Peavey Session 400 Mod not available?

Roger Andrusky · Post by **Roger Andrusky** » 16 Jul 2003 12:37 pm

Has anyone had the "LeMay" mod equivalent installed in their mid 70's vintage Session 400? According to Peavey, they never made one - only the Session 400 LTD. I thought I read that someone had this mod installed, but now I'm not so sure. Thanks.

Brad Sarno · Post by **Brad Sarno** » 16 Jul 2003 3:28 pm

Check out:
http://steelguitarforum.com/Forum11/HTML/003851.html

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Brad Sarno
Blue Jade Audio Mastering
St. Louis

Roger Andrusky · Post by **Roger Andrusky** » 17 Jul 2003 4:00 am

Brad,

I see in the Peavey upgrade for the LTD that the C6, which is the input coupling cap to the preamp also gets replaced with a 2.2uF/50V cap. Also the bass tone control RC caps go from .1 to .056. What's your take on these? Are they worth replacing as well?
Also, Peavey suggested I replace the two 761 PNP pairs at the front end of the main amp with 2N5400's. He said that the 761's are notorious for becoming very noisy and the 5400's are much quieter. (5401's are the same beast with a little more current gain.)

BTW - thanks for the doing the website...it's just what I needed!

Brad Sarno · Post by **Brad Sarno** » 17 Jul 2003 6:20 am

Roger, the upping of the value of the input coupling cap from .1uF to 2.2uF is probably a good idea as it increases the bandwidth and opens up the low end. However, I have a problem with this mod as Peavey does it. I agree with upping the value to 2uF but I dont like how that mod offers a change from a film cap to an electrolytic. That's a step backwards as far as fidelity is concerned. The larger value does offer better bandwidth but the tonal quality of an electrolytic cap is a big compromise. My session mod's basically eliminate all of the electrolytic coupling caps and replace them with film types. So if you do what the Peavey mod kit suggests but instead use a film type cap at 2uF, the sound would be better.

You've got me interested in the input transistor change. I know very little about that situation. Both of my Session 400's are extremely quiet and the input devices are stock. I think that the power supply cap upgrade helps with the transistor performance due to the much cleaner power. Thanks for the ideas!

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Brad Sarno
Blue Jade Audio Mastering
St. Louis

Brad Sarno · Post by **Brad Sarno** » 17 Jul 2003 6:24 am

Also, I think that when you referred to the LTD mod kit, you're actually referring to Peavey's kit for the "Session 400 Limited" which is a different beast, and IC based amp and not an all discrete transistor amp like the LTD or Session 400. The bass tone cap you mentioned I believe is for extending the low end of the bass response of the bass tone control.

On my Sessions, the tone controls were kept stock with regards to values.

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Brad Sarno
Blue Jade Audio Mastering
St. Louis

Roger Andrusky · Post by **Roger Andrusky** » 17 Jul 2003 8:01 am

Thanks for the response...Yes, you are correct about the LTD. I did not know that the LTD and the 400 Limited were different animals. I assumed LTD meant Limited.

I'm going to try to make the changes to my amp in stages so I can see how much of a difference each change makes. I'll let you know what difference the power input PNP matched pair makes. I think, too, since the 2N5400 is about .27, I am going to replace all of that I can in the amp. Can't hurt!

Thanks again...<FONT SIZE=1 COLOR="#8e236b"><p align=CENTER>[This message was edited by Roger Andrusky on 17 July 2003 at 09:01 AM.]</p></FONT>