I'm in the process of building a mono LM4780 bridged amplifier identical to the application circuit in the datasheet, and I have a few questions:
I want the amp to be able to take a signal from either a CD/MP3 player, or an electric guitar. I assume that since the guitar signal is much weaker than the CD/MP3 signal, they will need to have separate inputs.
Can anyone point me in the direction of a pre-amp that I could use for the guitar input, and would it be best to have 2 separate volume adjustment pots at the pre-amp and LM4780 stages?
Andrew
I want the amp to be able to take a signal from either a CD/MP3 player, or an electric guitar. I assume that since the guitar signal is much weaker than the CD/MP3 signal, they will need to have separate inputs.
Can anyone point me in the direction of a pre-amp that I could use for the guitar input, and would it be best to have 2 separate volume adjustment pots at the pre-amp and LM4780 stages?
Andrew
I've moved to instruments and amps forum (with a one week redirect) hopefully that should get the attention of the right people.
an MP3/CD shouldnt need too much gain, a single op-amp stage with a fairly flat frequency response should be fine, a pot can be used in the feedback. A guitar preamp will need more gain, especially if your looking for some distortion, which will also require a frequency curve unsuited for music.
with a 120 watt output, are you looking for something to gig with? and are you looking for a fairly complex pre-amp that will get you a range of tone?
with a 120 watt output, are you looking for something to gig with? and are you looking for a fairly complex pre-amp that will get you a range of tone?
I would choose a schematic from a well known brand or one of your favorites.
My two favorites are the Marshall 8100 Valvestate and the Peavy Renown 400.
Either can be duplicated very easily !!!
FWIW
jer🙂
My two favorites are the Marshall 8100 Valvestate and the Peavy Renown 400.
Either can be duplicated very easily !!!
FWIW
jer🙂
Any hints on where I can find schematics for the Peavy?
Looking at the controls for it, it seems like they have a 'pre-amp' built in if you use the high gain input, unless I'm mistaken...
Looking at the controls for it, it seems like they have a 'pre-amp' built in if you use the high gain input, unless I'm mistaken...
Yes it can be found here,
Peavey Renown 400 Manuals, Support and Troubleshooting - Amps
And the Marshal 8100 as well as many others can be found here,
Marshall Amps Info & Schematics
Enjoy !!!
jer 🙂
I have owned both of these amps and their sound second to none except to the fully tubed amps, I still have the Peavey Renown400 but my Marshall 8100 was stolen. 🙁
Peavey Renown 400 Manuals, Support and Troubleshooting - Amps
And the Marshal 8100 as well as many others can be found here,
Marshall Amps Info & Schematics
Enjoy !!!
jer 🙂
I have owned both of these amps and their sound second to none except to the fully tubed amps, I still have the Peavey Renown400 but my Marshall 8100 was stolen. 🙁
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