yossarian83 wrote: ↑Thu Sep 28, 2017 12:47 am
AFAIK, the 90's OR120 power transformers are the same winds as the 70's. If the input voltage matches what the amp is set for, and the amps components are functioning correctly, the plate voltage will be ~470.
I did some digging and discovered that the line voltage in the Netherlands is 230 vac. swapping the leads on the PT would not be of any benefit in this case.
The safest bet would be to use the 240 voltage tap, which would put your amps internal voltages slightly lower than the factory schematic (probably around 450-460 on the plates). Then all the OP would have to do is get couple of 6V6's and have the amp biased in order to run them. (assuming the impedance switch is adjusted accordingly)
I'd like to try a pair of JJ's.Those review quite well and will be next on my list. However, as long as guitar amps have been running 6v6's, they've been running them outside of their published specs. Nothing new here, same with EL84's, EL34's, etc... you should be fine as long as you don't have 500 plus on the plates running 34's. That would put you well over with the JJ's as they don't pull as much current.
An attenuator is a good option, just much more expensive and may not give the results OP they're looking for. Not to mention, it's one more piece of gear... I really get a kick out of running this historically overwhelming beast around 20 watts and not losing much tone-wise
Lunchbox amps can bite me!
fiveightandten wrote: ↑Wed Sep 27, 2017 2:40 am
I'd like to hear that with the master cranked. Interesting.
I'll see what I can do
Yes! It's been so long since we talked OR-120/80 around here.
Most of the 70's amps I've seen have 115V primary taps for US voltage, whereas the 90's amps have a 120V tap. I've owned three 90's heads, and I haven't had any that were in the 470V range, but maybe my wall voltage is high around here.
My last 90's OR-120/80 used to run right around 500V, and my 70's head runs around 515V or so. I can't recall what my current 90's OR-80 is running at...I think it's 485V or so. I'd welcome lower B+, as most EL-34's technically aren't spec'd right for the screen voltages in these amps. They're ok, but still.
Anyways, back to European voltages, that's great that he can just run it off the 240V tap and get some safe voltages. As long as the heaters are ok, he should be fine. It's worth a try, IMO.
You might like the JJ 6V6s. They're beefy and have a lot of low end. I have a Hi-Tone HT30, which is their 30W Hiwatt clone. Rather than go with an EL-84 power section, they picked the beefiest most punchy sounding small bottle tube they could find and went with the JJ 6V6S. They're even larger, physically, than normal 6V6s. Check them out some time.
Do up a video of it running full tilt if you can! I'm interested in this. I've been running mine with the Fryette Power station and it sounds glorious. But, as you said, it's one more piece of gear to lug around. It would be great to get the sound I want out of a pair of 6V6's. Maybe I'll yank them out of the Hi-Tone to try them. I fear my plate voltage might be too high, but it's probably worth a try.
This got me in the OR-80 mood...I just jammed on mine for over an hour. These amps are absolutely savage compared to the new Oranges. The natural overdrive on them is just vicious, then you can roll back and get the great prickly edge of breakup. Truly unique sounding amps. I'm using this thing at our gig this weekend. I was going to bring the AD30, but this OR-80 sounds too awesome.
-Nick