Nobody can hurt you if you do not want it too. Κανεις δεν μπορεί να σου κάνει κακό αν δεν το θες και εσύ.

At your risk. Με δική σας ευθύνη.

By Lambros.  Λάμπρος.

Lambros had given me the book of philosopher Epictetus called Enchiridion, manual of living. Ο Λάμπρος μου είχε δώσει το βιβλίο του φιλοσόφου Επίκτητου με τίτλο Εγχειρίδιον.

Delay on voice is very important

 At your risk.

For example.

A Woman in Love - Barbara Streisand

The Year of the Cat - Al Stewart

Listening carefully one can realize that together with the direct signal of the vocal there is a delayed in time version added.

This can be done in many ways.

An echo chamber does it automatically as it takes time for sound to travel from the speaker to the microphone inside the sound reflective room.

By the way cylindrical pipes like for example drain pipes standing on floor can make the reverberation sweeter possibly due to diffusion scattering of the ways. If memory is correct having seen photos on the Abbey Road book, the echo chamber i think has such or similar scattering structures.

 

How to create an airgap in an output transformer for single ended power amplifiers?

 At your risk.

The Es can be stacked together. The Is are stacked together.

For example Scotch invisible tape can be placed on top of the Es before placing next to them the Is.

When there is DC current flowing in the winding of a transformer, an airgap can prevent magnetic saturation and even increase incremental inductance/

Further reading.

Magnetic Circuits - M.I.T. 

AI

The classic old MIT textbook on this topic is Magnetic Circuits and Transformers: A First Course for Power and Communication Engineers, written by members of the staff of the Department of Electrical Engineering at the Massachusetts Institute of Technology

Reading the small letters on food or beverage packaging

At your risk.

This is not a medical or nutritionist advice.

For example some beverages contain taurine which as fear as i know is a male hormone and these beverages can be seen to be drunk even by very your women.

Or for example cheap cookies or croissants that may contain hydrogenated palm oil (margarine?) which have a reputation or clogging arteries.

On the other hand I had been told told many years ago that sesame seeds or tahini, (made from sesame seeds) is a very good food that keeps arteries and health in great shape. The oil is good quality naturally produced from the sesame seeds. I still eat tahini, every day, see the Pleiades meal or earlier posts/

Is coffee bought in cafeterias contaminated with egg yolk powder?

 At your risk.

This is not a medical or nutritionist advice.

I do not know.

I heard in public transport that a cafeteria in Athens had been closed down in the past as it was found that they were using egg yolk in order to make the coffee velvety creamy etc.

Deaths for example from heart attack or clogged arteries were experienced in the area before there was an order to check the cafeteria for substances that may increase bad cholesterol. 

Hopefully modern cafeterias...

euroelectron antonis orchestral, choral, piano playlist

 

At your risk.

https://www.youtube.com/@renewablemusic/playlists

Update to Pleiades 2N3053 stereo single ended zero feedback power amplifier in class A operation

 

At your risk.

Class A operation means that electrons flow trough the active device (transistor in this case) all the time.

Here are some updates.

The two 1.2Ah 12V batteries were moved to the smaller bedroom.

Signal path:

Brothers in Arms - Dire Straits on un remastered CD - SonyD-EJ758CK CD Walkman line out - Celestion Ditton 150

Great, amazing sound.

Current for both channels was measured to be 32mA, due to higher temperature in Athens.

By chance only one 12V battery was then connected and the sound was even better, more easy and smoother. Current was just 14mA for both channels.

 

J. S. Bach

 

Allegri

 

and this is the famous version recorded just after Roy Goodman had played football:

J. S. Bach

 

Having the pleasure to meet Thymios today

 At your risk. (This is included on most euroelectron posts).

I had the pleasure to be introduced today by Philippos  at Underflow premises  to Thymios.

We talked about single ended low power electron tune power amplifiers. I told him about the 1920s Harold Arnold (see previous posts) design with just one input transformer, an output transformer, just one electron tube and 3 batteries. It sounds great to use a step up input transformer.

Also on electron tube preamplifiers, see previous post.

Also on full range loudspeakers.

Also on output transformers which may emit sound depending on varnish or no. 

An important advice from him is that the system should portray dynamics, micro dynamics as live music and this is why he likes so much such designs as mentioned above.

I pointed him to the pdf Tubes vs Transistors is there an audible difference by Russel O Hamm.

At the end it was mentioned how an electron tube with heater voltage applied automatically has a negative grid potential without anything else connected to it. This is by electrons approaching the grid or equivalently by electrons leaving the cathode leaving it positive. Therefore the electron tune cannot conduct 9have anode current) at a low plate voltage, say 6V. But if a say 8.2M resistor is connected between plate an grid, the grid becomes less negative and the electron tube can operate very well at say Vb=6V with nice grain and very low noise. The heater voltage can even be reduced with even better results, as the anode current is typically of the order of 100uA. For example a high gm variable EF183 triode connected. See Pleiades V6 microphone low level preamplifier.

Updates on Pleiades 3 K117 JFET phono 18V battery powered preamplifier

 At your risk.

At the moment frequency response is affected whether the great Sennheiser HD-580 are connected at the output or not (possibly due to load impedance changing with frequency and the fact that the preamp is a no negative feedback design).

Also the setting of the volume pot affects frequency response. Possibly due to the fact that the load resistors are 100K, 220K and 470K for the potentiometer. Maybe some values will be reduced in redesign of one of the channels. Both channels are still on breadboard but inside an aluminum box.

There is also some 1.5dB peak at say 4KHz.

But the preamp sounds great, effortless, with dynamics, smooth violins.

Possibly due to the fact that all source resistors are un bypassed (no electrolytic capacitor in parallel). Therefore each stage is at low gain. And the passive RIAA network is as close to the input are possible. just after the low gain 1st stage. 

So everything sounds smooth, undistorted, violins with no harshness. This is what was told to Thymios, having the pleasure of meeting such a nice engineer for the first time.

  

1224868 all time views on euroelectron

 

Thank you so much!

AI does the pitch increase trick at each note sung until it sounds correct to the listener's mind

 At your risk.

Rhythm of the Rain - The Cascades

 

The DUAL CL11 dipole full range speaker driven by the Pleiades BD650 12V less than 1 Watt power amplifier in class A

 At your risk.

Signal path:

Barbara Streisand's Guilty CD - Sony CD Walkman line out - Pleiades BD650 single Darlington amplifier - Dual CL 11 - big living room

Amazing sounding speaker. With deep bass, extended treble, sounding so real and sensitive. 

Tried for the first time today with the Pleiades BD650.

Only possible problem may be some king of mid high emphasis, by ear it sounds happening at around 4KHz. If this is the case it may be corrected with an inductor in series and a resistor or capacitor in parallel with said inductor, see older euroelectron posts on equalizing full range speakers

Some nice microphones live with Tony Bennet, K.D. Lang, Amy Winehouse

 At your risk.

Blue Velvet

 At your risk.

Today in Athens there is a kind a heat wave. About one hour ago while walking towards the National Library this song was being played at the outdoors cafe. 

While listening on my way I thought it can be heard how good singers build the note sung by increasing the pitch by glissando after attack until it sounds correct to the listener's mind.

The song was inspired by a woman wearing a blue velvet dress at a party watched  by songwriter Bernie Wayne.

https://en.wikipedia.org/wiki/Blue_Velvet_(song)

 

Ζητείται Ωραία Νότα, Nice Note Wanted

 

Joe Dassin

 

This was recommended to me by my friend Albert, the master tuner.

A few days ago he had tuned the piano for Nick Cave's concert in Athens.

A Pleiades derivative of the great Musical Fidelity A1 class A amplifier

 At your risk.

How would it sound if only the last 2 transistors are used with an output transformer say 2:1 and no negative feedback?

For example single ended with BD135 driving the 2N3055,  and Vb=24V.

Euroelectron playlist on YouTube

At your risk.

https://www.youtube.com/playlist?list=PLpEisBQ5la76mpSBX1IuTnT6iD1ywZCq6

Abrazame - Julio Iglesias

Acapulco Nights - G.J. Lunghi

Annabel - Xarhakos

Bad Boy - Den Harrow

Big in Japan - Alphaville

Cenerentola - Martinelli

Crazy - Patsy Cline

Interlude - Siouxsie, Morrisey

Maria Magdalena - Sandra

Miserere - Alegri, Roy Goodman, SIr Willcocks

Tha s' Agapo - Galani

The Captain of Her Heart - Double

The Hook - Hatzinassios

The Fate of Ophelia - Taylor Swift

The Power of Love - Frankie Goes to Hollywood

Year of the Cat - Al Stewart

My Army of Lovers - Army of Lovers

musicalike playlist name on YouTube has been changed to euroelectron playlist

 At your risk.

On renewablemusic YouTube Channel.

https://www.youtube.com/@renewablemusic

Pleiades BD650 one Darlington transistor power amplifier in single ended Class A

 At your risk. A suitable fuse must be in series with any battery for safety. Protect your ears from high SPL. There is a broadband click sound when turning off the amplifier.

It sounds very nice. Drums sound like the real thing.

Singal path: 

On the Border - Al Stewart (on origianl CD) - Sony CD Walkman line out - Marantz Imperial 5G (one speaker so far)

Power supply is just 12V from a 1.3AH lead acid battery. 

Ic is 120mA. So power output should be less than 1W.

Output hand wound transformer is about 3 to 1. So from an 8 ohm speaker the amp sees about 

8 ohms x 3 x 3= 72 ohms. Air gap is by gluing one layer of scitch invisible tape across the stacked Es.

The transformer used on this prototype is rather big.

Bias is by a resitor from collector to base.

There is a 50uF film wound input capacitor.

And a variable series resistor (rheostat)  connected to base for volume control.

It should be nice making 2 such monoblocks inside a transparent plexiglass box powered by 8 AA batteries in series with a suitable fuse.