A friend of mine may need one for a game he's restoring that's missing the S&T, but these have been out of stock for a long time.

Wow, wonder how it works? I read the thread someone was working on a reproduction S&T never heard more until now. Hats off to the builder if it works. Wonder why I do not hear about them in the US?

I put one in a Centaur which is long gone. Board worked flawlessly with and without out the reverb/echo effects board he offers.

I also tested the board in a friends EBD, burned EBD roms, changed the dips and voila....it worked in there too

I have one in my EBD. The speech seems just slightly different than stock. Deeper maybe? But it's built well, works well, and I have no complaints.

Too bad they are out of stock. You would think he could license this to a US distributor there would be a large market.

IIRC his problem is obtaining the proper chips.

Yeah, not really a redesign of the board but more of a repackaging. Same obsolete parts in several locations, only a few voice synthesizer IC's left on this planet (and I think a guy in Australia has pretty much cornered the market on most of them).

it depends on the TMS5200 speech chip. Each one sounds a little bit different ranging from darth vader end to the chipmunks end and you would experience this between different stock boards. I don't know if they came from the factory like that or time + oxidation or something like that makes it drift. The chip legs rot out bad on these speech chips... maybe it gets up into the package and effects things. I would try and sort them out and deeper ones for games like centaur and high pitch ones for games like EBD. You can get some adjustment by tinkering with the speech clock resistor, but can't make one on the far end of the spectrum sound the other way by speeding up or slowing down the speech clock.

The squawk and talk is pretty complex and that speech chip is very, very NLA. So nice job they are able to reproduce this board. I have always thought no way I would try and do it with the stock speech chip. Would have to be recorded playback of speech on top of the DAC and AY3-8910 sounds.

to bad it does not seem easily possible to reformat the ROMS to work with the much more available TMS5220. It almost works but some speech is garbled.

I've had some success with recording the S&T sound output right from the speaker with a microphone. The sounds are a bit different, when compared side by side, but after a game or so - you don't hear the difference. But I'm working on that. I'm going to try to re-equalize the sound recordings to get it closer. I might try connecting in right before the amplifier on the S&T, so long as I can float the ground correctly.

The logic isn't straight forward between the MPU and S&T. The S&T doesn't just play the sound or voice when commanded. There is some basic rules depending if its a sound, voice, or background. Then there is some game specific rules. I got it working pretty good on my MrMrsPacman (even sold a board), but first try with the same rules wasn't quite right on my Elektra.

Tried out an awesome Play-It-Again alternative too. The board is cheap ($6 or less). It uses the new PT2399 digital delay/echo chip. The chip runs off 5 VDC, but the board off 12 VDC.

08Feb22 Update: I have solved all the sound issues. My replacement S&T boards have great sound. They are customizable. They support nearly all S&T machines (and Xenon). The remaining games, as of this date, are due to be complete by spring 2022. See my website for information or purchase geeteoh.com

Just to reply to this, yes i still make my replacement boards and have been doing for nearly 10 years now. The latest batch was made last year and i still have a few left i think. Hundreds of games saved and many many nice comments about how great peoples games sound. The original thread on pinside for my board is here:

https://pinside.com/pinball/forum/topic/mypinballs-squawk-talk-sound-board-gordons-alive#post-2215922

My board is about using the original sound chips for authentic sound but with many upgrades, improvements to the design with modern pcbs and discrete parts for reliability. Having customers and boards running for nearly 10 years is no small feat and says it all

Jim