Can I run it at 4Ohms?

[toomanyslurpees]

Sorry, bit of an elementry question but I can't seem to google me up an answer, I have two heads, they both have 8Ohms writen at the output jack, but have a second parallel jack, no impedance switching, no mention of minimum impedance. One is a Traynor YRM-1 with EL34s, one is a lifco model 1000 (similar to a Traynor YBA-1) with 7027s. Is there a diffinitive way to tell? Thanks.

[navdave]

You probably could but I wouldn't the schematic only shows a single 8 ohm secondary for the Traynor amp dito for the Lifco 1000 a Traynor knock off.
You could run two 16Ω cabs with it. What kind of cab or speakers you got?

[toomanyslurpees]

Thanks, that's not devistating news, but it would have been possibly handy... I have a single 12 with an 8ohm which is cool (though it's a 30W speaker so I'll have to be careful), and I have a 212 with 2 8ohm webers, I kinda want to run the 212 in stereo which also is no problem but it might have sometimes have been handy to power the 212 mono with one of these heads, but of coarse I'm fine with not letting the smoke out of anything.

Do you have a schematic for the Lifco? That would make my day....

[navdave]

Are you running the Traynor on one speaker and the Lifco on the other speaker with that 2x12 cab?
If your running two 8Ω speakers using one of those amps that's a 4Ω load.
Nope cant find a Lifco schem anywhere never heard of em til your post. 

[LooseChange]

Both amps are built using beefy output transformers. I would not worry about running either amp on 4 ohms. A good match is always better.

[nateflanigan]

fwiw

http://www.londonpower.com/faq.htm

There's quite a bit of ranty information there, I found some of it very eye opening.

[toomanyslurpees]

That's some interesting info but I can't get over my fear off mismatching cabs after once plugging my 4ohm bass cab into the 8ohm output of my pignose bass head instead of the 4ohm one and a tube melt down very quickly followed.

[dynaman1]

FWIW, my band's bass player has been running his 50W Traynor Bassmaster into a monster Ampeg 9X10 cab for years with zero probs. I think that cab specs at 4 or 5 ohms.

[Latole]

Are you running the Traynor on one speaker and the Lifco on the other speaker with that 2x12 cab?
If your running two 8Ω speakers using one of those amps that's a 4Ω load.
Nope cant find a Lifco schem anywhere never heard of em til your post.

Old post;  Lifco 1000 schematic

I have one of these amp. I put new filter caps, bias pot........

I took readings and calculated the impedance of the transformer and I arrive at 16 ohms at the secondary.
I am used to these measurements and calculations

Many Lifco shematic here ;    http://web.ncf.ca/ac151/lifco_1000_nt.pdf

[mresistor]

It says in the notes that this person used an 8 ohm dummy load to caluculate all the voltages.

[mresistor]

   Was it you Latole?