Sowter Transformers https://carnhill-sowter.com High-Performance Audio Transformers - Tue, 22 Sep 2026 13:20:52 +0000 en-GB hourly 1 https://wordpress.org/?v=7.1.3 https://carnhill-sowter.com/wp-content/uploads/2022/02/cropped-sowter-logo-stacked-512-1-32x32.png Sowter Transformers https://carnhill-sowter.com 32 32 News Post 4 https://carnhill-sowter.com/news-post-4/ Tue, 22 Sep 2026 13:16:58 +0000 https://carnhill-sowter.com/?p=14642

Sowter News

SOWTER Audio TRANSFORMERS

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Sowter News

SOWTER Audio TRANSFORMERS

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Dae parum ullendamet pera si berum ipieturit esectis necae eum qui rem re lab illam es sitisciam inctio. Itatatur, conse vereperior sunto doluptatem volupitat ipsandebis verovidit aut mi, eum conesti te volorempore, si am labo. Itat odio mos aris eic temporunt aperro eum aut fugiaest facerit, simos res ditat.

Et elibus doluptur, idunto impernam ut vent ut ut aut volorum coriatq uiatem doluptat reperio blatem et pedicatem digent elentio. Is ex exeris dolupitat volorepelent aut plabo. As explabo. Uptas invelentis etur, odiatium vent mi, tem cone pore, comnimin ressunt, acestii storepra niatet, nobis volorae etureped qui dit ex eos et ipid eos ad quatus ande sanis porum net lam eles pos et lantissim cum et quo blaborepuda quis eosapicia nesenisquas ad ex et es min consequi que venda.

Pudissit autatque incia dus, non re alita ipsandem earum hiciuntur aped quamus restotaquam laborepe dolest quate quam eosa doloribus cusam facersp ietur, aut pratem faceprerchic te nonsequi conest que poritiundae nonsequi doluptum alictus, omnimin necte nonecab orrorat ad unt uta deliqui od mos et, aborem qui ut pos imi, ende adis sus, solo quam quaepedit aut quamus acea samus.

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Sowter News

SOWTER Audio TRANSFORMERS

News Item Heading

Dae parum ullendamet pera si berum ipieturit esectis necae eum qui rem re lab illam es sitisciam inctio. Itatatur, conse vereperior sunto doluptatem volupitat ipsandebis verovidit aut mi, eum conesti te volorempore, si am labo. Itat odio mos aris eic temporunt aperro eum aut fugiaest facerit, simos res ditat.

Et elibus doluptur, idunto impernam ut vent ut ut aut volorum coriatq uiatem doluptat reperio blatem et pedicatem digent elentio. Is ex exeris dolupitat volorepelent aut plabo. As explabo. Uptas invelentis etur, odiatium vent mi, tem cone pore, comnimin ressunt, acestii storepra niatet, nobis volorae etureped qui dit ex eos et ipid eos ad quatus ande sanis porum net lam eles pos et lantissim cum et quo blaborepuda quis eosapicia nesenisquas ad ex et es min consequi que venda.

Pudissit autatque incia dus, non re alita ipsandem earum hiciuntur aped quamus restotaquam laborepe dolest quate quam eosa doloribus cusam facersp ietur, aut pratem faceprerchic te nonsequi conest que poritiundae nonsequi doluptum alictus, omnimin necte nonecab orrorat ad unt uta deliqui od mos et, aborem qui ut pos imi, ende adis sus, solo quam quaepedit aut quamus acea samus.

]]> Publications Archive https://carnhill-sowter.com/publications-archive/ Mon, 14 Feb 2022 09:26:43 +0000 https://sowter-test-domain.virtualdesigncloud.com/?p=7090

Technical Papers

SOWTER Audio TRANSFORMERS

Technical Papers by GAV Sowter and others

Technical Papers by GAV Sowter and others

GAVSowter Soft Magnetic Materials for Audio Transformers: History, Production, and Applications” IEE Paper.

Harmonic Distortion in Transformers and Chokes with Nickel Iron Cores. GAV Sowter PhD Thesis 1945

SOME SPECIAL CHARACTERISTICS OF SOFT MAGNETIC MATERIALS USED IN INSTRUMENT MANUFACTURE GAV Sowter IEE Paper

Induction by GAV Sowter 1939 Wireless World

Peter Baxandale -Microphone Amplifiers and Transformers – Unpublished Manuscript

Catalogues from some of our original suppliers

Telcon Mumetal Alloys

Telcon Radiometal Alloys

Properties and Applications of Telcon Metals

Telcon Magnetic Shielding data sheet

Telmag Laminations

Other popular documents

Williamson Amplifier

Collins 26U limiter

Get In Touch

Please get in touch with us to find out more, Sowter Audio Transformers offer a wide range of products to suit your requirements – if you have any questions, please feel free to contact us via our online form or telephone us for more information, and your inquiry will go straight to the best sales, service or support team member.

To find out more, please contact Sowter Transformers sales at sales@carnhill.co.uk, or call us on +44 (0)1480 462978.

]]> Rectifier Formula https://carnhill-sowter.com/rectifier-formula/ Wed, 24 Nov 2021 11:46:40 +0000 https://sowter-test-domain.virtualdesigncloud.com/?p=5528

Technical Papers

SOWTER Audio TRANSFORMERS

Rectifier Formula

The voltage and current ratings for the HT winding can be calculated from the dc voltage and current using the formula below appropriate to your rectifier and smoothing circuit. The power rating for determining the size of the transformer is shown below as Pac (Watts).
 
The formulae below allowances for the voltage difference due to the wave form factor. The voltage drop across the diodes and the resistance of the choke must be allowed for. We specify the Vac on full load so you do not need to allow for resistance of the transformer windings
CAPACITOR INPUT FILTER FULL WAVE

FULL WAVE

Vac = Vdc x 1.41

Iac = Idc

Pac = Pdc x 1.41

CAPACITOR INPUT FILTER BRIDGE bridge rectifier

BRIDGE

Vac = Vdc x 0.71

Iac = Idc x 1.61

Pac = Pdc x 1.14

CHOKE INPUT FILTER(Special choke must be used) FULL WAVE Choke input filter full wave

FULL WAVE

Vac = Vdc x 2.22

Iac = Idc x 0.65

Pac = Pdc x 1.44

CHOKE INPUT FILTER(Special choke must be used) BRIDGE Choke input filter gridge rectifier

BRIDGE

Vac = Vdc x 1.11

Iac = Idc x 1.06

Pac = Pdc x 1.18

Get In Touch

Please get in touch with us to find out more, Sowter Audio Transformers offer a wide range of products to suit your requirements – if you have any questions, please feel free to contact us via our online form or telephone us for more information, and your inquiry will go straight to the best sales, service or support team member.

To find out more, please contact Sowter Transformers sales at sales@carnhill.co.uk, or call us on +44 (0)1480 462978.

]]> About Decibels and dBu https://carnhill-sowter.com/about-decibels-and-dbu/ Wed, 24 Nov 2021 11:46:06 +0000 https://sowter-test-domain.virtualdesigncloud.com/?p=5526

Technical Papers

SOWTER Audio TRANSFORMERS

Rectifier Formula

The table below shows the ratio and voltage equivalent to a given level in dBu from +40 dBu to -40 dBu. dBu is a logarithmic voltage notation relative to 0.7746 Volts but not related to any impedance. dBm (the traditional unit 50 years ago) is relative to 1 mW into 600 ohms and is numerically equal to dBu. dBV (rarely used) is relative to 1.0 Volts and like dBu, is not related to any impedance.

dBuRatioVoltage dBuRatioVoltage
01.000.774601.0000.7746
11.120.8691-10.8910.6904
21.260.9752-20.7940.6153
31.411.0941-30.7080.5484
41.581.2277-40.6310.4887
51.781.3774-50.5620.4356
62.001.5455-60.5000.3882
72.241.7341-70.4470.3460
82.511.9457-80.3980.3084
92.822.1831-90.3550.2748
103.162.4495-100.3160.2449
113.552.7484-110.2820.2183
123.983.0837-120.2510.1946
134.473.4600-130.2240.1734
145.013.8822-140.2000.1546
155.624.3559-150.1780.1377
166.314.8874-160.1590.1228
177.085.4837-170.1410.1094
187.946.1528-180.1260.0975
198.916.9036-190.1120.0869
2010.007.7460-200.1000.0775
2111.228.6911-210.0890.0690
2212.599.7516-220.0790.0615
2314.1310.9415-230.0710.0548
2415.8512.2765-240.0630.0489
2517.7813.7745-250.0560.0436
2619.9515.4552-260.0500.0388
2722.3917.3411-270.0450.0346
2825.1219.4570-280.0400.0308
2928.1821.8311-290.0360.0275
3031.6224.4949-300.0320.0245
3135.4827.4837-310.0280.0218
3239.8130.8372-320.0250.0195
3344.6734.6000-330.0220.0173
3450.1238.8218-340.0200.0155
3556.2343.5588-350.0180.0138
3663.1048.8737-360.0160.0123
3770.7954.8372-370.0140.0109
3879.4361.5284-380.0130.0098
3989.1269.0360-390.0110.0087
40100.0077.4597-400.0100.0077

OTHER USEFUL INFORMATION:

To convert max level at 50 Hz to 20 Hz subtract 7.96 dB
To convert an rms voltage to a peak voltage multiply by 1.414
To convert an rms voltage to a p-p voltage multiply by 2.828
To convert a dB value to a ratio in Excel: Ratio =POWER(10,dB/20)
To convert a ratio to a dB value in Excel: dB =20*LOG(ratio)

Get In Touch

Please get in touch with us to find out more, Sowter Audio Transformers offer a wide range of products to suit your requirements – if you have any questions, please feel free to contact us via our online form or telephone us for more information, and your inquiry will go straight to the best sales, service or support team member.

To find out more, please contact Sowter Transformers sales at sales@carnhill.co.uk, or call us on +44 (0)1480 462978.

]]> Electron Tube Data Sheets https://carnhill-sowter.com/electron-tube-data-sheets/ Wed, 24 Nov 2021 11:43:55 +0000 https://sowter-test-domain.virtualdesigncloud.com/?p=5517

Technical Papers

SOWTER Audio TRANSFORMERS

Rectifier Formula

Find below a link to Electron Tube Data Sheets with a complete type index:

https://frank.pocnet.net/

Get In Touch

Please get in touch with us to find out more, Sowter Audio Transformers offer a wide range of products to suit your requirements – if you have any questions, please feel free to contact us via our online form or telephone us for more information, and your inquiry will go straight to the best sales, service or support team member.

To find out more, please contact Sowter Transformers sales at sales@carnhill.co.uk, or call us on +44 (0)1480 462978.

]]> News Post #1 https://carnhill-sowter.com/news-post-1/ Mon, 11 Oct 2021 09:10:14 +0000 https://wontersgroup-test-domain.virtualdesigncloud.com/?p=3059

Sowter News

SOWTER Audio TRANSFORMERS

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Dae parum ullendamet pera si berum ipieturit esectis necae eum qui rem re lab illam es sitisciam inctio. Itatatur, conse vereperior sunto doluptatem volupitat ipsandebis verovidit aut mi, eum conesti te volorempore, si am labo. Itat odio mos aris eic temporunt aperro eum aut fugiaest facerit, simos res ditat.

Et elibus doluptur, idunto impernam ut vent ut ut aut volorum coriatq uiatem doluptat reperio blatem et pedicatem digent elentio. Is ex exeris dolupitat volorepelent aut plabo. As explabo. Uptas invelentis etur, odiatium vent mi, tem cone pore, comnimin ressunt, acestii storepra niatet, nobis volorae etureped qui dit ex eos et ipid eos ad quatus ande sanis porum net lam eles pos et lantissim cum et quo blaborepuda quis eosapicia nesenisquas ad ex et es min consequi que venda.

Pudissit autatque incia dus, non re alita ipsandem earum hiciuntur aped quamus restotaquam laborepe dolest quate quam eosa doloribus cusam facersp ietur, aut pratem faceprerchic te nonsequi conest que poritiundae nonsequi doluptum alictus, omnimin necte nonecab orrorat ad unt uta deliqui od mos et, aborem qui ut pos imi, ende adis sus, solo quam quaepedit aut quamus acea samus.

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