tubes for these OPT?, pri 1.75Kohm, sec 2.5, 4, 8ohm, taps 20%, weight 4Kg

[heinrichs]

hey

i got 2 OPT for free some time ago with these specs:

pri 1.75Kohm,
sec 2.5, 4, 8ohm,
taps 20%,
weight 4Kg
no ideer about wattage.


and i have no ideer what to use them for... guessing it would have to be some parallel push pull? but i could really use some ideers, as to what tubes would make sence with these OPT.

I am open to any ideers, dont have to be the usual tubes.

-heinrichs

 

[danFrank]

Hi,
They should be large enough for PPP EL34 (4 of them). I do not know the quality of the transformers, but they would do well for guitar amp service. Do you play guitar?
1.75K Ohm is pretty low for a single pair of tubes.
Daniel

 

[smoking-amp]

8.8 Lbs, sounds like maybe a 70 to 100 Watt OT (for 20 Hz low end, would be more, maybe 120 Watts for 30 Hz low end). The low primary Z sounds like for parallel tubes. On the 20% taps, is this 20% of turns or 20% of impedance (.45 turns)? If 20% of turns, I think maybe EL84 has this 20% spec for UL mode. Could be made to work for a UL sweep tube too if the DC level could be dropped as well.

 

[nicoch58]

mismatch the secondary the load will be 3.5k ....

 

[hidnplayr]

I would use EL36 in triode, push-pull parallel 🙂 (you could try in UL mode too, dont know how good it will work)
Should give over 30 watts, with those big OPT's you should have really nice bass I guess..