EAR Yoshino 834L Deluxe Preamp Review

[nagster]

Pressed sheet metal, US$3000, or chrome front panel is fine.
The same goes for methods such as class AB or class D, transistor or tube, British or Chinese manufacture, IC or discrete, AKM or ESS.
Manufacturers are free to decide on these, and those who like them buy them, and those who don't like them don't.

However, if it advertises as ``high fidelity,'' it is a scam. Looking at the results, this device is an effector for adding crosstalk and distortion to all music.
It is not a HiFi device.

 

[DualTriode]

2V output is rather high for this preamp. A typical use case for it was meant to be something like input from phono preamp EAR 834P to 834L, and output from 834L to a typical EAR power amp like 534, which has input sensitivity of 1V.

Hello,

For typical use you are correct,

For testing single end output line level devices two volts is the norm.

If this amp is operated at 1 volt output the distortion will be proportional to the output. As in reduced by ~ten to 20dB's.

Thanks DT

 

[GXAlan]

Hello,

For typical use you are correct,

For testing single end output line level devices two volts is the norm.

If this amp is operated at 1 volt output the distortion will be proportional to the output. As in reduced by ~ten to 20dB's.

Thanks DT

My real question is if that's how the pre-amp is likely to be used? I see how a SOURCE component output should be set for 2V for SE output, but unless you have some silly low gain amplifier that you're pairing with this tube pre-amp, 2V is going to be way too loud. We're really dealing with 50mV or 100 mV most of the time as the input.

Take the Hypex Nilai500 at maximum gain. <0.2 V already gets you 5W of sound. IF you do the math, a lot of the time, your amplifier lives at 5W or below for most speakers/most listening distances/most typical volumes.

 

[Rottmannash]

That makes his audience larger and his job as a writer more important. It’s like trying to play chess with pigeons here, seriously.

You assume you know @amirm 's mission statement. Maybe he isn't trying to become the end-all in reviewers, instead indulging one of his hobbies in a big way while letting us in on what he measures/reviews. I am truly grateful for what he has done and continues to do, as he has saved me mucho dollars and guided me into buying great measuring and sounding gear so no criticisms here.

 

[DualTriode]

My real question is if that's how the pre-amp is likely to be used? I see how a SOURCE component output should be set for 2V for SE output, but unless you have some silly low gain amplifier that you're pairing with this tube pre-amp, 2V is going to be way too loud. We're really dealing with 50mV or 100 mV most of the time as the input.

Take the Hypex Nilai500 at maximum gain. <0.2 V already gets you 5W of sound. IF you do the math, a lot of the time, your amplifier lives at 5W or below for most speakers/most listening distances/most typical volumes.

2 volts is a nominal value.

As you say normal usage will be well below 2 volts.

 

[lashto]

The general definition here would be as little noise and distortion as possible, and as flat a frequency response as possible from 20Hz to 20kHz. Here's the first definition I found...

View attachment 312240

So we could certainly say that this preamplifier is not a 'high fidelity' device.

I'd say you are playing fast & loose with the word certainly. But let's do that 'together'.

First, we take the DUT: a tube/12AU7 preamp. NFB-less (AFAICS). 59dB SINAD and 100 SNR.
We can be ~fair: it's a well engineered device with ~best possible measurements for its class. Price & build are quite shameless but at least it's honestly specced (even understated at ">0.1% THD, 80 SNR").
Or we can be mr. Fidler: the DUT is a "monstruosity" ... it is "certainly not high-fidelity" ... and all tubes are wrong anyway.

And second, we take this device. A phono preamp built and sold by @Michael Fidler. 73dB SINAD.
We can be ~fair: "a very accurate phono stage with very low noise and distortion". Excellent engineering and ~best in class measurements. However, the THD spec seems quite "optimistic":

Total harmonic distortion

<0.0005%, 20Hz to 22kHz

And the specified 81.5dB SNR is even worse than those "tubes are wrong". The build looks very solid but nothing special and it sells for the spicy amount of ~$800 (before shipping/tax/etc..).
Hmmm...
Or we can go full Michael on mr. Fidler: 73dB SINAD is a "distortion factory". It is "certainly not high fidelity". And Mr. Fidler's device is aiding and abiding the "horendous cult" of vinyl: people who pay $100000 for that horrible contraption called turntable and swear by their distortion-infested sound (a lousy ~50dB SINAD).

Hope you are having fun Michael!

 

[Michael Fidler]

I'd say you are playing quite fast & loose with the word "certainly". But let's do that 'together'.

We first take the DUT: a tube/12AU7 preamp. NFB-less (AFAICS). 59dB SINAD and 100 SNR.
We can be ~fair: it's an well engineered device with ~best possible measurements for its class. Price & build are quite shameless but at least it's honestly specced (even understated at ">0.1% THD, 80 SNR").
Or we can be mr. Fidler: the DUT is a "monstruosity" ... it is "certainly not high-fidelity" ... and all tubes are wrong anyway.

And second, we take this device. A phono preamp built and sold by @Michael Fidler. 73dB SINAD.
We can be fair: "a very accurate phono stage with very low noise and distortion". Excellent engineering and best in class measurements. However, the THD specs seem quite "optimistic":

Total harmonic distortion

<0.0005%, 20Hz to 22kHz

And the specified 81.5dB SNR is even worse than those "tubes are wrong". The build looks very solid but nothing special and it sells for the spicy amount of ~$800 (before shipping/tax/etc..).
Hmmm...
Or we can go full Michael on mr. Fidler: 73dB SINAD is a "distortion factory". It is "certainly not high fidelity". And mr Fidler's device is aiding and abiding the "horendous cult" of vinyl: people who pay $100000 for that horrible contraption called turntable and swear by their distortion-infested sound (a lousy ~50dB SINAD).

Hope you are having fun Michael!

Except of course the device you're referring to...

1. Isn't a line preamplifier - instead it has to amplify tiny input levels by 1400x at 1kHz
2. Doesn't produce >0.1% THD at normal operating levels
3. Genuinely produces less than 0.0005% THD with narrow FFT windows (no peaks visible above noise floor), so tell me again how it's a 'distortion factory'?
4. Has a noise figure of less than 6dB when paired to the transducer it's designed for so more than 87dB simply isn't even possible from 220Hz to 22kHz

So comparing vinyl records, or even a phono preamplifier, to a line preamplifier really is quite an absurd thing to do. One is a piece of electronics, the other is a format, in a different class really.

At the moment I have a line preamplifier in development with similar features to this one making 115dB SINAD on the test bench at 2V output... If I made something like this with solid-state technology I would be rightly lambasted for it but I can assure you that won't happen.

Pigeons and chess come to mind. There's no excuse for making small signal electronics for HiFi with more than 100ppm THD in 2023. Thanks for making it personal and proving my point in any case!

 

[Billy Budapest]

You could ask Bing (ChatGPT) which also verifies the definition of high fidelity even though it acknowledges preferences that exist for tubes.

----
That’s an interesting question. Tube amplifiers are often considered to be part of high fidelity, even though they are not strictly neutral. High fidelity is a term that means faithful reproduction of the original sound source, without adding or subtracting anything from it. However, some people argue that tube amplifiers can enhance the musicality and realism of the sound, by adding subtle harmonic distortion and compression that are pleasing to the ear. Tube amplifiers are also more responsive to the dynamics and nuances of the player, creating a more expressive and organic tone.

There are different types of tubes that can affect the sound of the amplifier, such as triodes, pentodes, and tetrodes. Each type has its own characteristics, such as gain, distortion, power output, and frequency response. Some tube amplifiers also have different modes of operation, such as ultralinear, pentode, or triode mode, which can change the sound and feel of the amp. Some tube amplifiers also use negative feedback, which is a technique that reduces distortion and increases stability, but can also affect the tone and damping factor of the amp[1].

Tube amplifiers are not necessarily better or worse than solid-state amplifiers, which use transistors instead of tubes. Solid-state amplifiers tend to be more reliable, efficient, and consistent than tube amplifiers, and can also produce a very clean and accurate sound. However, some people prefer the warmth and character of tube amplifiers, especially for certain genres of music, such as blues, rock, jazz, and country. Ultimately, it comes down to personal preference and taste.
----

The concept of "responsive to dynamics and nuances of the player" is in the non-linearity of the distortion (which also translates into peaks in FR and compression). The level-dependent treble boost I saw on my tube SET I measured, for example.

So while this isn't high-fidelity, and I wouldn't recommend this to anyone, and I wouldn't buy this myself either -- I acknowledge that someone might like the distortions and that's not offensive to me.

Relying on ChaptGTP for anything approaching truth is a dubious proposition.

 

[jmillar]

So... it's jewelry?

It's like a Morgan automobile. Impractical, obsolete, expensive. But some people like it. Not very many, this stuff is not built in large numbers.

 

[lashto]

1. Genuinely produces less than 0.0005% THD with narrow FFT windows (no peaks visible above noise floor), so tell me again how it's a 'distortion factory'?

Let's have a "very fast & loose" look at your numbers. 81dB SNR and 73dB SINAD. It seems to me that the 73 SINAD isn't noise-only, it contains some distortion too.
But then, I only have a "seems" and you are the EE expert. So you win. I missspoke and your device is not a "distortion factory". It's a "noise factory". Much 'better', hope you are happy

So comparing vinyl records, or even a phono preamplifier, to a line preamplifier really is quite an absurd thing to do. One is a piece of electronics, the other is a format, in a different class really.

Pretty sure that I compared "50 dB SINAD turntables" (i.e. "electronics") and did not even write the word "records". Otherwise, my vinyl/turntable comments weren't suposed to be 'fair' or 'right'. Glad you noticed that.

At the moment I have a line preamplifier in development with similar features to this one making 115dB SINAD on the test bench at 2V output... If I made something like this with solid-state technology I would be rightly lambasted for it but I can assure you that won't happen.

Just in case it wasn't 100% clear: I don't care (much) about SINAD numbers.
Since you seem to care, 115dB is "old/deprecated tech" nowadays and 120dB is the number to beat for preamps .. at least in that fairy-tale, distortion-free world

 

[lashto]

Thanks for making it personal and proving my point in any case!

Here's an 'advice' I would consider truly personal: it is generally considered "bad form" for audio manufacturers to comment on other manufacturer's devices. Especially when using words like "monstruosity". And joining "hot" debates may not improve your sale numbers.

Anyway, you are right that things got too personal around here. And quite heated. And not particularly ontopic.

Good luck with your business & feel free to ignore all my posts/advices/etc..

 

[G|force]

If anyone buys this pre, the first thing to do is turn on the soldering iron, break out the cutters and stripper and fix the mess inside.
Before making connections and listening.
Some sadists would turn on the iron before they open the carton, as a challenge.
There has to be a better way of preventing 'pops' when touching the controls then what has been done here.
TP has some acclaim from rebuilding Otari machines and making equalizers, IDK what to make of this.

 

[ABE43]

The anger and vitriol displayed by some in responses is disappointing to say the least. That one can be so animated around an electronic gizmo review and its associated data should give pause to many who participate in this forum.

Grow up, this has little to no effect on your life. Consider to yourself how this incessant arguing benefits anyone and also how it reflects on yourself. Turn off your computer and go outside, there is an entire world to explore.

 

[jmillar]

I think it would be best to put this EAR 834 phono based tube preamp and compare it to other similar phono tube preamps in same price category and see how it fairs and measures.

That's the whole point, e.g: the Pre90 or A90 (just mentioning things that I use) do a much better job at a fifth of the price. Obviously technology moves forward. Paravicini is a good (maybe even great?) engineer of the sixties and seventies ...but even then a basic Dynaco tube preamp did not cost a premium sum and did a sterling job.

 

[JSmith]

I was just watching an ol' Becker episode and this came up, @5:36


JSmith

 

[Mulder]

Regarding this that manufacturers participate in the discussion about the EAR product in question. Most often when manufacturers participate in the discussion I think it is as "engineers" rather than marketers. And I think it is most often the "engineer" speaking rather than the "businessman". There is a certain difference between contributing to a discussion with real knowledge of the subject vs. going to personal attacks or disparaging other products or otherwise make irrelevant arguments. Manufacturers, "engineers" or others with real knowledge in the field often contribute constructively to the discussion and raise the general level of the discussion here on the forum. At least that's something I appreciate. In general, it is my view that there is a connection between personal attacks and teasing tone and an unwillingness or inability to accept a distinctly engineering point of view. Of course, even "engineers" can cross the line for what is factual and well-motivated posts in the discussion, but generally it is not my impression that it is from that direction that the "overheated" arguments usually come.

 

[Endibol]

Regarding this that manufacturers participate in the discussion about the EAR product in question. Most often when manufacturers participate in the discussion I think it is as "engineers" rather than marketers. And I think it is most often the "engineer" speaking rather than the "businessman". There is a certain difference between contributing to a discussion with real knowledge of the subject vs. going to personal attacks or disparaging other products or otherwise make irrelevant arguments. Manufacturers, "engineers" or others with real knowledge in the field often contribute constructively to the discussion and raise the general level of the discussion here on the forum. At least that's something I appreciate. In general, it is my view that there is a connection between personal attacks and teasing tone and an unwillingness or inability to accept a distinctly engineering point of view. Of course, even "engineers" can cross the line for what is factual and well-motivated posts in the discussion, but generally it is not my impression that it is from that direction that the "overheated" arguments usually come.

Very good observations, well said!

 

[computer-audiophile]

Here's an 'advice' I would consider truly personal: it is generally considered "bad form" for audio manufacturers to comment on other manufacturer's devices.

I've had the same thought. I think it's good that you said it.

 

[Endibol]

I've had the same thought. I think it's good that you said it.

I don't see a problem in suppliers criticizing each other's products as long as it's purely based on objective argumentation and measurements. They should avoid "ad personam" type of arguments and stay polite.

I hope this will stimulate all suppliers to publish clearer specifications and measurements.

 

[Mulder]

Take a look at for example Topping A70 Pro balanced headphone amplifier and preamplifier. And compare it to this EAR-amplifer. In the Topping we see vanishingly low distortion. EAR on the other hand has in comparison very high harmonic distrtion, but also high IMD. In addition, the channel separation is poor. So, from a purely engineering perspective, it is clear that EAR performs far worse than what is possible to achieve in the current state of technology. Is this due to old-fashioned technology (tubes) or to incompetent design (or maybe it's just sly marketing and a genuine lack of interest in what could be objectively achieved.) I don't know, but regardless, the engineering conclusion must be that this amplifier performs poorly. So then I wonder. All of you who dismiss the "engineers'" criticism, and even resort to insinuating personal attacks, what is your argument why one should spend ten times more money on an EAR preamp compared to, for example, a Topping A70?