[santodx5]

Helo,
 
Here are some new photos:
 
https://s27.postimg.org/qo4b6k7qb/20161224_001950_resized_1.jpg
https://s27.postimg.org/ov1ei8mjn/Picture_20164928064949_resized_2.jpg
 
There are 15 opamps and they are all NE5532.
 
Right now I am waiting to test the PSU if I can use all class A opamp.
 
I read the link about Sonic Imagery but only a few post, hope someone else can give more feedback. It is the only discrete opamp that gives complete specs and test in the market but very few review so far.
 
Someone recommends LME 49720N in the line driver ( 6 near the caps), I am not knowledgeable about opamps, hope someone can give some advice.
 
Thanks

 

[raoultrifan]

I still like the old photo better, sorry.
I need a photo from where I can actually see the PCB traces and also what's written on opamps (inlcuding the soldered opamps too).
 
Meanwhile, I still think that on the left side there are 3 x PCM1794 DACs, each one followed by 2 x opamps used in I/V (the ones soldered on the PCB, SO8 type, perhaps NE5532 too), 1 x opamp for LowPassFilter (NE5532) and 2 x opamps used as buffers (NE5532). That means you can only upgrade with ease the 3 x opamps from each DAC and here's what I would suggest, in order of price: MUSES8820, MUSES02, BURSON V5i, BURSON SS V5, Sonic Imagery 994Enh-Ticha.
 
You contact Sonic Imagery and ask for their opinion about what you intend to do, maybe they'll tell you if their opamps are good for your application or not (I'm pretty sure they'll say YES).
 
Anyway, the most important would be the I/V part, but you need an electronics guy to help you out removing the soldered opamps and installing different opamps in there (perhaps MUSES01 via SO8 to DIP8 adapter, if possible, or just solder MUSES8920 in SO8 package already available; for faster opamps you might need additional decoupling caps and also an oscilloscope to test for unwanted oscillations). 
 
On the right side there might be the ADC part and you can use any of the opamps from above.

 

[santodx5]

Here you go again
 
They are all use DIP socket, no soldered connection.
 
https://s5.postimg.org/do7bnrulj/20170105_004644_resized.jpg
https://s5.postimg.org/69hzve8pz/20170105_004801_resized.jpg
https://s5.postimg.org/4rwjju3zb/20170105_004808_resized.jpg
https://s5.postimg.org/3ocf7vjc7/20170105_004812_resized.jpg
 
Btw why dont you mention Sparkos in your list? It is considered better than V5. V5 will not fit in my case so it is out of my list.

 

[raoultrifan]

OK, I think I got what those SO8 opamps are for: voltage comparators
 
So, schematic is quite simple,is actually the default one from TI's datasheet: first DIP8 opamp after the PCM1794 DAC takes care of I/V and the next 2 DIP8 opamps are dealing with LowPassFilter and output buffer too.
 
I/V: MUSES01 or MUSES8920
LPF: BURSON SS V5, BURSON V5i, MUSES02, MUSES8920.
 
I'm sure Sparkos are better than any of the above opamps, but never tried them and I'm not sure the default decoupling caps (2 x 1uF) are enough; also, this might apply to BURSON SS V5 too (please use a scope to check for oscillations). I do not have experience with Sparkos, so please forward the pictures to Sparko Labs and they'll analyze if the default 2 x 1uF caps are OK for their opamps and if they recommend you to use'em in both I/V and LPF.
 
For the ADC part, fell free to use any of the above opamps, but purely based on the specs, I'd vote for the Sparkos because are having the lowest noise possible. You should also check Sparkos dimension before ordering, to see if they can properly fit in there.
 
Good luck and keep us posted, pictures too!

 

[dukefx]

A few things to keep in mind that might help:
 
The SI opamps are huge (wide) and probably won't fit, no idea how they sound, never had one.
I wouldn't really recommend V5i unless you like bloated bass. Mids and highs are nice and clear. No idea about its big brother. Raul can probably compare them. Fitting can be done with right angle DIP sockets if height is an issue. Aries and Mill-Max manufacture such.
Sparkos opamps sound realistic while the V5i reminds me of tube amps.
If you want to use Silmics, better double check space as they tend to be bigger than most other caps.

 

[santodx5]

Hello,
 
Slimic will fit but I want to use Nichicon ES or AN Kaisei bipolar but they are too big.
 
My plan so far is to use 3 SI for I/V (the only place that will fit) and Sparkos for others.
 
@ raoultrifan The decoupling caps 1uf, do you mean the blue caps near the output? They are 220uf 35v that I will replace with slimic II.
 
I dont have a scope or know how to use it Hopefully all will work plug and play.
 
I will post review later. The original XTA already sounds really nice. I'm exciting how 15 discrete opamps will change the SQ.
 
Thanks

 

[raoultrifan]

I meant the non-polarised rectangular grey caps nearby the DIP8 I/V opamps (you also need to double check this yourself by following PCB traces and comparing if these caps are connected between V+/V- pins and GND). The big blue caps should be output audio caps for lowering DC output (if any). Instead ES I'd vote for the KA, but feel free to read their datasheets and compare. Anyway before upgrading the big blue output caps feel free to short-circuit them for good with some short wires ("best cap is no cap") and see if something got improved (measure the DC output prior to connect the XLR plugs to an amp and if DC output is higher than 5mV maybe you should check if the connected amp has DC-servo or DC protection caps in input/output signal path!); if nothing got improved, then don't bother upgrading these caps.
 
For the opamp decoupling I'd vote for 10uF/35V tantalum caps + 1uF+ 0.1 MLCC, if possible for both I/V and LPF stages (at least for the I/V). If do you intend to use only MUSES then existing decoupling might suffice. Anyway, sometimes wrong caps might do more wrong than good, so please use a scope if you intend to change decoupling caps (https://www.baldengineer.com/a-1uf-decoupling-capacitor-is-too-much.html).
 
If you don't want to bother with scope and soldering parts, just get the MUSES01 for the I/V and try a couple of BURSON V5i in LPF; check for overheating and if everything seems fine then purchase the remaining opamps. BTW, what's the voltage on V+/V- for these opamps, please?

 

[santodx5]

15+ - 15- is the voltage.

 

[viivo]

Figured it would be better to ask here than start a new thread.

Paste of the question I posted elsewhere:

"Replacing a dual op-amp with a single?

No doubt this is a simple question, but as I know nothing on the subject and found nothing from searching, I have to ask.

My motherboard (Gigabyte z170x Gaming-7) came with an OPA2134 as part of the onboard audio's headphone amplifier. For one reason or another, the one on mine has departed this mortal coil and must be replaced. The only other op-amp in my posession is the OPA134. Would there be any issues using it? There is also a gain switch for the amp on the motherboard with two settings - x1.5 and x7.5 - so I'm wondering if the single would work with the switch left at the lowest setting. Or are the pin-outs too different?

Thanks for any help."

 

[ph0n6]

You could buy a single to dual opamp adapter, don't plug in single to dual, you might ended up with a burnt opamp or even components.
https://www.google.com/search?q=dual+to+single+adapter+opamp&client=firefox-b-ab&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiMgOmGnq_RAhWJQpQKHU7eCmEQ_AUICCgB&biw=1280&bih=649#imgrc=_

 

[raoultrifan]

  15+ - 15- is the voltage.

 
This is would be the maximum voltage for SS V5, but they should be fine if there's enough room for ventilation inside the case. MUSES should be fine too (their max. voltage is +/-18V). Sonic Imagery 994Enh-Ticha and the Sparkos SS 3602 are also fine too (in case you can fit some of these inside the case).
 
BTW, is you can fit 994Enh-Ticha in the I/V stage you might give them a try, but it worth chatting with someone from Sonic Imagery if existing decoupling would suffice (picture should be enough so they can understand your point).
 

Figured it would be better to ask here than start a new thread.

Paste of the question I posted elsewhere:

"Replacing a dual op-amp with a single?

No doubt this is a simple question, but as I know nothing on the subject and found nothing from searching, I have to ask.

My motherboard (Gigabyte z170x Gaming-7) came with an OPA2134 as part of the onboard audio's headphone amplifier. For one reason or another, the one on mine has departed this mortal coil and must be replaced. The only other op-amp in my posession is the OPA134. Would there be any issues using it? There is also a gain switch for the amp on the motherboard with two settings - x1.5 and x7.5 - so I'm wondering if the single would work with the switch left at the lowest setting. Or are the pin-outs too different?

Thanks for any help."

OPA2132P is quite low-cost, just purchase a new one. Or go for the original OPA2134, should be the same sound.

 

[plainbriny]

Got two Chinese "47" op amp kits recently.
 
Both are using NE5532 (one comes with TI NE5532P and one comes with Signetics NE5532N).
They are both low cost (less than USD$6) and the building process is fun.
One is dual power (+ and - 9-15V, left), and the other is single power (3.7 - 30V, right).
 
The dual power version (left) comes with very low end components, so I replaced all the capacitors.
Both sound surprisingly good, considering their prices!
 

 
Just ordered some ops, will try different ops in the next couple days.

 

[santodx5]

I meant the non-polarised rectangular grey caps nearby the DIP8 I/V opamps (you also need to double check this yourself by following PCB traces and comparing if these caps are connected between V+/V- pins and GND). The big blue caps should be output audio caps for lowering DC output (if any). Instead ES I'd vote for the KA, but feel free to read their datasheets and compare. Anyway before upgrading the big blue output caps feel free to short-circuit them for good with some short wires ("best cap is no cap") and see if something got improved (measure the DC output prior to connect the XLR plugs to an amp and if DC output is higher than 5mV maybe you should check if the connected amp has DC-servo or DC protection caps in input/output signal path!); if nothing got improved, then don't bother upgrading these caps.

For the opamp decoupling I'd vote for 10uF/35V tantalum caps + 1uF+ 0.1 MLCC, if possible for both I/V and LPF stages (at least for the I/V). If do you intend to use only MUSES then existing decoupling might suffice. Anyway, sometimes wrong caps might do more wrong than good, so please use a scope if you intend to change decoupling caps (https://www.baldengineer.com/a-1uf-decoupling-capacitor-is-too-much.html).

If you don't want to bother with scope and soldering parts, just get the MUSES01 for the I/V and try a couple of BURSON V5i in LPF; check for overheating and if everything seems fine then purchase the remaining opamps. BTW, what's the voltage on V+/V- for these opamps, please?

I think those rectangular caps are 1nf. Hmm should i change them into better component?amtrans amch or wima mk5. What do you think?

 

[raoultrifan]

I think those rectangular caps are 1nf. Hmm should i change them into better component?amtrans amch or wima mk5. What do you think?

Well, I was only 1.000 times wrong, no big deal I'd say.
 
On pins 4 and 8 there are 2 SMD caps, feel free to measure them with a multimeter and power off, though I'm not sure the value will be correct, because caps should be measured outside the circuit. I would say not to worry too much for the moment with the decoupling, unless your upgrade opamps will not oscillate. I'm sure MUSES01 & 8920 will be fine with existing decoupling when used in I/V stage; for LPF I think most of the above mentioned opamps should be OK.

 

[viivo]

Thanks for the responses. I have a followup question: would an opamp work at all if damaged or is it all or nothing? I got impatient waiting for the replacement to arrive so I soldered the two broken pins back on and reinstalled it. I ask the above because, while it does work, it sounds off in ways I can't articulate. All I can say is that a pair of 600ohm DT-990s sound better unamplified on my tablet than with this.