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Volume pedal versus power attenuator?


Excelsior

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So, I was consdering a power attenuator.

 

Then I realize that the THD Hotplate is LAUGHABLY overpriced. I drew up a schematic for a home made Attenuator that would work with my Peavey ValveKing.

 

The homemade attenuator would have the following settings:

 

Full volume, 1/2, 1/4, 1/8th volume. It'd cost me under $20 to build, too.

 

So, why do people pay ridiculous prices for a THD Hotplate ($250+ New?)

 

It was also suggested that I just simply get a $20 volume pedal, and put it in the loop. Would a cheap volume pedal allow me to put max gain/volume, and still get the nice distorted sound without going deaf, keeping the sound somewhat intact?

 

Opinions? Ideas? If I build the Audio attenuator, I'll include the diagram/build progress, plus the equations to use for different impedance speakers.

 

-Excels

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You can't control the breakup from clean to dirty with a volume pedal.

 

A volume pedal just makes things softer or louder, while an attenuator allows you to drive the amp to 11, allowing for the breakup, but cuts the volume so you don't kill everyone on your block.

 

In summation.

 

Volume pedal = just volume

Attenuator = volume AND tone

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The Weber MASS and miniMASS are much better priced than the hotplates and I recall they can handle 4, 8 and 16 ohm loads.

 

Weber's attenuator site

http://www.tedweber.com/atten.htm

 

https://weberspeakerscom.secure.powweb.com/weber/mass.htm

 

https://weberspeakerscom.secure.powweb.com/weber/minimass.htm

 

I believe a 50 watt miniMASS would work well with your VK. You might be able to snag one on ebay or Craigslist

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Thanks to everyone for clearing this up.

 

Originally posted by 70 Cam Guy

The Weber MASS and miniMASS are much better priced than the hotplates and I recall they can handle 4, 8 and 16 ohm loads.


Weber's attenuator site

http://www.tedweber.com/atten.htm


https://weberspeakerscom.secure.powweb.com/weber/mass.htm


https://weberspeakerscom.secure.powweb.com/weber/minimass.htm


I believe a 50 watt miniMASS would work well with your VK. You might be able to snag one on ebay or Craigslist

 

Neg. I can make the equivalent of the "miniMAss" for under $30.

 

~$15-20 for the 50W WireWound resistors.

$4 for the DP3T Switch

$6-10 for the enclosure

 

$priceless for the gratification of doing it myself :thu:

 

Edit: Well, it wouldn't be the equivalent of the MiniMass, since it'd be resistor based, but it'd still get the job done.

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Originally posted by Excelsior

Thanks to everyone for clearing this up.




Neg. I can make the equivalent of the "miniMAss" for under $30.


~$15-20 for the 50W WireWound resistors.

$4 for the DP3T Switch

$6-10 for the enclosure


$priceless for the gratification of doing it myself
:thu:

Edit: Well, it wouldn't be the equivalent of the MiniMass, since it'd be resistor based, but it'd still get the job done.

 

 

Sounds like a cool project. I say give it a whirl. :thu:

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Originally posted by Excelsior

Thanks to everyone for clearing this up.




Neg. I can make the equivalent of the "miniMAss" for under $30.


~$15-20 for the 50W WireWound resistors.

$4 for the DP3T Switch

$6-10 for the enclosure


$priceless for the gratification of doing it myself
:thu:

Edit: Well, it wouldn't be the equivalent of the MiniMass, since it'd be resistor based, but it'd still get the job done.

 

give it a go then :thu:

 

I nearly tried it too when I was toying with DIY pedals but never got around to doing it. Make sure you get some decent 1/4 jack connectors :)

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Originally posted by Excelsior

Thanks to everyone for clearing this up.




Neg. I can make the equivalent of the "miniMAss" for under $30.


~$15-20 for the 50W WireWound resistors.

$4 for the DP3T Switch

$6-10 for the enclosure


$priceless for the gratification of doing it myself
:thu:

Edit: Well, it wouldn't be the equivalent of the MiniMass, since it'd be resistor based, but it'd still get the job done.

How do you get rid of the excess heat?

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Originally posted by hondro

I'm gonna go out and say a power attenuator and volume pedal are ENTIRELY different things that are nothing alike

+1

 

I like people who are willing to try to make their own solutions to things. So I am very positively disposed to you for being willing to design a power attenuator. I'm saying the following with respect:

 

If you equate a volume pedal with a power attenuator, then it's clear you don't understand what a power attenuator does. Or, alternatively, you don't understand what a volume pedal does.

 

I think you should learn about how an attenuator works before trying to design one. You want your efforts to be as fruitful as possible.

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One more thing -- power attenuators are not created equal. Endless fru-fru has been written about the differences between various models of attenuator. Some of the less expensive models have their adherents.

 

Nevertheless, the gold standard for power attenuators is still the Hot Plate. Gibson, for example, has chosen to brand the Hot Plate, and offers it as a Gibson item. It is the most expensive. It also has features other attenuators do not have, features that are important to many players. It has sound quality advantages, according to many players. These are subjective opinions, of course.

 

But the Hot Plate is the attenuator that many, many players shoot for, as a matter of course. They hear their friends play a Hot Plate. they WANT the Hot Plate. To my mind, $300 is less than a hundred more than the Weber -- and I get one of the few things that a majority of tube users can agree on!!!

 

EDIT: it's been available on ebay for years at about $260, including a speaker cord, from an outfit in Nevada.)

 

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Originally posted by guitarNed

+1


I like people who are willing to try to make their own solutions to things. So I am very positively disposed to you for being willing to design a power attenuator. I'm saying the following with respect:


If you equate a volume pedal with a power attenuator, then it's clear you don't understand what a power attenuator does. Or, alternatively, you don't understand what a volume pedal does.


I think you should learn about how an attenuator works before trying to design one. You want your efforts to be as fruitful as possible.

Or they don't know how a volume control works on an amp.

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Originally posted by tlbonehead

How do you get rid of the excess heat?

 

They're 50W Wirewound Resistors with aluminum housing, attached to heatsinks :thu:

 

Also, if I need it, I'll add a small PC fan to the circuit.

 

Originally posted by guitarNed

+1


I like people who are willing to try to make their own solutions to things. So I am very positively disposed to you for being willing to design a power attenuator. I'm saying the following with respect:


If you equate a volume pedal with a power attenuator, then it's clear you don't understand what a power attenuator does. Or, alternatively, you don't understand what a volume pedal does.


I think you should learn about how an attenuator works before trying to design one. You want your efforts to be as fruitful as possible.

 

Oh ye of little faith :D

 

The latter would be true. I don't have any experience with volume pedals, unfortunately. Someone simply suggested it on an IRC Channel, and I felt dismayed that they said "a volume pedal would do the same thing for $20."

 

I do realize how a power attenuator works, and I've got my schematic worked up with parts on the way soon for a simple attenuator that takes into account impedance matching as well.

 

Originally posted by bryvincent

i'm not an expert on power attenuators but, be careful with that homemade attenuator. if something goes wrong with that, you will seriuosly damage your tube amp and probably will cost more to repair than just buying a Hotplate.

 

I'm aware of the risks involved, also, I made sure to make it so there's always a second resistor in parallel along with the attenuating resistor, to make sure the amplifier always sees 16 ohms of impedance, no matter on what setting.

 

Originally posted by tlbonehead

Or they don't know how a volume control works on an amp.

 

Originally posted by guitarNed

Ya, that too. And +1 on the volume control. (tlbonehead)

 

Well, putting the gain up, and the volume at 1/2, it sounds pretty weird. It's not nearly as nice as the distortion when I turn the volume just a bit more up. The problem is, with gain near 8, and volume near 5, it's already deafening. Hence the attenuator...

 

Don't worry, I'm not a virgin to electronics work. Wish me your best, call me a fool, or move on :p

 

I'm still trying to locate the circuit diagram schematic for the THD hotplate to see what exactly the "Added" features are, electronically speaking. I've checked out the power break and a few other attenuators circuit diagrams, and so far for simplicity, I'm going to make a large box with a lot of ventillation and the simple attenuation design, later I'll add more features if it works and if it's neccessary, hopefully.

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looks like you chose the L-pad type?

 

i've built several L-pad type attentuators with great results, but i've only used them on lower watt tube amps: valve jr head(el84), diy champ clone(6v6), electar tube 10 w/ a el34 power tube.

 

i use small metal enclosures and haven't any problems with heat. though i think i'm eating tubes faster then before.

 

keep us posted.

 

edit: fyi: i could only cut about 8 db's before the tone got ugly. So i only gained about a 1/4 turn on the volume knob. not sure what the powered ones will do before the tone goes ugly.

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Originally posted by LowMach

looks like you chose the L-pad type?


i've built several L-pad type attentuators with great results, but i've only used them on lower watt tube amps: valve jr head(el84), diy champ clone(6v6), electar tube 10 w/ a el34 power tube.


i use small metal enclosures and haven't any problems with heat. though i think i'm eating tubes faster then before.


keep us posted.


edit: fyi: i could only cut about 8 db's before the tone got ugly. So i only gained about a 1/4 turn on the volume knob. not sure what the powered ones will do before the tone goes ugly.

 

 

Interesting.

 

I have up to 1/8 power on the setting up there, a 1/8 power /should/ be linearly related to 1/8 noticible volume, no?

 

I suppose I'll find out once I build it. I had no lcue they were called "L Pad type," though. Also, from the schematics of "L Pad" attenautors, it seems mine has the resistor in parallel before the resistor in series.

 

I'm kind of interested in this part:

 

"If you want to experiment with equalizing it, you can try different values of nonpolarized capacitors across R1 for a treble boost, different values of inductors for a bass boost, or a combination of both. These are low impedances, so the values would be in the microfarads and 10's of millihenries."

 

I may think about adding equaliziation controls if the project is successful...

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