An old Forte' model 3 made new


 This is an odd topic just because what I will be discussing is an old Forte' model 3 power amp that has been completely rebuilt and designed differently than the original. Years ago, it started with a loud popping noise in one channel. That was enough to take a look inside. I found out that this model uses a chip for the input and the chip had a reputation for this problem. When looking inside the unit, I decided it was time to change out the power caps, replace the bias setting pot, and hope for the best. Shortly thereafter, I knew that I was in over my head, and looked for a tech out there that would be of assistance. Almost by accident, I ran into John Dee, a former engineer at Sudgen? audio located in Europe. Point being John was just the right person for the job. It took a long time to complete the project due to personal reasons, but now the amp is up and running in my system. John converted it to class A bias, and also reduced the number of output transistors. Probably close to all the transistors were changed out due to catastrophic failure (you can thank me for that). A better diode bridge was installed, faster caps replace throughout, and numerous other parts I am sure were dealt with as well. Since my speakers are quite efficient at about 94 db, I had John set the bias for a mere 20 watts class A. It sports a damping factor of 600, has a much faster rise time, and electrolytic caps were all bypassed with Wima caps IIRC. The sound? Well, as expected the bass is to die for, the midrange has power that makes the music 'right there', and truthfully, I do have the hearing to give an honest opinion of the treble, but I feel that it is a bit light. I suppose that I could rig up an adapter and use headphones, giving me the chance at hearing more accurately what the signature of the amp is. Probably sometime soon, I will do that. I just felt that this sort of project is more common amongst some of us and would like to hear your impressions of said projects.
128x1284krowme
Will this drive 2ohms? Or a pair of thiel 3.6? 2.5 ohm average throughout the low mids to high frequency range
Hard for me to say about that. Those sound to be pretty low dips in impedance. Perhaps someone here could better answer that question. Low impedances are tough for many amps, so I am not eager to answer without some experience in such a case.
There is a picture of the frequency impedance graph unfortunately can’t post here so you guys would have to look it up
Will this drive a pair of Thiel 3.6

If your asking about the Forte’ model 3?
I say yes fine, as they are much just a resistive load, and above 2ohm. The -30’ phase angle at 70hz isn’t combined with a low impedance at that frequency, so it’s not too bad.

I had one of those for repair, good cheap powerfull amp, 20!! x complimentary push pull Toshiba output fets total . And a decent sized linear supply and low negative feed back.

Cheers George