euroelectron antonis orchestral, choral, piano playlist

 

At your risk.

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

Update to Pleiades 2N3053 stereo power amplifier

 

At your risk.

The 2 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.