What IC Chips in LeMay Mod for Nash-400?

Larry Robinson · Post by **Larry Robinson** » 6 Sep 2003 4:26 am

I recently acquired a Nashville 400. The seller didn't know if it had been modified. I ordered PV mod. While installing the mod, I noticed that 5 of IC chips were TL0072C instead of 4558 on Peavey schematic and 1 chip was Ratheon RC5532AN. All resistors and caps in the kit were already in place on PC board. I know think this amp has been modified, but I have no info on the LeMay mod. Does anyone know if these IC's match those included with Lemay mod?
Regards,

Larry Robinson

JB Arnold · Post by **JB Arnold** » 6 Sep 2003 5:55 am

You may be able to find out here-
http://www.miracle-audio.com/

JB

------------------
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"All in all, looking back, I'd have to say the best advice anyone ever gave me was 'Hands Up, Don't Move!"
www.johnbarnold.com/pedalsteel
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http://www.nrpsmusic.com/index.html

Bill Terry · Post by **Bill Terry** » 6 Sep 2003 6:28 am

The LeMay mod doesn't use TLO72 ICs opamps.

Ken Fox · Post by **Ken Fox** » 6 Sep 2003 9:48 am

http://steelguitarforum.com/Forum11/HTML/003431.html

Check the link above. The chips are OPA2604AP, by T.I.<FONT SIZE=1 COLOR="#8e236b"><p align=CENTER>[This message was edited by Ken Fox on 06 September 2003 at 10:49 AM.]</p></FONT>

Larry Robinson · Post by **Larry Robinson** » 6 Sep 2003 10:15 am

Thanks for all the info guys. I'm going ahead and install all the parts in the mod kit. I thought since the caps and resistors were already installed that someone had put another mod kit in it. Please close the thread.

Regards,

Larry Robinson

Blake Hawkins · Post by **Blake Hawkins** » 7 Sep 2003 3:17 am

Larry,
The earlier Peavey Mod kits used the TL072
chips. The first kit I bought from Peavey had them. So your amp has had the Peavey kit installed.
My understanding is that the LeMay kit has the IC's painted so that you can not see the numbers.
Blake

Brad Sarno · Post by **Brad Sarno** » 7 Sep 2003 6:58 am

It's hard to beat the sound of the Burr Brown 604 series opamps for guitar.

That's what came with my Peavey Vegas mod kit a year ago.

------------------
Brad Sarno
Blue Jade Audio Mastering
St. Louis

Blake Hawkins · Post by **Blake Hawkins** » 7 Sep 2003 7:16 pm

Brad,

I upgraded my amp to the OPA 2604 chips about a month ago.
At the same time another steeler friend, who's ears are much better than mine, upgraded his.
Neither of us could tell a tone difference over the TL072 chips.
We think the noise floor may be a little lower with the newer chips.
Both of our NV400s had the "Original" Peavey mods which included TL072s. His came from the factory with the mod.
I installed mine.
Blake

Ken Fox · Post by **Ken Fox** » 7 Sep 2003 8:59 pm

I agree about the old TLO72 chips. It has a great tone. I replaced some 4558 chips someone had put in a Peavey Mace VT series amp with the older original TLO72 chips that were originally in the amp. I tried the Burr Brown chips in it as well. I prefereed the TLO72 chips, as they would overdrive better in this amp.
The noise floor is supposed to be lower in the Burr Brown chips and they are a nice chips for the steel player who is not using preamp overdrive (as the Mace is capable of). They are the same chip used in the Profex 2 upgrade as well.

Michael Brebes · Post by **Michael Brebes** » 8 Sep 2003 7:23 am

The main difference you should hear between the TL072's and the Burr-Brown IC's is noise. The Burr-Brown IC's are much quieter. I believe the slew rate is similar between the two ICs so there is probably not much of a tone difference. There is a big difference between the 4558's and the other two chips. First, they are noisy. And second, the slew rate is very slow, so they suffer on the high end, especially when you try to boost high frequencies.