[rafjr00]

Hello everyone,
So I was given a Mos-fet 120 basket case awhile back, I posted asking about a replacement for the SK133.
I found a few and would like to get this amp up and running.
I problem I have is that I do not have the PCBs. I received the chassis, with transformer and heatsinks attached, and a box of parts.
It came with with a parts list/schematic from Jensens, everything seems to have been in the box.
I have a friend that is happy to design  some new PCBs, but I have concerns about the schematic I have.
It has some hand written changes to it.
If someone would take a look at the scans and give me some insight I would be so appreciative.
Thank you so much for any help,
Riki

http://imageshack.us/photo/my-images/845/120l.png/
http://imageshack.us/photo/my-images/24/120001.png/

[Mark Korda]

Hi Rafjr00, I didn't even look at the things you posted with your question. I will tell you that the Jensens Mos-Fet 120 was an earlier design by Frank VanAlstine who put it in a Dynaco Stereo 120 chassis. Before he named his business Audio by VanAlstine he called it Jensens Stereo Shop in honor of his mentor. He is very much alive and giving all sorts of free advice right on this forum. If you want to cut to the chase you should e-mail or call him and your amp will be up and running...Mark Korda

[rafjr00]

Thanks Mark,
Yea I have searched here and else where a few times over the last year looking for info.
I have learned that this one is one of the early ones. This is why I would like to get it
Up and running instead of just sending it to Frank to be made current.
I belive all of the mosfets to work. I just wish I had the original PCBs for it, but I am not a stickler
For originality.
I don't mind waiting for Frank or anyone to post. He has a business to run and is kind to help people out.
Thanks,
Riki

[avahifi]

This was a first generation amplifier of ours, so old I don't even remember doing that audio schematic.. 

Anyway if you want that old Dyna ST-120 chassis turned into a modern Insight+ 170 power amplifier, then don't bother doing any restoration to the unit as is.  it won't be economical or easy to repair it as is in any event.  We do not have these old boards or any of the parts for them

All we need is the chassis and cover (you can clean them up first if you want), two of the big heat sinks stripped bare, the red and black output jacks, the fuse holder and the long standoffs and hardware for mounting the audio boards on the heat sinks.  All internal circuits will be new, including the power transformer.  Here is a link to the Insight+ 180 at our web site

http://avahifi.com/index.php?option=com_content&view=article&id=155&Itemid=221

Note that if you click on the horizontal arrows below the picture it will bring up more pictures of the insides.

Regards,

Frank Van Alstine

[rafjr00]

Thanks Frank, I was actually going to make new PCBs for it. That's why I was trying to find out about the hand written changes to the schematic.
Frank am I right in that the sources of Q4 and 5 are connected to the positive output?
According to the parts list I have everything, but the PCBs, and I be I have enough good mosfets for the amp.
The newest version of the amp, is it still MOSFET based?
I wish I could just send it to you but I do not have the funds for it at the moment.
Thanks,
Riki