Fox Chip Upgrade for Session 400?

Steel guitar amplifiers, effects, etc.

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Johnny Thomasson
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Fox Chip Upgrade for Session 400?

Post by Johnny Thomasson »

Does anyone know if Ken offers a Burr-Brown chip upgrade for the Session 400? I found the upgrade kit for the Session 500 on his website, but didn't see one for the Session 400.

Second question, I intended to get Ken's intensive mod done on my Session 400 once I got the cash rounded up, but it looks like I waited too long. :( Does anyone know if anyone else doing this upgrade? I still don't have the cash for the intensive mod, but haven't given up on the idea. The chip upgrade goes a long way; at least it did on my NV400.

Many thanks in advance,
Johnny Thomasson
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Bill Terry
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Post by Bill Terry »

Johnny, no chips on the Session 400, it's all discretes. The mod you're thinking about is probably the cap upgrade that Brad Sarno worked up. I had all that info pre-fire, but lost it. Somebody will probably post it.

Coming to FW on Sept. 8 at the Thirsty Armadillo, wanna hook up for coffee somewhere?
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Ken Fox
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Post by Ken Fox »

I will still be doing the upgrades and mods through the end of this year. As stated there are no IC chips in the Session 400 and LTD400 amps.

From the website:

The "intense mod" for the Session 400 or LTD 400 (not the newer Session 400 Limited amp) replaces 32 capacitors in the amp.

The audio coupling caps are replaced with film. These are more expensive caps compared to the original electrolytic caps in the original amp. The film caps have a smooth, warm tone. The tone caps are replaced with films caps as well.

All jacks are checked and cleaned. I also test and clean pots as needed. Reverb harness connections are cleaned and re-tensioned. A special type of anti corrosive is applied to the connections

Finally the amp is reassembled and load tested with a scope and 1000hz tone on a 400 watt load bank. After that it is tested on a shop speaker.
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Lane Gray
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Post by Lane Gray »

How much does that run?
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Johnny Thomasson
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Session 400

Post by Johnny Thomasson »

Bill - Sure! Give me a holler! I'll let you have a look at that old fiddle in its current condition.

Ken - Don't know where I got the idea, but I thought you were working on vintage tube amps only. Are you still doing intensive mods on the old Session 400s? This is an early one with the metal knobs. If so, how much time do I have before you retire?

Thanks!
Johnny Thomasson
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Jack Stoner
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Post by Jack Stoner »

I did the Lemay cap replacement "mod" to the preamp board on a Session 400 for a local Steeler. Made a big (positive) difference. It had some "white noise" and all of that was gone after the cap replacements.
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Peter Freiberger
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Post by Peter Freiberger »

Don't know how this differs from The LeMay or Fox mods but it gave me two very quiet Session 400's with a lot of high end. Got the parts from Mouser Electronics and installed them myself after a short soldering tutorial from a friend.

http://home.earthlink.net/~bradsarno/se ... 0page.html
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Ken Fox
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Post by Ken Fox »

Until the end of this year. Just not doing repair work on non working transistor/solid state gear. Repair work limited to vintage tube amps. The Session 400 mod is $225.00 or 235.00 if using PayPal.
Johnny Thomasson
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Post by Johnny Thomasson »

Great, thanks Ken. I think I might be able to get under the wire. :)
Johnny Thomasson
Brint Hannay
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Post by Brint Hannay »

Just a testimonial--Ken did the "Intense Mod" on my rough Session 400 3 years ago and it sounds great! You won't be sorry.
Johnny Thomasson
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Post by Johnny Thomasson »

I sold my NV400 to raise the dough. Ken, I'll email you for shipping instructions, etc.
Johnny Thomasson
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