My DC-3 combo seems to have more power and volume than I can ever use. Even after doing the volume mod. With the output dialed back, I may be missing the sweet spot of the power amp by playing at lower volumes (although I think it still sounds pretty good). Some people add an attenuator to drive their amp harder with less volume. But can I achieve basically the same thing by plugging the 8 ohm V30 speaker to the 4 ohm output? The impedance mismatch should lower the volume level. Will this allow for more power amp saturation and a smoother sound? Does an attenuator also work the same way by changing the output impedance? Or does it dissipate some of the signal through heat loss, like a resistor? Is there any chance that I would damage the amp or the speaker?
plug to 4 ohms instead of using attenuator?
- Thread starter photogold
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welshboogie
Well-known member
Its safe to plug into the 4ohm (well it is on my MKIV as I do this too!!)
It does somewhat "soften" the attack.
As far as att's are concerned, there is a load resistor to soak up some of the output but to my knowledge there is no change of impedance.
It does somewhat "soften" the attack.
As far as att's are concerned, there is a load resistor to soak up some of the output but to my knowledge there is no change of impedance.
SonicProvocateur
Well-known member
Yes...and no.
It loads up voltage on the amps power transformer and the tubes, thusly shortening tube life and putting extra load on the transformer (hence the softer attack and lower volumes...)
You can damage your amps components by doing this alot or running it at high volumes (lots of voltage...remember Boogies are strong amps)
The attenuator works by soaking voltage load through resistors which (through the laws of physics) gets turned into heat...its much safer to use an attenuator IMO than loading up your amps transformer by mismatching your impedance.
Also remember that an amps "sweet spot" is hit sometime by driving the speaker to a certain volume, and you may just have to play a little louder to hit that sweetness. Mesa wouldn't load their amps with quality speaker's unless they intended you to make em move a little :wink:
It loads up voltage on the amps power transformer and the tubes, thusly shortening tube life and putting extra load on the transformer (hence the softer attack and lower volumes...)
You can damage your amps components by doing this alot or running it at high volumes (lots of voltage...remember Boogies are strong amps)
The attenuator works by soaking voltage load through resistors which (through the laws of physics) gets turned into heat...its much safer to use an attenuator IMO than loading up your amps transformer by mismatching your impedance.
Also remember that an amps "sweet spot" is hit sometime by driving the speaker to a certain volume, and you may just have to play a little louder to hit that sweetness. Mesa wouldn't load their amps with quality speaker's unless they intended you to make em move a little :wink:
babow2
Well-known member
+1 on the attenuator.
In addition to the risk of damage to your transformer, shorter tube life and general risks that others have raised, using the 40hm output into 8ohm load only give you a little attenuation. the few times I tried it, I got very little attenuation, and it didn't really enable me to turn the output up to any meaningful difference. Also, you only get what you get, and have no control.
A decent attenuator (THD Hotplate, Weber, etc.), on the other hand, enables you to dial in the db attenuation. So, you can adjust the level of attenuation nearly to infinity enabling you to find the "sweet spot" setting on the amp. So, an attenuator is the safest way to enable you to make the amp's power section work harder with more flexibility.
In addition to the risk of damage to your transformer, shorter tube life and general risks that others have raised, using the 40hm output into 8ohm load only give you a little attenuation. the few times I tried it, I got very little attenuation, and it didn't really enable me to turn the output up to any meaningful difference. Also, you only get what you get, and have no control.
A decent attenuator (THD Hotplate, Weber, etc.), on the other hand, enables you to dial in the db attenuation. So, you can adjust the level of attenuation nearly to infinity enabling you to find the "sweet spot" setting on the amp. So, an attenuator is the safest way to enable you to make the amp's power section work harder with more flexibility.
emperor_black
Well-known member
However, an attenuator sucks tone hence defeating the very purpose. :roll: I used to run a weber minmass with a 5150 head. I lost quite a bit of tone and felt it wasnt worth it. But it was a long long time ago and maybe the newer ones are better? But the general consensus on attenuators is that they suck tone. Dont buy the Marshall power brake or whatever its called. The THD's are supposedly best bang for your buck and the ultimate attenuator is supposed to have the least tone suck. That's what I've read on many forums. 
That said, boogies, I'm told get most of their gain and distortion from their preamp stage and not from the power amps like old Marshalls. Hence you're not going to get much by turning up a boogie too much.
That said, boogies, I'm told get most of their gain and distortion from their preamp stage and not from the power amps like old Marshalls. Hence you're not going to get much by turning up a boogie too much.
babow2
Well-known member
Neither my 4ohm or 8ohm THD hotplates "suck tone". Of course, based on acoustics and physics, lower volume has a higher psychoacoustic impact on highs and lows, so we perceive lower volume as diminishing the lows and the highs MORE than the mids. Some people call that tone suck. But, the THD has both a high and low boost switch.
Oh, and I learned that the tone knobs on my amp actually move beyond my normal "concert" setting. So, I find the right balance in volume using my attenuator and ouput on the amp, and then EQ the tone to fit the volume/output I seek. No "tone suck" when you EQ to the volume, rather than EQ at concert volume then knock down the volume and expect no change. That's how I do it, and I seem able to get great tone at whatever volume I desire.
It works for me. Your results may vary.
Oh, and I learned that the tone knobs on my amp actually move beyond my normal "concert" setting. So, I find the right balance in volume using my attenuator and ouput on the amp, and then EQ the tone to fit the volume/output I seek. No "tone suck" when you EQ to the volume, rather than EQ at concert volume then knock down the volume and expect no change. That's how I do it, and I seem able to get great tone at whatever volume I desire.
It works for me. Your results may vary.
acorkos
Well-known member
there's more than one way to use a thd hotplate.
most people put them in series between amp and speaker, and click away the decibels, sucking some power into the resistive circuitry of the attenuator, with a net result of less overall volume (and some tone, at higher db reduction settings)
another (less common) way to use the hotplate is to make sure it's rated the same impedence as your speaker cab....plug the speaker into one 4 ohm output jack, and the hotplate into the other 4 ohm jack. a parallel connection, like a silent extension speaker cab. now, half of your output power is sucked into the attenuator, the other half into your speaker. try it and see if the tone suck is different than series configuration.
most people put them in series between amp and speaker, and click away the decibels, sucking some power into the resistive circuitry of the attenuator, with a net result of less overall volume (and some tone, at higher db reduction settings)
another (less common) way to use the hotplate is to make sure it's rated the same impedence as your speaker cab....plug the speaker into one 4 ohm output jack, and the hotplate into the other 4 ohm jack. a parallel connection, like a silent extension speaker cab. now, half of your output power is sucked into the attenuator, the other half into your speaker. try it and see if the tone suck is different than series configuration.
straitouttahell
Well-known member
babow2 said:
Same feeling here.
In effect, when I had it, I had the feeling that, at similar sound pressure levels, the tone did not change AT ALL when the Hotplate was connected, unless I cranked the amp to the point where the power tubes started to saturate (which I personally don't like). That's the reason why I soon got rid of it.
The treble and bass boost switches are useful but not enough to justify the investment IMO.
Running the amp with an 8ohm load in the 4 ohm output is perfectly safe in your Boogie.It will actually make your power tubes run somewhat "cooler",not hotter as someone else said.Your OT is more than capable of handling the mismatch.Unfortunately because tubes are such inefficient devices,unlike solid state output transistors,you wont realize a whole lot of volume reduction with this set-up.It will soften your tone somewhat,but it isnt going to give you a lot of volume reduction.I have been running my IIC+ for 20+ years in the 4ohm output because I prefer the tone,but there is no noticeable volume loss.
Tweeked
Well-known member
Get a smaller amp.
Either the attenuator or mismatched impedence will eventually blow the output transformer.
Not to mention bad tone.
Either the attenuator or mismatched impedence will eventually blow the output transformer.
Not to mention bad tone.
welshboogie
Well-known member
stokes said:
Jeez, I'm glad someone confirmed this - I thought I was loosing my mind....**** old age and loud amps!!!! :lol:
And +1 on the O/Ts on Boogies - you will have to be totally stupid to blow one of these!!!
An impedance mismatch in this direction,8ohm load on a 4ohm out,absolutely will not harm the OT on that amp,or any Mesa or Fender amp.I dont use attenuators,but I do know the theory and a well made one should not hurt an OT either.It mearely soaks up some of the current before it hits the speaker,your tubes and OT have no idea what you do with the current after they deliver it.It does not cause your OT to "load" anything.Tweeked said:
emperor_black
Well-known member
That is what I've always heard. A "more than recommended impedance" is always OK. But someone in this thread is suggesting a guy to plug his IIC+ into a 4 ohms cab. Yikes! :shock:
http://forum.grailtone.com/viewtopic.php?f=27&t=41368&start=30
http://forum.grailtone.com/viewtopic.php?f=27&t=41368&start=30
And that will not necessarilly damage your OT either.Fender and Mesa OT's can safely withstand a 100% mismatch in either direction.What it will do is cause your power tubes to run hotter,and of course,hotter power tubes means shorter tube life,and I dont mean they will die in a matter of hours,if you like the tone it will be okay,but expect to change tubes more often.If you happen to have tubes that are not in the best condition and would have had a short life at the ideal impedance,they will die rather quick at the less than ideal lower load mismatch scenario,so there is some amount of chance there.But using a higher load in the lower ohm out is actually better for your tubes,but not necessarilly your tone.emperor_black said:
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