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Audio transformers and chokes

Buran81

Member
2016-03-10 8:47 pm
The pair of output transformers for the tube 6s33s

I have made them myself, having used my experience of making tube amplifiers and transformers for them.

The transformers are made on C-core HiB (0,23mm) cores, manufactured in ISRAEL, with their losses no more than 0.9W/kg. You also can see on the photos that the devices are winded frame less. It is a very neat kind of winding which does not allow any inaccuracies. The core air gap is chosen for DC current 250mA and generates a no signal core flux density of 0.9 Tesla. So it leaves a flux density swing of 0.9 Tesla for the signal. The primary coil resistance is 18ohm. The primary inductance is 8,5H (checked through an electrical outlet -50Hz)

Primary impedance: 1Kohm to 8ohm ( 7watt power)
Frequency characteristic: 7Hz-100Khz -3dB
500ohm to 4ohm (12watt power)
Frequency characteristic: 7Hz-62Khz -3dB

It is checked on tube amplifier 6S33S and 6AG7, with maximum power.!!
Quality of insulation: is more then 20Gohm checked with a megger 2500V,during 1 minute.

The insulation material is Mylar,which allows to make High Frequency Transformers!

The weight of each device is 5.9Kg

The price of the pair is 399$, NOT including the shipping
 

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Buran81

Member
2016-03-10 8:47 pm
The pair of output transformers for the tube 300B.2A3 .....
I have made them myself , having used my experience of making tube amplifiers and transformers for them.
The transformers are made on M6 EIcores ,manufactured in Italy . You also can see on the photos that the devices are winded frame less . It is a very neat kind of winding whichdoes not allow any inaccuracies.

The core air gap is chosen for DC current 80mA and generates a no signal core flux density of 0.8Tesla. So it leaves a flux density swing of 0.8Tesla for the signal.
The primary coil resistance is 162ohm.
The primary inductance is 40H (checked through an electrical outlet -50Hz)
Primary impedance: 3Kohm to 8ohm . 10Hz-50Khz -3dB
It is checked on tube amplifier GU50 and 6AG7 , with maximum power.!!

Quality of insulation : is more then 20Gohm checked with a megger 2500V ,during 1 minute .
The insulation material is Mylar,which allows to make High Frequency Transformers!

The weight of each device is about 3.7Kg

The price of the pair is 259$, NOT including the shipping
 

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Buran81

Member
2016-03-10 8:47 pm
The pair of the Interstage Transformers 1:1 (10Kohm:10Kohm) for such tubes like 6SN7, 6S2S,12AU7..…

I have made them myself, having used my experience of making tube amplifiers and transformers for them.

The transformers are made on C-core HiB (0.23mm) cores, manufactured in Israel. You also can see on the photos that the devices are winded frame less. It is a very neat kind of winding which does not allow any inaccuracies.

The core air gap is chosen for DC current up to 10mA.
The coil's resistance is 600ohm.
The primary inductance is 445H (checked through an electrical outlet -50Hz)
Frequency characteristic: 9Hz-19Khz -1dB. 6Гц-30кГц -2дБ. 4Hz-41Khz -3дБ (checked with the tube 6SN7. Rp is 8Kohm ).
Quality of insulation: is more then 20Gohm checked with a megger 2500V, during 1 minute.
The insulation material is Mylar,which allows to make High Frequency Transformers!
The weight of each device is 1.8Kg
Dimensions are 88*92*87mm
The price of the pair is 322$, NOT including the shipping.
 

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Buran81

Member
2016-03-10 8:47 pm
The pair of output transformers for the tube300B.2A3 ,6B4G,GU-50.....
I have made them myself , having used my experience of making tube amplifiers and transformers for them.
The transformers are made on HiB (0.23mm)
C-cores ,
manufactured in China . You also can see on the photos that the devices are winded frame less . It is a very neat kind of winding whichdoes not allow any inaccuracies.

The core air gap is chosen for DC current 100mA and generates a no signal core flux density of 0.8Tesla. So it leaves a flux density swing of 0.8Tesla for the signal.The primary coil resistance is 105ohm.
The primary inductance is 64H (checked through an electrical outlet -50Hz)
Primary impedance: 5Kohm to 8ohm . 6Hz-67Khz -3dB
It is checked on tube amplifier GU50 and 6AG7 , with maximum power.!!Quality of insulation : is more then 20Gohm checked with a megger 2500V ,during 1 minute .
The insulation material is Mylar,which allows to make High Frequency Transformers!
The weight of each device is about 6Kg


The price of the pair is 455$, NOT including the shipping
 

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Buran81

Member
2016-03-10 8:47 pm
The NEW pair of PP output transformers 5K to 4 and 8ohm . for the tube300B.2A3 ,6B4G,GU-50.....

The transformers are made on M 090-23.
HiB(0.23mm) C-cores ,
manufactured in Israel . You also can see on the photos that the devices are winded frame less . It is a very neat kind of winding which
does not allow any inaccuracies.
The primary coil is fully divided and its full resistance is 320ohm.(160ohm+160ohm)
Primary impedance: 5Kohm to 8ohm .Frequency response is 7Hz-52Khz -3dB
5Kohm to 4ohm .Frequency response is 7Hz-42Khz -3dB
The max.output undistorted power on 20Hz is 30Watt.
The max.current in the primary coil may be up to 125mA (each tube)
Quality of insulation : is more then 20Gohm checked with a megger 2500V ,during 1 minute .
The insulation material is Mylar,which allows to make High Frequency Transformers!
The weight of each device is about 3.9Kg

The pice of the pair is 340$ + the shipping

 

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Buran81

Member
2016-03-10 8:47 pm

The pair of output transformers 16K to 4 and 8ohm. 8K to 4ohm, for the tube GM70 .211.845
I have made them myself , having used my experience of making tube amplifiers and transformers for them.
The transformers are made on
M 090-23. HiB(0.23mm) C-cores ,manufactured in Israel The devices are winded frame less . It is a very neat kind of winding whichdoes not allow any inaccuracies.


The core air gap is chosen for DC current 90mA but may be changed.
The primary coil resistance is 330ohm.

Primary impedance: 16Kohm to 8ohm. 16Kohm to 4ohm. 8Kohm to 4ohm.

The transformers are checked in real tube amp . with GM70 and 211 tubes.

The frequency responce of the whole amp. GM70 (100mA DC current) is 7Hz- 35kHz -3dB (the secondary coil is grounded through the resistor 12Kohm).

The frequency responce of the whole amp. 211 (59mA DC current) is 9Hz- 29kHz -3dB (the secondary coil is also grounded through the resistor 12Kohm).



Quality of insulation : is more then 20Gohm checked with a megger 2500V ,during 1 minute .
The insulation material is Mylar,which allows to make High Frequency Transformers!
The weight of each device is about 6Kg

The pice of the pair is 440$ + the shipping
 

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Buran81

Member
2016-03-10 8:47 pm
The pair of output transformers 10K to 8ohm or 5K to 4ohm, for a project of two parallel tubes like GM70 .845
I have made them myself , having used my experience of making tube amplifiers and transformers for them.
The transformers are made on
M 090-23. HiB(0.23mm) C-cores ,manufactured in Israel The devices are winded frame less . It is a very neat kind of winding whichdoes not allow any inaccuracies.


The transformers are 70Watt power on 20Hz

The core air gap is chosen for DC current 200mA but may be changed .

The max.DC current may be up to 350mA


The primary coil resistance is 204ohm.



The transformers are checked in real tube amp . with one GM70 ( they may be used also with one tube)

The frequency responce of the REAL amp. GM70 (100mA DC current) is 7.5Hz- 36kHz -3dB (the secondary coil is grounded through the resistor 12Kohm).




Quality of insulation : is more then 20Gohm checked with a megger 2500V ,during 1 minute .
The insulation material is Mylar,which allows to make High Frequency Transformers!
The weight of each device is about 10.6Kg

The pice of the pair is 590$ + the shipping
 

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Buran81

Member
2016-03-10 8:47 pm

The pair of amorphous output transformers 8K to 4ohm. 16K to 8ohm, for the tube GM70 .845.211
I have made them myself , having used my experience of making tube amplifiers and transformers for them.
The transformers are made on
Amorphous Duble C-cores
,manufactured in Chine The devices are winded frame less . It is a very neat kind of winding which does not allow any inaccuracies.


The max.power on 20Hz is 25Watt

The core air gap is chosen for DC current 100mA but may be changed.

The primary coil resistance is 330ohm.

The transformers are checked in real tube amp . with GM70

The frequency responce of the whole amp. GM70 (100mA DC current) and with 1watt output power is 7,5Hz- 30kHz -3dB (the secondary coil is grounded through the resistor 12Kohm).




Quality of insulation : is more then 20Gohm checked with a megger 2500V ,during 1 minute .
The insulation material is Mylar,which allows to make High Frequency Transformers!
The weight of each device is about 6Kg

The pice of the pair is 520$ + the shipping
 

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