TRANSFORMERS

      A good transformer for Hi Fi has to have some particular characteristic that differentiates it from a common transformer for
industrial use.
     Besides the elevated quality of the materials employed (wheats irons directed to low loss, nucleuses to C, etc.), the accuracy of the project is reached when it is perfectly dimensioned for the valve used and has a
perfect constructive execution.
     This is worth both for output transormers and for impedances, transformers of joining valves and also for those employed in power supply.
     The elevated constructive quality is what has determined the success of products that become famous in Italy in a recent past.
     Our firm, that uses the great experience of our technicians, guarantees an accurate design of a handycraft high-level construction in small quantities or even single pieces by the employment of modern machines and the best available materials on the market.
     An almost extreme care is used in the isolation, in the perfect symmetry of the wrappings and in the necessary shrewdness to hold low the distributed capacitance and the lost inductance as a perfect joining among
primary and secondary.
     All of this things, joined to a pleasant look, create our particular and competitive products that give also a good rate between quality and price


     OUTPUT TRANSFORMERS

     A good output transformer must be build by material of first-quality, with a particular care in realization phase. The matured experience in about forty years of work in design and constructions, allows us to affirm that some techniques are strongly to prefer to others. An excessive tension of the wire can provoke, for instance, stretchings and improper extensions of
the same one, creating mechanical tensions that are harmful both for the quality of the frequency answer and for the duration of the same transformer. For this reason, our realizations are performed always without the employment of automatic machines but only
handed by experienced artisans.

     An extreme care is used in the stratification of the wrappings and in the filling of the caves and in the isolations, with double immersion in resin, warm and cold.
     Besides iron plates of the best quality are employed, combined with wire of simple or double coverage of enamel according to the type of realization.
     Our final point is to conjugate an extreme accuracy to a reasonable cost, taking care also of some aesthetical details. Everything we obtain is tied up to the realization.

 

TRANSFORMERS OF EXIT FOR THE FOLLOWING FINAL  VALVES:

 

ECL80; ECL 82; ECL 86, EL 95; EL 36; EL 41; EL 42; EL 86;

 

6AQ5; 6CL6, 6080; 6C33; 6L6;

 

807; 1619; 1622; 25L6; ecc.

 

 

MODELS FOR HIGH FIDELITY

 

Mod. ND 6-04  transformer for EL84 valve; 6V6 and so on

Primary impedance: 5000 ohm; Secondary: 8Ohm.  Power: 6W

Inductance: 35 Henry nearly

Core-plate at low waste: 1.2 W/kg.

Passing band:23-20800 Hz

N.) 4 windings.

 

Mod. ND 6-04-01 The same but with a tape for screen grid.

 

Mod. ND 6-04-02  The same but with 5 windings, core-plates at oriented grains with lost of 0.6 W/kg.  Passing band: 17-28000 Hz

 

Mod. ND 11-04 transformer of counter-bands ultra-linear of EL 84, 6V6 6AQ5,etc.

Primary impedance 8000 Ohm, power : 11 W  Inductance; 70 Henry

Oriented core-plate with lost: 0,5 W/Kg. Passing band: 18 Hz-26 KHz

N) 10 balanced windings

 

Mod. ND 14-04 transformer for counter-phase of EL 84. Primary  impedance 8000 Ohm.

Power: 14 Watt  Inductance: about  58 Henry  Passing band from 22 Hz to 21000 Hz

Core-plate with a low lost. N) 6 balanced windings

 

Mod. ND 8-03 transformer for valve 6L6 at pentode. Primary  Impedance: 2500 Ohm.

Secondary: 8 Ohm  Power 8 W. Inductance: about 18 Henry.

Passing band: 22-21800Hz. Core-plate at low waste. N) 6 windings

 

Mod. ND 8-03-01 The same but 4000 Ohm of impedance.

 

Mod. ND 22-04 Transformer for counter-phase-parallel of EL 84 ( two valves for branch in parallel) Primary impedance: 3700 Ohm. Secondary Impedance: 8 Ohm. Power: 22 Watt. Inductance: about 36 Henry. Passing band: 16-25 KHz Core plates at oriented grains.

 N) 10 balanced windings

 

Mod. ND 25-03 Transformer for counter- phase of EL 34. Screen grid tap for ultralinear.

Primary impedance 6600 Ohm. Secondary impedance: 8 Ohm Power: 25 Watt: Inductance: about 60 Henry. Passing band: from 18 Hz to 25 KHz. Core plates at oriented grains.

N)10 balanced windings

 

Mod. ND 30-04  Output transformer for counter phase of El 34. Configuration at pentode.

Primary impedance: 3400 Ohm. Secondary impedance 8 OHM. Power: about 30 Henry.

Passing band: 18-24 KHz. Core plates at oriented grains. N) 10 balanced windings.

 

Mod. ND 18-04 Transformer for counter phase of EL 34.

Configuration at triode. Primary impedance: 10.000 Ohm. Secondary impedance: 8 Ohm.

Power: 18 Watt.

Inductance: about 90 Henry. Frequency: 18-24 KHz Core-plates at oriented grains 0,5 W/Kg

N) 12 balanced windings.

 

Mod. ND 16-04-01 The same but with impedance of 5000 Ohm.

 

Mod. ND 15-04 Transformer for counter-phase of 807 “ William Configuration “

Primary Impedance: 10.000 Ohm: Secondary Impedance: 8 Ohm. Power: 15 Watt Inductance

 

Mod. ND18-03 Transformer foe counter-phase of 6L6 or KT 66 configuration at pentode. Class A  Primary Impedance: 5000 Ohm  Secondary Impedance 8 Ohm  Power 18 Watt  Inductance: 45 H.

Passing-band: 18 Hz-20500 Hz

Core-plate at low loss. N) 6 balanced windings.

 

Mod. ND 31-04 Transformer for counter-bands of 6L6 or KT 66 configuration at pentode in class AB  Primary impedance: . Secondary Impedance: 8 Ohm

 

 

FEED TRANSFORMER

 

Mod. ND 36-200 Feed transformer for radio at valves or for small amplifiers with max. 3 valves. Power: 36 secondary Watt

1)      200 V; 90 mA  2) 6,3 V 1.2 A. Induction: 1Wb/mq

 

Mod. ND 55-250 Feed transformer for radio and amplifiers. Power: 55 Watt  Secondary: 250 V 130 mA. Secondary 2): 6.3 V  2.9 A. Induction: 1.05 Wb/mq

 

Mod. ND 60-300 Feed transformer for big radios or Hi-Fi amplifiers. Power 100 Watt Secondary: 1) 280+280  120 mA  2) 6.3 V 3 A; 5 V 2A. Induction: 1.05 Wb/mq

 

Mod ND 100-280-01  The same transformer but with a secondary at 6.3 Volt at the place of the one at 5 Volt.

 

Mod. ND 100-300 Feed transformer like the model of 280 but with secondary at 300+300 V 120 mA. Induction: 1.05 Wb/mq .

It can be supplied on request with core-plate at oriented grains.

 

Mod. ND 100-320 Feed transformer like the model 280 but with a secondary at 320+320 V 110 mA. Induction: 1.05 Wb/mq

 

Mod ND 100-350 Feed transformer like the model 280 but with a secondary at 350+350 V 100 mA. Induction: 1.05 Wb/ mq

P.S. All these models can be supplied on request also in the version 01, that is, with secondary at 6.3 Volt.

For particular uses they can be supplied also with core-plate at oriented grain.

 

 

IMPEDANCES

 

We deal with different types of impedance. We are able to build under project  particular and non commercial models.

 

 

 

Regular models always avalaible.

 

Mod. NDI  80/8 ( 80mA, 8 Henry)

 

Mod. NDI  100/8 (100 mA, 8 Henry)

 

Mod.NDI   100/10 (100 mA, 10 Henry)

 

Mod.NDI   200/12 (200 mA, 12 Henry)

 

 

Further information on request.

We can also build output transformers for every kind of valve. Estimates for particular carrying out.

P.S. All the answers about frequency are +- 3db.

Transformers are supplied with fixing flange and close-parcel.

At your request it is possible to have them in a soft-iron box of 2 mm thickness fire painted with a fine aspect.


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Ennedi Instruments