Burr Brown

[Martin]

I hate to flogg a dead horse but I got my hands on a Burr Brown opamp, can anyone tell me before I delve in which board I should be looking at for IC3.... thanks

 

[disassembled]

The rear main board. It is clearly marked.


Greg

 

[Martin]

The one nearest the jack sockets ...correct !?!

 

[disassembled]

There are possibly 2 IC3's in your Triaxis....one is a 16 pin the other is a 8 Pin. You are looking for the 8 Pin IC3 Opamp TL072.



Greg

 

[Martin]

Yeah thanks Greg, I knew it was an 8pin package type but just wasn't sure where it was located is all.
I have done loads of opamp replacements in the past. One thing I read somewhere on here was mention of the OPA427... least I think that's the number. It's been a few years but it's the dual version of the OP27. Those are great opamps. I used to comfigure those to run in class A but I don't have the drawing of how I used to do it, it'a all back home in Scotland, anyhow I have used those and can recommend that they are definately well worth trying.

 

[disassembled]

I have some but never bothered to try them since someone did some testing with a scope and showed that the Burr Brown chips were the most dynamic.



Good luck with replacing yours. Some of the early TA's Already have sockets for IC3 from the factory but most do not. Have fun.


Greg

 

[gezza]

Hey Guys,

I'm still waiting for some Pics.

Greg, did you forget about me????

Can you take some pics Martin??

also i don't suppose you can record a before and after!!!

As no one here has done so.

It would be a great, no hugh help.

Thanks,

Gezza

 

[Martin]

Greg,

It's probable that the Burr Brown chips are better, I was just saying that the OP27's are excellent also, there probably is a better spec on the BB's as they are a much newer design.
Unfortunately I don't have the ability to do a before and after recording or I would do so to help out.
I took a look last night at the board, it looks tricky to access and strip down.
I was too tired to do it so will wait till the weekend most likely to follow through and complete the work.

Incedently bypassing the electrolytic caps with high quality polypropelene caps in paralell will give you a sweeter high end treble the onlt problem may be space. I haven't looked into the practicality of that yet.

 

[disassembled]

Hey Guys,

I'm still waiting for some Pics.

Greg, did you forget about me????

Can you take some pics Martin??

also i don't suppose you can record a before and after!!!

As no one here has done so.

It would be a great, no hugh help.

Thanks,

Gezza

My Triaxis is racked and at my rehearsal space so it isn't really practical for me to take apart my entire rack just to show you a pic right now.

If you join the yahoo group for the Triaxis there are pics there or you can take the cover off of your triaxis and take a look.


Greg

 

[disassembled]

Greg,

It's probable that the Burr Brown chips are better, I was just saying that the OP27's are excellent also, there probably is a better spec on the BB's as they are a much newer design.
Unfortunately I don't have the ability to do a before and after recording or I would do so to help out.
I took a look last night at the board, it looks tricky to access and strip down.
I was too tired to do it so will wait till the weekend most likely to follow through and complete the work.

Incedently bypassing the electrolytic caps with high quality polypropelene caps in paralell will give you a sweeter high end treble the onlt problem may be space. I haven't looked into the practicality of that yet.

You have to remove the bottom cover and move the TX4 board out of the way in order to cleanly access the IC3 opamp. It takes a good hour or two to do everything and to make sure you do it cleanly without burning any wires.

Whatever you do I recommend adding a socket so you can change out the Opamp to whatever suites your tastes best.

I just don't have time to worry about doing an A/B test with the different opamps (whether it be stock or other) because I know that before the change I wasn't too crazy and afterwards I felt it made enough difference to keep me from selling the TA.

Greg

 

[Martin]

Did you feel it helped with your lead tones also ?

 

[disassembled]

Yes, but only for the ones with less gain. When the gain is run high it's hard to tell a difference because of all of the compression going on.

You might not HEAR that much of a difference but it should FEEL different as far as dynamics go. The dynamics of the Quad Preamp are what made me sell my first Triaxis but the versatility of the Triaxis far outweighs that of the Quad. With the Opamp mod the Quad was still better for dynamics but I could match the tone with the Triaxis to be "close enough."

I wish I had more time working with my band but we've all been so busy I haven't had a chance to even dial anything in other than a broken clean, squeaky clean, and a mild gain. Unfortunately the band I am in has a lot on their plate and our group is kind of a small deal so it gets pushed to the backburner. I also just added a digitech GSP110 so that changes things too.


Greg

 

[Martin]

I can understand that. I was looking at possibly adding an Alesis programable EQ to my rig so that I can call up different EQ settings via midi depending on what I'm doing, mainly for the benefit of my lead tones cutting through.
Lately, I have been having a hard time hearing what I'm doing at gigs.

 

[CoG]

Good luck finding one of those MIDI-switchable DEQ230Ds, bro. I think Alesis built like six of them and has ceased production. Which sucks, b/c I wanted one too. I have been calling people for months.

The DEQ230 is still available but isn't MIDI-switchable.

 

[Martin]

Thanks for letting me know that, I had no idea they were out of production... hhmmm oh well back to the drawing board !

 

[CoG]

If you have a Triaxis you aren't gonna have too much of a problem with signal degradation in the line (since you can just crank the output) if you slap in three or four EQ pedals, which is about what you'd spend on the Alesis anyway.

 

[Martin]

I just did the mod and as expected it took me longer to strip it down that to do the actual job.
On powering up and listening it does seem like the dynamics are better across the board. When you dig in you can notice a change in feel and responce.
I'd say that this was worth doing, I will see how I feel in a couple of days and let you know. it should sweeten up a little when it burns in.

I noticed a couple of other simple mods that would improve performance around the power supply but there is so little space.

 

[RobertH]

I'm still waiting for my BB to show up in the mail to do this mod. I'll take pics of the process for the peps on here.

 

[leadfootdriver]

I'm still waiting for my BB to show up in the mail to do this mod. I'll take pics of the process for the peps on here.

Where did you order from? WHat was the part #???

 

[RobertH]

http://www.futurlec.com/index.shtml

Op Amp:
OPA2134PA


8 pin socket:
ICS8

I'll post back when I actually receive this stuff just to make sure everything is on the up and up, I placed the order 3weeks ago:?