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DIY Stompboxes => Building your own stompbox => Topic started by: vanhansen on April 22, 2005, 04:35:04 PM

Title: Amp Emulation + Ruby Amp
Post by: vanhansen on April 22, 2005, 04:35:04 PM
Ok, here's the scenario.  I'm looking at making a new practice amp by combining the ROG Ruby with one of the amp emulators, like the Thunderchief or even Electric's JCM800 emu.

The entire front end of the Ruby would be replaced with the emu circuit going in to pin 2.  The question I have is in regards to the order of the master volume and low-pass filters.  Would it be better/smarter to put the low-pass filters before the output volume (Thunderchief) or put them after the master volume?  

I'm asking because Electric's JCM800 emu doesn't have the dual low-pass filters like the Thunderchief and if I want to put them in or need them, I'll have to perf them with the Ruby circuit on a daughter board.  If the volume should go after the filters, then the wiring to the volume would have to move from the emu PCB to the daughter perf board.

Just trying to plan ahead here.
Title: Amp Emulation + Ruby Amp
Post by: space_ryerson on April 22, 2005, 05:08:34 PM
Wow. It's like you read my mind. I don't the answer, but please do share your progress, since sometime this summer I was planning on making a 'mini-jcm' of sorts as well.

Good luck!
Title: Amp Emulation + Ruby Amp
Post by: nero1985 on April 22, 2005, 09:57:23 PM
i was told by the guys from ROG that using an emulation there would make u lose the characteristics of the emulation.... it would be worthless
Title: Amp Emulation + Ruby Amp
Post by: B Tremblay on April 22, 2005, 10:58:57 PM
Actually, what I said was:

"When placing a FET-based amp emulator circuit before a 386-based amp, you need to keep the output volume of the emulator at the same level as the dry guitar signal.  Otherwise, you'll overdrive the 386 and lose the character of the emulator."

Regarding the low-pass filters, it depends on the speaker you're using.  If you're using a smaller speaker, you'll probably want them.  Keep them before the Master Volume.
Title: Amp Emulation + Ruby Amp
Post by: vanhansen on April 22, 2005, 11:09:18 PM
Thanks, Brian.  I thought it was something like that but couldn't quite remember.