Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: LooseChange on September 29, 2010, 10:00:30 am
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Thanks!
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4 + 8 without a doubt
a few crossed wires and you can reconfigure a 16 ohm cab into 4 or 8
leaves the possibility of running into a single 16 ohm speaker, rare on this side of the Atlantic.
Funny you bring this up, not an hour ago I just wired up a 4 and 8 output jacks on a small SE amp I threw together.
Remember that funny Switchcraft jack I sent you a long while ago with an isolated switch?
I used two of them one for the 4 and one for the 8. The 8 ohm lead lands on the switch of the 4 ohm jack and after the switch goes to the tip on the 8 ohm jack. and the 4 ohm lead lands on the switch of the 8 ohm jack etc.
So when you plug into the 8 ohm jack, the isolated switch opens and disables the 4 ohm jack, a vice versa when you plug into the 4. Keeps people like my step son from trying to plug a 4 ohm 2x12 into the 4ohm and a single 8 ohm into the 8 ohm jack at the same time. After all they were labeled that way right!
Ray
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Yup, I remember those jacks... I think they went into a Mesa.
Thanks for voting.
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Bumped... It's a close race. Please add your vote. Thanks!
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+ 1 for 4ohm and 8ohm options
Kagliostro
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Why not one jack and an impedance switch?
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I was waiting for that! Took seven days. :smiley:
Because I don't like those rotary switches. It's funny, you don't see them very much except with Marshalls. I see a lot of multiple holes.
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Because I don't like those rotary switches.
It doesn't have to be a rotary switch, you could also use a toggle switch.
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I too went with 4 and 8, the most common configs I use.
I have a 4x12 16 ohm wired to stereo 8 or mono 4.
My 2x12 is 8.
And most of the singles I have kicking around are either 4 or 8 ohm.
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It doesn't have to be a rotary switch, you could also use a toggle switch.
Only have two holes. Either one for each load Or a toggle and a jack to switch between the two loads. Got a nifty toggle that will switch three??
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Got a nifty toggle that will switch three??
Well, I'm not completely sure what the requirements are for an impedance switch, but it seems that it needs to be some kind of heavy duty switch. So you can search an SPTT or SP3T (single pole triple throw) switch.
Or you could use a heavy duty Apem on-on-on switch as a 1x3 switch.
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I was waiting for that! Took seven days. :smiley:
Because I don't like those rotary switches. It's funny, you don't see them very much except with Marshalls. I see a lot of multiple holes.
4 and 8.
I'm thinking of just going with 4/8/16 jacks on any new builds like my previous combo that I did. Cost less and don't need to mess with that bulky impedance switch.
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Doug sells a 'non-bulky' switch guys.One small hole and a knob or no knob.
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Doug sells a 'non-bulky' switch guys.One small hole and a knob or no knob.
I really like Doug's impedance switch. It's beefy with a very solid feel when you rotate the knob. However, you better get one physically in your mitts before drilling a hole in the chassis unless yours is really deep. It will fit in a Blackface Fender chassis (1.75" high) IF you drill the hole dead center vertically and then bend the tabs over so that they are parallel with the floor of the chassis. You can see the tabs bent over in this pic:
(http://i222.photobucket.com/albums/dd298/Chipster457/Super%20Reverb/GutsPoweramp.jpg?t=1286417729)
I prefer one speaker jack and the rotary switch over multiple speaker jacks or even two parallel speaker jacks and the switch. YMMV
Cheers,
Chip