Threshold s150 or Forte 4a amplifier?

I have not worked on any for almost 20 years, but I do not recall that much difference between them.

Actually......I like the output transistors in the Forte much better.

Yes, Forte was a Threshold company. Threshold was able to market products at a lower price point using the Forte name. I had heard the Forte 4A driving Thiel 1.5 and Martin Logan Aerius, and it was a great amp at that time for that price. Because of the power requirement of my Thiel 2.2s then, I ended up getting the Forte 6 (the 200 watt A/B version of the otherwise-the-same-design of 4A).

They share the same sound characteristics with their more expensive Threshold "cousins". Since you have both amps, why not trust your ears and make the judgment yourself?

FrankC

I have been Listening to both and over all they seem to produce very similar sound. The Forte does produce a more definate lower end, the bass guitar in The Greatful Dead's "Working Mans Dead" each note stands out and rings as the strings hit the frets. When playing the same on the Threshold the notes on the bass guitar are a bit muddy. I have read things on power cord up grades and also somthing about moving the transformer away from the out put section. If anyone has some good advice on this I would like to hear it! Also I am currently using my Home theater Pre-amp Processor with these and would like to soon pick up a nice solid simple 2 channel preamp with in put for CD. Any suggestions?

Thanks!

Well I have had Both as well, My favorite for musicality out of all the thresholds still stands the best valued S150, I like the forte 4a A lot as well but I did not have the Class A' 50 watt version mine was configured in AB, and still very good, I had a s300 as well and the s150 always sounded much better to me, but could be the Synergy situation with certain components and speakers.

I have a S150 and a Forte model 6, I have not heard a model 4 but I know they have some very good reviews and are supposed to be a very very good amp. It was that reason why I bought model 6 and it is a very good amp. I got both amps within a month or so of esch other and have had not a lot of time to try them in my system, for the past 6 months due to health problems with my brother I have been at his place most of the time. I live in Vancouver and my brother lives in the Mountains the other side of Whislter B.C. No A/C there we run off a generator and no computer. I say this because I owe a few in this thread an email, sorry Jeff but I'm home for the winter now and Ar_t I owe a big email to and a big THANK YOU for telling me about how to Modifly my S150 by moving Transformer away from the circut board. The S150 has the Transformer bolted to the back of the faceplate and is butting up against the circut boards more the left ch. and I guess the magnetic field of the Transformer reacts with the circut boards. I moved the faceplate with the transformer a full 4" forward from the amp (circut board). The way I did it is one can put it back to stock without anyone being able to tell. But will I NO,NO,NO,NO, The S150 was Know as Thresholds lower powered amp in the S series but many thought it was the best sounding and as you can hear with your own ears it is a sweet sounding amp. OK,OK, you want to know how it sounds. Well it's like you went out and spent a lot more $$$$ on another Amp. The differance blew me away I didn't think the mod would have that much affect, was I wrong, the sound stage was much wider and grew in height and depth, placement of the instruments seemed better with more focus and the Bloom of the instruments is what really got me I was not prepared for that, it took a little getting used to there was so much more bloom. I run a pair of Maggies which are 4 ohm and my plan is to run the S150 on the top end + mid and the Forte 6 on the bottom of my Maggie III but my IIIs are down and over the winter I will do a rebuilt so right now the S150 is on my Maggies MG1 imp. I guess you know which amp I would pick, the S150 a very good amp made even better Thanks to Ar_t. I have on order some Vampire Pure copper female RCAs and just got some Eidson pure copper binding posts and a furtech IEC incert and when I was checking the fuses a good size piece of metal came off the inside of the fuse holder so I ordered some cryo jena labs fuse holders Although I might by pass the speaker fuses (output) and live dangerously. If you keep the S150 and want more info email me and I can help you with the Mod. Ofcourse you can talk to Ar_t who made this mod possible and I would just again like to Thank You Ar_t for helping me with this Mod. Oh one more thing can anyone tell me if the other S series amps have the Transformer on the back of the faceplate. Thanks Ken.