Transformers & Chokes

One Electron

One Electron chokes and transformers are designed by John Atwood, to fill the need for high-quality yet affordable audio transformers and chokes that are not normally available elsewhere.

Marshall

Marshall guitar amplifiers are among the most recognized in the world. They are known for their Marshall "crunch".

Hammond

Hammond Manufacturing offers a full range of transformers, chokes and enclosures.
P-T290-FENDER-120-UP Transformer - Hammond, Guitar Amplifier, replacement for Fender, 120 V upgrade
  • Designed for drop in replacement of original units. Upgraded units with variable voltage.
  • Physically, parts were designed to look similar to original factory units (where possible).
  • Material used & design specs. were kept as close as possible to the original part to preserve the stock "tone".
  • See P-T290-FENDER-120 for 120 V basic transformers, P-T290-FENDER-240 for 240 V transformers

Warning: Not all amplifier models of the same name use the same transformer model.
Starting at $75.76
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Originally: $84.18
P-T290-YORKVILLE Transformer - Hammond, Guitar Amplifier, replacement for Yorkville / Traynor
  • Replacement for Yorkville/Traynor amplifiers
  • Designed for drop in replacement of original units.
  • Physically, parts were designed to look similar to original factory units (where possible).
  • Material used & design specs. were kept as close as possible to the original part to preserve the stock "tone".

Part No. Primary Secondary 1 Secondary 2 Secondary 3 Yorkville / Traynor Amp Yorkville / Traynor Part No VAC Hz. P-T290TRA 120 V 60 Hz. 320 V @ 600 mA 60 V @ 50 mA 6.3 V.C.T. @ 9 A 100 Watt Bass A-1380 P-T290TRB 120 V 60 Hz. 620 V @ 115 mA 6.3 V.C.T. @ 115 mA YBA2-B A-1314 P-T291JX 120 V 60 Hz. 320 V @ 500 mA 60 V @ 20 mA 6.65 V.C.T.
Starting at $68.85
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Originally: $76.50
P-T290-AMPEG Transformer - Hammond, Guitar Amplifier, replacement for Ampeg
  • Replacement for Ampeg amplifiers
  • Designed for drop in replacement of original units.
  • Physically, parts were designed to look similar to original factory units (where possible).
  • Material used & design specs. were kept as close as possible to the original part to preserve the stock "tone".



Part No.
Primary
Ampeg Model Names
Ampeg Part No
Bobbin/Paper Wound


VAC
Hz.




P-T291GX
120 V
60 Hz.
B25
12XA
Bobbin


P-T290CAZ
117 V
60 Hz.
Gemini VI 25W
PT 113
Bobbin


P-T290ETX
120 V
60 Hz.
Super Echo Twin
PT 109
Bobbin


P-T291HX
110 / 115 / 230 V
50 / 60 Hz.
V50H
94-270-030
Bobbin
Starting at $67.77
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Originally: $75.30
P-T290-FENDER-240 Transformer - Hammond, Guitar Amplifier, replacement for Fender, 240 V
  • Designed for drop in replacement of original units.
  • Physically, parts were designed to look similar to original factory units (where possible).
  • Material used & design specs. were kept as close as possible to the original part to preserve the stock "tone".
  • See P-T290-FENDER-120 for 120 V transformers, P-T290-Fender-120-UP for upgraded 120 V transformers

Warning: Not all amplifier models of the same name use the same transformer model.
Starting at $36.90
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Originally: $41.00
P-T1750ORF Transformer - Hammond, Output, replacement for Orange Rocker 30
Hammond output transformer - replacement for Orange Rocker 30 Specifications: Part No. Pri Ohms Sec Ohms Amplifier Type Watts Bobbin/Paper Winding Equivalent To P-T1750ORF 6,000 C.T. 8, 16 Push-Pull 35 W Bobbin OT199SL
$52.65
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Originally: $58.50
P-C194TB Choke - Hammond, replacement for Vox TB35C2
16H @ 40 mA guitar amplifier replacement for Vox TB35C2 Tony Bruno. Physically, parts were designed to look similar to original factory units (where possible). Material used & design specs. were kept as close as possible to the original part to preserve the stock "tone".
$19.58
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Originally: $21.75
P-T290-MARSHALL Transformer - Hammond, Guitar Amplifier, replacement for Marshall
  • Replacements for Marshall amps
  • Designed for drop in replacement of original units.
  • Physically, parts were designed to look similar to original factory units (where possible).
  • Material used & design specs. were kept as close as possible to the original part to preserve the stock "tone".
Starting at $86.85
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Originally: $96.50
P-T166F30 Transformer - Hammond, Low Voltage / Filament, Open, 30 VCT
  • Primary 115 VAC, 60 Hz.
  • Secondary 30 C.T.
  • Center tapped secondary.
  • Open style, channel bracket, two hole chassis mount.
  • Minimum 6" long leads.
  • Dual bobbin design - no electrostatic shield required.
  • Class B insulation (130 degrees, C).
  • Hi-Pot test of 2,000 V RMS.
  • UL listed (# E50394) & CSA certified (# LR3902).
$18.57
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Originally: $20.63
P-T109L Transformer - Hammond, 2W Audio Miniature Epoxy Potted
Features:
  • Perfect for audio input, line matching, isolation or output transformer applications.
  • 2 watt (± 1.5 dB, 300 Hz. - 50 kHz.).
  • Epoxy potted in an attractive black molded case, Pin type P.C. board mount (min. 0.187" length).
  • Power level ratings are maximum at lowest frequency rating
  • Power can be increased slightly at higher frequencies.
  • Will withstand soldering for 10 sec. @ 260 degrees C, ambient temp. 85 degrees C max.
$24.62
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Originally: $27.35
P-T126B Transformer - Hammond, Tube Driver Interstage
Audio watts: 4
Impedance: 5k ohms
D.C. Resistance: 178 ohms
Inductance: 44 henries
Rated D.C. Bias Current: 30 mA
Features:
  • Designed for driver use ONLY in single ended tube output amplifiers. These units replace coupling capacitor circuits for improved sound.
  • Closed style with minimum 8" long leads.
  • All models use bifilar wound windings for exceptional coupling and bandwidth.
  • Minimum frequency response 20 Hz. - 20 Khz (± 1db max. ref. 1 Khz.).
  • The core is gapped to support the specified D.C.
$75.28
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Originally: $83.64
P-T145J Transformer - Hammond, Audio Chassis Mount Driver, 4k primary
  • Application: Driver
  • Primary Impedance: 4000 ohms
  • Secondary Impedance: 600 ct
  • Primary D.C.: 8 mA
  • Primary D.C. Resistance: 340 ohms
  • Secondary D.C. Resistance: 24 ohms
  • Output: 135 mW
  • Dimensions A: 1.63
  • Dimensions B: 0.88
  • Dimensions C: 0.81
  • Dimensions D: 1.38

Features:
  • Small, economical, open, two hole horizontal bracket mount.
  • Insulated, color coded flexible leads, 4" long minimum
  • Frequency response 150 Hz. to 15 Khz. (+/- 1 db, reference 1000 Hz.)
  • When operating at impedances below nominal, power capability and the frequency spectrum are proportionately lower, conversely, at higher impedances power capability and frequency spectrum will be proportionately higher.
  • Net weight: 0.5 oz.
$16.33
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Originally: $18.14
P-T145N Transformer - Hammond, Audio Chassis Mount Driver, 10k primary
  • Application: Driver
  • Primary Impedance: 10000 ohms
  • Secondary Impedance: 2000 ct
  • Primary D.C.: 5 mA
  • Primary D.C. Resistance: 700 ohms
  • Secondary D.C. Resistance: 89 ohms
  • Output: 135 mW
  • Dimensions A: 1.63
  • Dimensions B: 0.88
  • Dimensions C: 0.81
  • Dimensions D: 1.38

Features:
  • Small, economical, open, two hole horizontal bracket mount.
  • Insulated, color coded flexible leads, 4" long minimum
  • Frequency response 150 Hz. to 15 Khz.
$16.33
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Originally: $18.14
P-T162F120 Transformer - Hammond, Power, Low Voltage PC Mount Dual Primary
  • Operate on 50/60 Hz current
  • Low profile, split bobbin design.
  • Dual winding secondaries, non-concentrically wound
  • Units are designed so that all windings must be used
  • Low primary to secondary coupling - no electrostatic shield required.
  • Universal dual primary 115/230V
  • High insulation - Hipot of 2,500V RMS.
  • Class B insulation - 130 degrees C.
$7.93
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Originally: $8.81
P-T166C50 Transformer - Hammond, Low Voltage / Filament, Open, 50 VCT
  • Primary 115 VAC, 60 Hz.
  • Secondary 50 C.T.
  • Center tapped secondary.
  • Open style, channel bracket, two hole chassis mount.
  • Minimum 6" long leads.
  • Dual bobbin design - no electrostatic shield required.
  • Class B insulation (130 degrees, C).
  • Hi-Pot test of 2,000 V RMS.
  • UL listed (# E50394) & CSA certified (# LR3902).
$18.14
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Originally: $20.16
P-T166EA24 Transformer - Hammond, Low Voltage / Filament, Open, 24 VCT
  • Primary 115 VAC, 60 Hz.
  • Secondary 24 C.T.
  • Center tapped secondary.
  • Open style, channel bracket, two hole chassis mount.
  • Minimum 6" long leads.
  • Dual bobbin design - no electrostatic shield required.
  • Class B insulation (130 degrees, C).
  • Hi-Pot test of 2,000 V RMS.
  • UL listed (# E50394) & CSA certified (# LR3902).
$11.82
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Originally: $13.13
P-T166X-36 Transformer - Hammond, Low Voltage / Filament, Open, 36 VCT
  • Primary 115 VAC, 60 Hz.
  • Secondary 36 C.T.
  • Center tapped secondary.
  • Open style, channel bracket, two hole chassis mount.
  • Minimum 6" long leads.
  • Dual bobbin design - no electrostatic shield required.
  • Class B insulation (130 degrees, C).
  • Hi-Pot test of 2,000 V RMS.
  • UL listed (# E50394) & CSA certified (# LR3902).
Starting at $17.73
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Originally: $19.70
P-T166G60 Transformer - Hammond, Low Voltage / Filament, Open, 60 VCT
  • Primary 115 VAC, 60 Hz.
  • Secondary 60 C.T.
  • Center tapped secondary.
  • Open style, channel bracket, two hole chassis mount.
  • Minimum 6" long leads.
  • Dual bobbin design - no electrostatic shield required.
  • Class B insulation (130 degrees, C).
  • Hi-Pot test of 2,000 V RMS.
  • UL listed (# E50394) & CSA certified (# LR3902).
$20.25
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Originally: $22.50
P-T166J16 Transformer - Hammond, Low Voltage / Filament, Open, 16 VCT
  • Primary 115 VAC, 60 Hz.
  • Secondary 16 C.T.
  • Center tapped secondary.
  • Open style, channel bracket, two hole chassis mount.
  • Minimum 6" long leads.
  • Dual bobbin design - no electrostatic shield required.
  • Class B insulation (130 degrees, C).
  • Hi-Pot test of 2,000 V RMS.
  • UL listed (# E50394) & CSA certified (# LR3902).
$9.02
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Originally: $10.02
P-T166K18 Transformer - Hammond, Low Voltage / Filament, Open, 18 VCT
  • Primary 115 VAC, 60 Hz.
  • Secondary 18 C.T.
  • Center tapped secondary.
  • Open style, channel bracket, two hole chassis mount.
  • Minimum 6" long leads.
  • Dual bobbin design - no electrostatic shield required.
  • Class B insulation (130 degrees, C).
  • Hi-Pot test of 2,000 V RMS.
  • UL listed (# E50394) & CSA certified (# LR3902).
$12.02
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Originally: $13.35
P-T166X-5 Transformer - Hammond, Low Voltage / Filament, Open, 5 VCT
  • Primary 115 VAC, 60 Hz.
  • Secondary 5 C.T.
  • Center tapped secondary.
  • Open style, channel bracket, two hole chassis mount.
  • Minimum 6" long leads.
  • Dual bobbin design - no electrostatic shield required.
  • Class B insulation (130 degrees, C).
  • Hi-Pot test of 2,000 V RMS.
  • UL listed (# E50394) & CSA certified (# LR3902).
Starting at $18.50
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Originally: $20.56
P-T167X-25 Transformer - Hammond, Low Voltage / Filament, Enclosed, 25 VCT
  • Primary 115 VAC, 60 Hz.
  • Secondary 25 C.T.
  • All secondaries center tapped, VAC (RMS)
  • Enclosed, 4 hole chassis mount.
  • Minimum 6" long leads.
  • Dual bobbin design - no electrostatic shield required.
  • Class B insulation (130 degrees C).
  • Hi-Pot test of 2,000V RMS.
  • UL listed (# E50394) & CSA certified (209651).
Starting at $27.58
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Originally: $30.65
P-T167J36 Transformer - Hammond, Low Voltage / Filament, Enclosed, 36 VCT
  • Primary 115 VAC, 60 Hz.
  • Secondary 36 C.T.
  • All secondaries center tapped, VAC (RMS)
  • Enclosed, 4 hole chassis mount.
  • Minimum 6" long leads.
  • Dual bobbin design - no electrostatic shield required.
  • Class B insulation (130 degrees C).
  • Hi-Pot test of 2,000V RMS.
  • UL listed (# E50394) & CSA certified (209651).
$31.45
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Originally: $34.94
P-T167L50 Transformer - Hammond, Low Voltage / Filament, Enclosed, 50 VCT
  • Primary 115 VAC, 60 Hz.
  • Secondary 50 C.T.
  • All secondaries center tapped, VAC (RMS)
  • Enclosed, 4 hole chassis mount.
  • Minimum 6" long leads.
  • Dual bobbin design - no electrostatic shield required.
  • Class B insulation (130 degrees C).
  • Hi-Pot test of 2,000V RMS.
  • UL listed (# E50394) & CSA certified (209651).
$43.52
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Originally: $48.36
P-T169C Transformer - Hammond, Isolation, 100VA
Capacity: 100 VA
Features:
  • Primary 115VAC, 60 Hz.
  • Secondary taps @ 90, 100, 110, 115, 120 & 130VAC
  • Electrostatic shield between primary & secondary
  • Connection by flexible leads, 8" minimum length
  • Perfect for critical line voltage needs (examples: older "classic" tube equipment or Japanese 100V equipment).
  • CSA certified (# LR3902)
  • Remember - These units do NOT convert line frequency
$54.41
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Originally: $60.45
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