Building a Solid State Amp. Really?

printer2

Poster Extraordinaire
Joined
May 24, 2010
Posts
8,277
Location
Canada
This is a simple amp, I want something small that I can plop down on top of my desk and have it take up the least amount of real estate. Originally I was going to make a pair of small cabinets with a 8" in each with a stereo tube amp for them. I built up the cabinets already but I would have to get rid of a paper tray holding work I need to get to and I am not ready to dump it. I already procrastinate getting to it and if I put it out of site, well it disappears and it is not a problem anymore. Not a good thing. So in the meantime a little amp would do me just fine.

I was going through my parts and have a pair of TDA2005 Chipamp IC's. I had them for a bunch of amp testing, SS watts as compared to tube watts and the like. Just to amuse myself. One day. For now one will be pressed into miniamp service. I have a 5" car speaker, the cabinet will be roughly 7.5" x 6.25" x 5". A laptop brick as a power supply, the chip can run bridged and will make about 12-15W depending on voltage and speaker impedance.

Seems funny something this small took all day to build. Mind you, you can only get so many clamps in play when the clamps are bigger than the box.

mcHPnAT.jpg
 

Nogoodnamesleft

Tele-Holic
Silver Supporter
Joined
Aug 19, 2020
Posts
759
Age
50
Location
Canaduh
I haven’t used that IC but I’ve had some experience with discrete components, making small amps with a FET and 2 BJTs as the power stage. Sometimes I think about blowing the dust off the old EE books and getting back into it. Fun stuff! Good luck with your project!
 

printer2

Poster Extraordinaire
Joined
May 24, 2010
Posts
8,277
Location
Canada
Going to try a BSIAB inspired circuit for the preamp. Going to have to figure out the amp component placement also. The pin spacing for the chip does not fit across a normal board spacing. But if you place it at a 45 degree angle you can finesse the pins in place. Two line normally run in the tab side of the circuit board, should be able to use a set of holes without them touching the heat sink. The heat sink will be a piece of aluminum mounted on the back of the cabinet. Thinking of lining the inside with aluminum foil as shielding. Will look ugly, not a great concern. Just an example of what the circuit will somewhat be. I messed around with it and a class D module way back when. Was debating on using one so for whatever reason I decided to make it portable. If the need arises I can always stick one in.

1E0rRc4.png


aSw7s11.jpg
 

NTC

Tele-Afflicted
Joined
Mar 17, 2003
Posts
1,164
So the amp is for guitar? I assumed this was for music playback. The tone controls has a distinctly guitar amp topology.
 

peteb

Friend of Leo's
Joined
Apr 25, 2003
Posts
4,817
Location
Cascadia
the chip can run bridged and will make about 12-15W depending on voltage and speaker impedance.

when the other thread mentioned the 50 W amp IC chip, I was thinking that an IC for a 10 W amp would be fun to play around with. I know the 1W amp chip is useful but only to a degree.


that is an interesting project.
 

printer2

Poster Extraordinaire
Joined
May 24, 2010
Posts
8,277
Location
Canada
when the other thread mentioned the 50 W amp IC chip, I was thinking that an IC for a 10 W amp would be fun to play around with. I know the 1W amp chip is useful but only to a degree.


that is an interesting project.
I have an amp that is a bridged car stereo amp with two transistors and a James tone control between them. Made it in the 90's, came back to it one day and was surprised how nice the guitar sounded clean through it. Has a 8" in a sealed enclosure and was originally intened as a bass practice amp. Did not know much on amp distortion back then, thought it might be fun to do a simple SS amp now. At some point I would like to dive deeper into a SS preamp. Along with a (relatively) bulletproof chipamp and laptop supply it might be a low voltage alternative for those interested in building an amp. I have a number of things I would like to see in it, like a compressor, but this one will be more basic. Only so much room for knobs.
 

chris m.

Doctor of Teleocity
Joined
Mar 25, 2003
Posts
10,208
Location
Santa Barbara, California
Building is fun and you should totally go for it. I have an EHX 44 Magnum and when I use a Joyo AC pedal into as the preamp it sounds really quite good. So there's no question that fairly simple SS tech can get the job done. Rather than worry about tone shaping in your build you might consider building a "clean pedal platform" and then using a pedal to shape the final tone.

I did a little Googling ("EHX 44 Magnum schematic") and apparently the key component in it is this chip:

1643062803625-png.943989
 

Attachments

  • 1643062803625.png
    1643062803625.png
    90.4 KB · Views: 2,244

printer2

Poster Extraordinaire
Joined
May 24, 2010
Posts
8,277
Location
Canada
Building is fun and you should totally go for it. I have an EHX 44 Magnum and when I use a Joyo AC pedal into as the preamp it sounds really quite good. So there's no question that fairly simple SS tech can get the job done. Rather than worry about tone shaping in your build you might consider building a "clean pedal platform" and then using a pedal to shape the final tone.

I did a little Googling ("EHX 44 Magnum schematic") and apparently the key component in it is this chip:

1643062803625-png.943989
Same idea of the module I used previously, the TPA3118.

aSw7s11.jpg


The preamp is a few building blocks used in many pedals. I am just adding a tone stack and possibly a basic clipping circuit. Rather than having a pedal that I would need to build and have on my desk as well as the cable between it and the amp, why not put it inside the box?
 

NTC

Tele-Afflicted
Joined
Mar 17, 2003
Posts
1,164
Yes guitar. How could you think anything but?

Rock on.

The best sounding "Champ" I made was when I came up with an attempt at replacing the 6V6 with a MOSFET. A 6SL7 preamp tends to make lits of things siund good. One should be able to get there with JFET's in the preamp.

There is no reason a solid state amp shouldn't sound good. I think the big problem is that the big companies didn't implement them well. That and we users expected amp distortion like a tube amp has without pedals.
 

chris m.

Doctor of Teleocity
Joined
Mar 25, 2003
Posts
10,208
Location
Santa Barbara, California
Same idea of the module I used previously, the TPA3118.

aSw7s11.jpg


The preamp is a few building blocks used in many pedals. I am just adding a tone stack and possibly a basic clipping circuit. Rather than having a pedal that I would need to build and have on my desk as well as the cable between it and the amp, why not put it inside the box?
I was thinking more along the lines of just using overdrive and dirt pedals you already own, not building one. The advantage of leaving the amp itself as a "clean pedal platform" is you can get a variety of amp sounds just by switching pedals such as from an AC to a British (Marshall) to an American (Fender) pedal-- multiple amps in one.
 

chris m.

Doctor of Teleocity
Joined
Mar 25, 2003
Posts
10,208
Location
Santa Barbara, California
Rock on.

The best sounding "Champ" I made was when I came up with an attempt at replacing the 6V6 with a MOSFET. A 6SL7 preamp tends to make lits of things siund good. One should be able to get there with JFET's in the preamp.

There is no reason a solid state amp shouldn't sound good. I think the big problem is that the big companies didn't implement them well. That and we users expected amp distortion like a tube amp has without pedals.
Check out the new Orange Super Crush 100. Its pre-amp JFET based, I believe, and it sounds amazing, at least via YouTube....



 
Last edited:

printer2

Poster Extraordinaire
Joined
May 24, 2010
Posts
8,277
Location
Canada
I was thinking more along the lines of just using overdrive and dirt pedals you already own, not building one. The advantage of leaving the amp itself as a "clean pedal platform" is you can get a variety of amp sounds just by switching pedals such as from an AC to a British (Marshall) to an American (Fender) pedal-- multiple amps in one.
But you are assume I have pedals. I also think a switch onboard that can convert from a Fender to a Marshall sound would be of use, wonder if I have room for one?

The Orange, the first 2:38 minutes sound like... ... crap. Ji-fet? No, not a mistake as he said it more than once. A video that is 97% high gain with enough reverb that it all sounds like mush. Clean also with reverb, just to show it is not a one trick pony. And that is the thing, easy to do clean or gainy stuff with SS. The world of almost clean to a mild dirt? Tubes still show how it is done.
 
Last edited:

Nogoodnamesleft

Tele-Holic
Silver Supporter
Joined
Aug 19, 2020
Posts
759
Age
50
Location
Canaduh
It’s more than tubes vs transistors. A big part of the ‘vintage’ sound we all tend to get excited about involves transformers. Building a ss amp including transformers didn’t really catch on beyond a certain point in time - I’m guessing as a cost cutting measure. The warmth or vintage sound of old preamps in mixing consoles tend to have transformers. The way they saturate is a crucial part of that sound. The recent thread on the ss amp Brian May uses on occasion has them in the design.
 

printer2

Poster Extraordinaire
Joined
May 24, 2010
Posts
8,277
Location
Canada
One man’s crap is another’s glorious stoner metal tone…..
Which is great if you are after stoner metal, which the reviewer seems to think is where the amp lives, little else to show off what the amp can or can not do. Which is a shame.

It’s more than tubes vs transistors. A big part of the ‘vintage’ sound we all tend to get excited about involves transformers. Building a ss amp including transformers didn’t really catch on beyond a certain point in time - I’m guessing as a cost cutting measure. The warmth or vintage sound of old preamps in mixing consoles tend to have transformers. The way they saturate is a crucial part of that sound. The recent thread on the ss amp Brian May uses on occasion has them in the design.
Still get the tube sound with master volume amps. I have a 10W transistor transformer output amp. Actually got the chips to do an A/B listening experiment with this amp and the Li'Tiger amp I have. The smaller transformer is the output transformer. Also has an input transformer for a balanced line.

Y9rdz2c.jpg


The Orange Super Crush is AB with traditional transformers, not Class D, because they concluded it sounds better that way.
You do have to put a clipping circuit before a Class D amp because they do not clip gracefully.
 

chris m.

Doctor of Teleocity
Joined
Mar 25, 2003
Posts
10,208
Location
Santa Barbara, California
There are lots of other YouTube reviews of the Orange Super Crush 100, including folks trying to get a more classic rock tone out of them-- such as Anderton's. The main reason I mention it is because it is one of the few AB powered amps that I know about aimed at a really wide spectrum of customers that is full analog SS, no digital modeling. I am also impressed with what a good job they did of making it sound like a real Orange. Might not be your cup of tea, but it's impressive, in my opinion, to hear it compared to a full tube amp like their Rockerverb.
 

printer2

Poster Extraordinaire
Joined
May 24, 2010
Posts
8,277
Location
Canada
There are lots of other YouTube reviews of the Orange Super Crush 100, including folks trying to get a more classic rock tone out of them-- such as Anderton's. The main reason I mention it is because it is one of the few AB powered amps that I know about aimed at a really wide spectrum of customers that is full analog SS, no digital modeling. I am also impressed with what a good job they did of making it sound like a real Orange. Might not be your cup of tea, but it's impressive, in my opinion, to hear it compared to a full tube amp like their Rockerverb.
Actually I was just saying the reviewer was not my cup of tea. Why not show the amp with different styles of playing? The amp might be fine for other things but the review does not show that.
 




New Posts

Top