Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: a90s2cs on February 16, 2018, 01:18:19 pm
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I have a quick question. I had a Sovtek Mig 50 back in the day, I sold it years ago and have regretted it ever since. This summer I saw EHX reissued them so I snatched one up. I dig it, pretty faithful to the original.
Anyway it has a voltage selector switch on the back for 100v, 117v and 240v. I've been running it at 117v. So the question is, what would happen if I tried the other settings? I seem to remember reading something like if you use the 100v tap with 110v coming from the wall you'd get a little less headroom and earlier breakup and it would be harmless. Would the opposite be true if you switched it to 240v, more headroom and later breakup? Would it damage anything?
That switch is taunting me, every time I look at it I want to try it but I always hear the voice of a pissed off race engineer in my head exclaiming "You haven't even gotten it out on the track yet and you've already f****d it up!".
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Use that switch to match your line voltage. DON'T USE IT AS A TONE SWITCH!
Probably mentioned somewhere in your user manual.
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The 100V input, on US outlets, will BLOW UP the amp.
The 240V input may not be blow-up, but will not play at all well, and long-term tear-up the tubes.
So not only a bad idea, but you heard it backward.
Don't believe most of the BS on the Internet. (Including my words.) Some wise hack-writer recently noted the internet may have much of human intelligence, but also most human UN-intelligence.
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I had no intention of using it as a 'tone switch'. I think I read that in some instructions for an amp kit that I am now very glad I didn't buy.
I was also asking because It's a slide switch with a weak detent and the 117v is in the middle so it would be really easy to inadvertently move it to the wrong position and not realize it. I'm not the only person who uses the amp and it gets moved a around a bit, so now that I know it's bad I'll make sure to put a piece of tape over it or something.
The manual for this amp is pretty sparse, it basically just says "set it to the correct voltage". Didn't say setting it to the wrong voltage could damage it.
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> a slide switch with a weak detent
Do you plan to move outside North America frequently?
Then (if you can do so safely!) open it up, figure what the slide switch does, bypass it with soldered permanent joints on the "117V" connection. Make a label "117V Only!".
Remember that messing with wall-power can electrocute a user or burn down a house. Do it right.
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Thanks for the advice. I opened it up and bypassed the switch and capped the 100v & 240 leads.
While I was in there I noticed the people at EXH have a sense of humor.