Attenuator, the cheap-ass way.

Johnny Storm

FWIW I bought an Epiphone Valve Junior a month or two ago but found it far too loud to get the full-on tube sound at a volume I could live with in the home. To cut a long story short I decided to get one of these. This is designed to control the volume of a stereo system where the speakers are built into the walls (you do have your house fully wired for stereo dont you ?;) ) but the amp is in another room. Normally these are high end audio components and in stereo, costing USD100+ but this one is the mono Radio Shack version :rolleyes:

Here it is




Next thing I got a Planet Waves speaker cable and cut it in two and put this gizmo in the middle. (The cable cost a good bit more than the gizmo:eek: ). This then plugs inbetween the amp and the speaker and hey presto I can fully crank the amp and turn the volume right down.
It works great except on the most attenuated setting when its actually like someone is turning down the volume as a note decays.
I tried several places to get a box to put it in, but couldn't find one that fits. Next step will be to loose the white plate on the front of it and mount it into an aluminium coffee can or similar.

In summary, not a bad inexpensive solution to keeping the volume down

deaddonkey

damn, i'd be all over that for my amp if it could handle more than 25watts.

-=al=-

good thinkin batman

rcaz

Any pictures of the finished thing? Sure, I could imagine it, but that takes too long and burns too many calories...

Johnny Storm

El Pr0n wrote:

Any pictures of the finished thing? Sure, I could imagine it, but that takes too long and burns too many calories...

LOL, I hear what you're sayin', ElPr0n, believe me.

This is the socket at the back of the amp as it normally is:



Here's the gadget itself with the butchered speaker cable attached (PS I have about 23 feet of speaker cable left over :rolleyes: ):


Here's the ......ehhh.... "finished" product connected between amp and speaker (also using a jack socket-to-socket connector which I forgot to mention earlier)


For your further delectation - Useful link 1 and 2

Eoin Madsen

Those things don't reduce the volume in any way linearly. There's a reason real attenuators cost so much. Just mod for an MV, it'll cost about €5, and it will sound better.

Johnny Storm

Eoin Madsen wrote:

Those things don't reduce the volume in any way linearly.

EDIT: Can you explain what that means please, Eoin?

I'm assuming MV = Master Volume. I always thought that if you turn down the Master Volume on a tube amp then you are not getting output tube distortion/saturation which is basically what makes tube amps sound good? So I dont see how that would be an advantage? Or am I getting it all wrong (most likely option)?

Eoin Madsen

Johnny Storm wrote:

EDIT: Can you explain what that means please, Eoin?

I'm assuming MV = Master Volume. I always thought that if you turn down the Master Volume on a tube amp then you are not getting output tube distortion/saturation which is basically what makes tube amps sound good? So I dont see how that would be an advantage? Or am I getting it all wrong (most likely option)?

Linear, as in the frequency response. Any given reduction in volume will affect all frequencies at different amplitudes. In particular, high frequencies are attenuated more easily. If you're seeking to preserve the tone of the amp before attenuation, this is a bad thing. Basically: you turn down the volume, it reduces the treble more than the middle, resulting in dullness of the sound.

MV is master volume, sorry. What makes valve amps sound different (good is subjective) is the fact that the signal is amplified using a valve circuit, which give completely different characteristics to amplification with a semiconductor based circuit. Further to this, saturation in a valve preamp sounds different than it does in a solidstate preamp. The same for the powerstages. But saturation is not at all the only time in which a difference in sound can be heard.

In my opinion, the advantages of distorting your powerstage are outweighed by the loss of perceived sensitivity that's caused by non-linear attenuation. Even well designed attenuators are a compromise between tone and volume, and tbh, you won't find many users who would disagree with that. So again - just in my opinion - you would be better to reduce volume from the output of the preamp or phase invertor (if it's a push/pull amp) and sacrifice your ability to overdrive the power valves in order to retain the overall clarity of the output.

...is as short as I can put it. I'm not great at explaining these things, sorry.

Johnny Storm

Thanks for the taking the time for the detailed explanation, Eoin.

FYI I did buy the EVJ with the intention of modding it but the instinct for self-preservation has stopped me from taking the back off so far :rolleyes:

Tonewise my Ratio Shark yoke sounds OK to me (except for the issue I noted in my first post) but I dont have the opportunity to A-B it with a real attenuator. It doesn't seem to be lacking in treble but it does sound better (fuller) when its louder. It certainly sounds a lot better to my ears than the clean amp.

Eoin Madsen

I guess to a degree its going to depend on the type of amp tone in the first place. On a 1959 and an AC30 the loss of clarity is quite noticable even with a THD Hotplate.