To get more information contact me at: firstname.lastname@example.org
This project is born to be simple
and secure but with high electrical performances and
great sonic results.
The sound quality has been obtain using the best components on the market and a good circuit.
All the test on first version confirm a very sonic high performances and I consider it like one of my best amplifiers.
The use of normal diode bridge instead of common vacuum tube diodes give a many advantages and the sound is always good.
This project use only common vacuum tube in current production because I don't like old stock items difficult to find and with short life time.
These are the characteristics of this design:
and in this last version:
All the audio transformers used in this project are Lundahl products and the distributor list is available here
|2||LL1620AM/90mA||Lundahl output transformers (350 euro each)||600|
|2||LL1671AM/20mA||Lundahl interstage transformers (237 eur each)||400|
|2||LL1638/8H 200mA||Lundahl power supply inductances (64 euro each)||130|
|1||Custom double R-core||-||170|
|3||159 ZJ||Hammond inductances||60|
|2||43 20Kohm||Spectrol multiturn cermet trimmer||2|
|2||534 2Kohm||Spectrol precision wire wound multi-turn potentiometers||20|
|2||845 vacuum tubes||Golden Drangon or Valve Art (from 120 to 400 euro per pair)||120|
|2||EL34 vacuum tubes||Svetlana||52|
|2||12AX7 vacuum tubes||Jan Philips or Mullard||50|
|1||100uF + 100uF 500V||Jensen Electrolityc Dual (price about 44 euro each)||44|
|6||220uF 500V||Jensen Electrolityc (price about 36 euro each)||216|
|2||0.22uF 600V||Jensen Copper film paper-in-oil (45 euro each)||90|
|6||10000uF 16v||Panasonic HA serie||30|
|Varies components + connectors||250|
|Total price about||2200|
to add input cables and DACT stepper attenuator cost
Lundahl is one of the world´s leading manufacturer of audio transformers used in many professional studio recording and radio stations so it has great experience and all these products use a custom audio C-core.
About passive components types, I don't leave many choices: Caddock resistances on the signal path, Sanyo OS-CON capacitors on cathode and Jensen AudioGrade electrolytc capacitors on power supply.
You can find many components of this project at Audiokit online shop.
I am using a DACT stepper attenuator instead of the normal ALPS or NOBLE solution, because the the sound is clearer.
About wire forget the teflon ! use only stranded tinned copper wire with pvc isulator.
A very good quality stranded tinned copper wire could be buy directly from E-Z-HOOK that carries an extensive line of fine stranded and extra flexible wire.
I have used the model 9506 with WVDC (Working Voltage Direct Current ) of 5000V for all the main power supply connections, the model 9504 for the signal and the model 9510 for the output loudspeaker connections.
All the wires near the tube socket have been cover by Sterling tubes in order to avoid that the high temperature will destroy them.
As visible in the photos to fix some components I have used some good PTFE Insulated Twist Eye Terminals by Grennan Audio.
After my big experience with the cables published on "Cable test" I can assert that the quality of cables is very important.
So like internal input cable I have used a good Q-Audio Tao
The power supply transformers are 2 custom made created on my specifications by:
Primaries 2 x 115V Secondaries first transf. 2 x 340v 0.4A 1 x 230v 0.2A 1 x 200v 0.2A
Secondaries second transf. 1 x 6.3v 4A 2 x 10v 4A Magnetic flux 70% of normal (13000 instead of 17000 gauss) Internal electromagnetic copper shield.