Console mod question

[jigobee]

Hello everyone,

I've got a general question that pertains to a specific project I'm working on.
I'm almost done modding a ramsa wr-s4424 board, just finished replacing the op amps in all of the channels (main amp and eq), and re conditioning all of the faders. Now I'd like to replace the op amps in the group and master sections, but realizing that I don't actually know which ones I need to replace. Truth is, I really don't know what I'm doing. I followed a thread on gearslutz (mod a ramsa wr-s4416 wr-s4424 - Page 2 - Gearspace.com), and when I a/b'd the first section of channels I modded against the unmodded ones through the headphone jack I immediately noticed an improvement in the sound, much more detailed and open sounding. And that was obviously before I touched the master/group section, else I wouldn't be here...
So my question is, which op amps should I swap? And more generally, what's the idea here? I'm assuming that it's the amps that feed the actual outputs. So as is, what I'm hearing through the headphones is maybe not representative of what is going out the xlr jacks? Or it is, but then that too can be improved by swapping the master/group amps? Should I swap the headphone amp as well? Everything I come across says that the master section is the most important to improve if doing it at all, but I'm using the board for tracking thru the direct outs as well as mixing, so I figure it's all important. It's been hunky dory thus far, if a lot of work, but now I'm at a place that I don't understand and any help or explanation would be greatly appreciated.

Here's a link to another thread on here with the schematics, probably helpful:
https://groupdiy.com/threads/ramsa-mixers-wr-s44xx.55632/
Thanks for your time!

 

[wpvalentine]

Hello everyone,

I've got a general question that pertains to a specific project I'm working on.
I'm almost done modding a ramsa wr-s4424 board, just finished replacing the op amps in all of the channels (main amp and eq), and re conditioning all of the faders. Now I'd like to replace the op amps in the group and master sections, but realizing that I don't actually know which ones I need to replace. Truth is, I really don't know what I'm doing. I followed a thread on gearslutz (mod a ramsa wr-s4416 wr-s4424 - Page 2 - Gearspace.com), and when I a/b'd the first section of channels I modded against the unmodded ones through the headphone jack I immediately noticed an improvement in the sound, much more detailed and open sounding. And that was obviously before I touched the master/group section, else I wouldn't be here...
So my question is, which op amps should I swap? And more generally, what's the idea here? I'm assuming that it's the amps that feed the actual outputs. So as is, what I'm hearing through the headphones is maybe not representative of what is going out the xlr jacks? Or it is, but then that too can be improved by swapping the master/group amps? Should I swap the headphone amp as well? Everything I come across says that the master section is the most important to improve if doing it at all, but I'm using the board for tracking thru the direct outs as well as mixing, so I figure it's all important. It's been hunky dory thus far, if a lot of work, but now I'm at a place that I don't understand and any help or explanation would be greatly appreciated.

Here's a link to another thread on here with the schematics, probably helpful:
https://groupdiy.com/threads/ramsa-mixers-wr-s44xx.55632/
Thanks for your time!

Hello Oakland! I've been re-reading that same GearSpace thread for YEARS now. I too have a (clean & functioning) RAMSA WR-S4424 that I would like to turn into something worth having. I would also enjoy learning some of this stuff. It appears you didn't get the reply you were looking for, BUT if you're interested in mentoring someone (me) I sure would appreciate it. I have a basic understanding of electronics (from an audio perspective) and I can solder (basic guitar pots, jacks, etc). I've been in my RAMSA several times trying to identify what's-what, and I do have the schematics downloaded. If you're interested in passing on what you learned in this process, I would love to hear about your journey. Hope all is well, thanks! bv

 

[ruffrecords]

It would help if you were to say what op amps were in the original. Unfortunately the schematics do not seem to contain this information.

Cheers

Ian

 

[wpvalentine]

It would help if you were to say what op amps were in the original. Unfortunately the schematics do not seem to contain this information.

Cheers

Ian

If you follow the link and read about their mods you'd see that the Master, Line & EQ opamps are NJM2068DD.

 

[wpvalentine]

Here is the Reader's Digest version of the original GearSpace thread. I only included comments by those that have done modifications:

Complete thread at: https://gearspace.com/board/geekzone/394838-mod-ramsa-wr-s4416-wr-s4424.html

From “buschfsu”

The board has these stock: Master, Line & EQ opamps: NJM2068DD.
I replaced those with: Mic/Line opa2134s and EQ ne5532, wimas for the eq caps and opa2604s for Groups.

- 4560s are the fader amps. won't make much difference."
- wimas are a well respected brand of capacitor that makes 5mm spaced film caps. sound great and they fit perfectly."
- lytics is short for electrolytic,, there are a few kinds of capacitors.
- film (small nonpolar usually good for audio)
- electrolytic (usually larger with a positive and negative leg..mostly good for power supplies filtering etc. not good for audio path elmas are decent for blocking dc in the audio path as are panasonic FC)
ceramic (very small nonpolar not good for audio path)

There are a few more but that's enough to get you by...

From my perspective, do the master first. dont mess with the psu its well built
2604s should be fine in the channels but may want a cleaner 2134 for a few channels keep in mind warmer sometimes means less focused and fuzzy. this desk to me should be clean so my pres and outboard can color the sound and the desk gets out of the way. i put 2604s in the busses for comps etc.. just get rid of those 2068s

Also the actual mic preamp is discrete. This means instead of a chip its made up of a few transistors. i think its ok so i left it.

2134s channel amps
5532s eq amp
4560s (stock) fader amps
2604s group buss amps
LM4562 2 per channel for the master section and i jumpered some of the dc blocking caps pre and post eq.

I'm very happy with mine. Especially the eq. better than most plugins if you want i can send some schematics but they are pretty big.

From effitall

Upgrade the OUTPUT sections first. Chances are you won't really hear much improvement in the mic pre if you're still running through the stock master section.

Perhaps go through and replace the coupling caps and all the PSU/local power caps first. This will run about $75 to $150 or so and will give you hours of work that would have to be done whether or not you choose to change the opamps.

From Bannny

I have just finished these upgrades (but not the EQ caps). I also upgraded the fader op amp to OPA2134 on a recommendation from a tech. I only did 12 of 24 channels and the master/group section. I noticed a difference right away. I can't hear any difference between the individual channels when A/B'ing the modded vs. the unmodded, but the master outs have a brighter and cleaner sound, and some of the murkiness in the low-mids has cleared up (the weakest area of this board). I am really happy with the changes, and recommend them to anyone that has this board. Not very costly (a little less that $100). Thanks very much to buscfsu for posting his suggestions!

Now I am anxious to do more upgrades. Any suggestions?

(I might try to bypass the EQ completely on 8 channels, and just use outboard EQ when I need some.)

From drumsandcymbals8

Using the info is this thread, this last weekend I modded the output section of my ramsa wr-r4412. I removed the ic1 and ic2 2068's in master L & R and replaced them with dip sockets and AD8512 opamps on brown dog adapters. The result is stunning! The frequency spectrum opened up on the extremes, transient response improved dramatically, and the murky lowmids cleared up.

I totally recommend this mod! Next up are the main opamps on the input channels and the headphone opamp. Thanks everyone for your info!

From Jim Williams

I did some extensive mods to one a couple of years ago. LM4562 opamps were used with some fet opamps. The front end design was reconfigured into a trans-amp design. With low noise transistors it did -129.5 db EIN, pretty good.

The EQ got the sweep ranges extended and good film caps used. The rear of the pcb's are littered with small caps for stabilization. Low end did 2 hz as many el caps were removed. It's a lot of work, probably not cost effective as better designs are available as donors.

From skipwave

I swapped the master bus opamps in a WR-S4416 awhile back. I threw in OPA2604s because I had some lying around. Drastic change, and I'll say improvement.

Half of IC1 is configured as a virtual earth summing amp, which has the side effect of flipping signal polarity - on the schematic the negative (-) symbol on pin 6 of IC1 where the master buss node is connected is indicative of this inversion. The other half of IC1 is configured as an inverting buffer amp, no voltage gain but corrected signal polarity. You can take the mix signal directly from this point using the master bus insert jacks or the "REC OUT" jacks, which as the name implies were intended for feeding your recorder and the designer even knocked down the signal level to -10dB using the R30/R31 voltage divider to keep your consumer tape machine inputs happy and not overloading. Given the era this was born in, they were probably thinking live shows were most likely being recorded onto cassette tape.

If you're happy recording your mix from the intended recorder output, then IC1 is all that you need to swap. If you want to use the board's master faders to knock the level down before your recorder/ADC, then half of IC2 as the master fader buffer amp is in your signal path along with IC3 providing the balanced signal. Given the light work these are doing, swapping those opamps shouldn't make much difference but the additional coupling capacitors in the signal path may.

Unless you want to drive some vintage 600ohm outboard gear with your mix output, use the ring of the master insert jacks. That's what I did and it sounded good to me.

About the headphone amp, it's IC5 - see the schematic in the file "masterR". The schematic notes "150mW / 400 Ω maximum". I can't remember what part they used there. If you swap that opamp it is likely worth upgrading the coupling capacitors as well. I always want to monitor a mix post-conversion, so did not look at the headphone amp and I suspect that's why no else has mentioned it in this thread.