Modifications to Peavey Amps

David Fields · From: South Carolina, USA

Why do these Peavey Nashville amps need modifications? I keep seeing threads and posts about ProFex mods? Do the new amps (112, and 400s) need them, or is it just the older ones?

Thanks!

Dave

Jack Stoner · From: Kansas City, MO

As an ex amp tech, some "mods" do improve tone, signal to noise level, etc and some are "marginal".

e.g. the "mod" for the Profex II replaces the analog op amps with a lower noise model and does make a "hearable" difference.

The mod for the later Nashville 400's is a big improvement (however the earlier Nashville 400's that came with the 1502 speaker really doesn't need it). Nashville 400's manufactured after a certain serial number (made after a certain date in 1996) have the "mod" installed at the factory as part of production.

The "mod" for the older Session 400's (with discrete components) just replaces all the electrolytic caps with new ones on the preamp board and "freshens" up the amp. It's worthwhile for an older Session 400 that is getting "noisy".

Ken Fox has some "intense" mods that along with changing out the old ops amps for the lower noise OPA2604 Op amps also does some "audiophile" cap replacements and more. Caps will deteriorate over time, especially electrolytics (which includes power supply caps) and some of the improvements are replacing some caps with a different (improved) type.

There is now a trend to replace the 4560 op amps in the Nashville 112 with the better OPA2604's. According to Mike Brown (Peavey) they opted to go with the less expensive 4560's to hold the cost down on the amp (personally, considering what the OPA2604 would cost a manufacturer buying in large bulk quantities, the end cost of the amp should not have been an issue).

David Fields · From: South Carolina, USA

Thanks Jack:
So all of the new amps don't need any modifications?

Dave

Donny Hinson · From: Glen Burnie, Md. U.S.A.

You can get your car painted for $500. You can also get your car painted for $15,000. If all you want is a basic paint job, the $500 job is fine. But if you want something really nice, something flawless, it may cost you $15,000.

We'd like to think that the new amps we buy are the best they can be. Often they're quite close, but a good tech can always make improvements to an amp that the manufacturer chose not to make on all the amps he produces. It's a competitive business, and though the difference between a price of $599 and $649 is rather insignificant, it does matter to some buyers. In short, any amp can be improved, but it's up to the individual buyer to decide how badly he wants it improved, and how much extra he is willing to pay for those improvements, which are sometimes unnoticeable to most players.

Luckily, the "tone mod" most players refer to is now included in all new Peavey steel amps.

Ken Fox · From: Nashville GA USA

The "Intense mod" replace some 38 components. It consist of all new power supply filtering caps, the Metzger reverb mod and the component values from the "Peavey Mod". The only thing I use from the Peavey mod is the Burr Brown audio chips. The rest of the components are the same value, but higher end parts. Also no inter-stage coupling is done with electrolytic caps, as is the case in the original amp, the Lemay mod and the Peavey mod. I use tantalum caps. They have a more tube like tone. If they clip, they produce even harmonics, like a tube. The sound is much warmer and it is easy to find a good sound quickly.

The mod info is free for anyone wanting to do it themselves. I do not sell kits. I have prepared spread-sheets, schematics and more for anyone wanting the info. All manufacturers part numbers, values and prices are on the spreadsheets. The Session 400 info alone took almost a week to finalize! It is very thorough.

With Brad Sarno and Bill Crook's help I put together a full set of board layouts for the Session 400 (power supply, preamp and power amp). Interstage coupling is done with film caps, as in the original Sarno mod. I also have done a photo the of the LTD400 board with all components identified. That amp was tough to at first as the preamp is not laid out like the Session 400!

Again all the info is free, I do not sell kits (too much tech support would be required). I will do the install for anyone needing it done.

Randy Sevearance · From: Crouse, North Carolina, USA

David I bought a new nash 400 and had a ken fox intense mod put in and it will absolutly blow your mind call ken and talk to him he is a great guy and will answer any questions Thanks Randy

Vernon Hester · From: Cayce,SC USA, R.I.P.

I Heard and used Randy's amp last Saturday in Gastonia.
Nice and all you need for a Steel.Good clean bell-tones.
Vernon Hester

Roger Francis · From: kokomo,Indiana, USA

Are there any mods for the valveking 112 yet?

Ken Fox · From: Nashville GA USA

None that I know of.

John De Maille · From: On a Mountain in Upstate Halcottsville, N.Y.

I installed the "LeMay" mod to my mid 80's Nashville 400. The mod made my 400 literally come alive. The bottom strings now have a more "rounder" bassy sound and the upper register is "sharp" and clear as a bell. Chimes or "harmonics" seem to last forever and not fade away so quickly.
I, also installed Ken Fox's chip kit to my Nash 1000 and again, the amp has come alive. The bass strings are are solid and rounder and the upper register is pure silk.
I did have to tweek both amp settings to find what I was looking for, but, the overall outcome was worth the procedures. There is no more "mid-range" honk in either amp. They were good investments for me. I would recommend these "mods".
Warning- I do believe that "modding" your PV amp will void your warranty, though.

Mike Brown · From: Meridian, Mississippi USA

David, as you can tell by the responses that were posted about modifying Peavey amplifiers, there are many opinions. As you can see, "modifying" literally means that what a product sounds like is one's "opinion". I agree with Jack Stoner, there was nothing wrong with the original design of the Nashville 400, ie; if you like what you hear, it is perfectly fine.

The Nashville 400 was proceeded by the Peavey Vegas 400, Session 400 Limited, the LTD 400, Session 500, and the original Session 400 amplifiers. Some of these used the same power section with a different preamp. The Nashville 400 was manufactured for 18 years until we introduced the Nashville 1000 and Session 2000 amplifiers, so that gives the Nashville 400 a little "clout" I would say. I believe that the reason for the popularity of the Nashville 400 is because of its size and clarity of sound. That is the very reason for a steel guitar amp in the first place. These are the reasons for the popularity of the Nashville 112 as well.

Here's the pitch..................................
We also market our own Nashville 400 mod kit and you can check all of our kits out here;
http://www.peavey.com/support/steelguitaristinfo/

All Nashville 400's with a serial number above #08575482 have the factory tone mod installed. However, we have been selling Nashville 400 tone kits for a few years now and if you bought a used Nashville 400, someone might have installed the kit aftermarket.

By the way, the Nashville 1000 and Nashville 112 have the mod kit installed as well when they ship from the factory.

If you have questions, please don't hesitate to call me here at Peavey by phoning 1-87-732-8391, ext. 1180.

Mike Brown
Peavey USA

Ronnie Sellers · From: Seymour Tenn

Mike the power module and preamp i sent you last week for repars, does it need the modifications the guys are talkind about?
Thanks Ronnie Sellers.
You have my # at work, let me know.

Mike Brown · From: Meridian, Mississippi USA

Ronnie, it was certainly a pleasure speaking with you last week. Thanks for using Peavey.

Fred Nolen · From: Mohawk, Tennessee, USA

I agree with Mike. I went from an N400 to an N112 as my "go to" amp; Out of the box, an outstanding amp. At a recent practice session, our guitarist remarked that the amp I was using sounded better than what I play out. I was using an 83 model N400 with no mod of any kind. Tone is, basically, in the ear of the listener, and that quite often changes.

I have played through Peavey amps for a lot of years. I too went through the "more expensive" phase but have yet to find an amp, of any kind, that beats a plain ol' Peavey. IMHO.

Ol' Fred

Mike Brown · From: Meridian, Mississippi USA

Thanks for using Peavey products.

J. R. McClung · From: Oklahoma, USA

Just got my NV400 back from Ken Fox who installed his "intense mod".

Ken took my late-model NV400, an already great amp, and turned it into an outstanding amp.

I just finished test-driving it for about 10 minutes, started with all the knobs in the 12 o'clock position, and immediately had to move the reverb knob down to about 8 o'clock.

Fender-like? Call it what you want, but I say that Ken's mod allows my PEAVEY to be all it can be...now it's an INTENSE PEAVEY.

Thanks to PEAVEY for cranking out these fine, AMERICAN MADE amps for so many years, and thanks to Ken Fox for applying his skills to them.

Ken Fox · From: Nashville GA USA

Thanks J.R. Glad I could be of service.

Joe's amp was the second one I have had in the shop with the Peavey mod already installed. It, like the other one, did not have Burr Brown audio chips in it at all! It would appear some of the early factory installed mods did not in fact have the Burr Brown audio chips, just the capacitors and resistors changed out.

The Burr Brown chips are warmer and much quiter for sure. They work great in the N-400, Vegas 400. Profex, Porfex 2, Bassfex, N-112 and N-1000 amps!

Blake Hawkins · From: Florida

Ken,
The earlier Peavey NV 400 factory mods came with TLO72 chips.
That is what was in my kit. Later I replaced them with the 2604.
Blake

Ken Fox · From: Nashville GA USA

That is interesting. The ones I saw had 4558 chips! I suppose they did not go to BB chips for some time.

Jack Stoner · From: Kansas City, MO

The NV400 I had was factory modded before it was sent to the dealer (at my request after talking to Mike Brown). It had the original IC's in it, just the caps and resistors were changed. Like Blake, I later replaced the original production op-amps with the OPA2604's. To be truthful I didn't hear any difference. The NV400 I had was probably the last of the production BEFORE the "mod" was made part of production as Mike Brown told me "I've been thinking of making this part of production and I think I will". Later that year Mike announced that it had been incorporated in production.

On a side note on the NV112 "mod" to OPA2604's. I sold a "kit" (OPA2604's) locally to a steeler that said he liked the sound of his NV1000 better than his 112. After he installed the OPA2604's in his 112 he said it now sounds like his 1000. I have to agree as that was my assesment too.

Bryan Daste · From: Portland, Oregon, USA

Is there a Ken Fox mod sheet available for the Session 500?

Ken Fox · From: Nashville GA USA

I did not pursue a mod for the Session 500. The Nashville 400, Session 400. Vegas 400 and LTD 400 amps are easier to ship, as it is a one piece chassis.

There is a Peavey mod available for it. I can install those easily. I just make up my own kit with their part values and my selected tone caps. Again, shipping the two part amp chassis just does not look like a good idea to me, so I have not pursued working on the Session 500 amps so far.

Bill Terry · From: Bastrop, TX

Just wanted to publicly thank Ken for the bill of materials and layout diagrams for the Session 400 'Sarno Mod'. I just did that mod on a friend's amp, and assumed I'd have to get the Supplier Catalog out and x-ref all the parts, checking the form-factor/size, i.e. will the 'upgrade part' fit on the PCB?, getting the correct part numbers, etc...

Being pretty lazy by nature, I emailed Ken first asking if he had a list already, and sure enough got the stuff back via email the same day, complete with Mouser part numbers. If you're going to do that mod, get Ken's info..THIS WILL SAVE YOU A LOT OF WORK!!!

Thanks again Ken!!!
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"I'm nuts about bolts"

Calvin Walley · From: colorado city colorado, USA

the serial number on mine starts with 02. so i'm sure it has not been modifided, however i could not ask for a better sounding amp just the way it is
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Mullen SD-10 /nashville 400
gotta love a Mullen!!!

Guitars that i have owned in order are :
Mullen SD-10,Simmons SD-10,Mullen SD-10,Zum stage one,Carter starter,
Sho-Bud Mavrick

Mike Brown · From: Meridian, Mississippi USA

Keep in mind the price of the various kits on the market. Small electronic components are not "that" expensive.

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