Ordered a Willsenton R300

@charles1dad 

Thank you for your response. 

@whitestix 

Thoughtful comments! 
I’ll admit that I have not heard or even seen the Willsenton R 300 amplifier. The company has been around long enough to have established a track record of both sonic performance and reliability. From what I gather on both accounts they do well.

Willsenton appears to fill a void between  ultra cheap Chinese amplifiers and say Line Magnetic level of products. Even then, Line Magnetic has different model ranges based upon price and presumably sound quality. Purely a gut feeling on my behalf but I think that based on owner feedback, Willsenton is a very solid choice.

I look forward to your listening impressions with considerable interest. Given your posted experience with other amplifiers. I believe that you are certainly able to separate the wheat from the chaff (Both sonically and judging build quality).

Charles

Don makes a good point, mirroring what others who are aware of how better caps, etc, improve the sound of electronics.   The labor cost is no different if one puts in plebian caps vs better caps, the delta is just the cost difference in the caps.  Not that one has to go to Mundorf Silver/Oil or Dueland caps, but am sure that Don is right that for a modest additional cost, ~$100 in better caps would likely make the amp a better performer.  Charles is right too in that they design to a price point and decisions about components must be made within those constraints.  I did see another Chifi integrated amp for sale for $750 which a couple of owners liked very much, which just amazes me.  How do they do it?  

@donsachs 

Agree with every point that you made. However only so much can be accomplished for a given price target. I have no doubt that your 300b is superior in numerous ways, but no way could it sell for only1500.00 USD either.

You unavoidably pay a cost to have better parts, transfomers, stout driver stage and power supply. I suspect that the Willsenton R300 is a very good introduction to a 300b SET amplifier at an inviting price. You can probably do much worst for1500.00  So I believe it is a very good value proposition. Those willing or able to spend more can step toward your 300b effort.

Charles

.

Oh I am sure people can upgrade them.  Still, the poorly designed driver section is a limiting factor, even with better signal path parts.  It could be improved by either CCS or choke loading of the driver, which would make it much better able to drive the 300b, or interstage transformer coupling would do the same thing.  That said, I am sure it can be made to sound much better with better signal path parts.

@donsachs

Honestly, they could build the same amp at a $100 higher price point and improve it considerably just looking at the photo

I absolutely understand that observation.

When you price an audio component to meet a strict price point, corners will inevitably be cut somewhere. Word of mouth feedback says that this is a good sounding amplifier despite it’s very low price (For a 300b SET amplifier). However if the building blocks (Output transformer and power supply) are good, you can improve things noticeably with better quality capacitors and tubes.

My suspicion is that the Willsenton R-300 probably has good quality transformers and power supply even at the modest price point. They probably cut cost via cheap resistors/capacitors. That’s OK these can easily be upgraded if one chooses to do so.

Charles

will also depend on their output caps.  The photo showed what look like your typical $5 Chinese MKP caps with their fancy labeling.   Klipsch used caps that looked like that in the Cornwall IV crossover.   Changing them to something like a vcap odam will make a very noticeable improvement, but as charles1dad said, the iron will matter.  Also the fact that they driving a 300b with a mediocre driver stage will limit the whole thing...   Honestly, they could build the same amp at a $100 higher price point and improve it considerably just looking at the photo....

If the Willsenton R300 has at least decent quality output transformers and power supply it should be okay. If good rather than merely decent quality then should be quite good sounding pairing.

Charles

I also think the R300 has a fairly good chance of working with my JMR Offrande speakers.  A few years ago I built the 8wpc Nelson Pass AMP Camp Amp.  The Offrandes were not happy with this pairing.  They sounded decidedly underpowered.  However, I also tried them with another 8wpc amp, the Antique Sound Labs Wave 8.  Some of you may remember this one from 2002.  They were sold for $98 each for a pair.  They came with ECL82 tubes.  The Offrandes sound great with those little amps.  I rarely had to exceed the 9:00 position on the volume control.

Ibought a Wells Audio Innamorata SS amp earlier this year -- by far the greatest SS I have ever had, and by memory I thought it might be more revealing than the Kootenai. I swapped them recently and it took just a few moments to realize the Kootenai was much better

I’m not surprised.😊

It will be interesting to see how the Kootenai compares with the Willsenton  R 300 and definitely Don Sachs’ new 300b push-pull amplifier. Fun times ahead.

Charles

gregdude,

I do use Don's preamp, being the 3rd purchaser of his initial version and now with the latest and greatest version.  It is a fantastic match for the Kootenai.   I bought a Wells Audio Innamorata SS amp earlier this year -- by far the greatest SS I have ever had, and by memory I thought it might be more revealing than the Kootenai.  I swapped them recently and it took just a few moments to realize that the Kootenai was much better.  I won't be parting with either.   I would like to compare the Supratek Chandonnay preamp to Don's sometime.   Whitestix

I don’t know a lot about the JM Reynaud Audio speakers but I am aware that they are generally said to be amplifier friendly speaker loads and match well with many tube amplifiers. So the likelihood of success with this 300b SET is reasonably good compared to the KEF LS50. Particularly in a smaller space at normal/moderate listening levels. Could work out very well.

Charles

I was an early purchaser of the LS50 and I struggled to make them sing with a 175 wpc Plinius SS integrated amp.  I agree with Charles1dad that the R300 would not be a good match. 

@voodoolounge 

I wouldn’t recommend it. 85 db sensitivity and behaves as a 4 ohm speaker impedance load per Stereophile.  You will not get near the true capability of what the 300b SET has to offer. This pairing favors neither the amplifier or the speakers. See below.

I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the KEF LS50's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield and spatially averaged room responses. My estimate of the LS50 Meta's voltage sensitivity was 84.5dB(B)/2.83V/m, which is the same as that of the original LS50 and within experimental error of the specified 85dB.

The solid trace in fig.1 shows how the Meta's impedance magnitude varies with frequency. Below 200Hz, it is almost identical to that of the 2012 LS50 (fig.2, solid trace), but at higher frequencies the impedance traces are quite different. The Meta remains closer to 4 ohms for longer in the midrange but has a considerably higher magnitude in the crossover region. The new speaker's electrical phase angle (fig.1, dashed trace) is occasionally high, and I used the formula in a 1994 JAESpaper to calculate the "equivalent peak dissipation resistance" (EPDR, footnote 1). The LS50 Meta has minimum EPDRs of 1.66 ohms between 135Hz and 140Hz and 1.7 ohms between 660Hz and 725Hz, both regions where music can have high energy. The partnering amplifier needs to be comfortable driving 4 ohms.

Do you think the R300 can power Kef LS50's?

Good for you.   I note that my expected delivery time period is between 11/10 and 11/29.  

I've ordered the Willsenton R300 as well.  Like whitestix I ordered through Amazon because of the ease of return if needed.  I've never owned a 300B amp.  This seemed like a good opportunity to satisfy that curiosity with minimal risk.  It will be used with JM Reynaud Offrande Supreme v2 speakers, rated 90db.  It's a small room and because it's an apartment listening levels are moderate.

What the hell do I do if I like it better than My Cary SLP-05/First Watt M2x?  Nah.  That won't happen.  I think.

@whitestix 

I’ll be very interested in hearing your thoughts about the Willsenton amp. I have always been interested in getting a 300b amp, but have never had the speakers to make them sing.

AC versus DC filament heating has been debated forever it seems. Some do argue that AC heating is more purist in approach (Require hum pots). However many/most of the highest regarded 300b amplifiers do choose to utilize DC heating (Do not require hum pots). As is typical for high end audio, there’s never 100% consensus on anything.

Charles

Depends on how they are doing the DHT filaments.   I use regulated DC and they may well have DC filaments?

I meant hum pots. Damn spell check  

“Hum balance pots are usually found with filament type tubes being operated off AC. AC on one pin is in opposite polarity of the other filament lead. The hum balance pot adjusts to a point where it cancels.  

Some used a center tapped resistor rather than pot. This works but not all tubes are exactly the same. The pot can adjust for differences”

@zazouswing 

My gut is not to trust a directly hearted triode without him puts 

What do you mean?

Charles

I’m also interested in hearing feedback on the R300. Interesting to see dual mono rectifiers at this price. My gut is not to trust a directly hearted triode without him puts - unless they are there but not described. Hard to fault an amp if it sounds good and costs less than a tube change. 

@donsachs

Thanks for the additional clarification. Push-pull topology, that explains the 27 watt power output from the 300b (4 of them). Zero negative feedback is a purist approach and I mean this in a very positive manner. Sounds like you and the esteemed Lynn Olson are developing something quite special.

Charles

Hi

It is a push pull amp comprised of 4 individual SETs, 2 per channel.   Class A, zero feedback of any sort.   There are a couple of little tricks beside that, but that is the basic topology.  The OPTs combine the two out of phase halves of each channel.  Trust me it works beautifully.   I am not done tweaking.  The next iteration will have the custom ITs and be mono blocks because I can then fit more power supply tweaks in the boxes.  But the current one is the best amp I have heard to date anywhere.  Semi-retirement is fun:)

@whitestix I'll give your Kootenay a good home if it ever comes up for adoption 🙂 do you use a Sachs preamp with it?

@donsachs

but it is basically 4 single ended 300b amps in one box.

So is this a PSET rather than a push pull circuit?
My 300b SET uses the 6EM7 as the driver rather than the 6SN7 (For the reasons you mentioned). Also it utilizes an interstage transformer in place of coupling capacitors.

I have no doubt that your 300b amplifier will be a fantastic product. Best wishes to you. The 300b properly implemented is superb sounding.

Charles

Hi, Don Sachs here.   First, this is not an attempt at advertising in any way.  The amp whitestix refers to is now in the second prototype and there is no commercial product.   

If you see a 300b that uses a 6SN7 to drive the 300b it will sound ok, but you will never hear what a 300b can do because a 6SN7 tube cannot adequately drive a 300b.   Search the web for Lynn Olson's symmetric Reichert.   What we have done is to start with that sort of design and then completely update the driver section and the power supplies.  The driver is now a triode connected 6V6 for each 300b and it will be coupled with custom wound interstage transformers from Dave G at Cinemag.   I tried a version with CCS loading and it was the best amp I had ever heard.   I have tweaked that further with choke loading and it is better and the IT version will be the best.  There are lots of other tricks in there, and many little secrets, but it is basically 4 single ended 300b amps in one box.  Phase split is done up front with a super high quality input transformer.   The result is an amp that has all the transparency of the flea watt SETs and the drive of a push pull.  It is about 27 watts/ch in this form and sounds like 60 watts/ch.  I love the Kootenay amp, but it doesn't sound like this amp.....  to my ear it is the best amp I have ever heard.

Quicksilver 300B tube amp, only 20 pairs made, see below:

Mike

https://www.audiocircle.com/index.php?topic=123019.0

Charles1dad,

Don gave me quite a detailed summary of the internals of his 300b, which he is developing in association with Lynn Olson.  As with his other gear, he believes it will far outperform much more expensive 300b amps on the market.  I will suggest to Don that he chime in on this thread if he is interested in a further description of his new amp. 

Hi,

I just mentioned this because I believe that @whitestix is specifically interested in the 300b.

Charles 

@charles1dad You're right. It's a tube amplifier, integrated, around the same price point (a bit above). But no, not 300B. That could be a deal breaker for many, but not for all. 

To my knowledge, Quicksilver does not build a 300b amplifier. @whitestix that is quite an endorsement from Don Sachs. Did he explain why he believes that his 300b amplifier is superior to his Kootenai KT 88 amplifier?

Charles

If you don’t like, you might consider an American competitor with a great track record for customer reviews as well as a reputation for service and reliability.

http://quicksilveraudio.com/products/integrated-amplifier/

carlsbad

That is what Don Sachs suggested.

evank

Good for you.  Shocking how inexpensively China can produce these amps.

I don't see any shipping date for my unit yet. The other thing that swung my decision to buy the amp was that repairs are available domestically. 

@whitestix

I ordered the R8 from China Hifi and received it in 4 days. The units are here in the states. It was shipped from the same place that is listed on Amazon. They just hit you with the shipping charge from China. I still saved close to 400.00 dollars.

You might want to go straight to the hard stuff.   

I bought it on Amazon for the oppty to return it if I don't fancy it. I think it can be sourced cheaper from China, but with more hassle, possibly. My tube guru Don Sachs has created a new 300b amp that he claims is significantly better than my Kootenai KT88 amp so this Willsenton amp might be my "gateway drug" to Don's new amp.  His Kootenai amp is superb.

Nice, I'm loving my R8. Tempted to order the r300. Did you order it on Amazon or direct or from China Hi-Fi?