The sound was in many ways fine, but had a very hard sound from upper midrange and up. So I decided to open it, remove the balance and input switch and make a change to the feedback loop as described on AudioNotes homepage. (remove cap 18 from 6 and connect it to ground.)(http://www.audionote.co.uk/technical/amppeak/). Unfortunally the amp didn't work after the modification, but I think maybe the Quad cap can went dead. (Removing the preamp board could mayby affect the power transformators regulation so the output voltage would rise a little, and stress the parts a little bit more???)

Anyway before working more on the unit, I took a closer look at the schematics. It looks like there are 360 V on the plates of the EL84 tubes? And the datasheets on el84 states 300 V as max.? I am not used to read schematics, so I could have misunderstood something.

I then thougt it maybe was better to strip everything out, use the good parts and get replacement for the old caps. So if anybody have tried mods of Sca-35's I would like to know.
My ideas are as follow:

1. Put a choke or tube rectifier in the powersupply to get the voltage down to 250 - 300 V. There are some nice space where the preampboard was.

2. Use my surplus Jensen 50+50 uf 350v in the powersupply.

3. Remove the global feedback loop, c18, r37 and c21. Remove the c24 in parralel with the bias resitor r24 to get some local feedback instead. (Allen Wright recommends local feedback and no caps there)

4. Remove c7 and r29 and add the volume pot instead. There is a cap in the output of my cd anyway.

5. Do the trio trick on the el84. And of course change values for the plate and cathode restistors.

6. That's nearly a new amp, so mayby a change from 7199 to my surplus 6dj8 or 6sn7?

I hope to get some good advices. (I am not totally new to tubes, have the Bruce Rozenblit book on tube for beginners, but have only build a singel ended amp before, two tubes very easy!)

Regards pufff