Hello!
I have a low experience with guitar amps. Specifically, I know that the amp is a combination of a power source, preamp, effect loop, power amp and the speaker.
I found a power amp module and thought to build an amplifier with it.
My plan is this:
-For power source I was thinking to use a laptop adapter (there are a lot of 18 Volt with max 5 A- 90 watt)
-The power amp module I found is this
Dc 12V-24V TPA3118 BTL 60W Mono Digital Audio Power Amplifier Board Amp Module A | eBay
-For a preamp I was thinking a tl072 based preamp with the features:
-pregain,
-tonestack-maybe a marshall like tonestack
-followed by a tube screamer clipping stage
-a unity gain buffer followed by a volume control
Is there a way that this concept will fail completely?
edit: Rephrasing the question "Is there a possibility that this project will work at all?"
I have a low experience with guitar amps. Specifically, I know that the amp is a combination of a power source, preamp, effect loop, power amp and the speaker.
I found a power amp module and thought to build an amplifier with it.
My plan is this:
-For power source I was thinking to use a laptop adapter (there are a lot of 18 Volt with max 5 A- 90 watt)
-The power amp module I found is this
Dc 12V-24V TPA3118 BTL 60W Mono Digital Audio Power Amplifier Board Amp Module A | eBay
-For a preamp I was thinking a tl072 based preamp with the features:
-pregain,
-tonestack-maybe a marshall like tonestack
-followed by a tube screamer clipping stage
-a unity gain buffer followed by a volume control
Is there a way that this concept will fail completely?
edit: Rephrasing the question "Is there a possibility that this project will work at all?"
Last edited:
Should work ok.
Might need a little tweaking to get the gain right.
I have designed a couple of guitar amps.
I used a standard hi fi amp but added a "soft limiter" to give it a warm valve sound.
I sold it on and he used it in a band and was delighted with the sound.
Might need a little tweaking to get the gain right.
I have designed a couple of guitar amps.
I used a standard hi fi amp but added a "soft limiter" to give it a warm valve sound.
I sold it on and he used it in a band and was delighted with the sound.
With all the modeling and effects boxes available, one would think a straight up amp [power supply, amp, speaker] would work just fine as a back end to a pedal board - which would have ALL the tone, gain, compression, reverb, echo, cab modeling, wah, phrase looping, Leslie, phase shift, ring modulator and infinite sustain effects done ahead of the amp.
Such a setup might involve a double cord to the guitar, so the effects see a constant level from the guitar, while the guitar volume controls the level going into the amp. I think Jerry Garcia was setup that way for a while.
Such a setup might involve a double cord to the guitar, so the effects see a constant level from the guitar, while the guitar volume controls the level going into the amp. I think Jerry Garcia was setup that way for a while.
As a concept there is no problem. While not as common on guitar, many pro bass rigs are built around PA power amps. Eddie Van Halen's rig uses the tube head as giant tone box that gets attenuated and then goes to PA power amps.
There are a few areas that are important to get right. A passive guitar pickup output is high impedance, so you need to get shielding, grounding, and high impedance for your input stage correct. Heat sinking and ventilation are important. The power supply must be adequate, check what your brick can really do.
There are a few areas that are important to get right. A passive guitar pickup output is high impedance, so you need to get shielding, grounding, and high impedance for your input stage correct. Heat sinking and ventilation are important. The power supply must be adequate, check what your brick can really do.
Famous and respected Rod Elliott would answer:
"Hold my [insert Australian brand here] Beer"
100W Guitar Amplifier (Mk II)
Save time and effort, do it right from the beginning, buy an original PCB straight from him.
ESP - Complete Price List
Why not go for a proven kit?
The thing is, if your not an experienced designer, your not likely to get the sound you want.
So my advice would be to, first figure out what kind of sound you want, then get the kit that gives you that sound.
An example of that would be: You like the raw blues sound of the 50's-60's, then get a Fender 5F6-a kit. (with the tube screamer in front, you can get a lot of beautiful sounds from clean to scream and everything in-between.)
Or if your a complete noob, get a 5F1 kit. If your into metal and have some experience, get a SLO 100 kit.
Not a lot of SS kits out there. Not even a lot of preamp designs unless you pick your favorite pedal and find a schematic of it. But they are usually designed to go before a guitar amp which usually have tone shaping.
Can't be overstated. The basic idea you have is fine* but you need to know that the result is what you want.
Rod Elliot's (excellent) pre-amp will provide plenty of '80s fizzy fuzz. But it won't give you "tone" or "raawk".
The other two standard links (now you've found Rod Elliot) are RunOffGroove (who have lots of sound samples of how their circuits sound) and Rob Robinette, who explains how a bunch of (tube) guitar amps get their sound.
*I'm about to do the same thing but with a Supreaux Deux as a front end.
The TPA3118 amps sound great, I've got a 2.1 hifi amp with a pair of them.
In mono mode the amp actually runs as two amps in bridged mode each at 4 ohms. So with each amp at 30W and 4 ohms it only needs 11V, so a 12V power supply will work fine, and there are lots of options for those.
If you're actually hoping to get the full 60W it's going to take 5.5A to get there, best get a power supply with some headroom there. I wouldn't recommend a laptop power supply since their enclosures don't dissipate heat well. The bigger the audience, the louder the stage volume, the more likely it's going to die at the worst possible moment.
I'd get this one and mount it to the side wall of the cabinet:
Ac110v-240v to dc12v 10a 120w switching power supply 187*45*35mm Sale - Banggood.com
In fact I'd probably just have the power amp, power supply, and speaker in the speaker cabinet, allowing for preamp options to change with time, or maybe you want different preamps for different genres etc.