Phillips hi-Z/bi-amp speaker info?

[Pauld35]

Hello,

I have a couple of 1960/61 Phillips hi z amp radios that both use the hi impedance little 6" octagonal speakers with the high voltage to the speakers. one model uses small OT's and el84's the other has no OT and el86's.

I have some 10" hi z 800 ohm speakers with no OT's attached i wish to connect. the extension speaker out plug has 3 pins. please see schem. do the extension speakers ment to have OT's with them as well and will they work on both models and how is 3 pin wiring?

thank you for any help if know about these amplifiers.

 

[audiowize]

800 ohm speakers are probably not intended to be used with output transformers, and especially not with the 5K:4 transformers that are common to those amps.

You might try triode strapping the EL84 and putting a cap at the plate (maybe 47uF) to keep the DC off the speaker. (Or just make yourself a little OTL amp for those speakers)

 

[djmiddelkoop]

UK Vintage Radio Repair and Restoration - Philips High Impedance Speakers

 

[artosalo]

I have a couple of 1960/61 Phillips hi z amp radios that both use the hi impedance little 6" octagonal speakers...

The schematic you have attached (with single EL84) seems normal low impedance SE circuit to me.

What is the type code of that radio ?

 

[Pauld35]

hi, its is a bi-ampli plano model. here is schem. both use 800ohm

 

[Pauld35]

800 ohm speakers are probably not intended to be used with output transformers, and especially not with the 5K:4 transformers that are common to those amps.

You might try triode strapping the EL84 and putting a cap at the plate (maybe 47uF) to keep the DC off the speaker. (Or just make yourself a little OTL amp for those speakers)

hi, these are slightly different style of OT's i have had the speakers running as mains, am not sure why the 3 pin output for extension speakers.

 

[artosalo]

am not sure why the 3 pin output for extension speakers.

The EL84 SE also seems to be for 800 ohms speaker. The output transformers have some 2.5 turns ratio (5k to 800 ohms).
Extension speaker should be connected between pins 2 and 3. Pin 1 (to 3) seems to be for extra tweeter only.

I have not seen this sort of output stage for 800 ohms speakers before, only the EL86 single ended push-pull.

 

[davorin]

In addition to the EL86 (PL84 and UL84) tubes, SEPP also work with 6FE5 (50FE5), 7695 (7754) tubes and EL82 (PL82).

 

[Pauld35]

The EL84 SE also seems to be for 800 ohms speaker. The output transformers have some 2.5 turns ratio (5k to 800 ohms).
Extension speaker should be connected between pins 2 and 3. Pin 1 (to 3) seems to be for extra tweeter only.

I have not seen this sort of output stage for 800 ohms speakers before, only the EL86 single ended push-pull.

Thanks , I got confused too when i saw the output transformers at first. the other model uses four el86 and has none.