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Topic: OPA2604 Op Amps in Nashville 1000 - WOW |
Jack Stoner
From:
Kansas City, MO
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Posted 1 Apr 2010 7:06 am |
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I had a set of OPA2604 op amps that I had tried in my Nashville 112 but didn't like the new sound in the 112 so I took them out.
Last week I took my Nashville 1000 out on a job for the first time in about 2 years or more (mostly it collects dust at home). I didn't like the sound, after becoming used to the great sound of the 112 amp and "fought" with it the entire time of the gig. That was a Saturday night gig and I had another job there the following Tuesday (day) so I left the amp there and used it the following Tuesday and it was the same - it just didn't sound right and nothing I changed helped.
This morning I decided to install the OPA2604's in the Nashville 1000. As soon as I tried it I could hear the improvement in tone and it now sounds as good as my Nashville 112. The 1000 will still be relegated to a "dust catcher" and backup for my Nashville 112 but I now have a "useable" amp. The EQ on the 1000 is set the same as my 112 - another plus as I can use the same basic EQ setup. |
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Ken Fox
From:
Nashville GA USA
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Posted 1 Apr 2010 12:14 pm
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That's great Jack! We have done a lot of N-1000 amps and most agree it helps
I am testing the newer OPA2134PA next week in a N-112 against another N-112 with OPA2604AP chips.
This new chip is their new "Sound Plus" high performance audio chips. FET based chip like the OPA2604 and draws a bit less current. We checked them in a Nashville 400 and were very pleased. |
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Jack Stoner
From:
Kansas City, MO
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Posted 1 Apr 2010 1:40 pm
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Ken, let us know what how that new chip works out. These have apparently been around for a long time (the data sheet has a 1996 date), I wonder why someone hasn't tried these before (Maybe they did?). Looking at this at Newark it's about half the price of the OPA2604.
I knew the OPA2604 is a much better chip than the 4560 but it didn't work out for me in my Nashville 112. |
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Keith Hilton
From:
248 Laurel Road Ozark, Missouri 65721
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Posted 2 Apr 2010 9:11 pm
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| Jack and Ken, I have been using OPA134PAs for a couple of years now in my Hilton pedals, instead of the OPA604s. I got tired of the production delays and dealers being out of the OPA604s. I can't tell any difference in the quality of sound between the 604s and the 134s. Of course you guys know a (2) in front means the dual version of these chips. The good thing about the 134s is they cost about half what the 604s cost and they are always available. Jack I have a bunch of different amps, but I have recently been using a little Peavey Tripple XXX 40 watt tube amp that has a 12 inch speaker. This little Tripple XXX tube amp is doing what I want for E9th. |
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Jack Stoner
From:
Kansas City, MO
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Posted 3 Apr 2010 2:26 am
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One thing that got me thinking on the 2134's is that the spec sheet has a 1996 date so they have been around for a long time. If they are as good as the 2604's, and since they cost less, I wonder why Peavey went with the 2604's in their Nashville 400 tone mod kit? If they are "as good" the less expensive chips would have either made the kits cheaper or provided them a better profit margin.
A (approximate) 50% cost reduction, even at the large quantities that Peavey buys, is a major production cost saving.
Keith, I'm perfectly happy with my Nashville 112 - as my main amp. As noted the 1000 gets very little use. |
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David Nugent
From:
Gum Spring, Va.
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Posted 3 Apr 2010 2:30 am Op amps
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| Jack...Are the chips installed in the preamp or power amp section? Please forgive the obviously rudimentary question, but I have a Peavey "PX 300" that I use occasionally and am not entirely pleased with the tone I am achieving (using a Sarno classic preamp in front)....Thanks. |
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Jack Stoner
From:
Kansas City, MO
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Posted 3 Apr 2010 4:23 am
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| These are in the preamp section. |
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Ken Fox
From:
Nashville GA USA
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Posted 3 Apr 2010 6:36 am
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We tested them in a Profex 2 yesterday and all was good. One thing about the OPA2604AP is that on rare occasion they can go into oscillation. I have seen it a few times, very rare. Jim Evans has experimented with them, on my advise and really likes the chips. He did use a 470pf cap from the output the inverting input, as he was getting oscillation in his headphone amp project.
The OPA2134 also has less current draw, another plus.
Cost, about $1.00 per chip less, not 1/2 for sure in the quantities I buy in.
I have 2 Nashville 112 amps here to test next week with the new chips as well. I just got in 200 of the OPA2134 chips. |
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Mark Dunn
From:
Suffolk, England
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Posted 3 Apr 2010 9:25 am
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Ken,
I've used the OPA2604P in one or two designs myself. Even though the power supplies are well decoupled etc. I've seen them go into oscillation too; especially when used as a summing amplifier with a fairly high feedback resistor. But, I've never needed to put anything like a 470pF across the feedback resistor, 33pF usually kills any oscillation completely. I'd be interested to the know the circuit components where a 470pF was required; this might be something I've yet to encounter! It would certainly be a pain if it did happen!
Mark
Last edited by Mark Dunn on 7 Apr 2010 12:13 pm; edited 1 time in total |
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Brint Hannay
From:
Maryland, USA
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Posted 3 Apr 2010 10:27 am
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Ken,
Please forgive an ignorant question, but a couple of years ago I got from you the battery replacement chip and also the "Burr Brown" audio chips for my Profex II and Tubefex. Are the chips (any of the number designations) mentioned here the "Burr Brown" chips I got, or are these something else? Just curious. |
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Ken Fox
From:
Nashville GA USA
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Posted 3 Apr 2010 11:42 am
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| Brint, all I have ever sold are the OPA2604AP chips, same as Peavey sold in their kits. |
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Ken Fox
From:
Nashville GA USA
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Posted 3 Apr 2010 11:44 am
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| Mark, I might have been way off on that value! I will ask Jim next time we talk. |
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David Spangler
From:
Kerrville, TX USA
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Posted 3 Apr 2010 4:24 pm OPA2134PA chip in Music Man Amps
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| I'm in a band with a friend who is an EE and designs and builds recording studio gear. He recommended the OPA2134 in place of the preamp chips in my old Music man RD100 amp. I could not believe the improvement in tone. Apparently, one advantage besides what Ken has mentioned is an increased slew rate, resulting in a faster chip. They are usually available from Mouser and are Burr-Brown. They will directly replace LF353, TLO72 and several other dual op-amps in 8-pin DIP configuration. |
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Keith Hilton
From:
248 Laurel Road Ozark, Missouri 65721
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Posted 5 Apr 2010 9:00 pm
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| I use a 39pf capacitor from the output, pin 6, to the inverting input, pin 2. Possible oscillation is the reason I have put this in the Hilton pedal for the last 14 years. Jack and Ken, I think this whole 604 and 2604 chip thing started way back when Hartley Peavey sent me a magazine article. I think it started when Hartley Peavey sent me an article out of an electronics magazine about a headphone amp design. In the design they had 2604 chips. Back then Hartley didn't think I should use an expensive chip like the OPA604. Well----I could hear the difference between the really cheap chips and the more expensive OPA604. I personally think most everyone in the Steel Guitar world started tinkering with the 604s and 2604s because that was what was in the Hilton pedals. I don't know any other reason, seeing as there are thousands of chips out there. Same with the 134s, people see them in the Hilton pedals. I am the first one I know of using the 604s in the world of steel guitar, and the same with the 134s. I have a new experiment coming out soon and it uses two totally new chips. Maybe they will be hits also. By the way--I admire Jack and Ken. Two guys like me--with their nose to the grind stone. |
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Kevin Mincke
From:
Farmington, MN (Twin Cities-South Metro) USA
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Posted 6 Apr 2010 2:58 pm
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I like reading these kinds of posts  believe it or not  |
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Ken Fox
From:
Nashville GA USA
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Posted 6 Apr 2010 3:19 pm
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Tried the 2134 in a N112 against an un-molested N112 with stock chips. Usually I can only hear a subtle difference with the OPA2604 chips, but a nice change. These chips are night and day better than the stock chips for tone and clarity in the mids. Just makes the N112 sing! Superb string separation and a warm tone to boot.
Got 200 in and will have the kits ready to ship when we get back from Maine on the 13th!! |
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Mike Bowles
From:
Princeton, West Virginia, USA
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Posted 9 Apr 2010 6:45 am chips
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hi jack i too have a nv 1000 i am not pleased with the sound i was wondering how much difference the chips make i also have the 112 too thanks for any help im either gonna mod or trade it for another 112 thanks again
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Mike Bowles |
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Jack Stoner
From:
Kansas City, MO
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Posted 9 Apr 2010 6:55 am
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Mike the preamp chip change made a world of difference in my NV1000. It almost sounds like my NV112 which is stock no modifications.
I put in the OPA2604's, which I had from previously trying them in my NV112. I don't have any of the 2143's to try and compare. |
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Ken Fox
From:
Nashville GA USA
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Posted 9 Apr 2010 7:03 am
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| Jack, when I get home I will send you a sample kit to try out. I value your opinion and would like you to try out the OPA2134, it exceeded my expectations by far! Let me know if you want a set (no charge)!!! |
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Jack Stoner
From:
Kansas City, MO
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Posted 9 Apr 2010 10:58 am
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Ken, that's great. I sent you a PM.
Thanks/Jack |
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Mike Bowles
From:
Princeton, West Virginia, USA
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Posted 9 Apr 2010 12:13 pm chips
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thanks jack i might try a set in my 1000
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Mike Bowles |
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Nick Reed
From:
Russellville, KY USA
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Posted 10 Apr 2010 10:18 am
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I really like hearing this information. I still feel like the Nashville 1000 can be a great Steel Guitar amp.
Jack, glad you found this Mod works positively.
Nick |
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