Adding an effects loop

Fatfingers

I fancy adding one to my Ampmaker P1800 and wondered whether anyone had any suggestions as to a suitable kit?

There are lots and they vary considerably in price and complexity. I only need it to work with stomp boxes.

Does anyone have any knowledge about any of these?

This one is cheap.

http://www.tube-town.net/ttstore/Kits/Misc-Kits/Kit-Seriel-FX-Loop-LND150::5973.html?MODsid=ocjkva4n7j72idj244os4p9hg0

This one's a lot more but seems similar.

http://www.tubeampdoctor.com/en/shop_Surplus_amp_Specials/DISCRETE_HI_VOLTAGE_SERIES_EFFECTS_LOOP_FOR_TUBE_AMPS_3035

And this one seems extremely complex.

http://www.ironsounds.com

ICBM

Does the amp have a master volume?

If not, fitting an FX loop is fairly pointless, and completely so for pedal effects. If you can't put the effects after the amp's distortion, the only benefit would be to run line-level effects that don't work well in front of the amp.

robinbowes

ICBM;994664" said:

Does the amp have a master volume?

If not, fitting an FX loop is fairly pointless, and completely so for pedal effects

Unless the loop does level attenuation and gain recovery, like this one: http://riotdevices.com/products/accessories/

I can recommend the company - I've had couple of those loops off them. He makes some nice pedals too.

R.

Fatfingers

No, it has VVR and lots of the distortion is power stage as a result. So I guess I might as well not bother then.

Thanks ICBM.

Fatfingers

robinbowes said:

ICBM;994664" said:

Does the amp have a master volume?

If not, fitting an FX loop is fairly pointless, and completely so for pedal effects

Unless the loop does level attenuation and gain recovery, like this one: http://riotdevices.com/products/accessories/

I can recommend the company - I've had couple of those loops off them. He makes some nice pedals too.

R.

That's a sweet looking thing. Is it of any use to me? At the very least, would it not allow me to use a clean boost pedal as a volume boost?

ICBM

robinbowes said:

Unless the loop does level attenuation and gain recovery, like this one: http://riotdevices.com/products/accessories/

That will work, but does nothing useful because the effects will still be pre-distortion if the amp doesn't have a master volume, because all or most of the distortion is coming from the power stage. You may as well save the bother and just put them in front of the amp.

FX loops only serve any real purpose to put effects after the amp's distortion.

There are even some amps *with* master volumes that don't get this right, most notoriously the Soldano SLO - the loop is in the preamp, before the stage that most produces the characteristic overdrive.

Fatfingers

Fair enough.

robinbowes

Yes, I was totally missing the point regarding MV.

You could get a Bad Cat Unleash

R.

Fatfingers

What's one of those then?

ICBM

A re-amplifying dummy load system. Unlike most attenuators which simply divide the amp's power between the speaker and a dummy load in a controllable ratio - and which inevitably affect the way the amp reacts with the speaker, so are notorious for taking away the 'life' from the sound (although that's a bit of an exaggeration in my opinion) - it works by sending all of the amp's power to the load, then reamplifying the signal with a separate power amp so the speaker is still seeing an *un*attenuated amp output, if that makes sense!

It also means you can break the signal path after the load and before the re-amp, and insert the effects there.

I have an 'Ultimate Attenuator' which is another variation on the dummy load/re-amp theme but doesn't have an FX loop… yet. I have been thinking of modding it exactly for that reason, using the Tube Town kit. The 'Ultimate Attenuator' is a piece of junk by the way, so don't buy one to do this unless you're prepared to completely rebuild it to make it safe and reliable.