Help to build something simple?

hotpickups

Well I was told it was simple but I have no knowledge or trust myself to do it right or safely.

I was going to go for an attenuator but I have discovered the use I want one for all I would need is one of these:-

http://www.ebay.co.uk/itm/L-Pad-Attenuator-50W-8-Ohm-Wirewound-Volume-Control-/331244213682?hash=item4d1fb195b2:g:z6UAAOxy38tTmBDS

However, as said I'm next to useless at such things. It's simply to reduce the volume of my J20 to bedroom levels etc. If I bought the bits and got them shipped to anyone here who could wire it all up for me plus I'll pay them for their time would anyone be up for that? As long as it doesn't damage my amp or cost an earth – pun not intended

ecc83

I have not handled one myself but ICBM has said I am sure that those L pads are NOT actually rated at 50 watts and that figure applies to the overall power handling of a two way speaker, the pot being used merely to balance the tweeter level.

A 20W valve amp could put out almost twice that if hardly pressed and that pot might only have an honest rating of 10W.

Dave. (love to help BTW but no longer really can)

p90fool

I have a 100w L-pad I've never risked on any guitar amp over 12watts.

hotpickups

p90fool said:

I have a 100w L-pad I've never risked on any guitar amp over 12watts.

Are they risky then? Mine is a 20watt amp

normula1

I've a 100 watt LPad in my 5 watt Laney and it gets quite warm so I wouldn't risk using a 50 watt one.

hotpickups

@ICBM  ?

hotpickups

Couple of Schematics I've been given (see below). Starting to think it'll be just easier to simply buy an attenuater already made.

http://i1111.photobucket.com/albums/h471/gibby12345/Schenmatic_zpsvwnphhc7.jpg

http://i1111.photobucket.com/albums/h471/gibby12345/Schenmatic_Bypass_zpsht6r8i0d.jpg

ThePrettyDamned

I use a 50 watt one on a 5 watt amp, and I may make a 100w one for the ac15 just to make the volume control less touchy. 

Doesn't the lazy J sound good at low volume? I quite like the clean tone of tweed deluxe amps. 

hotpickups

ThePrettyDamned said:

I use a 50 watt one on a 5 watt amp, and I may make a 100w one for the ac15 just to make the volume control less touchy. 

Doesn't the lazy J sound good at low volume? I quite like the clean tone of tweed deluxe amps. 

Most of the best dynamics happen around 2.5 on the J20 which is still quite loud for home use etc. I have to bring it down in volume so I can practice my sounds/fx with it. Hence the attenuator route.

Did you wire up your L-Pad yourself then @ThePrettyDamned ;

ThePrettyDamned

hotpickups said:

ThePrettyDamned said:

I use a 50 watt one on a 5 watt amp, and I may make a 100w one for the ac15 just to make the volume control less touchy. 

Doesn't the lazy J sound good at low volume? I quite like the clean tone of tweed deluxe amps. 

Most of the best dynamics happen around 2.5 on the J20 which is still quite loud for home use etc. I have to bring it down in volume so I can practice my sounds/fx with it. Hence the attenuator route.

Did you wire up your L-Pad yourself then @ThePrettyDamned ;

Yup. Easy peasy. I drilled an old biscuit tin for it  

It does get warm, hence giving it a decent size box. But not exactly hot - just a wee bit warm. 

I did modify it by adding a treble switch, but it's pointless - I got better results just attenuating less and dialling the amp in. 

olafgarten

The 50w should work if you heatsink it properly.

The L Pad is a very simple concept, just 2 resistors, if you don't need it to have a variable attenuation then it can be very cheap. 

For example, a 12 dB L Pad for the 18w Lazy J would need a ~6 Ohm 15 Watt Resistor and a ~2.7 ohm 4 watt resistor, of course you need higher ratings if the amp will distort but you can get 50w resistors for 2.69 each. 

www.mouser.co.uk/Search/m_ProductDetail.aspx?ARCOL-Ohmite%2fHS50-3R-F%2f&qs=sGAEpiMZZMtbXrIkmrvidNw3CpujCJIJZaXxOeacQxczFw%2ftaMIu3w%3d%3d


www.mouser.co.uk/Search/m_ProductDetail.aspx?ARCOL-Ohmite%2fHS50-6R-F%2f&qs=sGAEpiMZZMtbXrIkmrvidNw3CpujCJIJJp5dQOL1gn9xnQYdQdJQyQ%3d%3d

Rocker

I can't understand the thinking behind attenuating the output of a guitar amp to "bedroom levels". Get a (bedroom) valve amp with an output in the region of a quarter of a watt maxed. In other words is it really necessary to get the sound of an amp that will fill the Royal Albert Hall, in your bedroom?

hotpickups

olafgarten said:

The 50w should work if you heatsink it properly.

The L Pad is a very simple concept, just 2 resistors, if you don't need it to have a variable attenuation then it can be very cheap. 

For example, a 12 dB L Pad for the 18w Lazy J would need a ~6 Ohm 15 Watt Resistor and a ~2.7 ohm 4 watt resistor, of course you need higher ratings if the amp will distort but you can get 50w resistors for 2.69 each. 

www.mouser.co.uk/Search/m_ProductDetail.aspx?ARCOL-Ohmite%2fHS50-3R-F%2f&qs=sGAEpiMZZMtbXrIkmrvidNw3CpujCJIJZaXxOeacQxczFw%2ftaMIu3w%3d%3d


www.mouser.co.uk/Search/m_ProductDetail.aspx?ARCOL-Ohmite%2fHS50-6R-F%2f&qs=sGAEpiMZZMtbXrIkmrvidNw3CpujCJIJJp5dQOL1gn9xnQYdQdJQyQ%3d%3d

Hmmmm this is why I think I should leave well alone. I just don't understand a word of that. Just not my field of expertise

hotpickups

Rocker said:

I can't understand the thinking behind attenuating the output of a guitar amp to "bedroom levels". Get a (bedroom) valve amp with an output in the region of a quarter of a watt maxed. In other words is it really necessary to get the sound of an amp that will fill the Royal Albert Hall, in your bedroom?

Don't think the mrs is going to appreciate another amp in the house. Anyway I want to know how my fx will sound with this particular amp so need it to be the same sound as gig level within reason but quite for home use. So I'll know roughly how my fx will sound when connected to that amp. Trouble is I start to twiddle with fx knobs at rehearsals because I couldn't do this work at home because its too friggin loud even at it's lowest setting

ThePrettyDamned

hotpickups said:

Rocker said:

I can't understand the thinking behind attenuating the output of a guitar amp to "bedroom levels". Get a (bedroom) valve amp with an output in the region of a quarter of a watt maxed. In other words is it really necessary to get the sound of an amp that will fill the Royal Albert Hall, in your bedroom?

Don't think the mrs is going to appreciate another amp in the house. Anyway I want to know how my fx will sound with this particular amp so need it to be the same sound as gig level within reason but quite for home use. So I'll know roughly how my fx will sound when connected to that amp. Trouble is I start to twiddle with fx knobs at rehearsals because I couldn't do this work at home because its too friggin loud even at it's lowest setting

I don't know if that'll work as your perception of sound changes with volume - so quieter sounds duller. But an l pad will help get better low volume control. 

hotpickups

ThePrettyDamned said:

hotpickups said:

Rocker said:

I can't understand the thinking behind attenuating the output of a guitar amp to "bedroom levels". Get a (bedroom) valve amp with an output in the region of a quarter of a watt maxed. In other words is it really necessary to get the sound of an amp that will fill the Royal Albert Hall, in your bedroom?

Don't think the mrs is going to appreciate another amp in the house. Anyway I want to know how my fx will sound with this particular amp so need it to be the same sound as gig level within reason but quite for home use. So I'll know roughly how my fx will sound when connected to that amp. Trouble is I start to twiddle with fx knobs at rehearsals because I couldn't do this work at home because its too friggin loud even at it's lowest setting

I don't know if that'll work as your perception of sound changes with volume - so quieter sounds duller. But an l pad will help get better low volume control. 

That'll do. I'm not too attached to it to be honest. It's this or the Swart Night Light which I really like but need to try one first but they are so expensive and I'll probably never use the line out feature or the features of other known attenuators

ecc83

Hotpickups, you are on a bit of a hiding to nothing if you think you can get a 20W amp down to "bedroom" levels and keep anything like the same sound quality. Even the seriously expensive power soaks such as the Motherloads only APPROACH that ideal.

Reducing a valve amps power by up to 1/10th is probably the best you can do and get anything like a decent tone, even 0.1 watts will still produce 90dB SPL at a mtr from any decent 12" guitar speaker and that is louder than your telly will go by 10dB in all probability. Yes, you CAN smash a 20 watter down to 100 milliwattts or less but the tone will be crap and probably tell you nothing about how it will sound at stage volumes.

All that said, I would still urge you to have a go at a DIY power soak, there is a thread going on at the moment. The basics you will need are a £20ish digital multimeter, a decent solder iron (Maplin do a "Solder Station" for around a nifty, had one for years, V good) and some basic metal working tools such as a battery drill and bits, couple of files, stuff anyone who has a car or house should have anyway!

Learning these skills will always be useful to you, fixing/making cables for just on example.

Dave.

hotpickups

Do you know what I'm starting to go off the idea. I do realise it won't be like gig sound but just want it not so loud. I guess by the time I get all the parts needed, time soldering etc I may as well have bought a ready made attenuator

thanks for the advice 

olafgarten

It's seriously a very simple circuit, you only need to solder those 2 resistors and 2 jacks together with about 5 pieces of wire.

If you buy the potentiometer version you linked there is only 3 pins on the thing, so you need 2 jacks and that device.

hotpickups

olafgarten said:

It's seriously a very simple circuit, you only need to solder those 2 resistors and 2 jacks together with about 5 pieces of wire.

If you buy the potentiometer version you linked there is only 3 pins on the thing, so you need 2 jacks and that device.

lol everyone is saying how easy it is but I'm not comfortable doing it tbh Think I'll save up for a Swart night light

ecc83

hotpickups said:

olafgarten said:

It's seriously a very simple circuit, you only need to solder those 2 resistors and 2 jacks together with about 5 pieces of wire.

If you buy the potentiometer version you linked there is only 3 pins on the thing, so you need 2 jacks and that device.

lol everyone is saying how easy it is but I'm not comfortable doing it tbh Think I'll save up for a Swart night light

Since you are saving up and not rushing to buy I strongly suggest you wait for ICBM to comment. He has experience of a few soaks and amp combinations and can probably tell you what is best for your amp.

Dave.