually rebranded Sovtek (Reflector) Russian 6H9Cs.

 

Just wait to judge the R8 until it's been run for a few weeks. I did not like it at first because it was too edgy sounding. It smoothed out quite a bit over that period and the soundstage opened up. Some say the caps are being burned in during this time, or perhaps it was the stock tubes settling in, but there was definitely a big change for me. The R8 is now my main amp.

Edited December 7, 2020 by echorec

[Phrangko]

On 14/09/2020 at 9:24 AM, Atmaj said:

I am not an expert on tube amp like many on this forum however writing this blog to help those who are thinking of buying Willsenton R8 or those who owns it and want to know bit more about it. I am not good with ears as Audiophile guys but can provide some technical insight.

 

Initially I was thinking of building my own tube amp as I am a keen DIYer but then looked on the net and saw hype about R8. Pulled the trigger in the hope that it is Point to Point wired amp so if not good, I will enjoy modifying it rather than building from the scratch.

 

Received my amp 5 days ago and first thing I did is that I opened up back cover before even trying it out. I was curious to know the quality of soldering, and the internal voltage switch is correctly set to run on 240V. To my surprise, it was great. I did not have to re-solder any point, all the components used are of good quality, relays and electrolyte caps are of reputed Japanese brands. Coupling caps and Grid bypass cap in driver stage are own ‘Willsenton’ branded but looks good (and looking at the way it sounds, I don’t think there is a need of replacing those with better branded caps or PIO caps). All the components and cables are laid out properly and tied together. The only flaw I found was that the outside sticker displays 240V but the inside voltage selector switch shows 230V. Also, I could not see Capacitor discharge resistor on main filter caps.

 

After satisfied with the build quality, I connected the amp to my system and wow… it sounds amazing and better than my other tube and SS amps. It is dead quiet when no signal and the sound is just clean, open and excellent coverage at both bottom and upper end. While it was sounding great, I found that the outer casing of power transformer was warming up a bit. The casing felt like a thick sheet of metal hence was bit concerned about the actual temperature of the transformer itself. Also, the bias was bit on the higher side when I checked first time which created the doubt that they have actually used 230V trannie and just put the sticker of 240V.

 

However, with these concerns in the mind, I decided to partially tear down the amp over the weekend to check the Power transformer rating, measure all voltages, trace down Schematic and install a discharge resistor on the filter cap. Supplier sent me the Schematic but it was too basic and wanted to confirm that it is accurate.

 

Below are my findings.

 

1. About 30% of resistor values in amp are different to actual schematic. The capacitance multiplier circuit is also different and there are some typo errors as well. I ended up drawing my own.
2. Transformers are potted in the casing (which is a great thing) hence did not remove those  as it would require de-soldering of too many connections. However, when measured the heater voltage, it was precisely 6.33V at my home supply voltage of 245V which indicates that it is a 240V transformer and switch labelling is not correct. The potting of transformer also explains that the heat on the casing is a conduction from transformer and not the radiation (which would be in case of hollow casing), so nothing to worry about it. Potted transformers also explain why this unit is so heavy and outer casings feel like made of a thick metal sheet.
3. KT88/EL34 switch changes the negative Grid voltage to power tubes and calibrates front Bias meter. I was expecting this switch to change the B+ voltage for different tubes but that’s ok, you can’t get everything at such a low price. B+ measures about 440V. This is optimum for EL34 but KT88 would have performed better with bit more voltage of about 500V or more.
4. The soft start delay circuit does not delay B+ supply voltage to tubes but rather mutes input signals for 30 seconds after turning it on. At least something is better than nothing.
5. I am not 100% sure about the Pre-IN input but I think it is not directly fed to driver stage bypassing pre-amp section. It still goes through pre-amp and volume control is bypassed to mimic the Power amp only condition. I do not use this input so didn’t bother going into further details.
6. The designer has taken great efforts to minimise noise in the amp by adopting Capacitance Multiplier using tubes to remove ripples from the supply voltage before it is fed to Pre-amp tubes. An elevated heater supply using virtual ground is also used to heat preamp tubes to prevent humming. 6SL7 are great tubes for audio application but at the same time they are high gain tubes and hence prone to noise and humming. With implementation of these 2 measures, amp is extremely quiet and noise free.
7. The elevated heater supply circuit also works as a capacitor discharge and no need to add additional resistor on the cap. I measured that after turning off the amp, there is hardly any voltage on power caps within 3 seconds, so it is very safe from that point of view.
8. One drawback of this amp is that it uses digital circuit for input and TR/UL selection but there is no memory function. If you are using CD as an input source and TR mode, then you do not have to do anything. For anything else, each time you turn on amp, you will have to select the source and the mode. A simple rotary selector switch would have been a better option here.

 

In conclusion, this is a great amp as a value for money. I am not an audiophile and do not own too many amps so I would leave those reviews and comparison for Youtubers but from the technical point of view, you will not get anything better sounding and better-quality product in this price. Looking at how it performs in bottom and top end, I am sure that the output transformers are also of great quality which is heart and soul of any tube amplifier.

 

I don’t’ think spending thousands of $ and buying Prima Luna or something like that will give any kind of added benefits. Just roll few tubes on this and it will shine like those branded amps costing multi-folds. This is my personal opinion considering my own circumstances and others may have different opinion and I respect that as well.

 

As a summary, it is nicely designed for flexibility of tube rolling, manufactured with quality components, built with care and professionalism, very reasonably priced and most important, it also sounds great.

 

Waiting for lock down in Melbourne to open so that I can try some tube rolling .

 

Cheers,

Atmaj hi. Great job! The R8 feels, looks and sounds quality indeed. I have a question in mind though. When the R8 arrived I immediately enjoyed it and after 3 1/2 hours of listening I noticed something. I'm not familiar with how tube amps work but is the middle transformer at the back of the tubes really that hot? I mean a lot hotter than the two on the sides. It is even slow to cool down. My previous amp had only two transformers and did not heat up that much.

Edited December 7, 2020 by Phrangko
Additional thoughts

[xlr8or]

6 hours ago, Phrangko said:

I'm not familiar with how tube amps work but is the middle transformer at the back of the tubes really that hot? I mean a lot hotter than the two on the sides. It is even slow to cool down. My previous amp had only two transformers and did not heat up that much.

 

The middle transformer is the power transformer for the unit and it's typical for it to get hot. The outer ones are the output transformers; one for the left channel and the other for the right channel. Now you maybe asking yourself how hot is hot. You'd be able to touch it and not burn yourself. If it's any hotter than this then a few things need to be checked including the input AC voltage matching the rated line voltage of the power transformer and the bias points of the power tubes.

[Atmaj]

@xlr8or explained it correctly. Just make sure that your bias is set properly and enjoy the amp. It is normal that power trannies goes warm.

[Phrangko]

4 hours ago, xlr8or said:

 

The middle transformer is the power transformer for the unit and it's typical for it to get hot. The outer ones are the output transformers; one for the left channel and the other for the right channel. Now you maybe asking yourself how hot is hot. You'd be able to touch it and not burn yourself. If it's any hotter than this then a few things need to be checked including the input AC voltage matching the rated line voltage of the power transformer and the bias points of the power tubes.

What a relief to know. Thanks a lot friend. I'll enjoy the R8 now more freely.

[muon*]

....................

Edited July 22, 2021 by muon*

[Phrangko]

12 hours ago, xlr8or said:

 

The middle transformer is the power transformer for the unit and it's typical for it to get hot. The outer ones are the output transformers; one for the left channel and the other for the right channel. Now you maybe asking yourself how hot is hot. You'd be able to touch it and not burn yourself. If it's any hotter than this then a few things need to be checked including the input AC voltage matching the rated line voltage of the power transformer and the bias points of the power tubes.

Another one for you or Atmaj. My R8 is fairly new. It is true my hand does not burn when I touch it for a period of time. After switching it off how long should I expect it to cool off? The smell like paint coming from the R8. Is that normal? I noticed it out of the box as well.

Edited December 8, 2020 by Phrangko
Added thoughts

[Candan]

4 hours ago, muon* said:

Think you will find that the new production Mullards are nothing like the NOS production ones, the only similarity is the name.

New sensor purchased the names of most of the legendary tube brands around 2000 or 2001.

Yep.  Agreed.  Not trying to compare new vs NOS.  New EL34 bought to compare against new stock KT88 only. 

[muon*]

........................

Edited July 22, 2021 by muon*

[Candan]

1 minute ago, muon* said:

I misunderstood, apologies.

No worries!  I'll eventually get NOS but this is my starting point! 

[muon*]

......................

Edited July 22, 2021 by muon*

[xlr8or]

11 hours ago, Phrangko said:

After switching it off how long should I expect it to cool off? The smell like paint coming from the R8. Is that normal? I noticed it out of the box as well.

 

After switching off the amp, it should take around 30 minutes for the power transformer to return back to room temperature. The paint smell is normal for a new amp and will go away with time.

Edited December 8, 2020 by xlr8or

[Atmaj]

12 hours ago, Phrangko said:

Another one for you or Atmaj. My R8 is fairly new. It is true my hand does not burn when I touch it for a period of time. After switching it off how long should I expect it to cool off? The smell like paint coming from the R8. Is that normal? I noticed it out of the box as well.

R8 has potted transformers so the outer casing takes time to warm up as well as cool down. I don't have any reason for this but I have noticed that with use, the warming up of power transformer has gone down a bit. Paint smell is very normal and will go off in few days.

[echorec]

On to testing my 4th set of power tubes: The Tung Sol 6550s arrived last week and I've been spending some good time with them. These are new production from Upscale Audio. They burn in all power tubes for 72 hours prior to shipment. Some comparisons to the stock KT88s that come with the R8 in combination with NOS RCA Red Base 5691s (which are my current favorite 6SL7 variant):

 

To sum things up - Huge soundstage, but aggressive and fatiguing. Compared to stock KT88s, the 6550's soundstage is bigger, the highs are brighter, and there is more bass. In fact, I had to insert my Schiit Loki into the chain to dial down the bass and highs. The 6650s also have a more forward presentation. I couldn't tolerate them for long in UL mode. It's just too fatiguing for me and those highs are too sizzly. Some other negatives were that, while the soundstage is undeniably wider, it is also blurred a bit and lacks the depth and holography of the stock KT88. There's just no warmth anywhere to be found in these *in my system* and the midrange is dry. The 6550s really remind me more of my solid state amplifier, in that you may be initially wowed by their soundstage and energy, but feel the need to turn it down soon thereafter. I really prefer the stock KT88 here and have really come to appreciate that tube. The stock KT88s are a good power tube.

 

If you have soft dome tweeters or generally warm and laid-back speakers, I think these 6550s could possibly be better match.

 

[Candan]

38 minutes ago, echorec said:

On to testing my 4th set of power tubes: The Tung Sol 6550s arrived last week and I've been spending some good time with them. These are new production from Upscale Audio. They burn in all power tubes for 72 hours prior to shipment. Some comparisons to the stock KT88s that come with the R8 in combination with NOS RCA Red Base 5691s (which are my current favorite 6SL7 variant):

 

To sum things up - Huge soundstage, but aggressive and fatiguing. Compared to stock KT88s, the 6550's soundstage is bigger, the highs are brighter, and there is more bass. In fact, I had to insert my Schiit Loki into the chain to dial down the bass and highs. The 6650s also have a more forward presentation. I couldn't tolerate them for long in UL mode. It's just too fatiguing for me and those highs are too sizzly. Some other negatives were that, while the soundstage is undeniably wider, it is also blurred a bit and lacks the depth and holography of the stock KT88. There's just no warmth anywhere to be found in these *in my system* and the midrange is dry. The 6550s really remind me more of my solid state amplifier, in that you may be initially wowed by their soundstage and energy, but feel the need to turn it down soon thereafter. I really prefer the stock KT88 here and have really come to appreciate that tube. The stock KT88s are a good power tube.

 

If you have soft dome tweeters or generally warm and laid-back speakers, I think these 6550s could possibly be better match.

 

 

Great review! 

 

Although I'm still waiting for my amp, with stock KT88 and my re-issue Mullard EL34s to arrive, it's good to hear what you're saying about the stock KT88.  It doesn't sound as though I'm missing out by not ordering 6550s out of the gate!   I'll be pairing with very forward sounding speakers and was concerned about them being too intense.  

 

It felt like I ordered my amp 2 months ago.  But it's only been 2 weeks since it shipped!  Another month I guess.  Sigh  

[echorec]

22 minutes ago, Candan said:

 

Great review! 

 

Although I'm still waiting for my amp, with stock KT88 and my re-issue Mullard EL34s to arrive, it's good to hear what you're saying about the stock KT88.  It doesn't sound as though I'm missing out by not ordering 6550s out of the gate!   I'll be pairing with very forward sounding speakers and was concerned about them being too intense.  

 

It felt like I ordered my amp 2 months ago.  But it's only been 2 weeks since it shipped!  Another month I guess.  Sigh  

 

Thanks! I popped the stock KT88s in after I posted my review and it only confirmed my personal opinion of the two tubes. I much prefer the stock KT88 to the TS 6550. The stock KT88s have really grown on me. On this amp it's interesting because when you switch between the EL34 class and KT88 because, for me, I instantly miss the liquid mids of the EL34. But when my ears adjust to the KT88, I definitely appreciate their qualities too and end up enjoying them just as much, but with different music. For example, reverb and echoes really extend into the soundstage with the KT88s and there is more energy. With EL34s I listen mostly to jazz and classical. With KT88 it's electronic time. One of the main reasons I purchased this amp was the various tube options and that is really paying off in enjoyment for me.

 

I'm really looking forward to hear your experiences with the R8 and your Kantas!

[Flash]

On 15/12/2020 at 11:50 AM, echorec said:

On to testing my 4th set of power tubes: The Tung Sol 6550s arrived last week and I've been spending some good time with them. These are new production from Upscale Audio. They burn in all power tubes for 72 hours prior to shipment. Some comparisons to the stock KT88s that come with the R8 in combination with NOS RCA Red Base 5691s (which are my current favorite 6SL7 variant):

 

To sum things up - Huge soundstage, but aggressive and fatiguing. Compared to stock KT88s, the 6550's soundstage is bigger, the highs are brighter, and there is more bass. In fact, I had to insert my Schiit Loki into the chain to dial down the bass and highs. The 6650s also have a more forward presentation. I couldn't tolerate them for long in UL mode. It's just too fatiguing for me and those highs are too sizzly. Some other negatives were that, while the soundstage is undeniably wider, it is also blurred a bit and lacks the depth and holography of the stock KT88. There's just no warmth anywhere to be found in these *in my system* and the midrange is dry. The 6550s really remind me more of my solid state amplifier, in that you may be initially wowed by their soundstage and energy, but feel the need to turn it down soon thereafter. I really prefer the stock KT88 here and have really come to appreciate that tube. The stock KT88s are a good power tube.

 

If you have soft dome tweeters or generally warm and laid-back speakers, I think these 6550s could possibly be better match.

 

I’m really glad I saw this. I’m running stock Cayin KT88s, but have been tossing up whether to try some 6550s, or go for Gold Lion KT88s. At this point I’m leaning toward the latter.