| Author |
Topic: Any obvious ways to determine if my Peavey has been modded? |
Chris Johnson
From:
USA
|
Posted 12 May 2011 2:49 pm |
|
Hey Guys,
I have a Peavey Vegas 400 that sounds great... Better than other Vegas' I've played on even tested side by side. That got me to thinking if my amp could have been modded in the past prior to my ownership.
I'm pretty sure it hasn't had the fox mod due to the lack of Sprague Caps. One thing I've noticed is that my amp doesn't have DDT. Neither visually with the blinking yellow light or audibly with the lack of compression at very high volumes (which I prefer compared to my Peavey modded Nashville 400).
Are there any obvious ways to determine if my Peavey has been modded?
Thanks |
|
|
|
Clete Ritta
From:
San Antonio, Texas
|
Posted 13 May 2011 1:31 am
|
|
Not sure if Burr Brown chips are part of the mod. If they are, look at the chips on the circuit board inside. You may need glasses, its fine print.  If you see BB or Burr Brown on them, they are replacement chips. Not obvious, but one way to tell.
I got them from Ken for my NV1000 and they did make a difference. There were two models of chips. One was 2604 I think.
Clete |
|
|
|
Chris Johnson
From:
USA
|
Posted 16 May 2011 1:58 pm
|
|
Thanks for the help Clete,
I just checked the board and found no labeled BB chips. All the chips inside read 314 RC4558P except for one that says RCA-310. The oddball RCA-310 does look a bit older than the other chips for what it's worth.
Still wondering why the great sound difference from other Vegas' and how the DDT compression seems to be on bypass.
Any other info? Amp Gurus? |
|
|
|
Clete Ritta
From:
San Antonio, Texas
|
Posted 16 May 2011 9:34 pm
|
|
Im not familiar with the Vegas 400 or its modification, but Ken Fox or Jack Stoner may chime in here with a definitive answer. 
Clete |
|
|
|
Curt Langston
|
Posted 18 May 2011 1:01 pm
|
|
| Chris , the 4558s were stock. Kens first mod had the 2604s, then he discovered the amazing 2134s, which are the very best IMHO. |
|
|
|
Ken Fox
From:
Nashville GA USA
|
Posted 18 May 2011 2:24 pm
|
|
| You may have a bad compressor chip or a 4558 bad that is part of that DDT circuit. Could not tell for sure without the amp on the bench, a signal generator and a scope to monitor it. |
|
|
|
Chris Johnson
From:
USA
|
Posted 19 May 2011 12:20 am
|
|
Thanks for the reply guys,
I'm starting to think that it's just the BW 1501SB is whats making my Vegas sound better than the Vegas with the stock 1502.
Curt, how did the 2134 differ in sound from the 2604 chips?
Ken, Do you know exactly which chip controls the DDT?
I want to make sure not to change that one out ever. I love the disabled DDT. It seems to make the lows really boom out unrefraimed and big chords dont go "squish" when pushing the amp (when compared to another Vegas and my Nashville 400 both with DDT).
Maybe disabling the DDT can be a small mod in these amps...? I would definitatly do it to my Nashville if it isnt something difficult to do.
Thanks |
|
|
|
Ken Fox
From:
Nashville GA USA
|
Posted 19 May 2011 4:43 am
|
|
The DDT compression was the best thing to keep steel amps from burning out speakers. As the frequency response of the steel is demanding in the low end, a lot of BW and other speakers were being blown prior to the invention of the circuit.
I would never disconnect one or even tell someone how to do it. More of an ethical issue for me, I quess. Over and over I have tested the DDT circuit on the bench with a scope, audio generator and a test load. It clearly keeps the amp at 200-210 watts RMS, a perfect sine wave. Yes, that is a form of limiting/compression. However it is a great speaker saver for sure. Without that circuit there would be a much greater market for replacement steel guitar speakers. |
|
|
|
Curt Langston
|
Posted 19 May 2011 7:21 am
|
|
| Quote: |
Curt, how did the 2134 differ in sound from the 2604 chips?
|
Deep, rich and warm lows, sweet and smooth highs, with firm, full bodied mids without the nasal honk.
Also, the amp operation is almost silent, with very little or no white noise upon powering up.
This is my take on the chips alone. If you get the Intense Mod, it takes you to a whole other level! For instance, the reverb comes alive and the amp has much more definition.
Well worth the investment!
 |
|
|
|
Chris Johnson
From:
USA
|
Posted 19 May 2011 9:48 pm
|
|
Thanks guys,
Curt, I'm quite satisfied with my amp now but all the talk about the upgraded chips have me in the "what if" stage.
Ken, Thanks for the advise. I know that the old Session 400 could total the JBL if not careful. I dont think that I've ever gotten close to damaging the BW speaker (even at very high volumes). For live volumes, my lows never see beyond +3.
Does the factory peavey mod use the same chips? |
|
|
|
Curt Langston
|
Posted 20 May 2011 3:47 pm
|
|
| Quote: |
Does the factory peavey mod use the same chips?
|
Chris, I believe Peavey is still using the 2604s.
Ken is the guy that got these 2134s on the map.
I have (6) 2604s, that I took out of a Peavey modded Nashville 400.
If you want to try them, I'll send them to you free. It would definately be a step up from your 4558s.
I have a nice static guard bag and foam to ship.
Here they are:
 |
|
|
|
Chris Johnson
From:
USA
|
Posted 21 May 2011 11:17 pm
|
|
Thanks for your incredible generosity Curt,
I will PM you.
Thanks for all the help guys |
|
|
|
Curt Langston
|
Posted 24 May 2011 9:31 am
|
|
No problem Chris. It's good to be able to help out. I got the chips in the mail today. Shoot Ken Fox an email, and I bet he will will send you the schematic for the Vegas, so you'll know what chips to replace. Ken has all that sort of stuff.
 |
|
|
|
