dori2o Posted September 11, 2008 Report Posted September 11, 2008 I want to make an acoustic amp using a simple preamp circuit and the Ruby from runoffgroove. Both requires a 9v power input. Question is, can I simply link the 2 power inputs to the same lug, or will both circuits require their own seperate power supply. Secondly, is there a circuit I can make that will do the job for me instead of having to do it as described above. (Here is the link to the preamp) Preamp Quote
bluesy Posted September 11, 2008 Report Posted September 11, 2008 I want to make an acoustic amp using a simple preamp circuit and the Ruby from runoffgroove. Both requires a 9v power input. Question is, can I simply link the 2 power inputs to the same lug, or will both circuits require their own seperate power supply. Secondly, is there a circuit I can make that will do the job for me instead of having to do it as described above. (Here is the link to the preamp) Preamp The only issue that can arise is, sometimes, the preamp will need extra power supply filtering and isolation from the signal that the power amp will impose on the power supply rails. The preamp circuit you linked has a capacitor to additionally filter the power supply, and my guess is that it'll work OK. Quote
psw Posted September 11, 2008 Report Posted September 11, 2008 You can run the two circuits from the same supply...the tillman and the ruby are very basic...and would work as well as the fetzer/ruby that most use for sustainer circuits. The problem is that these amps are incredibly low powered and tend to distort, typically for any kind of decent acoustic sound you would need an amp with a lot more headromm and more than a simple battery can supply. You might consider something like this for headphones. You may also get away without the preamp if there is already a preamp in the guitar...perhaps a little more detail of what you are seeking to achieve might help pete Quote
dori2o Posted September 12, 2008 Author Report Posted September 12, 2008 (edited) You can run the two circuits from the same supply...the tillman and the ruby are very basic...and would work as well as the fetzer/ruby that most use for sustainer circuits. The problem is that these amps are incredibly low powered and tend to distort, typically for any kind of decent acoustic sound you would need an amp with a lot more headromm and more than a simple battery can supply. You might consider something like this for headphones. You may also get away without the preamp if there is already a preamp in the guitar...perhaps a little more detail of what you are seeking to achieve might help pete I've got a squire acoustic that I have inserted a piezo pickup into, The sound is very 'Tinny', and I've run it through a preamp and it improves the sound 10 fold. I want to make a small practice amp that I can use in the house. If I wanted to make something a little more powerful, could somebody please reccommend a good amp schematic. Also with the idea I've had, would I still need to run the seperate curcuits to have their own power supply i.e. a connection to the power supply from each circuit, or would I put the power through the preamp and just connect to the amp and let the power filter through? Edited September 12, 2008 by dori2o Quote
psw Posted September 12, 2008 Report Posted September 12, 2008 You could simply connect the battery to both, the preamp draws very little power, but the "ruby" will drain the battery fairly fast and tends to get fairly distorted as it drains down. If you use a regulated power supply on it, it will sound better of course. The speaker has a lot to do with it too...a tiny computer speaker won't sound too good, but a larger one can sound ok. If you can build this, you have virtually built the sustainer circuit pete Quote
dori2o Posted September 12, 2008 Author Report Posted September 12, 2008 You could simply connect the battery to both, the preamp draws very little power, but the "ruby" will drain the battery fairly fast and tends to get fairly distorted as it drains down. If you use a regulated power supply on it, it will sound better of course. The speaker has a lot to do with it too...a tiny computer speaker won't sound too good, but a larger one can sound ok. If you can build this, you have virtually built the sustainer circuit pete The idea is to power the amp via a 9v adaptor, so as you say it should sound better from a regulated source. The plans for the Ruby suggest a 4ohm speaker. Would an 8ohm speaker not be better? (Not meaning to sound thick, but what is a sustainer circuit?) Quote
Ripthorn Posted September 12, 2008 Report Posted September 12, 2008 I'm sure pete will tell you to check out the sustainer thread and see for yourself. It is his baby. He's a freakin' genius, by the way. Quote
psw Posted September 12, 2008 Report Posted September 12, 2008 Most just say freakin **** ...opps, set off the spam filter again! The ruby and similar are based on the LM386 chip and will tolerate between 4 and 16 ohms or even your 32 ohm headphones at a pinch. 8 ohms is probably the best and usual...the ruby and other ROG designs have some strange ideas IMHO, but they work, the data sheet designs can be better... If you see the thread pinned to the top of this section "sustainer ideas" you will see what I really am doing here...running my own private forum within the forum...hehehehe My designs use simple low powered amplifiers usually based on the LM386 chip to run a signal through a special coil near the neck to produce a feedback loop and so infinite sustain and automatic harmonic drive amongst other things. In my signature below are some more easily digestible threads or better yet, look at my new telecaster thread or this months GOTM and press the sounds link also to hear what it sounds like direct recorded with on a clean direct guitar with no overdubs. (sounds better with distortion or a real amp of course) Of course...please consider the guitar come the end of the month as there is not "sustainer of the month" prize so I am up against a bunch of fabulous and varied entries....plug, plug! pete Anyone notice, the more I post the more people take a look at these threads...cross marketing at work...watch it backfire when the effects of over exposure take hold! Quote
imwellstrung Posted June 9, 2009 Report Posted June 9, 2009 Okay, smarty pantses....... awkward silence.... how would one rig up this preamp to have two output channels, i.e. low and high? I want to get the bass responsiveness with a sub, and the treble with a horn driver. How 'bout it, eh? Quote
JohnH Posted June 10, 2009 Report Posted June 10, 2009 Okay, smarty pantses....... awkward silence.... how would one rig up this preamp to have two output channels, i.e. low and high? I want to get the bass responsiveness with a sub, and the treble with a horn driver. How 'bout it, eh? It could easily be done, but Im not going to tell you Quote
Donovan Posted June 12, 2009 Report Posted June 12, 2009 Here's a hint. Each will have something like this. http://focus.ti.com/lit/an/sloa093/sloa093.pdf Quote
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