Upgrading opamps in I/V stage

[5th element]

Hi there I have a TEAC DT1 serving DAC duties and was wondering if I would get any worthwhile benafits from chaging the opamps in the IV stage.

Currently the devices uses NJM2114L in the output, these are dual ops in a SIL package, very annoying that they dont use DIL but what u gonna do about it. Anyway would it be worthwhile replacing these with OPA2134's.

On paper the 2134's are better with lower distortion etc and everything after the DAC is a 2134 or better in an active xover so I would imagine there would be gains to be had.

Just wondering what you lot think.

Cheers Matt

[Cobra2]

I would give it a try.
I used a quad op-amp for the conversion once, just straighten the legs on one side, worked great,
-or just solder extension-wires to a 8-DIL.
Picture : Quad...

Arne K

[Cobra2]

Picture DIL :
(NB...use a dual op-amp)

Arne K

[Elso Kwak]

Hi,
I found the OPA604 superior for IV conversion after trying many, many opamps including OPA134. But I did not get much support for this finding....
Doesn't Browndog make a SIL to DIL or SO8 adapter?

[Cobra2]

I also think the OPA(2)604 sounds better than (2)134...
A "SIL-to-DIL" adapter is one of the few things missing at "Browndog"...

Arne K

[5th element]

Well I have 134's readily available and no 604's! So I guess 134's will have to do, I'll let you all know how it turns out.

The D1 doesnt sound too shabby in the least as it is, so if 134's give me a worthwhile gain I'll be happy. Theres always the opportunity to upgrade again after the 134's. But I doubt Ill need that as Im planning to build my own DAC anyway (based on the PCM1794) , after a line of other projects that require building first. I have the PCB already designed, I just need to check the layout to see if its OK.

Cheers

Matt

[JonPike]

I've played around with a few, on a friend's old Cambridge CD2 that I've been slowly improving, some months ago..

It's been a while, but I think I used an AD825 with rather audible improvement over the 5534's that were in there. Actually an AD826 is much better, but dual, so it wasn't a easy drop in test. I have had audible improvement in a phono preamp over the OPA2134 with this chip. Maybe in doing that DIP to SIP conversion you could try this one.

I turned up a very nice chip, the AD797, that is used for I/V on the data sheet example circuit of AD's top DAC chip.. it is a single, but unforturnately it's very high freq response caused it to oscillate in the Cambridge.. (not a good layout on their boards) Didn't have time to play with it more and tame that oscillation and give it a good review...

Both of those are very high gain/hi frequency chips, so layout and just enough of capacitance in the feedback is critical. But if you can tame them, they should be excellent..

Jon

[Elso Kwak]

Originally posted by Cobra2
I also think the OPA(2)604 sounds better than (2)134...
A "SIL-to-DIL" adapter is one of the few things missing at "Browndog"...

Arne K

This site has SIL to SOIC adpaters:
www.audiotuning.de
Go to IC-Adapterplatinen.