Here is a very brief description of the 404.

In a nutshell--- it is a small signal ( <3 watts) autoformer with a nominal "primary" impedance of 5K and nominal secondary impedances of approx 500\600 down to four ohms. It has often been used as a linestage outut trans and also an earphone output transformer. It is parafeed only and you must use blocking cap in front of transformer (i.e., in btwn plate of tube and input on pri side).

If you use the search engine with TL-404 there is close to two hundred posts on this guy.

Last call on a truly Peerless design.

$600 a pair plus shipping.

Email me at acrosound@aol.com

Builder of MagneQuest & Peerless transformers since 1989

 Some additional specs on the TL-404 autoformer - mqracing 13:47:36 02/04/17 (1)
 RE: Some additional specs on the TL-404 autoformer - OldNuke 22:25:49 05/05/17 (0)

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 Some additional specs on the TL-404 autoformer - mqracing 13:47:36 02/04/17 (1)
 RE: Some additional specs on the TL-404 autoformer - OldNuke 22:25:49 05/05/17 (0)

The nominal secondary (load) impedances are 4, 10, 50, 200, 500 ohms.

These load impedances may be varied plus or minus 25%.

Frequency response +/- 1dB from 20 hz to 100 khz as shown in graph below.

The MOL at 25 Hz is 100vrms across full "primary"

The MOL at 30 Hz is 125vrms across full "primary"

Builder of MagneQuest & Peerless transformers since 1989

• TL-404 frequency response graph