Iron

Transformers and Chokes

The Heart of Analog Path

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Output Transformers (TVZ)

Prototype: PL 16×36

Parameter	Value
Core	PL 16×36 (laminated permalloy)
Winding	Hand-wound, 3P+2S (sectionalized)
Primary	5000 turns, 0.25 mm wire
Secondary	For 4/8 Ohm load
Inductance	~80 H (at 100 Hz)
Mounting	Through-chassis

Production: OSM-0.063 (Factory Made)

Parameter	Value
Core	ШL 20×25 (OSM-0.063)
Steel Cross-Section	5.0 cm² (effective ~4.5 cm²)
Primary Winding (I)	3600 turns (wire 0.18–0.2 mm)
Secondary Winding (II)	118 turns (for 8 Ohm, wire 0.5 mm in 2 strands)
Sectionalizing	3P + 2S (P-S-P-S-P)
Raa (reflected)	~7.5 kOhm
Low Frequency (fL)	~25 Hz (-1 dB)
Production	Factory winding, quality control

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Power Transformer (TS)

OSM-0.16 (Factory Made)

Parameter	Value
Core	ШL 32×40 (OSM-0.16)
Rated Power	160 W (×2 margin from consumption)
Anode Winding	2 × 260V (0.25A) — for "dual mono"
Filament Winding 1	6.3V (4A) — output tubes + driver
Bias Winding	50V (0.1A) — for fixed bias and curve tracer
Service Winding	12V (1A) — for Arduino Nano, relay and motor
Production	Factory manufacturing

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Filter Chokes

OSM-0.036 (2 pcs)

Parameter	Value
Core	ШL 16×25 (OSM-0.036)
Iron Cross-Section	~4.0 cm²
Inductance (L)	5.0 — 8.0 H (under load)
Max Current (Imax)	0.2 A (200 mA) — margin for G-807
Resistance (R)	~120–150 Ohm
Wire (copper)	0.22 — 0.25 mm (PETV-2)
Turns	3500 (to fill window)
Non-magnetic Gap	0.1 mm (one layer of office paper)
Production	Factory manufacturing

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Winding Data (For DIY)

TVZ on OSM-0.063

Primary Winding:
  - Wire: PETV-2 0.18–0.2 mm
  - Turns: 3600
  - Sections: 3P+2S (P-S-P-S-P)
  - Resistance: ~150 Ohm

Secondary Winding:
  - Wire: PETV-2 0.5 mm (2 strands)
  - Turns: 118 (for 8 Ohm)
  - Sections: 2 parallel

Insulation:
  - Inter-section: Lacquer cloth 0.1 mm
  - Inter-winding: 3 layers paper
  - Impregnation: Paraffin + beeswax

TS on OSM-0.16

Anode Winding:
  - Wire: PETV-2 0.25 mm
  - Turns: 2 × 1100 (260V)
  - Current: 0.25A

Filament Winding:
  - Wire: PETV-2 0.8 mm
  - Turns: 24 (6.3V)
  - Current: 4A

Bias Winding:
  - Wire: PETV-2 0.15 mm
  - Turns: 200 (50V)
  - Current: 0.1A

Service Winding:
  - Wire: PETV-2 0.4 mm
  - Turns: 48 (12V)
  - Current: 1A

Choke on OSM-0.036

Winding:
  - Wire: PETV-2 0.22–0.25 mm
  - Turns: 3500
  - Gap: 0.1 mm (office paper)
  - Inductance: 5–8 H at 200 mA

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Materials

Cores

Type	Material	Permeability
OSM-0.036	Steel E310	μ ~ 2000
OSM-0.063	Steel E310	μ ~ 2000
OSM-0.16	Steel E310	μ ~ 2000

Wires

• PETV-2 — Polyetherimide enamel, heat class F (155°C)
• Copper — Oxygen-free, 99.99%

Insulation

• Lacquer cloth — 0.1 mm, class F
• Paper — Capacitor grade, 0.02 mm
• Impregnation — Paraffin + beeswax (1:1)

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Measurements

TVZ Frequency Response (OSM-0.063)

25 Hz  : -1 dB
100 Hz : 0 dB (reference)
1 kHz  : 0 dB
10 kHz : -0.5 dB
40 kHz : -1 dB

Phase Response

20 Hz  : +5°
1 kHz  : 0°
20 kHz : -3°

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Kit Contents

Factory components: transformers (TVZ OSM-0.063, TS OSM-0.16), chokes (OSM-0.036), enclosures, pre-assembled PCBs.

For enthusiasts: we publish specifications for DIY transformer and choke fabrication at home.

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