Quiet Tube amp

Started by served, April 02, 2010, 03:32:03 AM

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served

Hi.

Is there a way to make a 15W tube amp to sound as good as it does with full volume, but quieter. Something like a converter, that will make 15W sound as loud as 1W amp?
I just can't cranck my amp, its too loud, but the best sound is hidden somewhere in the "too loud" section. I would like to play with it but I dont want to start a civil war with my neighbors.

There is something called tube amp attenuator, is it what I am searching for?

EDIT: So I found http://www.tedweber.com/atten.htm Weber MASS products. But, they don't seems to offer low wattage attenuators. I am afraid that for my bedroom use, I'll have to come up fith something new. Or it has been done before?

A.

markeebee

Check this out, from Bane's site:

http://diy-fever.com/misc/l-pad/

I'm pretty sure there's someting on geofex as well.

therecordingart

There are attenuators (the THD Hotplate or Marshall PowerBrake), but 1 watt isn't 15 times less quiet than a 15 watt amp. Let's say your speaker cab sensitivity is 100dbspl. That means when you put a 1 watt/1khz tone through that speaker you'll read 100dbspl at 1 meter. Since this is logarithmic and not linear this is about the readings you'd see at other wattages:

2 watts - 103db
4 watts - 106db
8 watts - 109db
16 watts - 112 db

Although the difference between 100dbspl and 112dbspl is actually pretty big...100db is still pretty loud! I have a Firefly tube amp that I can barely give an volume so I'm running a Sansamp GT-2 or my Line 6 Pocket POD into it so I can get some breakup without shaking the windows. This is one area that SS amps take the cake.

petemoore

  Think of the speaker as a load on a spring.
  It puts a springy load on all the amplifier things.
  [that are relevant to this thread].
  If you don't drive the motor, the cone won't jump.
  The loads of the impedances lose the cool humps.

  A pure resistive load will distort the tubes.
  If you're into active loading sound, these are for the newbs.
  Whether a MAttenuator does it and you dig..
  Remains to be seen after you hook it to your rig.

  15 to 1?, I suppose it could be done..
  Regardless..look at speaker for the tone change if there's one.
  About the speaker too.
  One thing you can do.
 
  Find a speak that loads the amp,
  before your neighbors fuse.
  That'd be: a low Db,
  speaker in massy cabinet, sealed [~filled too].
  If the sound seems like it's clamped,
  it may be time for smaller watts amped.
  I just felt like rhyming something which is unintelligible again.
  The logic with attenuators sometimes takes the speakercone kinetic energies and their effect on loading, and the interfacing of OT/PT sections of the amplifier to the air and this sometimes leads to avoidance after experience.   
Convention creates following, following creates convention.

jacobyjd

You don't need a low-wattage attenuator--that wattage rating is basically the MAX wattage you should run through it. To always be safe, you'll want to make sure you have at least 2x the wattage rating on your attenuator.

I have a Weber Mass, and it is absolutely fantastic. I use it with both my 30w amp and my 5w amp. That's exactly what you're looking for.
Warsaw, Indiana's poetic love rock band: http://www.bellwethermusic.net

fpaul

I've recently started reamping the 50 watt Marshall clone I made.  I plug an 8 ohm 300 watt ohmite resistor into one speaker jack for a dummy load and made a line out box(voltage divider with a 5k pot) to plug into the other (parallel) speaker jack.  The line out output goes into the front of another amp(pignose G60vr tube amp).  Crank up the first amp and control volume with the second amp.  A bonus is that my cloned amp doesn't have an effects loop and my pt80 delay sounded like crap.  But when I put the delay between the line out and the second amp it sounds great.

You can probably get a second amp as cheap or cheaper than alot of attenuators or may already have one.  I already had the amp.  I paid about 10 bucks for the resistor at a local surplus store and the line out cost maybe 5 bucks total.  Only drawbacks are the resistor gets very hot, and if it fails it can damage tubes and output transformer.  Tube amps have to have a load at all times.  But I really like it.  I don't even need a distortion pedal any more.

Of course any way you do it it will still sound better turned up a bit.  The speaker needs to be pushed a little bit to sound good. But I can play MUCH quieter than I used to.
Frank

MikeH

Hehe, most people get 15W amps so that they DONT have to use an attenuator.  I've only ever used a THD hotplate, and it really worked well.  My friend had a Marshall powerbrake that he really liked as well.  There aren't many DIY options for attenuators (comparatively anyway) and commercial ones are not cheap, unfortunately. 

Speaker choice may also have a little to do with it- If you're running it into a 100W speaker or cab, you'll get very little speaker breakup.  But if you run it into lower watt speaker, say 15-25 watts you'll get more breakup at lower volume and that "Sweet Spot" will be a little quieter.  Not sure how much quieter though.
"Sounds like a Fab Metal to me." -DougH

petemoore

  Speaker is Loud = the room is 'Soundy', which could be a lions share of the characteristic sound you're experiencing.
  A loud speaker made quiet may sound somewhat 'pallid' or 'tepid', and bass 'emptiness' may seem unavoidable.
  When the volume changes, the tone changes, although SS amps and certain types of speakers have the widest range before the volume/tone relationship becomes unmistakably apparent.
  The tube amp/speaker thing involves...anything you can think of except a few things as far as amp/speaker relationships go, here's a fewthings:
Distortion [good bit of this comes from speaker, some less, some more,,and output tubes to some degree or more.
Impedance loading: a relationship between the amplifier, speaker, air, cabinet, guitar, voicing...very complex, try taking any one of the 'elements' out and of course a portion of the character will at least be altered.
Convention creates following, following creates convention.

Paul Marossy

Quote from: MikeH on April 02, 2010, 02:58:22 PM
Hehe, most people get 15W amps so that they DONT have to use an attenuator.

The problem is that the decibel is not additive, it is based on a logarithmic scale. To increase the sound level by 3dB, which is only a slight increase, you need twice as much energy to achieve that. Basically, it takes ten times the wattage to double the perceived loudness of an amp.

The loudness of a sound, specifically the sound pressure level or audio level, is stated in decibels. A decibel can be defined as the smallest change in an audio level that the human ear can detect. If the audio level is increased by 10dB, the sound appears to be twice as loud. For a 10dB increase in sound, it takes ten times as much energy.

A 15 watt amp is still very loud when cranked. It's nearly as loud as a 100 watt amp cranked up half way.

jacobyjd

lol my Little Giant is far too loud for the settings I like, even in 3w mode--I still don't know where the people who don't use attenuators play--even at a live show with, say <200 in the crowd, a 15w amp cranked to where it sounds great is a serious annoyance to any sound guy. I tried it once with my 30w, and while it sounded amazing, it did nothing for anyone else there.

We live in a modern world, where you can crank your amp AND be able to hear later.
Warsaw, Indiana's poetic love rock band: http://www.bellwethermusic.net

Derringer

Quote from: petemoore on April 02, 2010, 08:35:37 AM
  Think of the speaker as a load on a spring.
  It puts a springy load on all the amplifier things.
  [that are relevant to this thread].
  If you don't drive the motor, the cone won't jump.
  The loads of the impedances lose the cool humps.

  A pure resistive load will distort the tubes.
  If you're into active loading sound, these are for the newbs.
  Whether a MAttenuator does it and you dig..
  Remains to be seen after you hook it to your rig.

  15 to 1?, I suppose it could be done..
  Regardless..look at speaker for the tone change if there's one.
  About the speaker too.
  One thing you can do.
 
  Find a speak that loads the amp,
  before your neighbors fuse.
  That'd be: a low Db,
  speaker in massy cabinet, sealed [~filled too].
  If the sound seems like it's clamped,
  it may be time for smaller watts amped.
  I just felt like rhyming something which is unintelligible again.
  The logic with attenuators sometimes takes the speakercone kinetic energies and their effect on loading, and the interfacing of OT/PT sections of the amplifier to the air and this sometimes leads to avoidance after experience.   

this post did not go unappreciated

well executed!



As for the volume issue ... look into a less efficient speaker and/or try to build a pedal to run into the front end of the amp that mimics the amp's tone at loud volumes

served

Thank you so much! I am actually understanding the whole thing finally.
But theory is one thing and now that I know a little fraction of it, I think I'll start experimenting. First Dummyloads (from the first post).
Second, I found some attenuator schematics, so these things will be my second try.

http://freestompboxes.org/viewtopic.php?f=2&t=2287&start=0

Here are some good ones. I think one of them is worth a shot!

I am sorry, that my replay came so late, I was visiting my relatives and didn't have a chance to use a computer.

Thanks to everybody who shared their thoughts!