Funny I came across this looking for something else.. ha ha
The S 200 used a 330VA XFMR that has different taps. The S200 benefits most from larger main caps and a FRED (IXYS) rectifier.
Class A will tend to have a more laid back presentation and the higher register frequencies will be cleaner. In other words any harshness or grain is eliminated.
The S 200 used a 330VA XFMR that has different taps. The S200 benefits most from larger main caps and a FRED (IXYS) rectifier.
Class A will tend to have a more laid back presentation and the higher register frequencies will be cleaner. In other words any harshness or grain is eliminated.
Threshold s/300
Can you guys help here a little. My Nakamichi PA-7 gave up the ghost in a rather large and smoky manner. So i bought a Threshold s/300 in mint condition. Optical bias, serial # 2004. How do I find out its manufacture date? Where do I get a schematic/ service manual? Although the amp is working fine, I would like to go through it and replace caps, any known noisy transistors etc. i am an amateur electronics hobbyist, so this should be no problem. Any suggestions on what should be done and what replacement parts to use? I will be pairing this up to a very rare set of RTR DR-1's, again in mint condition. Rich rmatlantis@cox.net
Can you guys help here a little. My Nakamichi PA-7 gave up the ghost in a rather large and smoky manner. So i bought a Threshold s/300 in mint condition. Optical bias, serial # 2004. How do I find out its manufacture date? Where do I get a schematic/ service manual? Although the amp is working fine, I would like to go through it and replace caps, any known noisy transistors etc. i am an amateur electronics hobbyist, so this should be no problem. Any suggestions on what should be done and what replacement parts to use? I will be pairing this up to a very rare set of RTR DR-1's, again in mint condition. Rich rmatlantis@cox.net
If your AC line is 120V and your transformer has windings for 240V, then by using
them with 120V and cranking up the bias you can convert to Class A. Otherwise
new transformer.
them with 120V and cranking up the bias you can convert to Class A. Otherwise
new transformer.
I think bias may be the key to better sound. I have an old pair of SA/1s, circa 1986, non-opto and I replaced the transformer with a 2.4kva unit and the 2 60k uf caps with 8 95k uf caps with a 2.2 mf larger wire gage inductor between sets of 2 for a CLC configuration. Had to stretch the chassis to hold all those caps.
With the Sinks at 42C as before it sounded about the same, still great, but then at almost double the bias the sinks stabilized at 50C and the sound was more open and maybe a little sweeter if I can use that term for audio, it was damn good.
The output devices can easily stand more current, just watch the temps.
Have a good one.
With the Sinks at 42C as before it sounded about the same, still great, but then at almost double the bias the sinks stabilized at 50C and the sound was more open and maybe a little sweeter if I can use that term for audio, it was damn good.
The output devices can easily stand more current, just watch the temps.
Have a good one.
Mr. Pass thank you for the advice, very wise approach, but not my case as I live in the 240 world.
But sure, someone from 120 can use this primary switch trick.
Another question came into my mind, will this be fair for the s/300 ii 650W transformer w/o OB.
From the voltage point off view sold be workable.