Alright I’ll start off with, it has one issue, took me a while to find out what I did wrong ! BUT, it works perfect and I accomplished my goal!
What was wrong ? I somehow missed a wire in the pcb drawing process and didn’t tie input sense to the speaker terminal, very important wire too!
After finding the issue and making the missed connection she came alive and worked perfectly ! Now onto revision 1.5, made a few changes and have a few more ideas for different versions for new applications.
Yes ! A new amp in the build, one of the guys I think is the best at Amplifier designs. I’ll go into depth about that a little, i’m not saying his designs are 100% the best because yes there are other ones out there that “could” be better BUT Nelson Pass puts more energy into helping people and contributing to builds and ideas on DIY audio.com more than any other designer I know of! AND THAT from my pint of view is the best !
Now I have’t built many class AB amps in years, most of my amps in the last 10+ years have been Class A, so this one is going to be pretty sweet! At only 100 watts, I’m pretty sure it will go over the 100watt mark, and to be honest do I need more ? ( we will find out )
Photo of the boards & a few nice 1% Dale resistors installed so far !
After a few months of working on this project it’s finally into the next stage! the PCB stage 😛
I have to admit, I had some issues, but not because of the circuit issues, but because of the lack of looking at the CORRECT pin out’s on the “VOM” ic 🙂 Stumbled upon my issue when going through my notes & measuring every point with my DMM, after I realized that I wired the VOM backwards and then connecting it properly IT SPRUNG to life! DERP! Live and learn !
I’ve been working on this for a very long long time ! And first I would like to say Special thanks to Thomas Uhd Larsen, a good close friend of mine on Facebook for helping me and making this possible 😛
Now, what is a SSR ? A “SSR” is a Solid State Relay, in audio they are used on the speaker output of an amplifier to protect the speaker if anything goes wrong with the amplifier. When an amplifier has problems or is going to blow up or has blown up, it sends FULL DC voltage AKA rail voltage to the speaker terminals VERY BAD and this will COOK your voice-coils and spew out TONS of smoke 😛 Not something you want !
Tipically in amplifiers they use “relays” but this is much better and faster 🙂
Short story of the circuit is here : https://sound-au.com/articles/mosfet-relay.htm
But mine is a bit different 😛 Pictures below ! When the led is on, the FETS are on passing audio signals! When the led is off! it’s in protect mode !
Been working on this project for a few months now, just about to order the pcb. After months of working on this, I have come to the conclusion that it’s much easier and less hair loss when doing pcb designs.
However, to accomplish this near perfect “test” pcb, you need to make sure all pin out’s on the pcb for the components are proper IE ECB or GDS are all accurate and point to pint ! :p Let’s not go down that rabbit hole and explain what happens when you don’t 😛
Whats a “SSR” ? SSR stand’s for Solid State Relay, these are not anything new BUT starting to become really popular in amplifier designs instead of using relays. SSR’s are much faster & don’t wear out!
Picture of my schematic !
Here is a picture of my first Printed 1:1 on paper to make sure all the pins align & look correct for spacing !
And a picture of it in 3D mode from Kicad !
Hopefully next week I get a chance to order the pcb’s and start testing and making sure everything works !
Over the last few weeks I have been working on my Jean Hiraga amps, these are not the final boards but boards that work that allow me to do testing with.
First test was with a regulated front end circuit, this is done by removing the 2 22v zener diodes on the board, and installing a off board regulator circuit. The regulator circuit uses IRFP9610 / IRFP610’s, they do a very good job, and soon I should have my newet regulator boards using all SMD components, more on that later!
Next test is changing the output’s from 2SC2922/ 2SA1216 to MJE21196/96’s.Doing this change allowed me to test better outputs that are more common and easier to get, although the 24 BJT’s that i just got are obsolete now, and newer versions are out BUT hey, I got 24 free ones from a close friends so I will use them 🙂
Little hint, I’m currently working on a Full “SMD” version of this amp, since power resistors now’a days are quite capable of dissipating current in a SMD package, I am going to do it!
Id like to first say special Thanks to Eddie from KissAudio, this guy’s youtube page is just “AWESOME” been watching his videos and learning alot! Hat’s off to this guy for doing his vidoe’s and teaching people things. Link to one of the videos he does that describes this post!
I reached out to Eddie and asked for his simulation file so I can learn about simulations of all the amplifiers i work on, and he replied back with the file ! THATS AWESOME! Now i can play and learn, the bonus part is, i know the schematic he sent with the simulation, and of course its my favorite person Nelson Pass. !
Id have to say most of my Class A amplifiers are all Nelson Pass designs from the Aleph Mini to the Larger Aleph 2’s and 0’s.
Do breadboards suck ? ( yes ) I mean they serve a purpose, BUT they are so 50/50. Some times the parts in the pin holes touch and make contact, sometimes they don’t.
Lastnight working on a long project of mine “The-SSR” and I had to check over the circuit may times to be sure. Im almost going to say designing the schematic in Kicad & pcb and ordering from JLCPCB.com is easier ? yeah ?