Session 400 mod kit

Alvin Sydnor · Post by **Alvin Sydnor** » 2 Sep 2003 5:41 pm

What components are included in the old Session 400 mod kit Peavey #90500049
Prior to the release of this kit I did some cap replacements, etc.

Thanks any help
Alvin

Alvin Sydnor · Post by **Alvin Sydnor** » 3 Sep 2003 7:05 pm

Should this question have been directed to Mike Brown ?

Larry Robinson · Post by **Larry Robinson** » 4 Sep 2003 2:50 am

You can find information about the tone mods as: http://www.peavey.com/support/steelguitaristinfo/

Regards,

Larry Robinson

Mike Brown · Post by **Mike Brown** » 4 Sep 2003 5:45 am

Alvin, check the link that Larry provided. It will provide the answer. If you need further info, please feel free to contact me toll free at 1-877-732-8391.

Mike Brown
Peavey Electronics Corporation

Brad Sarno · Post by **Brad Sarno** » 4 Sep 2003 10:09 am

Check out this page:
http://home.earthlink.net/~bradsarno/session_400page.html

The mods for the old Session 400 aren't really mods as much as upgrades. This amp is an engineering masterpiece and most seem to agree that the values of components should remain the same except perhaps for the power supply filter capacitors which can be upgraded to a larger value. However the amp really responds well to replacing a few key capacitors in the signal path from the old ones to newer film types keeping the values the same. The mod's on the newer amps actually change values and shift around the equalizer's frequencies. The Session (also LTD) doesn't need these changes. The website listed above will give more detail on this issue.

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Brad Sarno
Blue Jade Audio Mastering
St. Louis

Alvin Sydnor · Post by **Alvin Sydnor** » 4 Sep 2003 11:27 am

Thanks Brad, that was what I wanted to know.
I have replced the key capacitors except I want to replace the P.S.electroyltics. Can you recommend a source and values.
The amp works wonderful and sounds great. In a way I am glad I got rid of my old vibrosonic except for the money I lost in giving it away,I did help heat the room, Ha, Ha. Oh well that was many years ago.
Thanks to you and the forum
Alvin

Brad Sarno · Post by **Brad Sarno** » 6 Sep 2003 6:59 am

Alvin, go to Digi-Key or Mouser online. Look for the various series of Panasonic electrolytics. I think the HFS or HFQ series are good for this application. I cant remember exactly but you'll figure it out. The stock value is about 6000uF/50v. I recommend going to 10,000 or 12,000 and about the same voltage or a little higher. It's amazing how small cap's have gotten over the years. The real key is to bypass the filter caps with smaller film types. Any film cap around .5 to 1uF should do the trick for cleaning up the high frequency noise. You'll be astounded at how silent the Session becomes with these little film bypass caps. You wont even know it's on except for maybe some occasional hum from the reverb tank, which is unavoidable as far as I know. By cleaning up the high frequency garbage from the supply and the wall, the transistors operate in a very clean manner. It effects the whole sound in a positive way.

Enjoy,

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Brad Sarno
Blue Jade Audio Mastering
St. Louis

Alvin Sydnor · Post by **Alvin Sydnor** » 6 Sep 2003 7:22 am

Thanks Brad for the info.I asked you to respond on the forum so many others can see.I do a lot of dealing with Mouser.So no problem.
I wonder about the increased current drain when going to higher values?
When I do this I will measure the current before and after.
Thanks again
Alvin

Ken Fox · Post by **Ken Fox** » 6 Sep 2003 11:25 am

You should only see an increase in the in-rush current to charge the larger filters. After they are charged, there is no diffence in standby current. I would consider an upgrade in the bridge rectifier diodes (higher ampacity) to compenstate for the larger in-rush at startup.

Alvin Sydnor · Post by **Alvin Sydnor** » 6 Sep 2003 3:07 pm

Thanks Ken that is exactely what I had planned to do, replace the rectifier diodes with some higher current ratings. This will help in not having to go back later.Ha.
I really appreciate all the input the forum offers.
Thanks to All
Alvin