Warmth Of The Sound - WOTS

Warmth Of The Sound - “WOTS LeGrand”.

Very few words to introduce this thrilling preamp: in the listening room of RS Multimedia in Rottofreno (Italy) it gave us goosebumps for the warm softness and ethereal transparency of its sound.

Someone has judged it to be a piano preamp for the accuracy of the reproduction of this noble instrument; others marveled that for the first time they experienced almost the same feeling of attending a live event.

I was standing with a shiver that kept running down my spine.

In another session there were four hidden preamplifiers in comparison on a not really expensive chain but pretentious just enough. The “WOTS LeGrand” was the undisputed winner for expressed musicality, indeed very characteristic but completely devoid of color.

Different thing is to say `Linearity, “Aikido” is on the podium here. But is linearity more important than musicality?

Someone to answer.

I stop here, the schematic speaks for itself. A handful of components ... not so much a "handful", not the components runnning in your drawer, but high quality goods. There would be a lot to say about a simple topology with unconventional configuration, but I will do only is somebody is interested and asks for it.

It was the year 2003. The pictures are related to mine, 2007 build.

You will excuse me if I don't dwell on it, if I don't tell you the philosophy of the project, the various phases of analysis ... The truth is that “WOTS LeGrand” was born as a joke! Just a couple of concepts put together.

The success of this joke was great among my audiophile friends and friends of friends. One of them, dear Franco, who now listens from up there, forced me to design a solid-state version because he didn't like working with tubes. But he asked me that its sound must have been the same. Thus was born the “WOTS Tre”, which we developed together during one whole day to find the polarization with the best sound, the same imprinting of “LeGrand”.

The delay you see in the schematic is mandatory, it shorts the output for a pre-configured time to let the eqipment settle stably.

Simple schematic, impressive sound. You have to try. Oh boy, you have to!
 

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It is a zero feedback line preamplifier.
Any source usually has a "line" level output that needs "post-amplification", if you want to say so, before going to the main amplifier. A pre(post) amplification usually 20db.
I forgot to post its picture, here it is.
 

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It is a zero feedback line preamplifier.
Any source usually has a "line" level output that needs "post-amplification", if you want to say so, before going to the main amplifier. A pre(post) amplification usually 20db.
I forgot to post its picture, here it is.
A line level output is either 0dBm (775mV @600ohm) or between 1-2V. The sensitivity of a power amplifier is in the same order of magnitude, often less. If you amplify a typical CD player output (2Vrms) you get 20V. You need to attenuate it again to get usable input level for the power amplifier. Except if your source is in the 100mV output range.
 

adason

Member
Paid Member
2004-11-10 8:31 pm
Maryland
I am in the process of replacing all my solid state preamps with tube pre. Since it gives more pleasing sound to me. Yes, some call it effect boxes. Whatever. Point is what pleases you most.
Solid state pre, no matter how clean and sterile is still an effect box.
Some say pre has no role if we do not need amplification before the power amp. In my experiments passive pre sounds flat and boring. It does not drive anything properly. Buffered pot is the way to go.
Or tube pre. My secret is to put one more...long post sorry.
 
I am in the process of replacing all my solid state preamps with tube pre. Since it gives more pleasing sound to me. Yes, some call it effect boxes. Whatever. Point is what pleases you most.
Solid state pre, no matter how clean and sterile is still an effect box.
Some say pre has no role if we do not need amplification before the power amp. In my experiments passive pre sounds flat and boring. It does not drive anything properly. Buffered pot is the way to go.
Or tube pre. My secret is to put one more...long post sorry.
I think you are searching for the emotion to come out.
The sound shaping is made by the topology and, minimally, by the technology.
Look at the schematic of the "Tre" posted here: it has the same sound of its brother LeGrand.
The key points are two:
  • zero feedback;
  • current inside active components as high as possible.
Then I want to add a third: no CCSs.
Obviously, a good power supply is needed, my preferred is the "Virtual Battery".
Another important point is to limit the number of stages. So you have to forget about a non-inverting preamp because, if you want the input and output signal to have the same phase you should use a more complex long-tail or cross-coupled circuitry, or add another inverting stage. Take a look at the ARC LS22 schematic, for example, how complicated to have an inverting no-gain second stage to rephase the signal. I sure prefer to swap the speakers' connectors.
I have two Aikidos: excellent tube topology you can define them as a "wire with gain". They are perfect but no emotion from them. A good idea for a good VAS in a main amp, I'm working on it.
 

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I agree with you. Not for me too, to be used as a preamplifier. I will build the "WOTS LeGrand" starting in January.
But very good to be used as a VAS, I'm working on it with a low priority. Take a look. All values of the VAS must be confirmed, perhaps the first tube could better be a 12AT7 and the second a 6H30. The core values of the "Paragon Follower" are tested and definitive. A main amplifier with zero feedback.
 

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  • WOTS WHA-337 Schematic.JPG
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"WOTS WHA-217 E2" (was posted on NHB-108 thread).
This is a 200Wrms/8Ohm main amplifier I made on the NHB-108 base.
Main feature: no feedback from the speaker output.
Read the "Read Me First - WOTS WHA-217 E2 Project.pdf" document you find here enclosed.
 

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  • Electronics 01 Schematic 01 Amplifier.JPG
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  • Electronics 01 Schematic 06 Power Supply.JPG
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It is a line preamp (or post amp according to someone's suggestion in this thread). Someone else finds it boring. I know, it seems to be the usual follower to anyone looking at it without any attention. Just another follower, I saw thousands!
I'm glad to receive your interest. As per schematic and values, its gain is around 20dB, perhaps a little less but it is suitable for the purpose. The key is to use a tube able to drive the capacity GS of the following mosfet.
 
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