2 watt amplifier

[Bone]

I have just won two speakers with output transformers attached. They are 2 watt speakers and the transformers have 3K primaries.
If I wanted to make single ended amplifiers for them, what valve (tube) would be suitable for these.
Can I use a 6V6 for example as I have some of these?

Tony.

[costis_n]

Well, are your transformers designated for single-ended operation? if you do not know, you can check how they are stacked (if you can see the laminations of course).

Also 3K for 6V6 = low load, higher distortion, lower allowed HT=lower output power. Better with EL34 or KT77 or 6L6.

[Frank Berry]

A 6DN7 might work. You should be able to get a couple of watts out of a single tube.

[toprepairman]

You'll be Ok with 6v6. They're good normally for around 4.5watts, but as you won't run them at more than 2 then all will be Ok.
Could help a bit if you ibclude the secondaries in the cathode circuit.

[Shoog]

EL86 might work well.

Shoog

[Yvesm]

Mmmh ?
Loudspeakers with attached transformers was usually designed to be attached on a 70 or 100 volts distribution system.
Transformers has no gap nor center tap so they can't be used in classical SE no more than in PP configuration.
However some totem pole arrangements like SRPP or SEPP could do the job.

Yves.

[Shoog]

Originally Posted by Yvesm

Mmmh ?
Loudspeakers with attached transformers was usually designed to be attached on a 70 or 100 volts distribution system.
Transformers has no gap nor center tap so they can't be used in classical SE no more than in PP configuration.
However some totem pole arrangements like SRPP or SEPP could do the job.

Yves.

Many of the old vintage German speakers used to have attached SE transformers. It was not that uncommon.

Shoog

[DF96]

Old radio sets sometimes attached the OPT to the speaker frame. Given the 2W power rating, my guess is that this is where they came from. 3K is quite a low impedance for that power level so I guess they were intended for a low HT voltage.

[kevinkr]

Seems like a 2A3 or 6AH4 might be other options worth considering depending in current rating of those transformers. A picture of the speaker and magnet would be help determine whether they have enough core area for this use..

[Bone]

The transformers have the py & sy impedences marked 3K & 3.2 ohms. I dont know what they were originally out of or what valve would drive them possibly a ECL82/86? The speakers are marked Victor P D loudspeaker. In English.