A Way to Make Time Last for Very Long...

 At your risk.

Is to act (or not) in every day assuming that it lasts for infinite time.

By (philosopher) Lambros

Πριν τη Βάρκιζα

Το ουράνιο τόξο

Πάνω στο μικρό στήθος

Ο μικρός παράδεισος

Με τον απαλό φωτισμό των αστεριών

 

Η μουσική της 

Μ' εμάς

Το στήσιμο των ζεστών αγαλμάτων

Και ο χρόνος να χάνεται

Σαν αστραπή στην ανάγλυφη σιωπή

Οι εικόνες χάνονται απο την ομορφιά τους

Πως θα παγώσουμε τον χρόνο;

Μα είναι άπειρος

Έκαιγε και η υπόλοιπη νύχτα στη Βάρκιζα

Κι ήταν το ονειρικό της άρωμα στο χέρι του

Can a Man Act as a Lesbian?

Lovers with Friendship Benefit

Gigliola Cinquetti

Foot Massage reflexology - Ann Swanson

 

At your risk.

Riccardo Cocciante (con Cecilia Gasdia) – Due, Modulation from C minor to E minor to A minor to C# minor

 

1:24 modulation to the key of E minor

1:59 modulation to the key of A minor

2:45 modulation to the key of C#minor

Vicky showed me the importance of key change within a musical composition.

Sergio Mentes, Brazil 66

 It was played a few days ago by Yiannis Petridis on Hellenic radio.

George Michael

 

Is high gm, high current desirable for low noise?

At your risk.

Experience from Pleiades amplifier designs brings out that very small currents of the order of 50 to 100 microamperes give very low noise on electron tubes or JFETs. 

An explanation seems to be that at low voltage, (hence low current), secondary electron emission is minimum on electron tubes, see much earlier posts.

For example the Pleiades V6 battery powered electron tube microphone booster. The Pleiades DC90 RIAA preamplifier. The Pleiades 3 K117 RIAA, no hiss can be heard even with volume control at maximum. The Pleiades K117, 1.3V microphone pre preamplifier.

No wander this approach is also used on classic condenser microphones.

Having said this most of the devices chosen for these Pleiades low noise preamplifier experiments are high gm such as EF183 or K117. But they are used at low current hence low gm.

2nd Pleiades 3 K117 RIAA MM Preamplifier Prototype continued

At your risk. protect your ears from high SPL.

A 10K load resistor was added at the 3rd stage which is a K170 JFET. The output transformer used is about 10 to 1. Quiescent current is 1mA at Vb=24V, Vd=14V. It sounds nice and loud driving the Sennheiser HD580 in mono i.e. (150ohms).

A source resistor bypass capacitor of 100uF was added to the 1st K177 stage otherwise overall gain is too low (an input transformer has not been tried yet on this preamplifier).

The potentiometer separating 2nd and 3rd stage is at the time being 470K log.

The preamp driven at the time being by a Lipshitz RIAA inverse network sounds very nice (one channel tested only in mono).

I Believe in the Power of Music

This is part of a song dreamed a few days ago.

All that could be remembered is the chorus and the bass line of the verse.

Key is E minor.

Female singer.

There was a beat.

Chorus:(bass code, melody, lyrics)

o    means pause

-     means sustain

              o    o    B    A                   I  be-

Cmaj7   B    -    B     A     lieve     I  be-

Am9      B   o    #F   3F    lieve  in the

Bm       #F   #F   A    G     po-wer of mu-

Em         o    E    B     A    sic         I  be-

Cmaj7    B    -    B     A     lieve     I  be-

Am9       B   o   #F   #F     lieve     in the

Bm       #F  #F    A    G      po-wer of lo-

Em         -     -     o     o      ve

Original lyrics must had been:

I believe, I believe in original music...

Verse bass code:

Em

Bm

Fmaj7

Am or D

repeat

Funnily enough a BLUTHNER s/n 139765 upright piano appeared out of the blue at the entrance of the block of flats. So the bass and melody could be tried out and roughly recorded.

 

Renaud Capuçon records Main Theme, Gabriel's Oboe from The Mission (Ennio Morricone)

 

It is interesting to see the microphones too.

Second Pleiades RIAA MM Preamplifier Prototype

 

At your risk. A suitable fuse must be in series with any battery. Please take all other safety precautions.

Under preparation.

Instead of  one 9 volt battery this is supplied by batteries of total 18V or 24v.

Instead of 2 stages this has 3 stages but without source resistor bypass capacitor.

Even more similar to the Heathkit class A 10W integrated electron tube amplifier. 1st stage has a 100K drain resistor, second stage a 220K drain resistor. 3rd stage will possibly have a 10K drain resistor, said stage driving through a coupling capacitor a 10 to 1 output transformer.

A 1M potentiometer will drive the 3rd stage.

The passive RIAA filter, all 4 time constants, is at the time being between 1st and 2nd stage.

 

  

Σπάει η Φωτιά τον Πάγο?

Ήταν φωτιά και έτρεχαν

Ήρθε λεπτή νύμφη, ψηλή τρομαγμένη

Καθώς έσβηνε, άναψε μέσα μου

Στο σώμα της

There is nice Christmas music inside the Athens' tram from Easy 97.2 MHz radio station

 

Happy Christmas!

On Making an Adaptor Cable to Connect a Dynamic Microphone to a Mobile Phone

At your risk. Please take all safety precautions. For example soldering fumes must not be inhaled, solder must only be touched with gloves, listening to playback with headphones must be at a very low level,... 

On this example....

1

A Shure SM58 Mexico microphone is used for male singing voice at 24in from mouth, mic pointing towards the nose. Microphone placed much higher than head. At 24in there is almost no bass boost proximity effect. The mic is used outdoors (balcony) in order to avoid recording thousands of annoying, blurring short delayed reflections from walls.

2

A step up signal transformer is used to step up the microphone voltage and impedance. So at this stage the signal level is like a condenser capsule with the added advantage of the much less harmonic or non linear distortion at high frequencies (see older posts with references). The step up transformer used was a 1 to 10 step up ratio with a low primary inductance (typically 280mH) which further corrects bass. This is a low value of inductance so the mic can be used a bit closer or a higher inductance transformer can  be used while keeping the mic at 24in. But it all depends on song, register and singer. The transformer stops RF energy picked up by the mic cable and the step up process creates a unique low noise (hiss) recording. The transformer used is a German one inside an female to male XLR barrel. 

3

The high impedance signal is connected directly to the Gate of a JFET. A K117 JFET is used. The Pleiades K117 mic preamplifier is built inside the female XLR connector. For more details, schematic please see older posts a few yeas back. The circuit is as minimal as it can be for purest sound and lowest noise. Just a K117 JFET, a resistor connected to the Source terminal for bias and nothing else. Amplified signal is taken from the Drain terminal. The load resistor where the amplified voltage is developed is in the following circuit which also supplies the 1 or 2 volts needed to power the low noise JFET preamp. The other end of the cable is connected to a 3.5mm male headphone mic jack connector.

4

An Apple 3.5mm (headphone, mic) to USB C adaptor is connected. It was bought for 10euros in Athens Public shores. It contains all needed ADC for mic and DAC for headphones.

5 

A Galaxy mobile phone is connected at USB C

6

Recording made with the camera app of the mobile phone.

7

That's it.