opa1656 in front end of FOSI V3 Mono

[jokan]

I tried my trusty opa1656 with otherwise stock op-amps in the V3 mono 5Amp PS, and what I heard was a noisy presentation. It wasn't noise in the sense of white noise or popping, or clipping. It just was harsh. I swapped to opa1622's as I had several sitting around and the noise was gone instantly.
I've played with the other 2 op-amps also and have been trying several front-end RCA/XLR op-amps to see if there is anything to be gained, so far there seems to be very little in it.

Just out of curiosity, have others noticed that the stereo V3 with the extra venting holes might be swappable to with the mono V3. It looks like many of the holes line up, just not sure if it will actually work. Someone, maybe I have to give it a shot. Though I've never had the issue of the V3 mono shutting down, the do get a little warm for comfort.

Going back to the original OPA1656 question, does anyone have a recommendation for the RCA/XLR op-amp? I'm open to any and all suggestions including ancient op-amps if they sound right. Thanks guys.

 

[JSmith]

There is no need to alter the stock opamp... you're chasing fairies.


JSmith

 

[jokan]

There is no need to alter the stock opamp... you're chasing fairies.


JSmith

I'll chase Greek fairies or Persian ones, I just want to know if there is something that has even a marginal improvement.

I'm with you with chasing fairies. I know the operation is purely for RCA/XLR use but there must be some separation, some gain, some slew rate advantage to something else. I won't spend a thousand dollars on op-amps nor do I think I'll use discrete for this use, but perhaps there is something that is better than stock. I have the stock op-amps saved up. I'm very impressed with FOSI with how they design their products. Sound is their priority. I can appreciate that!

 

[GXAlan]

I'll chase Greek fairies or Persian ones, I just want to know if there is something that has even a marginal improvement.

best investment would be an E1DA Cosmos ADC to do the measurements yourself. When I op amp swapped my phono equalizer to MUSES, it worked great and I could measure the difference. What was cool is that the MUSES op amps are super expensive and have mediocre advertised specs but the actual performance was stellar.

You have no idea if your existing op amp happens to be a golden copy or a regular one, etc. etc. Measuring it lets you get an answer.

 

[JSmith]

I just want to know if there is something that has even a marginal improvement

There won't be... at best there will be no change, at worst the amp will go into oscillation and things will sound bad.

Continuous oscillation can potentially put stress on the amplifier too, leading to overheating or damage.


JSmith

 

[KSTR]

Replacing the stock 5532 with something as fast as an OPA1656 on a DIP adapter is inviting trouble. Next time try OPA2891 for even more trouble ;-)
Rolling OpAmps is plain silly and should never be done by lay-people who have zero clue of what's going on under the hood of a circuit.

 

[jokan]

I was well aware of the performance of the opa1656 being far in excess of what was required, I tried it anyway having had a lot of luck with it in the past.

I might go Can style, pre lme47920HA which I have several NOS condition. I have even older ones such as the LH1458H.
I know that it will likely disappoint me but what the hell, it's worth a shot.

If you guys have any legitimate suggestions please let me know, I'm happy to try it out.

 

[AnalogSteph]

What are you hoping to gain over the stock part? Looking at measurements for the V3 Mono, the limiting factor in distortion performance clearly is the Class D power amp section, not the input buffer.

 

[jokan]

What are you hoping to gain over the stock part? Looking at measurements for the V3 Mono, the limiting factor in distortion performance clearly is the Class D power amp section, not the input buffer.

Yes, I was looking at the typical op-amp RCA/XLR converter, I don't think there is any return in time or investment.

i guess I'll give up on this one.

thanks everyone for the help!

 

[jokan]

My current solution and op-amps that are to my liking.

RCA/XLR op-amp replaced with OPA1622 which I had lying around, it also seems to improve transients and attack slightly.

OP-Amp *2 as stated by Fosi I replaced with several until I settled on the OPA1656, I tried combinations with OP-Amp *3 with various combinations to see what sounded the least shouty and most detailed while not sounding too forward.

Op-Amp *3 was eventually replaced with LME49860. I found this combination to be the most pleasing to my ears and listening habits.
I found the sound to have a sort of analogue sound to the lower octaves, never seemed to run out of steam and could play complex classical music with relative ease *Yes there are better like my 3 tube amps sitting in my closet*.

Has anyone tried running the 10amp power supply to each amplifier with success? I'm afraid of component failure. And the cost seems rather ridiculous.
If anyone has experience, please let me know!

 

[JSmith]

legitimate suggestions

These have already been provided...

RCA/XLR op-amp replaced with OPA1622 which I had lying around, it also seems to improve transients and attack slightly.

OP-Amp *2 as stated by Fosi I replaced with several until I settled on the OPA1656, I tried combinations with OP-Amp *3 with various combinations to see what sounded the least shouty and most detailed while not sounding too forward.

Op-Amp *3 was eventually replaced with LME49860. I found this combination to be the most pleasing to my ears and listening habits.
I found the sound to have a sort of analogue sound to the lower octaves, never seemed to run out of steam and could play complex classical music with relative ease *Yes there are better like my 3 tube amps sitting in my closet*.

So how did you test to arrive at such conclusions?

I'll give up on this one

That would be for the best.


JSmith

 

[Scrivs]

Should have quit whilst you were sheepishly getting ahead brotha

Too early in the year for trolling here in Hawai’i, only Aku around

 

[DACsNoMore]

My current solution and op-amps that are to my liking.

RCA/XLR op-amp replaced with OPA1622 which I had lying around, it also seems to improve transients and attack slightly.

OP-Amp *2 as stated by Fosi I replaced with several until I settled on the OPA1656, I tried combinations with OP-Amp *3 with various combinations to see what sounded the least shouty and most detailed while not sounding too forward.

Op-Amp *3 was eventually replaced with LME49860. I found this combination to be the most pleasing to my ears and listening habits.
I found the sound to have a sort of analogue sound to the lower octaves, never seemed to run out of steam and could play complex classical music with relative ease *Yes there are better like my 3 tube amps sitting in my closet*.

Has anyone tried running the 10amp power supply to each amplifier with success? I'm afraid of component failure. And the cost seems rather ridiculous.
If anyone has experience, please let me know!

Thanks for spending your time and effort to find what worked for you the best. Also thanks for sharing the results. I was initially skeptical of opamps making difference, but they do. Original NE5532 is very hard to beat though as it is one of the best all around opamp ever made.

My understanding of RCA/XLR op-amp #1 in V3 - it supposed to make an exact "mirror/opposite phase" copy of the input signal of RCA "wire" to second "wire" used in XLR logic, so then XLR input logic will combine signal of both "wires" to get rid of interference (will be same phase on both wires) (should be negligible as it is extremely short distance to catch any interference inside the amp). So in this case, any deviations from the original signal on the "wires" - it will be treated as noise. I am sure the #1 opamp circuit is configured to enforce strict input/output match with strong feedback, so this is why fosi suggests that changing it would not yield any difference in sound.

 

[JSmith]

I was initially skeptical of opamps making difference, but they do.

What are you on about? Your initial scepticism was correct... seems you didn't read the thread, all the others and missed this;

Op-amp Rolling Using Sparkos on Fosi V3 Mono

This is a study of measured differences if one swaps up the TI NE5532p dual IC op-amp in a Fosi V3 Mono amplifier with a "discrete" opamp from Sparkos. It is a test requested in the youtube comments of my video test of the same using Douk A5 and Sonic Imagery op-amp. The Sparkos SS3602 retails...

www.audiosciencereview.com

JSmith

 

[olieb]

Op-Amp *3 was eventually replaced with LME49860. I found this combination to be the most pleasing to my ears and listening habits.
I found the sound to have a sort of analogue sound to the lower octaves, never seemed to run out of steam and could play complex classical music with relative ease

I get all these improvements (and more) by just turning the power plug on the power supply by180 degrees.
And turning it another 180 degrees is even better. Everybody should try that.

 

[Jimster480]

My current solution and op-amps that are to my liking.

RCA/XLR op-amp replaced with OPA1622 which I had lying around, it also seems to improve transients and attack slightly.

OP-Amp *2 as stated by Fosi I replaced with several until I settled on the OPA1656, I tried combinations with OP-Amp *3 with various combinations to see what sounded the least shouty and most detailed while not sounding too forward.

Op-Amp *3 was eventually replaced with LME49860. I found this combination to be the most pleasing to my ears and listening habits.
I found the sound to have a sort of analogue sound to the lower octaves, never seemed to run out of steam and could play complex classical music with relative ease *Yes there are better like my 3 tube amps sitting in my closet*.

Has anyone tried running the 10amp power supply to each amplifier with success? I'm afraid of component failure. And the cost seems rather ridiculous.
If anyone has experience, please let me know!

Honestly, I have these amplifiers and they are connected to a set of Klipsch RP-8060FA II speakers. I can tell you that there were no details missing in any of the music that I played. This setup was some of the most detailed speakers I've ever heard in my life playing through my entire complex "songs to test audio quality" Playlist. Containing complex classical, jazz, trance and pop music all that contain different complex or revealing parts in each track.

I was honestly blown away by the quality of these amps and the overall clarity I was able to achieve from something that is so cheap. As I have been on this forum for a long time, it is only recently that there have been amps which are very affordable that are able to actually drive speakers to these levels while maintaining clarity.
At 50% volume on my DAC; these speakers are quite loud in my house... That is about as loud as I would want to run them. Time will tell how these amps work out in my church.

I like the setup so much that I now want to purchase my own set of speakers + amps for my house... After not being too interested in speakers in the past (atleast at this level).

 

[DACsNoMore]

What are you on about? Your initial scepticism was correct... seems you didn't read the thread, all the others and missed this;

Op-amp Rolling Using Sparkos on Fosi V3 Mono

This is a study of measured differences if one swaps up the TI NE5532p dual IC op-amp in a Fosi V3 Mono amplifier with a "discrete" opamp from Sparkos. It is a test requested in the youtube comments of my video test of the same using Douk A5 and Sonic Imagery op-amp. The Sparkos SS3602 retails...

www.audiosciencereview.com

JSmith

From engineering prospective - skeptical, but from perception - not skeptical. I do not need extensive posts to determine any differences - I just have identical amps and do A/B test for myself and make conclusions, for myself. Not really expensive at this point with chi-fi amps, mouser/digikey and sometimes a soldering gun or hot air station or heat plate (whatever one prefers). I do not listen to those chi-fi amps normally - I have separate pro setup for that, those is just to explore and experience. One thing for sure - I would never consider replacing IC opamps with discrete dinosaurs costing $$$ - it is just top ridiculous.

 

[DACsNoMore]

Time will tell how these amps work out in my church.

I observed some DJ at the restaurant full of people running 2 speakers 50 feet left and 50 feet right wing - the sound was very clear, so I was intrigued what he was using - all I saw was H letter on the speakers with one TSR wire coming to each and small mixing set. Later I found it - Harbinger M200-BT Portable PA: https://www.guitarcenter.com/Harbin...d-Custom-Carry-Bags-10-Mains-1500000277141.gc
Those are even cheaper, more powerful, versatile, rigid and for sure would suite church and auditorium for 100-200 people easy. And it cost laughable $350 for 800W class-d amp (2x400W)- means divide by 4 for RMS a whole set with 5 channels XLR, single + BT + outputs and 2x passive 10inch woofer/compression tweeter speakers

 

[Jimster480]

I observed some DJ at the restaurant full of people running 2 speakers 50 feet left and 50 feet right wing - the sound was very clear, so I was intrigued what he was using - all I saw was H letter on the speakers with one TSR wire coming to each and small mixing set. Later I found it - Harbinger M200-BT Portable PA: https://www.guitarcenter.com/Harbin...d-Custom-Carry-Bags-10-Mains-1500000277141.gc
Those are even cheaper, more powerful, versatile, rigid and for sure would suite church and auditorium for 100-200 people easy. And it cost laughable $350 for 800W class-d amp (2x400W)- means divide by 4 for RMS a whole set with 5 channels XLR, single + BT + outputs and 2x passive 10inch woofer/compression tweeter speakers

Pretty nice! We had a cheap setup at the church before, but now I have put together a real high end setup that should serve our church for many years to come! Unless the amps themselves fail.
This is my thread incase you are interested!

Suggestions on a nice Wireless Speaker Setup + Wireless IEMs for Elderly

Hey everyone, I have been tasked with upgrading the sound system in my small church. Mostly elderly people there and some of them are now hard of hearing. They are asking me to do a wireless rear speaker system + upgrade the main speakers + provide wireless monitors for hard of hearing people to...

www.audiosciencereview.com

 

[JSmith]

I just have identical amps and do A/B test for myself and make conclusions, for myself.

Great, as long as properly level matched and no peeking, all for it.

I appreciate you're a new member here, so may not know about this one, but we do try and avoid that term used in your post;

Let's Avoid the Term Chi-Fi

I often see the use of the term "Chi Fi" to describe audio products from China. I see the intention and don't think anyone is trying to be racist and what have you. Still, I like us to show the highest respect to products from around the world. As avid readers of this forum know...

www.audiosciencereview.com

No biggie though.


JSmith