Tube Amps 6: Attenuators

[@rwj1313]

Ok kids, here's some important information. I will use a 100W Marshall as an example. Sound Pressure Level is measured in dbSPL (decibelSoundPressureLevel). If you apply an attenuator to the output of the 100W Marshall and set it to minus 3db, the 100W Marshall will now output 50W. On average, the human ear needs to have about a 3db change in power, up or down, to notice a change in volume. It is possible to detect smaller changes. People that are trained to listen, such as an audio engineer or record producer can usually detect a 1db change. A 100W Marshall is NOT twice as loud as a 50W. It's just enough that you can tell it is louder. For every 3db you reduce the power you will cut the power in half. So a 100W reduced 3db becomes a 50W. If you reduce it another 3db to -6db a 100W will output 25W. If reduced another 3db to -9db the 100W becomes 12.5W. Reduced to -12db it becomes 6.25W. Reduced to -15db it becomes 3.125W. Testing has shown that most people need about a 10db change in order for something to "sound" twice as loud or half as loud. So try this on for size. Adding an extra 100W Marshall to your existing 100W, will not make it twice as loud. You would need to add 2 more 100W and a 50W. Now it will sound twice as loud.

[@Tonetwisters]

All I know is, a 100 watt Marshall is loud enough. I grew up playing through a 40 watt Super Reverb. Eventually had to use a 100 watt Traynor to meet the demands of playing a college campus, outside in the early '70s. After 57 years of playing electric guitar (currently, in year 58), I will say that the crickets in my ears are still looking for Buddy Holly. Stay with the 40 watt amp. If you have to use bigger than that (there ARE exceptions, e.g., playing Beatles with heavy mids and bottom end, or bassy jazz tones), go find another band ... one that is smart enough to know that ears aren't forever ...

[@jamesha175]

​ "ears are not forever" yalls should heed that advice because while ears are not forever, *deaf is forever!*

[@strplox0wn]

What you are saying here is not correct. 3db makes the sound twice as loud or as silend in general, hence the effect on wattage

[@rwj1313]

@@strplox0wn The information I posted is correct. I have almost 40 years experience running sound "front of house". I did my first show in the summer of 1981. I toured with the rock band Brother Cane in the early nineties and have run sound on arena size PA systems. This picture is from the Skynard/Bad Company show at Red Rocks in Denver. www.flickr.com/photos/109161978@N03/49103924408 If you have information that supports your claim you should post it.

[@hannuak]

You contradict yourself in the end. If 10db makes people percieve a sound twice as loud, you would need 9 more 100w Marshalls to achieve that.

[@billville111]

Attenuators work best when still loud enough that the police show up but stay their car and think about it for a while.

[@sonnyseabury4051]

Lmao

[@jamesha175]

hilarious

[@heliobluesrock]

You're the guy who taught me Rude Mood! Now, I'm learning about amps. Thanks!

[@Crunchifyable2]

It's not always about distortion. Just being able to get the amp halfway or even to three produces some compression and sweetness. The sweet spot is basically compression before the distortion.

[@coolcustomer31]

this guy actually knows what he is talking about, unlike most other people with demos.

[@Texasbluesalley]

@angrygoldfish The attenuator actually allows you to overdrive the power tubes while controlling the volume to the speaker. Without an attenuator, as you push the power tubes harder and harder, your volume goes up and up. So the attenuator doesn't really affect the inner workings of the amp (preamp / power tubes) , it mainly just limits volume. However, it does affect the tone as it does this as I showed in the video.

[@Nghilifa]

I found that the Ultimate Attenuator was the most transparent attenuator out there. Its expensive, but well worth the money. But any attenuator is going to "suck" tone from your sound, since at highly attenuated volume levels, the speakers aren't "pushing" as much air, and our ears perceive the different aspects of sound (highs,lows, mids etc) better at higher volume levels. (that is one of the reasons why people with hearing loss turn the treble all the way up, because you lose the HF first.)

[@dannyrybeck]

Thanks Anthony, all of your gear videos are very informative, you have helped me make some decisions, keep up the great videos D.

[@Texasbluesalley]

@CTuxford Not quite. A master volume lowers signal to the tubes causing them to run cleaner (quieter), an attenuator lowers the signal level before the speaker, i.e. the tubes can be cranked, and still get low volume.

[@CTuxford]

Thanks Steve. With my Fender Supersonic 60 I realise now that the master volume on the second channel is basically a built-in attenuator. The gain 1 is the pre-amps, gain 2 is the power tubes then master is the attenuator. Cool! :)

[@Texasbluesalley]

@sparkdoggy A pedal can boost the overall signal level going into your amp, which will overdrive the tubes further, but if your master volume is down, that prevents them from overdriving, even with the increased level. You can add distortion to your signal with a pedal, but then you're putting a distorted signal into your amp, before it even hits the preamp tubes. This is not a bad thing, but it rarely sounds 'like' distorted power tubes.

[@Texasbluesalley]

@guiitarist Not really, if you keep the volume pedal really low, you're limiting that amount of signal that enters the amp, so no matter how high you have the preamp or master volume, you're only feeding it a little bit of signal, so the tubes won't overdrive.

[@Daracon1010]

I own a THD Hotplate... I did a lot of testing with it inside a sound isolation cabinet and using my TSL-100 to see what effects it had on the tone. It's really only good to use up to about -8dB, otherwise it kills the tone too much.... and if you turn the power-amp section way up and the hot plate attenuation up, you get power-amp valve saturation but the tone sounds dead. It's best to get a blend - cut back on power amp drive and use the hot plate sparingly.

[@usalespaul59]

I found the last sentence best: nothing comes for free, if you overdrive your amp and use a powersoak, it's not gonna sound like a truly overdriven amp. It will cut back the volume, but you WILL suffer some tone loss. Glad this guy was*** honest*** and was not trying to sell anything.

[@Texasbluesalley]

@TheShuffler94 Not necessarily. It takes more power to amplify low end cleanly, so a 3 watt amp will give you overdriven power tubes at a lower volume than a 30 watt amp, but most likely the bass will be much muddier. There are always tradeoffs no matter which route you go.

[@playingforfunagain]

Mate - congratz on your series of videos - i am a complete technical ass but you made actually understand some stuff - and i am using my valve amps completely different now - and M8 - It sounds GREAT :d - thanx from Belgium here

[@hellbenttexasman]

@satjathamma : It's not a matter of which one is best, it's a matter of which one matches the impedence need by your amp's output...same as choosing a speaker configuration. If you can't figure out which one goes with your amp, then talk to the guys at THD or a knowledgeable dealer before buying. If your cab has only one speaker, then look to see how many ohms it is. If your cab has 2 or more speakers, then the overall ohms depends on how they are wired together.

[@marksargent7319]

Anthony, thanks for a great informative set of vids. Am looking to upgrade from my very small SP-10 and your vids have empowered me ;-)

[@Stratomacaster]

I've had that same Hot Plate and a Dr. Z Air Brake and as simple as the Air Brake is, it doesn't squash your tone as much as the Hot Plate. It may react differently on different amps of course, but I'm using a Carr HammerHead II and it's SUPER loud, and the Air Brake does a much better job with this amp. I sold the Hot Plate, but as you said, they do exactly what they were built for and the tonal quality will suffer the more you push the volume down. They're both pretty good products.

[@50j0urn3r]

vibroverb ... what a beautyful tone ...

[@cast390]

@Martinijos The harder you push your amp (louder)The more load (output) you put on the power tubes.So yes it will clip or distort.When using this type of power tube overdrive in conjunction with your preamp overdrive,you'll get at tone thats preferred by many pros.This is the type of tone tube amp lovers cream in their pants over.Hope this helps.

[@Texasbluesalley]

@Martinijos Can't say for sure with other amps, but with mine, the amp distorts much more quickly as I roll the attenuator lower.

[@Texasbluesalley]

It depends how many people you're playing with. I used a 15w Blues Junior in a 5 piece band, with 2 guitarists, and it worked fine. However, at a larger venue, you'll need to have a mic on the amp, which is a good idea regardless of what amp you're using.

[@Texasbluesalley]

@MrNebelful Not exactly. I use a Samamp VAC 23 amplifier, and the Samamp amps have a different type of power scaling that uses light bulbs, far better sounding than an attenuator.

[@Gitaaroverlast]

So I's basicly makes you have the tone a very loud amp, but at low volume? Exactly what i was looking for!

[@Texasbluesalley]

@Stratomacaster Thanks for the info on the Air Brake.

[@RunawayThumbtack]

You'll notice that you still will have plenty of distortion, but this time, it's coming from your power tubes, not your preamp, and, if you move around your amp, you should be able to tell a great difference in the quality of the distortion. Normally, you don't need to have your amp fully cranked, but this should give you and idea of what to listen for. Sorry about writing so much, but I believe that (having) an attenuator is the single most important piece of gear in your rig.

[@brocholivier]

Very good video.

[@lstierney]

Once again - nice playing mate

[@MNGuitars]

just and amazing tone man, every video!

[@jjulch]

Its a great example of how to use the attenuator. Great Video. Here's a question though... Would anyone use a 15 Watt Amp for stage or band practice? I'm trying to step up to the next level, but do I need a louder amp????

[@rev101ben]

1:50 - 3:20 Basically, you want to get the distortion of the power tubes without the extreme volume needed to achieve this. In a nutshell.

[@keithremedy]

If you have an amp over 15 watts you want a attenuator. I’d suggest people getting one that has a treble boost or presence just so you keep that high end and punch.

[@leslawrenson]

@jjulch 15w is more than plenty for tubes. I use an Orange Dual Terror, rated at 30w, but can be stepped down to 15w and 7.5w. There isn't much difference in the volume levels between the three. The only difference is that I can overdrive the power tubes at a lower dial setting on 15w & 7.5w. Even at 7.5w, the amp is loud enough to play over our drummer, and I play rock. More than 30w is wasted at most semi-pro gigs, because you can't push the tubes hard enough before drown out the band.

[@rjarcusa]

I'm gonna go back to a distortion pedal and no Hot Plate for a while and give my poor amp a break. I also got another Fender tweed tube amp as a back up. It's a Fender Blues Deluxe with a single 12 inch Emminence speaker.

[@jjulch]

Ok, so my 15 watt tube amp should work... Thanks for the videos!

[@Texasbluesalley]

@Angelfish25000 Got the last available one from Sweetwater right before they were discontinued.

[@bellinghammond]

the PR is very clean...if you don't want that gorgeous hi-volume, tube-driven sound at lo-vol., skip the THD

[@pfarina]

@lespaulman1 yes, the master volume controls the amount of signal to the power tubes; consequently, you'll get more power amp distortion.

[@punkybrewsterrr]

thank you very much for this video!

[@SmokeyJoe4991]

great info great playing

[@Donald_Trumpin_onem]

@lespaulman1 yea the attenuator will just control how loud it is through the speaker, and the higher up you turn your amp volume, the hotter it will get

[@EuphoricRaccoon]

so in other words.. if you want to attain SRV break up at human volume levels you might need an attenuator right??.. From all the dudes inyou tube .. to me you are the most accurate for the SRV tone I look for.. is this attenuator thing you do in your vids?

[@Bflatest]

great job man thanks! I learned a few things.

[@LordOfThisWorld74]

You forgot one thing... These burn tubes through tubes way quicker. Its really the same as cranking the master ful blast. It really really really works the power tubes hard. Your gonna go through tubes quicker, but i guess thats the sacrifice you make for quiet volume.

[@JymeBale]

You stated you were getting some distortion at low volumes changing the db levels, this should tell you you are over driving something, not the amp the attenuator depending where you have it of course, I did not hear a big tone drop at all and I don't use pc speakers, I use a large surround sound system up fairly loud, I often play with ear plugs, when I was a pro drummer I always used ear plugs, they protect well. Nice demo.

[@Texasbluesalley]

@ThePyroHobo yes.

[@wreckoningday]

Cool... I'll have to check those out thanks

[@stevo946]

@J4m3z1 Yes he is, they suck at any volume

[@themaggot8]

Awesome video, i will get an attenuator, because my peavey 6505+ is waaaaaaaaay too loud, even if i'm playing with the volume at 2

[@RunawayThumbtack]

Third, I will say from experience that it is most likely not the power tube breakup which you are hearing at "3" (around 1/4 of full volume?); that's speaker distortion, which is another factor, but not the same. If you really want to hear what power tube distortion sounds like, turn your amp all the way to full power (save your ears and borrow an attenuator for this exercise) and bring the "gain" way back (if your amp has one)...

[@Texasbluesalley]

@RubyTuesday93 Absolutely necessary.

[@2latuile]

(continued) : FWIW, I got really nice tones out of my bjr, but at a volume that was just to low to cope with our drummer - was on the edge for rehearsals, didn't cut it for gigs, and where we usually play I can't rely on the PA. Now there's no 30w version of the bjr, and the closest amp (tonewise) I could afford was a hotrod, which is just too damned loud. So what do I do ? Yes, right: get myself an attenuator. Not the best solution but the best bang for the buck as far as I'm concerned.

[@nbgydf]

The point of an attenuator is to soak up power, not distortion, and while I agree with what you're saying, the point still stands against gr8bluesgtr's comment, an attenuator will work on all amps, not just tube ones.

[@2latuile]

Indeed. But that's not as simple. First thing is, for technological reasons, there are few tube amps in the "right" power / output level range to get THAT tone at rehearsal level. Then, when gigging, you sometimes need more volume, specially when playing in small/mid-sized clubs where the PA is, well, what it is (barely enough for the singer). And finally, not all amps sounds the same so when you do find THAT tone, well, you try to deal with the amp's output level.

[@massif20022000]

A Mark V at the 10watt setting, cranked to distortion, or a 100w Marshall JCM800 2203kk cranked (or nearly so) with the Hot Plate at -16db. Which would be "louder"? Would I still need an attenuator for a cranked 10w amp? Trying to decide between the Marshall and the MarkV. Need to have reasonable "home" volume. I would be happy if I could go with the Marshall and a Hot Plate and still meet home volume level. Maybe the MarkV with its varying wattage is the way to go? Thanks.

[@electrostatic1]

You can actually distort the output of a solid state amp, it's just hard to do in a way that sounds good.

[@hiro54st]

Hi I guess you mentioned the volume at full and then three... which is correct.. i want to know it coz i’m considering to buy one

[@MartinsVaratinskis]

Right, i've gone through many videos and seen many Attenuators, but still dont know which one would be good for me, i have a Peavey Valveking head 100 watt. Help me Steve, you look the most experienced one.

[@jakestewartmusic]

Important point on attenuators- Part of the "cranked amp" sound actually comes from the speakers working harder. You can crank up a 100 watt Marshall Plexi and attenuate it to whisper levels, but it's just not going to have the same crunch as a Plexi cranked up actually pushing a set of Greenbacks, for example. The speakers overdrive and add their own crunch and color to the sound. So I feel like attenuators don't really get the job done at bedroom volumes, because the speakers may barely be working if you're playing at apartment volumes. That said, an attenuator seems useful for guys who can still play quite loud, but need to fine tune the amount of power tube breakup and still keep a manageable stage volume. Like say you were playing a tour of festival and bar gigs and you decided to bring along a Super Reverb to crank up into overdrive. You may be able to get there at the bigger festival gigs with minimal to no attenuation, but you're bound to need to turn that cranked Super down in a bar or club. You won't get the exact same tone, but you'll at least get close and get the power tubes crunching a bit.

[@rockinron3215]

I'm thinking maybe for me to change from a 4x12 to a 2x12 or 1x12

[@massif20022000]

Maybe this can help me understand; 2 amps a full throttle: First amp: 100W with attenuator @ -16db --> 4db Second amp: 10W with attenuator @ -6db --> 4db So, both amps would then sound as "loud". (100W-->20db, 10W-->10db and the attenuator just cuts out db's so: 100W-->20db - 16db=4db 10W--> 10db -4db = 4db Is this how it is figured out?)

[@FreeMusicBeat]

Very Useful THANKS :)

[@angrygoldfish]

So, if you tend to use a lot of preamp distortion, but also want poweramp distortion at the same time, using an attenuator is not the best idea? But if you just want poweramp distortion alone, it is? Am I right?

[@iangray7410]

Gee, a dB meter would have helped see the change in volume/attenuation that is companded by the camera mic.

[@ebmx66]

Anthony, first off thanks for these videos VERY informative and VERY useful Do you plan on doing any videos about the reason people use pedals such as the TS-808 or BD-2 instead of the amp's power/preamp tube distortion? I mean strictly for tone not for volume and/or more distortion

[@RunawayThumbtack]

First off, attenuators don't harm the amp. All that happens is that, when you're playing at higher volumes, you're stressing the power tubes much more. Don't worry; they're made to be pushed like that, but they will invariably die faster if you push them more often (go figure; if you use it, it will wear out; if you use it more, it will wear out faster).

[@martinrindalsholt]

Is the Hot Plate going to make make amp sound distorted like in this video, or can i get a clean and clear sound with it? I have a Fender Blues Deluxe, btw.

[@electrickithara]

Might the Hotplate work better with different amps. Maybe like a plexi of some sort?

[@kyle.buss_guitar]

What is your opinion on graphtech saddles??? I have Two strats, and a tele. Im debating on upgrading the saddles. does it help the tone at all?

[@edmiglia]

Will a E.H. Signal pad work the way you have this set up? (It's a passive attenuator) I tried putting it between the amp (super champ xd) and the speaker using a speaker cable, and it didn't work correctly. The volume on the attenuator works in line with my effects in front of the amp, but not on the back end. I wanted it to use with my 68 champ. (which would need a speaker out mod)

[@RunawayThumbtack]

No; tube amps are designed to be played at very high volumes. Just make sure you have proper ventilation; it's improper heat dissipation that will hurt your amp. Your power tubes will expire more quickly, but that's just because you're actually using them; typical players should get between 1/2-1 year of life from a set of tubes, depending upon how much and how you play.

[@jakemk21]

Ok, please let me know if I got this right. Besides some blues, I mainly play 70s/80s hard rock. I play on a 100watt head and at home I can only play with the volume at about 1. If I get an attenuator, I can get the tone of my amp at a higher volume, but the attenuator will actually drain some of that tone? Have I got that right?

[@airtap1982]

my amp has a 4-8-16 ohm setting. the attenuator's come in each setting. Which is the safest to use, and does it make a difference in tone?

[@MemoirsofanAsshole]

I have a bugera 6262 120watt tube amp that is just really too loud for my playing at home and I'd like to be able to get the volume up to 3 to get the full tone it produces, but then throttle it back so I'm not annoying the neighbors. Is it a better idea putting a volume pedal in the effects loop (which sits between the pre and power amp sections) or to use one of these attenuators? I've also heard attenuators can harm the amp

[@AugieCookeNesme]

@gr8bluesgtr Ah thanks. It's a shame they were discontinued :/

[@morbe77]

Ive heard that using an attenuator can burn up output transformers and power tubes. Is this true. I have a 70 watt 81 super reverb i want to quiet a bit will a hotplate mess up my amp?

[@kyle.buss_guitar]

@gr8bluesgtr Thanks man, Do you think you could do a demonstration on the saddles? I dont think there are any on youtube?

[@Zyworski]

Sounds like a resistor network to me.

[@nutmegger1957]

Would you use the Attenuator on a Solid State Amp, or just a Tube Amp? Some great demo editing and overlay work. Still don't know if I gain (no pun intended) anything by owning one.

[@KrisPlaysGuitar]

wow, i didnt you had a vibroverb!

[@shredx81]

Valve amplifiers are designed to be cranked. The attenuator itself doesn't eat the tubes, excessive use at high output does. That said, running a powerful amp at a very low volume isn't good for the tubes either. So really, excessive use of an amplifier will wear the tubes out quicker. That said again, a tube can last anywhere between 6 months & 5 years. They're fairly unpredictable really. I simply play the amp & make sure I have a stock of spare tubes.

[@OurgasmComrade]

Is this a passive attenuator? If so I believe the output impedance will increase as more attenuation is dialed in if it's an L-pad design which explains the tone loss (basically the output impedance interacting with the characteristic capacitance and inductance of the speaker to form a high pass filter that attenuates the lower frequencies which make up a more full tone). Active attenuators would allow buffering to maintain output impedance and tone but they'd need to handle the amp's juice lol

[@wb5mgr]

That attenuator is literally functioning as a speaker load and soaking up your amps power to burn it off as heat! The only way it could hurt the amp is if the speakers it's in series with changed the impedance enough to create a load the amp did not like, but tube amps can generally drive a 100w light bulb so that's not likely. Sounds like a money suck to me though, better off to just move your amp twice as far away from the audience/you (inverse 2 law) which gives you a 3db relative reduction.

[@MNGuitars]

great video man, u think if i got this for my twin reverb and kept the volume up near all the way and used the hotplate i could get it to break up like a deluxe reverb? also i need to replace the tubes in my twin reverb, iv never retubed an amp, what tubes should i go for?

[@TheHappyCritters]

I have a Krank Rev SST. It's a solid state amp hybrid with a tube pre-amp. It's awesome, but it's 200 watts. What kind of attenuator would I need?

[@massif20022000]

Of course, I meant 10W--> 10db -6db = 4db

[@br1rocks]

Thanks for the review and info. I have been looking at the possiblity of an attenuator for my Mesa Dual Rec...I love the amp and espeically the driven tones but it just doesn't sound great at reasonable volume for many places where I play out. I have switched the amp down to 50W from 100W. In the case where you are looking to really overdrive the amp (like I am) and get that nice full breakup, it sounds like you wouldn't really recommend the attenuator. Is that true? Thanks again

[@murphysborounderdark]

I have a Peavey ltd 400 200w steel guitar amp. I want to od it with a guitar. I get a buzz when I use a pedal between the guitar and amp so I can turn up the amp all the way (Pedal level down as a master). Will this buzz go away if I put an attenuator between the amp and speaker? I put a dist pedal back there to test it, but it cut the signal too much.

[@NakedUndone]

I didn't think many amps had direct inputs to the speaker. Did you have to modify the amp?

[@wreckoningday]

Have you tried the Rivera Rock Crusher? Wondering your thoughts on that one seems to keep ur tone pretty close, at least on vids that I've seen. I need an attenuator but can't deal w that much loss in tone. thanks for the vid it helped!

[@riseofthefallen301]

You said: Here's the Vibroverb at full volume, then you said the volume was just around 3. Which one was it?

[@hiro54st]

i got confused as well... i wanna know which..

[@Zhorellski]

Sounds Thinner the more it attenuate the volume of the tube amp! is this normal on all attenuators?

[@Zarzosa]

I've heard that you can take some tubes out of the amp in order to make it sound good at low volumes, is it true?, if so, how do I do it?

[@LabelBob]

An attenuator like a Faustine or an Aracom won't rob your highs

[@joshpunk9160]

Would it sound good if I got a marshall jmp 100 watt head and brought it to apartment volume

[@MariosPsarianos]

Hey.. i have a 73 super reverb silverface without the master volume.. i cant even think about playing in bedroom level so i ended up playin with guitar rig (it sucks) if wanted to keep the fullness of tone the amp has at 3-4 is it possible with the attenuator to cut so much that actually i can hear the amp volume at 1-2? and stay clean and shinny?? im suffering here hahaha sorry for my english, plz response :)

[@SamLibman]

what ohm would you use for a 100w marshall plexi?

[@50j0urn3r]

power-attenuator is a smart tool, but the sound looses his typical shape. cos the behavior of speakers at high volume is missing.

[@rodrigogaldamezdis]

does tone changes only setting down volume? I mean, because you have a tube pre-amp inside, not sure if it affect.

[@RunawayThumbtack]

Second, the volume pedal won't achieve the same result as an attenuator because the power tube overdrive comes directly from the level which is _output_ from the power tubes, _not_ what you put into them.