Burr Brown

[Martin]

If you took out the bridge rectifier in the Triaxis and simply replaced it with four Shottky diodes it will sound better. The bass will be tighter and the treble more focused.
This is not a huge difference but it will be a difference, I used to do this with HI-Fi power amps.
Also the reservoir capacitors could be changed for low ESR ones, but with a higher value, like Elna Cerafines, these in turn can be bypassed in parallel with smaller value low ESR polypropelene caps to further lower the resistance at high frequency. This will make not only the bass tighter but the treble sweeter as well as the over all dynamics would be improved. The only restriction to all of this is space.

 

[Martin]

The 2604 arrived yesterday, I'll fit it on Saturday and run the looper though it for a day and listen to it on Sunday after a 24 hour burn in. I'll let you know what I think.

 

[Martin]

Ok,well I just did the mod, alittle later than planned but i did it.

My initial impression is that this IC (2604) has definately more gain and a tighter bottom end than the 2134. The treble is a little crisp but that will smoothe out as the chip burns in.

The dynamics way better also I think.

The difference is immediate and I can tel I will most likely keep this in the amp.

I will post again after a day or so, I will put the looper through it and let it run for 24 hours.

 

[leadfootdriver]

I'm glad you liked it! I wonder how much better it could be with 2-OPA627's? :idea:

 

[Martin]

I will listen tonight when I get home from work, the chip has been burning in since yesterday (12-9-07) at 1pm so it should sound pretty sweet by the time I get home.
I am curious about using two single op-amps now.... I wonder if there would be any noticeable difference, would be cool to use two and power them independantly through their own power supply....hmmmm food for thought !!

 

[gezza]

Hi Guys,

Now I'm not trying to burst any bubbles.

But, so far I have not heard any tonal difference in the recordings.

Hearing is Believing after all.

I contacted MB and they said quote.

The OP-Amp TL72 vs. OPA-2134 is the addition of continuous parameter
control. Usually not worth swapping it out in my opinion.

I know you guys are now using the OPA2604, but back then it was the OPA2134.

I had a really good look last night, man what a horrible position for the IC3 to be in.

I wish It was in a easier position, too hard for me.

Looking forward to hearing some clips!!!!!

Thanks,

Gezza.

 

[Martin]

Gezza,
No one is bursting my bubble. My take for what it's worth is this.

Mesa can say it's a waste of time all they like. The truth of the matter is that the difference in sound quality is pretty substantial and you'd need to be deaf not to hear it.

I could care less what they say, they will never admit that it's an improvement as this would force them to implement it in production, change bills of materials, do evaluations and basically re-engineer their design for production....that's not going to happen unless the current chip becomes obsolete.

I have no way of recording my amp for you and even if I did I am not sure how effective it would be compared to actually being there so to speak.

The difference in the 2604 is huge in my opinion, not just in terms of tone (you can hear every nuance of your guitar) but the feel is much more vocal I think. Whether it's to your taste is another matter.

I just burned mine in for over 24 hours straight and it sounds incredable I think, very punchy clean tones with loads of head room and the lead tones soar and are way more dynamic .....definately worth while I'd say.
I also notice my effects way more, reverb is much more effective as are all the effects I use, way more resolution.

 

[Blackface tweed]

Ok, Someone likes 2604, others likes 2134, but did anyone tried opa 2132? I've heard it's more Hi-Fi than 2134 and its far more expensive than 2134.

 

[Martin]

I may try the 2132 at a later date, think I'll stick with listening to these two for a couple of weeks first.
I have a rehearsal on Friday so that will be the acid test, will be interesting to see how it sounds with another guitar and keys etc..hopefully it will not get lost in the mix.

 

[FastRedPonyCar]

Here's another similar but slighly unrelated question regarding these chips.

I've got an overdrive pedal that uses the TI 4558P opamp. would there be any benefit to swapping it out for the 2604?

 

[Martin]

Probably.....at the end of the day even if you don't like the chip you're only gambling with around $5

 

[FastRedPonyCar]

On mouser's site there looks to be several variety of the 2604.

Which one of the little 8 pin chips would I need to get?

 

[Martin]

Just match up the package type, if it's through hole (pins going through the PCB) then it will be an 8 pin DIP, if it sits on the board and there's no holes then it will be an S08 surface mount package.

I'd advise buying a socket and mounting the socket in the board if there's room. That way you can easily swap it out should you want to try a different chip at a later date. be mindful of the orientation of the chip when changing it out, they are directional and will have a notch or a spot on one end to let you know.
Put it in the same way it came out.

 

[FastRedPonyCar]

it's got a socket.

http://smg.photobucket.com/albums/v212/fastredponycar/Guitar/Eden/?action=view&current=IMG_8769.jpg

 

[Martin]

Then that mod is so easy, 8pin DIP is what you need !! :lol:

 

[Martin]

This is how my amp sounds now, I was not even going through the PA system.
Sorry this is alittle rough but it will give you an idea.

http://s17.photobucket.com/albums/b53/kmfs/?action=view&current=PigsJan1-08.flv

http://www.youtube.com/watch?v=9_Nao1MoSbM

www.youtube.com/watch?v=6IWrFsqGjeY

 

[tramp]

Guys what the hell are you on about !! seriously are speaking in tongues!!.... what is this a mod for the tri???

HELP!! I'm British...

Regards

Iain

 

[Martin]

Ian,

I'm Scots !!...The mod is IC3 on the main board, I swapped it out. Read back on the thread and it should allbe explained.

 

[Paul Secondino]

Sorry to be a pain but can anyone type in the mouser part number(s) I checked the mouser site for opa 2134 and there are a variety of parts under that number like :

595-OPA2134UAG4

595-OPA2134UA

595-OPA2134PAG4

595-OPA2134PA -------[This ONE ?]

595-OPA2134UAE4

Also, can you tell the TI or Mouser part number for the correct OP 2064 to use ?

Thanks guys.

 

[leadfootdriver]

595-OPA2134PA

595-OPA2604AP