Tube Power amplifier using EL34 in Triode connection and CFB technique,paraphase inverter 12AX7

EL34 PP CFB

EL34 PP CFB

Sony TA N902 N900 N901 Esprit Solid State Class A Amplifier Clone II Switching Dual Power Supply

DIY 
My Sony Esprit Clone Power Amplifier!

Power Boards Hetasink

Switching power supply

My new GY50 50W  Hybrid Power amplifier DIY Board 
IRFP240
2SC3281 - MJL3281
2SA1302- MJL1302

Audiograde output capacitor

"ready to run" GY50 Boards

Ampeg SVT3 Pro Tube & Mosfet Electric Bass Amplifier - Bias Adj and Repair

Custom Power Transformer suitable for My GY50 Hybrid Power Tube Amplifier 4 x 12AX7 + BJT Power Stage

Custom power Transformer  for my GY50 hybrid Amplifier clone is ready!!

Trasformatore Alimentazione Hi Fi 300VA 

Primario 230Vac

Secondari:
1 x 230Vac x anodica
2 x 67Vac x stadi finali BJT
2 x 12.6vac x filamenti 12AX7

Schermo elettrostatico primario/secondari

DIY Do It Yourself KIT Headphones Hibryd 0fb Class A Tube Amplifier Using Boost Coverter Power Supply DC DC Coverter output 190Vdc 6.3Vdc starting from 12-24Vdc

Zero Feedback 100mW Hi Fi Tube - BJT Amplifer using Hi Voltage Power Supply by DC DC Boost Converter.

Boost and Buck Board provide to give:

VAS Tube Supply: 190Vdc
Curret Buffer Amplifer Supply: 30Vdc
Heater voltage 6.3Vdc by Step Down converter

All voltages obtained starting from 12-24Vdc power supply, as Desktop power supply or Battery

DC DC Step Up and Step Down Board

High End Tube Headphones Amplifier - Goodnight Project

One implementation of my 

"Goodnight "

Tube Headphones Amplifer

Luxman LV-105 Style Hybrid Amplifier 100W Simulated Project 6DJ8 (ECC88) Hitachi Mosfet 2SK1058 2SJ162

Similar to basic schematic of Luxman LV-103 / LV-105 , this project is made by only 3 simple stages: 

1. Input stage: is a BJT cascode(Q8,Q9) with current sink(Q11)
2. VAS stage: is a 6DJ8 (ECC88) SRPP (X7,X8) buffered by a emitter follower BJT (Q10) with MOSFET current sink (M9)
3. Output stage: is a B class Mosfet Push Pull  with two couple of 2SK1058 / 2SJ162  Hitachi 

100W Schematic 

Simulated FR

Simulated Distortion 0.041% at 32Vpp out

Project About Aloia's TriodoSolido Style Hybrid Amplifier 100W

Clone of Aloia's Amplifier called Triodosolido.
Semplified versione whitout Protection and Limiters circuits

Tubes are 2 x 6SN7 double triode.
Output BJT 2SC3281 2SA1302
Tube VAS Supply300Vdc
Catode Follower Rail Supply: 50Vdc, -50Vdc
No Negative Feedback (0 Negative Feedback)

"Operazione Goodnight" Tube & BJT Hybrid Class A Headphones Amplifier Project Schematics Layers SMPS Power Supply

My Goodnight Tube Headphone Project Schematics  

SMPS Power Supply 

Triode Amplifier Section ECC82 ( 12AU7)

Voltage Tube Amplifier Stage Schematic

Class A BJT Emitter Follower Current Buffer 

2SC2238 2SA968 

2SC1815 2SA1015

LM334Z

Current Buffer Stage Schematic

Top Layer and Components Amplifier Section

Switching Power Supply Based on Texas Booster Driver IC LM3478 and Buck IC LM22673.

Vin=12Vdc

Vout1=200Vdc

Vout2=30Vdc

Vout3=6.3Vdc

 Top Layer:

SMPS Buck-Boost

"Operazione Goodnight" Headphones Amplfier Using Vacuum Tube ECC82 ( 12AU7)

My  Project about a Vacuum Tube Headphones Amplifer for my Philips Fidelio X1:

My Tube Amplifier and My Headphones Philips

My Headphone Tube Amplifier 

Tube used for amplifier is a ECC82/12AU7 followed by a discrete Class A BJT Buffer
The First One mede uses ELNA Cerafine Audio Capacitors.
The Power Supply is my Board made by a mix of  Bust and Buck Switching Converters from main 12-24Vdc
So  From DC Supply we can obtain: 200Vdc for Tube circuit, 30Vdc for Buffer Circuit, 6,3Vdc 

"Goodnight" Powe Supply Board 

Switching Board with IC, Mosfet and Audio Board with Philips Miniwatt NOS ECC82  12AU7

NOS ECC82 Philps Miniwatt and Switching Power Suupply Board

Headphone Amplifier complete with a White Led on the base of Tube

TUBE

The Second One uses ELNA Audio Silmic II Capacitors

The Second One With ELNA Silmic II Audio Capacitors

 Boards and Headphones

Hybrid Power Amplifier Using 12AX7 as Input Stage and VAS, 2SK1058 - 2SJ162 as Current Buffer

In this days I'm working around an Hybrid Power Amplifer
Below the Microcap Simulation Schematic

M2 and M2 are Hitachi 2SK1058 Mosfet
M3 and M4 are Hitachi 2SJ162 Mosfet

Bias current is around 100mA

V1 and V5 are High Voltage Supply, around 300Vdc
V3 and V4 are 50Vc for Power Stage

X4 is TL071 Op Amp used to fix to 0Vdc the ampli's voltage offset.

The Negative Feedback Network is present

X3 is a SRPP as Input Stage
X1-X2 are used as VAS and to drive the Power Mos Stage

DIY Headphone Hybrid Amplifier Schematic Simulation

To semplify last project I choose to exchange Current Generator by a simple Resistor.
Power dissipate is about 4W so this component, 60ohm, shoul be composed by 2x120ohm/5W resistors.

Semplified schematic

Distortion increase, third harmonic

Distiortion increase, Vin=1Vpk, Vout=5Vpk but the power on the Haedphone is 400mW near the maximun power admitted, 500mW.

At 3Vpk out:

3Vpk output