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Topic: Taming The Session 400 Limited Treble |
Dennis Detweiler
From:
Solon, Iowa, US
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Posted 11 May 2011 7:28 pm |
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I recently purchased a Session 400 Limited and installed the Peavey upgrades (mod). The Treble control still bites and has to be rolled back to about 8:00 o'clock. Are there cap replacement recommendations for the treble control?
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1976 Birdseye U-12 MSA with Telonics 427 pickup, 1975 Birdseye U-12 MSA with Telonics X-12 pickup, Revelation preamp, Carbon Copy Delay and Hall Of Fame Reverb, Crown XLS 1002, 2- 15" Eminence Wheelhouse speakers, ShoBud Pedal, Effects Pedals. 1949 Epiphone D-8. |
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Ken Fox
From:
Nashville GA USA
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Posted 12 May 2011 4:00 am
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| No mods I know of, but a SICA Neo speaker will tame the high end bite that is inherent to the BW speaker. We have had great results with that on Evans and Steel King amps as well. |
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Franklin
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Posted 12 May 2011 5:03 am
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| If you want to capture what the amp was designed to sound like the BW is a great match..... Buddy, I, and several others used EQ pedals back in those Peavey days to control these issues......It tames the highs and helps to clarify the lows....A much cheaper resolve.......A Boss EQ is less than a hundred dollars.......If you want to change speakers......TC Furlong has a Neo eminence speaker tailored to his specs that is incredible sounding...The regular eminence does not sound the same....... .....Paul |
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Tim Marcus
From:
San Francisco, CA
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Posted 12 May 2011 8:26 am
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one inexpensive mod to steer your treble back into shape would be to remove any ceramic disk capacitors in the circuit and replace them with either a poly film or Mica capacitor. Ceramics as a whole sound pretty brittle compared to their mica counterparts. You can take it a step further and replace electrolytics as well with higher quality new caps.
Try to find NOS mica caps - the new dipped ones are good, but they are not the same as the old stock "domino" mica caps. If you do your homework you can find the old ones for the same price as the new ones.
Also - have you seen Brad Sarno's page?
http://home.earthlink.net/~bradsarno/session400pre.html
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Milkmansound.com |
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Jerry Overstreet
From:
Louisville Ky
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Posted 12 May 2011 8:34 am
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No disrespect to the parties already mentioned, but you might check with John LeMay here
John's Miracle Audio service is the first I'm aware of to address the Peavey shortcomings way back in the 90's. He did one for me back then and it sounds way better than the Peavey modded ones that I've played or heard.
He would probably be able to answer some questions for you about components and recommend a good replacement speaker as well as needed. |
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Lee Baucum
From:
McAllen, Texas (Extreme South) The Final Frontier
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Posted 12 May 2011 9:57 am
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I agree with Ken Fox, with regard to the SICA speakers. I have them in my Fender Steel King and my Evans FET-500LV.
Another good tool is Brad Sarno's FreeLoader.
_________________
Lee, from South Texas - Down On The Rio Grande
There are only two options as I see it.
Either I'm right, or there is a sinister conspiracy to conceal the fact that I'm right.
Williams Keyless S-10, BMI S-10, Evans FET-500LV, Fender Steel King, 2 Roland Cube 80XL's,
Sarno FreeLoader, Goodrich Passive Volume Pedals, Vintage ACE Pack-A-Seat |
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Jack Stanton
From:
Somewhere in the swamps of Jersey
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Posted 12 May 2011 10:49 am
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Paul,
Off the top of your head, would remember what frequencies you boosted or cut with the EQ pedal? If not specific frequencies (I know it was a long time ago) maybe the shape of the curve you used?
Thanks! |
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Bill Miller
From:
Gaspe, Quebec, Canada
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Posted 12 May 2011 12:33 pm
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| Dennis, I had one and like you I got the mod kit from Peavey. There was no one local who could do the mod so I ended up shipping the chassis both ways to a Peavey service center. It cost me an arm and a leg altogether and the amp still sounded cold and sterile. I tried my Boss Equalizer without much satisfaction. I tried a Sarno Black Box and that didn't do much for it either. ( although the Black Box is excellent with most anything else I tried it with ) In the end I sold that amp at a big loss and bought two NV112s which gave me a much richer tone. Some people get their noses out of joint when you put down the Session 400 Limited amps but I hated mine. And I've also noticed that whenever they come up for sale they seem to take a long while to unload. Hope you conquer yours but I never managed with mine. |
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Ken Fox
From:
Nashville GA USA
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Posted 12 May 2011 3:08 pm
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| For sure the Burr Brown OPA2134PA chips would help the amp. A much better sounding chip than the OPA2604AP that is in the the Peavey kits. We used the OPA2604AP for a very long time before discovering the OPA2134PA, sure glad we did! |
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Ken Fox
From:
Nashville GA USA
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Posted 12 May 2011 6:01 pm
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Dennis, if you are willing to be a tester for me on this amp, I will send a set of the new chips for you to test out. I wlll cover all the cost and make up a drawing for which ones to replace. Just let us know if it helps out.
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Bill Terry
From:
Bastrop, TX
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Posted 13 May 2011 7:36 am
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Just to state the obvious, the Session 400 and Session 400 Limited are two completely different amplifier designs... not even close.
_________________
Lost Pines Studio
"I'm nuts about bolts" |
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Leland Ogle
From:
Baxter Springs, Kansas, USA
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Posted 13 May 2011 1:29 pm
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Ken, I have two of these amps, one at church and one I use out. I would be willing to test these parts for you.
Lee |
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Ken Fox
From:
Nashville GA USA
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Posted 14 May 2011 6:43 am
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| Leland, looks like you are the man for the job! Email a shipping address to me via the forum email link and I will get that out Monday bu Priority Mail. |
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Dennis Detweiler
From:
Solon, Iowa, US
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Posted 16 May 2011 8:35 pm
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My computer has been down for a couple of weeks. Just got back online.
The Limited sounds better since I put the upgrades in it, but used the 2604 chips and the Peavey recommended caps. I have two session 400's (1974 & 1976). I installed Sarno upgrades in both of them and I'm very satisfied. I really like the lows and mids in the session 400 Limited, but the bite bites. I was hoping the treble tone stack could be softened by changing a few caps, but it sounds like the bite is characteristic of the Limited's nature. Let me know if the chip change allows the treble control to move into the normal range. Right now, I have to make a drastic treble cut and compensate with a higher setting on the presence.
I also tried a K140 speaker. It took a little edge off of the high's, but I lost clarity.
I'll try tweaking it with a Furman PQ3 and get back. Thanks all!
_________________
1976 Birdseye U-12 MSA with Telonics 427 pickup, 1975 Birdseye U-12 MSA with Telonics X-12 pickup, Revelation preamp, Carbon Copy Delay and Hall Of Fame Reverb, Crown XLS 1002, 2- 15" Eminence Wheelhouse speakers, ShoBud Pedal, Effects Pedals. 1949 Epiphone D-8. |
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Leland Ogle
From:
Baxter Springs, Kansas, USA
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Posted 17 May 2011 5:16 pm
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Ken, my email came back as undeliverable.I sent you a PM.
Lee |
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Ken Fox
From:
Nashville GA USA
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Posted 17 May 2011 5:30 pm
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| Chips are on the way Leland. My email to you also came back as undeliverable! |
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Tim Marcus
From:
San Francisco, CA
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Posted 17 May 2011 6:12 pm
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| Dennis Detweiler wrote: |
| Let me know if the chip change allows the treble control to move into the normal range. |
Doubtful. Transistors don't change frequency. I'm convinced it's all about cap values and type for you. If anything the new chips will give you more clarity than the old ones. The old chips probably rolled off some high and low end - new high speed op amps will let more of both through. They might also improve dynamic range in a preamp circuit.
Did you try removing those ceramic caps? That will make a HUGE sonic difference! And it's very inexpensive.
_________________
Milkmansound.com |
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Ken Fox
From:
Nashville GA USA
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Posted 18 May 2011 1:44 pm
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| Leland, you need to update your email address on the forum. When I try to respond the emails bounce back |
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Leland Ogle
From:
Baxter Springs, Kansas, USA
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Posted 18 May 2011 3:29 pm
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Ken, I just did.
Thanks |
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Robert Daniels
From:
Chicago, Illinois, USA
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Posted 28 Oct 2012 6:53 am Burr Brown OPA2134PA
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I know this is an old thread, but is the Burr Brown OPA2134PA still the best choice for the Limiteds? Curious if folks are happy with this mod. I've heard some of these Limiteds sound better than others, and the mint one I just found sounds pretty good to me, though it is my first try with the Peavey solid state amps. I have a Twin chassis I like a lot, but was interested in having another option.
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Emmons Student Model 3x4,Twin Reverb with JBL's, clams galore! |
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