[Emiliano]

Hi there!
i own a mesa 20/20 power amp and i use it usually with two 1x12 mesa cab
but lately i started to record some of my music on my pc
( and when i'll get it done i'll post some clips! )

i tryied recording with the slave out of my power amp and came out nicely, but i still need to use a high volume
and i usually find time to record only after dinner so volume is a seriuos issue!

i have a unused speaker from my old fender combo (75watt and 8 ohm)
and i was thinking about removing the paper cone without changing the electric part to get an almost silent speaker

this way i would connect that speaker to ( example ) the right speaker out
so i can use the right slave out even at high volume without my parents kicking me out of my home :P

i even searched the net for someone that has done it before me but i didn't find much

is there someone that have already try that before?
do you think that's a good idea?

i know that there are power attenuator out there like thd, marshall, etc
but i found this idea much cheaper and instead of simulate the load of a speaker
there will be a real speaker after my power amp

what do you think about this? maybe could be useful!

sorry for the long post

W sevenstring.org

[rogue]

hey im no experct but sounds like ti might work and i say give it a go, but be careful with the bits incase you need to try put it back together haha

[Emiliano]

yeah!
when i'll have time to do a little bit of surgery
i'll cut that damn speaker all the way!

i think that i can't do this mod
and then fix the cone

but i really don't need it anymore

so it will be fine

but i'll build a nice case for my newborn speaker!
so it will look good.......

and maybe play good too

[Popsyche]

Originally Posted by Emiliano

Hi there!
i own a mesa 20/20 power amp and i use it usually with two 1x12 mesa cab
but lately i started to record some of my music on my pc
( and when i'll get it done i'll post some clips! )

i tryied recording with the slave out of my power amp and came out nicely, but i still need to use a high volume
and i usually find time to record only after dinner so volume is a seriuos issue!

i have a unused speaker from my old fender combo (75watt and 8 ohm)
and i was thinking about removing the paper cone without changing the electric part to get an almost silent speaker

this way i would connect that speaker to ( example ) the right speaker out
so i can use the right slave out even at high volume without my parents kicking me out of my home :P

i even searched the net for someone that has done it before me but i didn't find much

is there someone that have already try that before?
do you think that's a good idea?

i know that there are power attenuator out there like thd, marshall, etc
but i found this idea much cheaper and instead of simulate the load of a speaker
there will be a real speaker after my power amp

what do you think about this? maybe could be useful!

sorry for the long post

W sevenstring.org

Don't do it!
The speaker voice coil uses the movement of air around it caused by the speaker motion to cool it. It probably would burn up in seconds! Use an attenuator, or go to Radio Shack and buy a bunch of big 8 ohm resistors and wire them in series/parallel to get near the wattage you are intending to run.

[Ken]

Well, I recorded my CD in my apartment where volume was obviously an issue as well. What I did was get an ART Tube-MP mic preamp. I could keep the amp volume low, and just give the mic a serious boost. Worked alright for me, because I did many, many, MANY takes, and never got a complaint.

[Emiliano]

The speaker voice coil uses the movement of air around it caused by the speaker motion to cool it

mmm....
i think that you are right!
maybe that is why noone else tryed that before.......

maybe i'll do some experiments with smaller speaker
just to see if this coil heating could be managed in some way
maybe a fan

thanks very much
it's a shame i didn't think about it myself

other suggestions or ideas?

if i can build somthing that actually is useful i'll post that
i'm an engineer wannabe, i like to build useful stuff!

[starsnuffer]

You seem like you're crafty enough to handle simple builds/mods. Here's a cheap alternative that you can easily make on your own from cheap parts:

http://richardbrice.net/hot_lamp.htm

-W

[Emiliano]

You seem like you're crafty enough to handle simple builds/mods. Here's a cheap alternative that you can easily make on your own from cheap parts:

http://richardbrice.net/hot_lamp.htm

i found about that mod this morning
and i think that's really nice
it's on my " things to do " list
after some speaker shredding

i love this forum because all of you people
i often say that my sevenstring guitar saved my life in many ways
and this forum is one of the reason i bought my rg1527

my only doubt about that mod is
the lamp is rated only for 20watt
mmmmmmm.......

however it looks like a simple circuit
i'll try to steal some transformer from my university lab
we'll see!!!!!!!

[noodles]

With the selector knob turned to Load, you can run a slave out, without a speaker cab connected, and not fry your amp.

[Emiliano]

the thd hotplate could be a nice solution for my problem
but it's expensive ( here in italy...and i'm a student )

all the attenuator on the market try to reproduce how a speaker behave when connected to a power amp
there's a lot of filtering and circuit to emulate the low pass response of a guitar cabinet and from what i know
they are pretty good

but what i'm trying to do it's different
:what behave like a speaker better than a speaker?

maybe there is a solution without adding too much electronic

a power amp love pure resistive load
and they like it even better if the resistors are wired so
that the impedance is bigger
( 16ohm vs. 8 ohm )
just because the amp will produce less current to drive the load
but it will react in a linear way ( ohm's law V=R*I is linear )

what really add to the tone of a speaker
is the compression that inductive load add when the speaker
is driven with AC ( musical signal are very complex form of AC )

the resistive value of the speaker is related to the frequency
that you get while you play different notes
so
a speaker rated 8ohm is likely to be 8 ohm in DC, maybe till 400Hz
and the variation of resistance give what we feel as
A Good Tone!

using a speaker from this point of view is much more simple
no filters, no active electronics.

i also thougth about AC in the speaker and heating problem
heat generated from AC is usually very low
( your amplifier take AC 110V 50Hz and the power cord could burn
only if happen a short circuit not under normal work condition )

BUT!!!!!!!

i noticed that this kind of mod will be useful to people
that have some kind of slave out from the poweramp like i do

for every other people that do not have such slave out
will not be useful as it is, it will need some kind of tweaking

SO!!!!!!!

my plans are to try and see myself if it will work as a load
and THEN try to work this up toward some kind of variable attenuator
( keeping it veeeery simple )

the lamp circuit still amuse me and i'll try it
in the mean time i'll work on some schematic i found on the net
( like the power brake! )

to understand this kind of circuit

thanks for the help

and don't worry
if nothing gets burned and it doesn't work
i'll buy myself an hotplate