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Topic: Attenuating power output |
Scott Appleton
From:
Ashland, Oregon
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Posted 18 Mar 2011 11:35 pm |
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Here is my question .. I love my Vibrasonic but its too loud for most shows .. I love my NV 400 but its too loud for most shows .. I was looking at the two ways to
tame down the output #1 is a power soak between output and the speaker and #2 is "The volume box" which goes in the effects loop and attenuates the preamp output to the power amp section .. Also is there a way to pull
2 of the 6l6's from the Fender output to lower the
total power output? I see some new amps with switches to change the output .. My question is which is the best
way to go #1or #2 and is it really possible to pull two output tubes and not cause damage to a Vibrasonic? any ideas .. |
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Ron Davis
From:
Lake Arrowhead, California... We're a mile high. ;)
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Posted 19 Mar 2011 1:48 pm
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Scott...
I sometimes use a Weber attenuator, for guitar stuff, on my Princeton Reverb, 7 AC/15. It works great.
_________________
Emmons 12 p/p, Revelation, Black Widows, (& way too many assorted goodies...)
Drummer with a pedal steel fantasy. 
www.LA-Zep.com
www.Desperado1.com
www.CMWChicagoTribute.com |
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Clete Ritta
From:
San Antonio, Texas
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Posted 19 Mar 2011 11:42 pm
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Look for a used THD Hot Plate.
I think they are discontinued now, but work very well for tube amps.
Just make sure you get the right model for your desired ohms.
Clete |
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John Billings
From:
Ohio, USA
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Posted 20 Mar 2011 9:54 am
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| Dr. Z Airbrake, designed by the late Ken Fischer(sp?). They all work well, up to a certain point, when your tone gets lost. But that usually only happens when you radically cut back the volume. I've had several over the years, and like the Airbrake the best. |
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Thom Ferman
From:
Las Vegas, NV, USA
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Posted 21 Mar 2011 12:57 pm
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Scott, I have one of the 90's Fender Custom Vibrasonic (PC board) amps and have routinely pulled 2 of the output tubes if I need to run lower power or dirty things up sooner. The trick is to pull either the 2 outer output tubes or 2 inner output tubes. Never the left pair or right pair as this will inevitably cause output transformer heating and possible failure. Note that you will approximately double the output impedance of the amp when you pull two tubes so watch your speaker loading (ie, my 4 ohm output became an 8 ohm output).
_________________
Thom Ferman
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Dave Grafe
From:
Hudson River Valley NY
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Posted 22 Mar 2011 9:22 am
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| I'm curious why you don't just turn the Fender's input volume or the NV400's master volume down to achieve what you are reaching for. I routinely rehearse with a vibrosonic and it sounds great at 2 or 3 if necessary, the NV400 has a master volume for exactly this reason, and pulling tubes from amps, while reportedly done successfully by many pickers, is just bad juju. Looking for best practices here you know... |
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Scott Appleton
From:
Ashland, Oregon
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Posted 22 Mar 2011 7:43 pm turning down
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Well that is a big question and the answer is not as simple as it seems. even at 2 or 3 the Vibrasonic is
too loud for most small 50 to 150 patron clubs.
The NV is another problem .. this one seems to respond well with the master vol control but the actual physical power of the amp still shines through even turned down. I have video taped the shows and the steel just dominates when It seems to be at a level where I like the tone and volume. That's why I use a Delux reverb or a Mesa maveric ..just less sound pressure coming out of the 12's compared to the 15's. so I thought maybe reducing the power to the speaker would improve that kind of sound pressure. I think it will work for the Vibrasonic not sure it will help the NV 400. Gonna try the AirBreak .. seems compact and will work up to 100 watts .. probably nothing I can do with the NV400 just save it for outdoor shows ..Also I like the VS because I play guitar as well as steel and it's easy with just one amp to set up for a show. |
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Dave Grafe
From:
Hudson River Valley NY
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Posted 11 Apr 2011 12:38 pm
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| Rather than pulling output tubes why not replace the front end 12AX7 with a 12AT7? It will lower the gain at the input stage and reduce inter-stage distortion, although it might not sound dirty enough for your guitar if that's your style. |
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