Universal Push Pull Tube Output Transformers
Author: kevin M Date Posted:3 November 2017
Universal Push-Pull Tube Output Transformers
Replacement and project output transformers for valve amps
- Push-pull output transformers from 3 W to 280 W for guitar amp and hi-fi builds.
- Primary impedance, maximum DC bias, secondary taps and suggested tubes are listed for every part.
- Click any part number to see price, stock and dimensions in our shop.
If you cannot find the item you wish to purchase on our website, email us at info@evatco.com.au.
No matching parts. Email info@evatco.com.au and we will help find one.
Universal Push-Pull Tube Output: 125A–125E
Compact universal units. Use the hook-up table below to wire the secondary lugs for your speaker impedance.
Hook-Up Data (125 Series)
Pick your voice coil impedance across the top and the secondary lugs down the side. Values are the total primary impedance in ohms, blue wire to brown wire.
| Secondary lugs | 1.5 Ω | 2 Ω | 3.2 Ω | 4 Ω | 6 Ω | 8 Ω | 12 Ω | 15 Ω |
|---|---|---|---|---|---|---|---|---|
| 1 & 2 | 27,000 | – | – | – | – | – | – | – |
| 2 & 3 | 18,000 | 24,000 | – | – | – | – | – | – |
| 3 & 4 | 16,500 | 22,000 | – | – | – | – | – | – |
| 4 & 5 | 10,000 | 13,500 | 21,600 | 27,000 | – | – | – | – |
| 5 & 6 | 8,500 | 11,000 | 18,000 | 22,000 | – | – | – | – |
| 1 & 3 | 5,400 | 7,200 | 11,500 | 15,000 | 21,600 | – | – | – |
| 2 & 4 | 4,200 | 5,600 | 9,000 | 11,200 | 16,800 | 22,500 | – | – |
| 3 & 5 | 3,300 | 4,400 | 7,000 | 8,800 | 13,200 | 17,600 | 26,400 | – |
| 4 & 6 | 2,400 | 3,200 | 5,100 | 6,400 | 9,600 | 12,800 | 19,200 | 24,000 |
| 1 & 4 | 2,150 | 2,900 | 4,600 | 5,800 | 8,700 | 11,600 | 17,400 | 21,500 |
| 2 & 5 | 1,550 | 2,050 | 3,300 | 4,100 | 6,150 | 8,200 | 12,300 | 15,500 |
| 3 & 6 | 1,300 | 1,700 | 2,700 | 3,400 | 5,100 | 6,800 | 10,200 | 12,800 |
| 1 & 5 | – | 1,400 | 2,200 | 2,800 | 4,200 | 5,600 | 8,400 | 10,200 |
| 2 & 6 | – | – | 1,700 | 2,100 | 3,150 | 4,200 | 6,300 | 8,000 |
| 1 & 6 | – | – | 1,200 | 1,500 | 2,300 | 3,000 | 4,500 | 5,600 |
General Replacement 8 Watt Push-Pull: 125H & 125J
125J connections
| Primary (plate to plate, brown to blue) | Secondary (Ω) | Use secondary leads |
|---|---|---|
| 4,000 C.T. | 6/8 | White – Green |
| 4,000 C.T. | 3.2 / 4 | White – Yellow |
| 2,500 C.T. | 6/8 | Black – Green |
| 2,500 C.T. | 3.2 / 4 | Black – Yellow |
A Series: 1608A–1650WA
The current range, with re-designed secondaries for easier hook-up. Operation and suggested tube types are shown for each part. Parallel operation means two or more tube pairs share the load.
| Part No. | Audio Watts (RMS) | Primary Impedance (Ω) | Max DC Per Side | Secondary Impedance (Ω) | Operation | Suggested Tube Types |
|---|---|---|---|---|---|---|
| 1608A | 10 | 8,000 C.T. | 100 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6AQ56V66BQ5EL84SV83 |
| 1609A | 10 | 10,000 C.T. | 100 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6AQ56V66BQ5EL84SV83 |
| 1615A | 15 | 5,000 C.T. | 100 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 2A36A36AQ56B4G6L66V6 |
| 1650E | 15 | 8,000 C.T. | 100 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6AQ56V66BQ5EL84SV83 |
| 1620A | 20 | 6,600 C.T. | 158 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6AQ56L66V6 |
| 1650FA | 25 | 7,600 C.T. | 128 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6L6GC6V68075881EL34 |
| 1645A | 30 | 5,000 C.T. | 128 mA | 4 - 8 - 16 - 70V | Push-Pull (2 tubes) | 6L6GC6V68075881EL34 |
| 1650G | 35 | 6,600 C.T. | 200 mA | 3.5 / 8 / 16 / 250 / 500 | Push-Pull (2 tubes) | 6L6GC8075881EL34 |
| 1650HA | 40 | 6,600 C.T. | 200 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6L6GC8075881EL34 |
| 1650KA | 50 | 3,400 C.T. | 318 mA | 4 - 8 - 16 | Push-Pull Parallel (4 tubes) | 6L6GC8075881EL346146B6550B |
| 1650NA | 60 | 4,300 C.T. | 318 mA | 4 - 8 - 16 | Push-Pull Parallel (2 or 4 tubes) | 6L6GC8075881EL346146B6550BKT88 |
| 1650PA | 60 | 6,600 C.T. | 200 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6L6GC8075881EL346146B6550BKT88 |
| 1650RA | 100 | 5,000 C.T. | 318 mA | 4 - 8 - 16 | Push-Pull Parallel (2 or 4 tubes) | 8075881EL346146B6550BKT88 |
| 1650TA | 120 | 1,900 C.T. | 403 mA | 4 - 8 - 16 | Push-Pull Parallel (4 or 6 tubes) | 6L6GC5881EL346550BKT88 |
| 1650WA | 280 | 1,900 C.T. | 806 mA | 4 - 8 - 16 | Push-Pull Parallel (6 or 8 tubes) | 6L6GC5881EL346550BKT88 |
Original Series: 1608–1650W
The original "classic" series. Most parts have been superseded by the A Series above, which has the same ratings. Where we no longer stock the original, the current equivalent is shown under the part number.
| Part No. | Audio Watts (RMS) | Primary Impedance (Ω) | Max DC Per Side | Secondary Impedance (Ω) | Operation | Suggested Tube Types |
|---|---|---|---|---|---|---|
| 1608Now supplied as 1608A | 10 | 8,000 C.T. | 100 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6AQ56V66BQ5EL84SV83 |
| 1609Now supplied as 1609A | 10 | 10,000 C.T. | 100 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6AQ56V66BQ5EL84SV83 |
| 1615Now supplied as 1615A | 15 | 5,000 C.T. | 100 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 2A36A36AQ56B4G6L66V6 |
| 1620 | 20 | 6,600 C.T. | 158 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6AQ56L66V6 |
| 1650FNow supplied as 1650FA | 25 | 7,600 C.T. | 128 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6L6GC6V68075881EL34 |
| 1645 | 30 | 5,000 C.T. | 128 mA | 4 - 8 - 16 - 70V | Push-Pull (2 tubes) | 6L6GC6V68075881EL34 |
| 1650HNow supplied as 1650HA | 40 | 6,600 C.T. | 200 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6L6GC8075881EL34 |
| 1650K | 50 | 3,400 C.T. | 318 mA | 4 - 8 - 16 | Push-Pull Parallel (4 tubes) | 6L6GC8075881EL346146B6550B |
| 1650MNot stocked. Email us | 60 | 1,400 C.T. / 800 C.T. | 318 mA | 4 - 8 - 16 | — | — |
| 1650NNow supplied as 1650NA | 60 | 4,300 C.T. | 318 mA | 4 - 8 - 16 | Push-Pull Parallel (2 or 4 tubes) | 6L6GC8075881EL346146B6550BKT88 |
| 1650PNow supplied as 1650PA | 60 | 6,600 C.T. | 200 mA | 4 - 8 - 16 | Push-Pull (2 tubes) | 6L6GC8075881EL346146B6550BKT88 |
| 1650RNow supplied as 1650RA | 100 | 5,000 C.T. | 318 mA | 4 - 8 - 16 | Push-Pull Parallel (2 or 4 tubes) | 8075881EL346146B6550BKT88 |
| 1650TNow supplied as 1650TA | 120 | 1,900 C.T. | 403 mA | 4 - 8 - 16 | Push-Pull Parallel (4 or 6 tubes) | 6L6GC5881EL346550BKT88 |
| 1650WNow supplied as 1650WA | 280 | 1,900 C.T. | 806 mA | 4 - 8 - 16 | Push-Pull Parallel (6 or 8 tubes) | 6L6GC5881EL346550BKT88 |
P Series (Potted): 1650RAP, 1650KP, 1650PP, 1650PAP & 1650RP
Potted versions enclosed in a drawn steel case. We stock the 1650RAP; the others are listed for reference.
| Part No. | Audio Watts (RMS) | Primary Impedance (Ω) | Max DC Per Side | Secondary Impedance (Ω) | Operation | Suggested Tube Types |
|---|---|---|---|---|---|---|
| 1650RAP | 100 | 5,000 C.T. | 317 mA | 4 - 8 - 16 | — | 8075881EL346146B6550BKT88 |
| 1650KPNot stocked. Email us | 50 | 3,400 C.T. | 318 mA | 4 - 8 - 16 | — | 6L6GC8075881EL346146B6550B |
| 1650PPNot stocked. Email us | 60 | 6,600 C.T. | 200 mA | 4 - 8 - 16 | — | 6L6GC8075881EL346146B6550BKT88 |
| 1650PAPNot stocked. Email us | 60 | 6,600 C.T. | 200 mA | 4 - 8 - 16 | — | — |
| 1650RPNot stocked. Email us | 100 | 5,000 C.T. | 317 mA | 4 - 8 - 16 | — | 8075881EL346146B6550BKT88 |
Need dimensions, mounting details or help matching a transformer to your build? Click the part number to open it in our shop, or email info@evatco.com.au.
